@article {pmid39278276, year = {2024}, author = {Somawardana, IA and Prasad, B and Kay, W and Hunt, C and Adams, J and Kawaguchi, B and Smith, TB and Ashton, N and Sadaphal, V and Tepper, J and Monogue, M and Ramirez, JI and Jones, OD and Shelton, JM and Evers, BM and Serge, R and Pybus, C and Williams, D and Chopra, R and Greenberg, DE}, title = {Alternating Magnetic Fields AMF) and Linezolid Reduce Staphylococcus aureus Biofilm in a Large Animal Implant Model.}, journal = {The Journal of infection}, volume = {}, number = {}, pages = {106271}, doi = {10.1016/j.jinf.2024.106271}, pmid = {39278276}, issn = {1532-2742}, abstract = {OBJECTIVES: We aimed to evaluate the effectiveness of alternating magnetic fields AMF) combined with antibiotics in reducing Staphylococcus aureus biofilm on metal implants in a large animal model, compared to antibiotics alone.<br><br>METHODS: Metal plates were inoculated with a clinical MRSA strain and then implanted into thirty-three ewes divided into three groups: positive control, linezolid only, and a combination of linezolid and AMF. Animals had either titanium or cobalt-chrome plates and were sacrificed at 5- or 21-days post-implantation. Blood and tissue samples were collected at various time points post-AMF treatment.<br><br>RESULTS: In vivo efficacy studies demonstrated significant biofilm reduction on titanium and cobalt-chrome implants with AMF-linezolid combination treatment compared to controls. Significant bacterial reductions were also observed in surrounding tissues and bones. Cytokine analysis showed improved inflammatory responses with combination therapy, and histopathology confirmed reduced inflammation, necrosis, and bacterial presence, especially at 5 days post-implantation.<br><br>CONCLUSIONS: This study demonstrates that combining AMF with antibiotics significantly reduces biofilm-associated infections on metal implants in a large animal model. Numerical simulations confirmed targeted heating, and in vivo results showed substantial bacterial load reduction and reduced inflammatory response. These findings support the potential of AMF as a non-invasive treatment for prosthetic joint infections.}, }
@article {pmid39277662, year = {2024}, author = {Pumirat, P and Santajit, S and Tunyong, W and Kong-Ngoen, T and Tandhavanant, S and Lohitthai, S and Rungruengkitkun, A and Chantratita, N and Ampawong, S and Reamtong, O and Indrawattana, N}, title = {Impact of AbaI mutation on virulence, biofilm development, and antibiotic susceptibility in Acinetobacter baumannii.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {21521}, pmid = {39277662}, issn = {2045-2322}, support = {Fundamental Fund: fiscal year 2023//Mahidol University/ ; N42A660376//National Research Council of Thailand/ ; }, mesh = {*Acinetobacter baumannii/genetics/drug effects/pathogenicity ; *Biofilms/drug effects/growth &amp; development ; Virulence/genetics ; *Anti-Bacterial Agents/pharmacology ; *Bacterial Proteins/genetics/metabolism ; *Mutation ; *Quorum Sensing/genetics/drug effects ; Gene Expression Regulation, Bacterial/drug effects ; Microbial Sensitivity Tests ; Bacterial Outer Membrane Proteins/genetics/metabolism ; Acinetobacter Infections/microbiology/drug therapy ; Proteomics ; }, abstract = {The quorum sensing (QS) system mediated by the abaI gene in Acinetobacter baumannii is crucial for various physiological and pathogenic processes. In this study, we constructed a stable markerless abaI knockout mutant (ΔabaI) strain using a pEXKm5-based allele replacement method to investigate the impact of abaI on A. baumannii. Proteomic analysis revealed significant alterations in protein expression between the wild type (WT) and ΔabaI mutant strains, particularly in proteins associated with membrane structure, antibiotic resistance, and virulence. Notably, the downregulation of key outer membrane proteins such as SurA, OmpA, OmpW, and BamA suggests potential vulnerabilities in outer membrane integrity, which correlate with structural abnormalities in the ΔabaI mutant strain, including irregular cell shapes and compromised membrane integrity, observed by scanning and transmission electron microscopy. Furthermore, diminished expression of regulatory proteins such as OmpR and GacA-GacS highlights the broader regulatory networks affected by abaI deletion. Functional assays revealed impaired biofilm formation and surface-associated motility in the mutant strain, indicative of altered colonization capabilities. Interestingly, the mutant showed a complex antibiotic susceptibility profile. While it demonstrated increased susceptibility to membrane-targeting antibiotics, its response to beta-lactams was more nuanced. Despite increased expression of metallo-beta-lactamase (MBL) superfamily proteins and DcaP-like protein, the mutant unexpectedly showed lower MICs for carbapenems (imipenem and meropenem) compared to the wild-type strain. This suggests that abaI deletion affects antibiotic susceptibility through multiple, potentially competing mechanisms. Further investigation is needed to fully elucidate the interplay between quorum sensing, antibiotic resistance genes, and overall antibiotic susceptibility in A. baumannii. Our findings underscore the multifaceted role of the abaI gene in modulating various cellular processes and highlight its significance in A. baumannii physiology, pathogenesis, and antibiotic resistance. Targeting the abaI QS system may offer novel therapeutic strategies for this clinically significant pathogen.}, }
@article {pmid39277594, year = {2024}, author = {Su, Z and Xu, D and Hu, X and Zhu, W and Kong, L and Qian, Z and Mei, J and Ma, R and Shang, X and Fan, W and Zhu, C}, title = {Biodegradable oxygen-evolving metalloantibiotics for spatiotemporal sono-metalloimmunotherapy against orthopaedic biofilm infections.}, journal = {Nature communications}, volume = {15}, number = {1}, pages = {8058}, pmid = {39277594}, issn = {2041-1723}, support = {82272512//National Natural Science Foundation of China (National Science Foundation of China)/ ; 82302718//National Natural Science Foundation of China (National Science Foundation of China)/ ; }, mesh = {*Biofilms/drug effects ; Animals ; Mice ; *Manganese Compounds/chemistry/pharmacology ; *Oxygen/metabolism ; *Oxides/pharmacology/chemistry ; Anti-Bacterial Agents/pharmacology ; Hydrogen Peroxide/metabolism ; Immunotherapy/methods ; Humans ; Ultrasonic Therapy/methods ; Nanoparticles/chemistry ; Signal Transduction/drug effects ; Antigens, Bacterial/immunology ; Staphylococcus aureus/drug effects ; Female ; }, abstract = {Pathogen-host competition for manganese and intricate immunostimulatory pathways severely attenuates the efficacy of antibacterial immunotherapy against biofilm infections associated with orthopaedic implants. Herein, we introduce a spatiotemporal sono-metalloimmunotherapy (SMIT) strategy aimed at efficient biofilm ablation by custom design of ingenious biomimetic metal-organic framework (PCN-224)-coated MnO2-hydrangea nanoparticles (MnPM) as a metalloantibiotic. Upon reaching the acidic H2O2-enriched biofilm microenvironment, MnPM can convert abundant H2O2 into oxygen, which is conducive to significantly enhancing the efficacy of ultrasound (US)-triggered sonodynamic therapy (SDT), thereby exposing bacteria-associated antigens (BAAs). Moreover, MnPM disrupts bacterial homeostasis, further killing more bacteria. Then, the Mn ions released from the degraded MnO2 can recharge immune cells to enhance the cGAS-STING signaling pathway sensing of BAAs, further boosting the immune response and suppressing biofilm growth via biofilm-specific T cell responses. Following US withdrawal, the sustained oxygenation promotes the survival and migration of fibroblasts, stimulates the expression of angiogenic growth factors and angiogenesis, and neutralizes excessive inflammation. Our findings highlight that MnPM may act as an immune costimulatory metalloantibiotic to regulate the cGAS-STING signaling pathway, presenting a promising alternative to antibiotics for orthopaedic biofilm infection treatment and pro-tissue repair.}, }
@article {pmid39277052, year = {2024}, author = {Gong, W and Zhang, H and Xue, M and Guo, L and Jiang, M and Zhao, Y and Liang, H}, title = {Electron-deficient wastewater treatment in membrane-aerated conductive biofilm reactor: Performance and mechanism.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131411}, doi = {10.1016/j.biortech.2024.131411}, pmid = {39277052}, issn = {1873-2976}, abstract = {A membrane-aerated conductive biofilm reactor (MA-CBR) was constructed for carbon-limited wastewater treatment and to reduce the stress of the electric field on nitrous oxide reductase (NosZ). Counter-diffusion with an embedded aerobic layer declined the effect of current on NosZ (K00376) for N2O reduction. Other coding genes for denitrification in cathodic membrane aerated biofilms, including K02568, K00368, K15864, K02305, and K04561, were also positively affected by the electric field and significantly accumulate in Thauera. NH4[+]-N oxidation can occur at the anode and cathode (membrane aeration biofilm). This cathodic synergistic NH4[+]-N oxidation provided more electrons to be directly utilized by the denitrifying bacteria at the cathode. Without additional organic matter, compared to the MABR, the total nitrogen removal efficiency of MA-CBR increased by 3.50 mg/L, 12.52 mg/L, and 17.82 mg/L at voltages of 0.25 V, 0.50 V, and 0.75 V, respectively.}, }
@article {pmid39276739, year = {2024}, author = {Zhang, S and Xing, Z and Li, Y and Jiang, L and Shi, W and Zhao, Y and Fang, L}, title = {Plastic film from the source of anaerobic digestion: Surface degradation, biofilm and UV response characteristics.}, journal = {Journal of hazardous materials}, volume = {480}, number = {}, pages = {135793}, doi = {10.1016/j.jhazmat.2024.135793}, pmid = {39276739}, issn = {1873-3336}, abstract = {This study simulates a major environmental scenario involving "organic fertilizer source" plastics, by exploring the key factors influencing the changes in plastic-films during anaerobic digestion (AD), as well as the responses of the anaerobically digested plastics to ultraviolet (UV) radiation exposure. The results demonstrate that the degradation effect of AD on plastics is reflected by their yellowish and ruptured appearance, slightly worn surfaces, hardening and opacity, and fragmentation. AD significantly increases the content of oxygen-containing functional groups and the degree of unsaturation in plastic films, with thermophilic temperature processes proving more effective than those conducted at mesophilic temperatures. Exposure to UV light has been found to amplify the degradative effects, suggesting the potential cumulative impact of AD and UV. Both AD and UV irradiation reduced the hydrophilicity of plastics. In particular, the hydrophobicity of polylactic acid films was completely disrupted under overlay-exposure. Furthermore, microbial populations on plastic surfaces were mainly bacterial. These bacterial populations were primarily influenced by temperature, and moderately by the plastic types. In contrast, archaea were predominantly affected by both temperature and digested substrate. This study offers a theoretical foundation for strategies aimed at preventing and controlling plastic pollution derived from organic fertilizers.}, }
@article {pmid39272546, year = {2024}, author = {Kang, S and Yang, Y and Hou, W and Zheng, Y}, title = {Inhibitory Effects of Lactobionic Acid on Biofilm Formation and Virulence of Staphylococcus aureus.}, journal = {Foods (Basel, Switzerland)}, volume = {13}, number = {17}, pages = {}, pmid = {39272546}, issn = {2304-8158}, support = {No. T2023312//Shanghai Agricultural Science and Technology Innovation Program/ ; No. LSNZD201607//Scientific Study Project of the Liaoning Province Education Department/ ; No. 32302257//National Natural Science Foundation of China/ ; }, abstract = {Staphylococcus aureus biofilm is a common bio-contaminant source that leads to food cross-contamination and foodborne disease outbreaks. Hence, there is a need for searching novel antibiofilm agents with potential anti-virulence properties to control S. aureus contamination and infections in food systems. In this study, the antibiofilm effects of lactobionic acid (LBA) against S. aureus and its influence on virulence were explored. The minimum inhibition concentration of LBA on S. aureus was 8 mg/mL. Viable count and crystal violet assays revealed that LBA inhibited and inactivated S. aureus biofilms. Microscopic observations further confirmed the antibiofilm activity of LBA on S. aureus that disrupted the biofilm architecture and inactivated the viable cells in biofilms. Moreover, LBA decreased the release of extracellular DNA (eDNA) and extracellular polysaccharide (EPS) in S. aureus biofilms. LBA suppressed biofilm formation by intervening metabolic activity and reduced virulence secretion by repressing the hemolytic activity of S. aureus. Furthermore, LBA altered the expressions of biofilm- and virulence-related genes in S. aureus, further confirming that LBA suppressed biofilm formation and reduced the virulence secretion of S. aureus. The results suggest that LBA might be useful in preventing and controlling biofilm formation and the virulence of S. aureus to ensure food safety.}, }
@article {pmid39271899, year = {2024}, author = {}, title = {An easier method to reduce biofilm.}, journal = {British dental journal}, volume = {237}, number = {5}, pages = {421}, doi = {10.1038/s41415-024-7885-7}, pmid = {39271899}, issn = {1476-5373}, mesh = {*Biofilms ; Humans ; }, }
@article {pmid39270757, year = {2024}, author = {Vadakkan, K and Hemapriya, J and Ngangbam, AK and Sathishkumar, K and Mapranathukaran, VO}, title = {Biofilm inhibition of Staphylococcus aureus by silver nanoparticles derived from Hellenia speciosa rhizome extract.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106933}, doi = {10.1016/j.micpath.2024.106933}, pmid = {39270757}, issn = {1096-1208}, abstract = {Staphylococcus aureus is the most common cause of serious health conditions because of the formation of biofilm, which lowers antibiotic efficacy and enhances infection transmission and tenacious behavior. This bacteria is a major threat to the worldwide healthcare system. Silver nanoparticles have strong antibacterial characteristics and emerged as a possible alternative. This work is most relevant since it investigates the parameters influencing the biogenic nanoparticle-assisted control of bacterial biofilms by Staphylococcus aureus. Nanoparticles were fabricated utilizing Hellenia speciosa rhizome extracts, which largely comprised physiologically active components such as spirost-5-en-3-yl acetate, thymol, stigmasterol, and diosgenin, enhanced with the creation of silver nanocomposites. GC-MS, XRD, DLS, SEM, EDX, FTIR and TEM were used to investigate the characteristics of nanoparticles. The microtiter plate experiment showed that nanoparticles destroyed biofilms by up to 92.41% at doses that ranged from 0 to 25 μg/ml. Fluorescence microscopy and SEM demonstrated the nanoparticles' capacity to prevent bacterial surface adhesion. EDX research revealed that the organic extract efficiently formed silver nanoparticles with considerable oxygen incorporation, which was attributed to phytochemicals that stabilize AgNPs and prevent accumulation. FTIR spectroscopy indicated the existence of hydroxyl, carbonyl, and carboxylate groups, which are essential for nanoparticle stability. TEM revealed that the AgNPs were spheroidal, with diameters ranging from 40 to 60 nm and an average of 46 nm. These results demonstrate the efficacy of H. speciosa extract in creating stable, well-defined AgNPs suited for a variety of applications. This work underlines the potential of green-synthesized AgNPs in biomedical applications, notably in the treatment of S. aureus biofilm-associated illnesses. The thorough characterization gives important information on the stability and efficiency of these biogenic nanoparticles.}, }
@article {pmid39270755, year = {2024}, author = {Kumbhar, V and Gaiki, S and Shelar, A and Nikam, V and Patil, R and Kumbhar, A and Gugale, G and Pawar, R and Khairnar, B}, title = {Mining for antifungal agents to inhibit biofilm formation of Candida albicans: A study on green synthesis, antibiofilm, cytotoxicity, and in silico ADME analysis of 2-amino-4H-pyran-3-carbonitrile derivatives.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106926}, doi = {10.1016/j.micpath.2024.106926}, pmid = {39270755}, issn = {1096-1208}, abstract = {Candida albicans (C. albicans) biofilm infections are quite difficult to manage due to their resistance against conventional antifungal drugs. To address this issue, there is a desperate need for new therapeutic drugs. In the present study, a green and efficient protocol has been developed for the synthesis of 2-amino-4H-pyran-3-carbonitrile scaffolds 4a-i, 6a-j, and 8a-g by Knoevenagel-Michael-cyclocondensation reaction between aldehydes, malononitrile, and diverse enolizable C-H activated acidic compounds using guanidinium carbonate as a catalyst either under grinding conditions or by stirring at room temperature. This protocol is operationally simple, rapid, inexpensive, has easy workup and column-free purification. A further investigation of the synthesized compounds was conducted to examine their antifungal potential and their ability to inhibit the growth and development of biofilm-forming yeasts like fungus C. albicans. According to our findings, 4b, 4d, 4e, 6e, 6f, 6g, 6i, 8c, 8d, and 8g were found to be active and potential inhibitors for biofilm infection causing C. albicans. The inhibition of biofilm by active compounds were observed using field emission scanning electron microscopy (FESEM). Biofilm inhibiting compounds were also tested for in vitro toxicity by using 3T3-L1 cell line, and 4b, 6e, 6f, 6g, 6i, 8c, and 8d were found to be biocompatible. Furthermore, the in silico ADME descriptors revealed drug-like properties with no violation of Lipinski's rule of five. Hence, the result suggested that synthesized derivatives could serve as a useful aid in the development of novel antifungal compounds for the treatment of fungal infections and virulence in C. albicans.}, }
@article {pmid39270539, year = {2024}, author = {Roszkowski, P and Bielenica, A and Stefańska, J and Majewska, A and Markowska, K and Pituch, H and Koliński, M and Kmiecik, S and Chrzanowska, A and Struga, M}, title = {Antibacterial and anti-biofilm activities of new fluoroquinolone derivatives coupled with nitrogen-based heterocycles.}, journal = {Biomedicine &amp; pharmacotherapy = Biomedecine &amp; pharmacotherapie}, volume = {179}, number = {}, pages = {117439}, doi = {10.1016/j.biopha.2024.117439}, pmid = {39270539}, issn = {1950-6007}, abstract = {We report the design, synthesis, and antimicrobial evaluation of a series of ciprofloxacin (CP) conjugates coupled with nitrogen-containing heterocycles. In vitro screening of these new hybrid compounds (1-13) against a panel of planktonic bacterial strains highlighted thiazolyl homologs 6 and 7 as the most promising candidates for further investigation. These derivatives demonstrated potent growth-inhibitory activity against various standard and clinical isolates, with minimum inhibitory concentrations (MICs) ranging from 0.05 to 0.4 µg/ml, which are higher or comparable to the reference fluoroquinolone. Both compounds effectively inhibited biofilm formation by selected staphylococci across all tested concentrations (1-8 x MIC), displaying greater efficacy at higher doses compared to CP alone. Notably, conjugate 7 also significantly eradicated existing biofilms formed by S. aureus of various origin. Molecular docking studies revealed that conjugate 7 engages in a broader range of interactions with DNA gyrase and DNA topoisomerase IV than CP, suggesting stronger binding affinity and enhanced flexibility. This may contribute to its potential in overcoming bacterial resistance mechanisms. The above findings indicate compound 7 as a promising candidate for clinical development.}, }
@article {pmid39269814, year = {2024}, author = {Fakher, S and Westenberg, D}, title = {The anti-biofilm efficacy of copper and zinc doped borate bioactive glasses.}, journal = {Future microbiology}, volume = {}, number = {}, pages = {1-14}, doi = {10.1080/17460913.2024.2398410}, pmid = {39269814}, issn = {1746-0921}, abstract = {Aim: Healthcare-acquired infections (HAIs) pose significant challenges in medical settings due to their resistance to conventional treatment methods. The role of bacterial biofilms in exacerbating these infections is well-documented, making HAIs particularly difficult to eradicate. Despite numerous research efforts, an effective solution to combat these infections remains elusive. This study aims to explore the potential of metal-ion (copper and zinc) doped borate bioactive glasses (BBGs) as a novel treatment modality to inhibit bacterial species commonly implicated in HAIs: Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa.Methods: The study analyzed the efficacy of both direct and indirect applications of BBGs on severe biofilms pre-formed under static and dynamic growth conditions; a comprehensive predictive modeling was developed, simulating diverse clinically relevant conditions.Results: Results demonstrate more than 4 log reduction in bacterial growth within 2 days for direct application and 3 days for indirect application of copper and zinc-doped BBGs. These findings were consistent across the three bacterial species, in both static and dynamic conditions.Conclusion: Copper and zinc-doped BBGs can be an effective approach in combating HAIs complicated by biofilms.}, }
@article {pmid39269114, year = {2024}, author = {Zykova, MV and Karpova, MR and Zhang, Y and Chubik, MV and Shunkova, DM and Azarkina, LA and Mihalyov, DA and Konstantinov, AI and Plotnikov, EV and Pestryakov, AN and Perminova, IV and Belousov, MV}, title = {The Influence of Silver-Containing Bionanomaterials Based on Humic Ligands on Biofilm Formation in Opportunistic Pathogens.}, journal = {Nanomaterials (Basel, Switzerland)}, volume = {14}, number = {17}, pages = {}, doi = {10.3390/nano14171453}, pmid = {39269114}, issn = {2079-4991}, abstract = {The uncontrolled use of antibiotics has led to a global problem of antimicrobial resistance. One of the main mechanisms of bacterial resistance is the formation of biofilms. In order to prevent the growth of antimicrobial resistance, it is crucial to develop new antibacterial agents that are capable of inhibiting the formation of biofilms. This makes this area of research highly relevant today. Promising candidates for these antibacterial agents are new bionanomaterials made from natural humic substances and silver nanoparticles. These substances have the potential to not only directly kill microorganisms but also penetrate biofilms and inhibit their formation. The goal of this study is to synthesize active pharmaceutical substances in the form of bionanomaterials, using ultradispersed silver nanoparticles in a matrix of coal humic substances, perform their characterization (NMR spectroscopy, TEM, and ICP-AES methods), and research their influence on biofilm formation in the most dangerous opportunistic pathogens (E. coli, Methicillin-resistant St. Aureus, K. pneumoniae, P. aeruginosa, St. aureus, A. baumannii, and K. Pneumonia). The results showed that all of the studied bionanomaterials had antibacterial activity against all of the opportunistic pathogens. Furthermore, they were found to have a suppressive effect on both pre-existing biofilms of these bacteria and their formation.}, }
@article {pmid39267932, year = {2024}, author = {Keyhani, S and Alikhani, MY and Doosti-Irani, A and Shokoohizadeh, L}, title = {Effect of Mentha longifolia essential oil on oqxA efflux pump gene expression and biofilm formation in ciprofloxacin-resistant Klebsiella pneumoniae strains.}, journal = {Iranian journal of microbiology}, volume = {16}, number = {4}, pages = {552-559}, pmid = {39267932}, issn = {2008-3289}, abstract = {BACKGROUND AND OBJECTIVES: Today, medicinal plants and their derivatives are considered to reduce the prevalence of antibiotic resistance. The aim of this study was to investigate the effect of Mentha longifolia essential oil on oqxA efflux pump gene expression and biofilm formation in ciprofloxacin-resistant Klebsiella pneumoniae strains.<br><br>MATERIALS AND METHODS: A total of 50 clinical strains of K. pneumoniae resistant to ciprofloxacin were studied. The minimum inhibitory concentration (MIC) of M. longifolia essential oil and its synergistic effect with ciprofloxacin were determined using the microbroth dilution method and the fractional inhibitory concentration (FIC) method. Minimum biofilm inhibition concentration (MBIC) of M. longifolia essential oil was detected. The effect of essential oils on the expression level of the oqxA gene was detected by Real-time PCR.<br><br>RESULTS: M. longifolia essential oil showed inhibitory activity against ciprofloxacin-resistant strains of K. pneumoniae. When M. longifolia essential oil was combined with ciprofloxacin, the MIC was reduced 2-4 times. In 28% of the strains, M. longifolia with ciprofloxacin showed a synergistic effect. M. longifolia essential oil reduces the strength of biofilm formation and alters the biofilm phenotype. A significant decrease in oqxA gene expression was observed in all isolates after treatment with M. longifolia essential oil.<br><br>CONCLUSION: Based on the results of this study, it was observed that supplementing M. longifolia essential oil can help reduce ciprofloxacin resistance and inhibit biofilm formation in fluoroquinolone-resistant K. pneumoniae strains.}, }
@article {pmid39267929, year = {2024}, author = {Owais, D and Al-Groom, RM and AlRamadneh, TN and Alsawalha, L and Khan, MSA and Yousef, OH and Burjaq, SZ}, title = {Antibiotic susceptibility and biofilm forming ability of Staphylococcus aureus isolated from Jordanian patients with diabetic foot ulcer.}, journal = {Iranian journal of microbiology}, volume = {16}, number = {4}, pages = {450-458}, pmid = {39267929}, issn = {2008-3289}, abstract = {BACKGROUND AND OBJECTIVES: Microbial biofilm is characterized by the irreversible attachment of planktonic cells to a surface and is usually associated with high antimicrobial resistance with worsening the wound healing. The objective of the study was to determine the prevalence of Staphylococcus aureus in diabetic foot ulcers (DFUs) of diabetic patients and to investigate antibiotic susceptibility patterns of these isolates. In addition to screen biofilm forming ability of isolated S. aureus.<br><br>MATERIALS AND METHODS: A total of 112 non-healing wound swabs of diabetic foot patients were collected and cultured on different culture media to identify and characterize 98 isolates. The S. aureus isolates were examined for their antibiotic susceptibility to different antimicrobial agents. Furthermore, S. aureus isolates were evaluated for their biofilm production capability using the Tissue Culture Plate Method (TPC). The level of icaA gene expression was determined by RT-PCR.<br><br>RESULTS: The results of this study showed that these non-healing wounds yield positive cultures, with an average of 1.67 organisms per sample. The isolates showed highest resistance against oxacillin (95.2%) and lowest resistance against linezolid (3.7%). All isolates were biofilm producers and a significant association with the icaA gene expression level was recorded.<br><br>CONCLUSION: This study showed that S. aureus isolates have a great ability to produce biofilms that are associated with the chronicity of wounds in diabetic patients. Routine screening for biofilm formers in chronic wounds and their antibiotic susceptibility testing will help in early treatment and prevent any other complications.}, }
@article {pmid39266450, year = {2024}, author = {Gnimpieba, EZ and Hartman, TW and Do, T and Zylla, J and Aryal, S and Haas, SJ and Agany, DDM and Gurung, BDS and Doe, V and Yosufzai, Z and Pan, D and Campbell, R and Huber, VC and Sani, R and Gadhamshetty, V and Lushbough, C}, title = {Biofilm marker discovery with cloud-based dockerized metagenomics analysis of microbial communities.}, journal = {Briefings in bioinformatics}, volume = {25}, number = {Supplement_1}, pages = {}, doi = {10.1093/bib/bbae429}, pmid = {39266450}, issn = {1477-4054}, support = {#1849206//National Science Foundation/ ; //Institutional Development Award/ ; /GM/NIGMS NIH HHS/United States ; P20GM103443/NH/NIH HHS/United States ; }, mesh = {*Biofilms/growth &amp; development ; *Metagenomics/methods ; Microbiota/genetics ; Cloud Computing ; Humans ; Computational Biology/methods ; }, abstract = {In an environment, microbes often work in communities to achieve most of their essential functions, including the production of essential nutrients. Microbial biofilms are communities of microbes that attach to a nonliving or living surface by embedding themselves into a self-secreted matrix of extracellular polymeric substances. These communities work together to enhance their colonization of surfaces, produce essential nutrients, and achieve their essential functions for growth and survival. They often consist of diverse microbes including bacteria, viruses, and fungi. Biofilms play a critical role in influencing plant phenotypes and human microbial infections. Understanding how these biofilms impact plant health, human health, and the environment is important for analyzing genotype-phenotype-driven rule-of-life functions. Such fundamental knowledge can be used to precisely control the growth of biofilms on a given surface. Metagenomics is a powerful tool for analyzing biofilm genomes through function-based gene and protein sequence identification (functional metagenomics) and sequence-based function identification (sequence metagenomics). Metagenomic sequencing enables a comprehensive sampling of all genes in all organisms present within a biofilm sample. However, the complexity of biofilm metagenomic study warrants the increasing need to follow the Findability, Accessibility, Interoperability, and Reusable (FAIR) Guiding Principles for scientific data management. This will ensure that scientific findings can be more easily validated by the research community. This study proposes a dockerized, self-learning bioinformatics workflow to increase the community adoption of metagenomics toolkits in a metagenomics and meta-transcriptomics investigation. Our biofilm metagenomics workflow self-learning module includes integrated learning resources with an interactive dockerized workflow. This module will allow learners to analyze resources that are beneficial for aggregating knowledge about biofilm marker genes, proteins, and metabolic pathways as they define the composition of specific microbial communities. Cloud and dockerized technology can allow novice learners-even those with minimal knowledge in computer science-to use complicated bioinformatics tools. Our cloud-based, dockerized workflow splits biofilm microbiome metagenomics analyses into four easy-to-follow submodules. A variety of tools are built into each submodule. As students navigate these submodules, they learn about each tool used to accomplish the task. The downstream analysis is conducted using processed data obtained from online resources or raw data processed via Nextflow pipelines. This analysis takes place within Vertex AI's Jupyter notebook instance with R and Python kernels. Subsequently, results are stored and visualized in Google Cloud storage buckets, alleviating the computational burden on local resources. The result is a comprehensive tutorial that guides bioinformaticians of any skill level through the entire workflow. It enables them to comprehend and implement the necessary processes involved in this integrated workflow from start to finish. This manuscript describes the development of a resource module that is part of a learning platform named "NIGMS Sandbox for Cloud-based Learning" https://github.com/NIGMS/NIGMS-Sandbox. The overall genesis of the Sandbox is described in the editorial NIGMS Sandbox [1] at the beginning of this Supplement. This module delivers learning materials on the analysis of bulk and single-cell ATAC-seq data in an interactive format that uses appropriate cloud resources for data access and analyses.}, }
@article {pmid39266402, year = {2024}, author = {Fakeeha, G and AlHarbi, S and Auda, S and Balto, H}, title = {The Impact of Silver Nanoparticles' Size on Biofilm Eradication.}, journal = {International dental journal}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.identj.2024.08.007}, pmid = {39266402}, issn = {1875-595X}, abstract = {INTRODUCTION: Efficient intracanal disinfection is required for a successful regenerative endodontic treatment. Thus, this study aimed to identify the silver nanoparticles' (NPs) size (AgNPs) with the highest antibiofilm efficacy when mixed with calcium hydroxide [Ca(OH)2] to eradicate an in vitro endodontic biofilm.<br><br>METHODS: The various sizes of AgNPs and mixtures were characterized by scanning electron microscopy, transmission electron microscopy, and ultraviolet-visible spectroscopy. A total of 168 dentin root segments were prepared, sterilized, and inoculated for 3 weeks with Actinomyces naeslundii and Fusobacterium nucleatum. Samples were randomly allocated to 4 experimental groups (n = 28/group): 2 nm AgNPs + 35% Ca(OH)2, 5 nm AgNPs + 35% Ca(OH)2, 10 nm AgNPs + 35% Ca(OH)2, and 35% Ca(OH)2 alone. Samples exposed to saline and triple antibiotic paste (TAP) acted as negative and positive control groups, respectively. After 1 and 2 weeks, samples were stained with LIVE/DEAD BacLight dye and examined under a confocal laser scanning microscope to determine the proportion of dead bacteria.<br><br>RESULTS: The characterization procedure revealed a spherical NP's structure with minor aggregations. Except for Ca(OH)2 group, all groups had significantly higher antibiofilm efficacy at 2 weeks. Both the 10 nm mixture (99.5%) and TAP (99.2%) exhibited the highest antibiofilm efficacy at 2 weeks and were not significantly different from one another (P > .05). No significant difference was noted between the 2 and 5 nm mixtures at 1 week (81% and 84%) and 2 weeks (89% and 91%).<br><br>CONCLUSION: The 10 nm AgNPs (0.02%) + 35% Ca(OH)2 mixture exhibited the highest antibiofilm efficacy at 2 weeks compared to all other mixtures at both observation periods. Interestingly, the 10 nm mixture performed similarly to TAP at 2 weeks. Excluding Ca(OH)2 group, longer application significantly improved the antibiofilm efficacy of all tested medicaments.<br><br>CLINICAL RELEVANCE: The 10 nm AgNPs + 35% Ca(OH)2 mixture revealed promising results as an intracanal medicament in the regenerative endodontic treatment protocol.}, }
@article {pmid39264564, year = {2024}, author = {Svitich, OA and Poddubikov, AV and Vartanova, NO and Leonova, AY and Kurbatova, EA}, title = {Biofilm Formation by Lactobacillus Strains of Modern Probiotics and Their Antagonistic Activity against Opportunistic Bacteria.}, journal = {Bulletin of experimental biology and medicine}, volume = {}, number = {}, pages = {}, pmid = {39264564}, issn = {1573-8221}, abstract = {The species identity of the studied lactobacillus strains was confirmed by matrix-activated laser desorption/ionization with time-of-flight ion separation (MALDI-TOF mass spectrometry). Lactobacillus strains differed in the dynamics of lactic acid accumulation and changes in the pH of the culture medium. The culture medium affected adhesion ability of lactobacilli. The ability to adhere does not affect the formation of biofilms by lactobacillus strains except for the L. acidophilus La5 strain, which has low adhesion ability and fewer microbial cells detected after mechanical destruction of the biofilm. The metabiotics of the lactobacillus culture medium have an antagonistic effect on conditionally pathogenic microorganisms. Adhesion, biofilm formation, and antagonistic activity of probiotic lactobacillus strains are strain-specific properties.}, }
@article {pmid39264555, year = {2024}, author = {Niboucha, N and Jubinville, &#xc9; and Péloquin, L and Clop, A and Labrie, S and Goetz, C and Fliss, I and Jean, J}, title = {Reuterin Enhances the Efficacy of Peracetic Acid Against Multi-species Dairy Biofilm.}, journal = {Probiotics and antimicrobial proteins}, volume = {}, number = {}, pages = {}, pmid = {39264555}, issn = {1867-1314}, support = {2016-049-C22//Consortium de Recherche et Innovations en Bioproc&#xe9;d&#xe9;s Industriels au Qu&#xe9;bec/ ; 2016-049-C22//Consortium de Recherche et Innovations en Bioproc&#xe9;d&#xe9;s Industriels au Qu&#xe9;bec/ ; 2016-049-C22//Consortium de Recherche et Innovations en Bioproc&#xe9;d&#xe9;s Industriels au Qu&#xe9;bec/ ; RDCPJ516460-17//Natural Sciences and Engineering Research Council of Canada/ ; RDCPJ516460-17//Natural Sciences and Engineering Research Council of Canada/ ; RDCPJ516460-17//Natural Sciences and Engineering Research Council of Canada/ ; }, abstract = {Biofilms may contain pathogenic and spoilage bacteria and can become a recurring problem in the dairy sector, with a negative impact on product quality and consumer health. Peracetic acid (PAA) is one of the disinfectants most frequently used to control biofilm formation and persistence. Though effective, it cannot be used at high concentrations due to its corrosive effect on certain materials and because of toxicity concerns. The aim of this study was to test the possibility of PAA remaining bactericidal at lower concentrations by using it in conjunction with reuterin (3-hydroxypropionaldehyde). We evaluated the efficacy of PAA in pure form or as BioDestroy[®], a PAA-based commercial disinfectant, on three-species biofilms formed by dairy-derived bacteria, namely Pseudomonas azotoformans PFlA1, Serratia liquefaciens Sl-LJJ01, and Bacillus licheniformis Bl-LJJ01. Minimum inhibitory concentrations of the three agents were determined for each bacterial species and the fractional inhibitory concentrations were then calculated using the checkerboard assay. The minimal biofilm eradication concentration (MBEC) of each antibacterial combination was then calculated against mixed-species biofilm. PAA, BioDestroy[®], and reuterin showed antibiofilm activity against all bacteria within the mixed biofilm at respectively 760 ppm, 450 ppm, and 95.6 mM. The MBEC was lowered significantly to 456 ppm, 337.5 ppm, and 71.7 mM, when exposed to reuterin for 16 h followed by contact with disinfectant. Combining reuterin with chemical disinfection shows promise in controlling biofilm on food contact surfaces, especially for harsh or extended treatments. Furthermore, systems with reuterin encapsulation and nanotechnologies could be developed for sustainable antimicrobial efficacy without manufacturing disruptions.}, }
@article {pmid39264339, year = {2024}, author = {Pradhan, L and Hazra, S and Singh, SV and Bajrang,  and Upadhyay, A and Pal, BN and Mukherjee, S}, title = {Surface modification of medical grade biomaterials by using a low-temperature-processed dual functional Ag-TiO2 coating for preventing biofilm formation.}, journal = {Journal of materials chemistry. B}, volume = {}, number = {}, pages = {}, doi = {10.1039/d4tb00701h}, pmid = {39264339}, issn = {2050-7518}, abstract = {Biofilm development in medical devices is considered the major virulence component that leads to increased mortality and morbidity among patients. Removing a biofilm once formed is challenging and frequently results in persistent infections. Many current antibiofilm coating strategies involve harsh conditions causing damage to the surface of the medical devices. To address the issue of bacterial attachment in medical devices, we propose a novel antibacterial surface modification approach. In this paper, we developed a novel low-temperature based solution-processed approach to deposit silver nanoparticles (Ag NPs) inside a titanium oxide (TiO2) matrix to obtain a Ag-TiO2 nanoparticle coating. The low temperature (120 °C)-based UV annealed drop cast method is novel and ensures no surface damage to the medical devices. Various medical-grade biomaterials were then coated using Ag-TiO2 to modify the surface of the materials. Several studies were performed to observe the antibacterial and antibiofilm properties of Ag-TiO2-coated medical devices and biomaterials. Moreover, the Ag-TiO2 NPs did not show any skin irritation in rats and showed biocompatibility in the chicken egg model. This study indicates that Ag-TiO2 coating has promising potential for healthcare applications to combat microbial infection and biofilm formation.}, }
@article {pmid39263769, year = {2024}, author = {Blanco Massani, M and To, D and Meile, S and Schmelcher, M and Gintsburg, D and Coraça-Huber, DC and Seybold, A and Loessner, M and Bernkop-Schnürch, A}, title = {Enzyme-responsive nanoparticles: enhancing the ability of endolysins to eradicate Staphylococcus aureus biofilm.}, journal = {Journal of materials chemistry. B}, volume = {}, number = {}, pages = {}, doi = {10.1039/d4tb01122h}, pmid = {39263769}, issn = {2050-7518}, abstract = {Stimuli-responsive nanomaterials show promise in eradicating Staphylococcus aureus biofilm from implants. Peptidoglycan hydrolases (PGHs) are cationic antimicrobials that can be bioengineered to improve the targeting of persisters and drug-resistant bacteria. However, these molecules can be degraded before reaching the target and/or present limited efficacy against biofilm. Therefore, there is an urgent need to improve their potency. Herein, PGH-polyphosphate nanoparticles (PGH-PP NPs) are formed by ionotropic gelation between cationic PGHs and anionic polyphosphate, with the aim of protecting PHGs and delivering them at the target site triggered by alkaline phosphatase (AP) from S. aureus biofilm. Optimized conditions for obtaining M23-PP NPs and GH15-PP NPs are presented. Size, zeta potential, and transmission electron microscopy imaging confirm the nanoscale size. The system demonstrates outstanding performance, as evidenced by a dramatic reduction in PGHs' minimum inhibitory concentration and minimum bactericidal concentration, together with protection against proteolytic effects, storage stability, and cytotoxicity towards the Caco-2 and HeLa cell lines. Time-kill experiments show the great potential of these negatively charged delivery systems in overcoming the staphylococcal biofilm barrier. Efficacy under conditions inhibiting AP proves the enzyme-triggered delivery of PGHs. The enzyme-responsive PGH-PP NPs significantly enhance the effectiveness of PGHs against bacteria residing in biofilm, offering a promising strategy for eradicating S. aureus biofilm.}, }
@article {pmid39262597, year = {2024}, author = {Pandey, A and Bhushan, J and Joshi, RK and Uppal, AS and Angrup, A and Kansal, S}, title = {Comparative evaluation of antimicrobial efficacy of chitosan nanoparticles and calcium hydroxide against endodontic biofilm of Enterococcus faecalis: An in vitro study.}, journal = {Journal of conservative dentistry and endodontics}, volume = {27}, number = {7}, pages = {750-754}, doi = {10.4103/JCDE.JCDE_219_24}, pmid = {39262597}, issn = {2950-4708}, abstract = {AIM: The aim of the study was to assess and evaluate the antimicrobial effectiveness of chitosan nanoparticles (CSNPs) with calcium hydroxide in the elimination of Enterococcus faecalis.<br><br>MATERIALS AND METHODS: Using the broth microdilution method, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of calcium hydroxide and CSNPs were measured. The antibiofilm effect of calcium hydroxide and CSNPs against E. faecalis biofilm was qualitatively analyzed using a crystal violet assay. A 7-day-old biofilms of E. faecalis grown on dentine discs were assigned to the following three groups (n = 11 dentine discs), normal saline (group I), calcium hydroxide (group II), and CSNPs (group III). Quantification of live and dead cells using confocal microscopy was done to evaluate the antibiofilm efficacy of the medicaments included in the study.<br><br>RESULTS: MIC of calcium hydroxide and CSNPs against E. faecalis was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. MBC of calcium hydroxide and CSNPs was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. Using Crystal Violet (CV) assay, calcium hydroxide and CSNPs showed biofilm inhibition at concentrations of 2.5 mg/mL and 0.625 mg/mL, respectively. Confocal laser scanning microscopy analysis found that both calcium hydroxide and CSNPs showed a significant decrease in viable cells at their MBC values compared to the control group's normal saline. CSNPs showed a significantly lower percentage of live cells than calcium hydroxide (P < 0.05).<br><br>CONCLUSION: The study results reveal that the antimicrobial efficacy of CSNPs is better than calcium hydroxide and normal saline against E. faecalis biofilm.}, }
@article {pmid39261342, year = {2024}, author = {Das, P and Mehra, A and Sachan, SG and Chattopadhyay, S}, title = {Screening different solid supports for Pseudomonas aeruginosa biofilm formation and determining its efficiency for decolorization and degradation of congo red.}, journal = {Archives of microbiology}, volume = {206}, number = {10}, pages = {402}, pmid = {39261342}, issn = {1432-072X}, mesh = {*Biofilms/growth &amp; development ; *Congo Red/metabolism ; *Pseudomonas aeruginosa/physiology/metabolism ; *Biodegradation, Environmental ; Wastewater/microbiology ; Water Pollutants, Chemical/metabolism ; Spectroscopy, Fourier Transform Infrared ; Coloring Agents/metabolism ; Germination ; }, abstract = {A global water crisis is emerging due to increasing levels of contaminated water and decreasing clean water supply on Earth. This study aims to address the removal of azo dye from wastewater to enable its reuse. Recently, utilizing microorganisms has been proven to be a practical choice for the remediation of azo dyes in wastewater. Hence, in this study, we employed a preformed biofilm of Pseudomonas aeruginosa on a solid support (called substrate) to degrade azo dyes. This process offers several advantages, such as stability, substrate portability, more biofilm production in less time, and efficient utilization of enzymes for remediation. From 50 ppm of initial Congo Red concentration, 75.74% decolorization was achieved within ten h using a preformed biofilm on a coverslip. A maximum of 52.27% decolorization was achieved using biofilm during its formation after 72 h of incubation. The Fourier-transform infrared (FTIR) spectroscopic analysis of Congo Red dye before and after remediation revealed a significant change in peak intensity, indicating dye degradation. Phytotoxicity studies performed by seed germination with Vigna radiata revealed that, after 5-7 days, almost 40% more seeds with longer root and shoot lengths were germinated in the presence of treated dye compared to the untreated one. This data indicated that the harmful Congo Red was successfully degraded to a non-toxic product by Pseudomonas aeruginosa biofilm grown on a glass substrate.}, }
@article {pmid39260724, year = {2024}, author = {Ke, Y and Sun, W and Xue, Y and Yuan, Z and Zhu, Y and Chen, X and Yan, S and Li, Y and Xie, S}, title = {Pipe material and natural organic matter impact drinking water biofilm microbial community, pathogen profiles and antibiotic resistome deciphered by metagenomics assembly.}, journal = {Environmental research}, volume = {}, number = {}, pages = {119964}, doi = {10.1016/j.envres.2024.119964}, pmid = {39260724}, issn = {1096-0953}, abstract = {Biofilms in drinking water distribution systems (DWDSs) are a determinant to drinking water biosafety. Yet, how and why pipe material and natural organic matter (NOM) affect biofilm microbial community, pathogen composition and antibiotic resistome remain unclear. We characterized the biofilms' activity, microbial community, antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and pathogenic ARG hosts in Centers for Disease Control and Prevention (CDC) reactors with different NOM dosages and pipe materials based on metagenomics assembly. Biofilms in cast iron (CI) pipes exhibited higher activity than those in polyethylene (PE) pipes. NOM addition significantly decreased biofilm activity in CI pipes but increased it in PE pipes. Pipe material exerted more profound effects on microbial community structure than NOM. Azospira was significantly enriched in CI pipes and Sphingopyxis was selected in PE pipes, while pathogen (Ralstonia pickettii) increased considerably in NOM-added reactors. Microbial community network in CI pipes showed more edges (CI 13520, PE 7841) and positive correlation proportions (CI 72.35%, PE 61.69%) than those in PE pipes. Stochastic processes drove assembly of both microbial community and antibiotic resistome in DWDS biofilms based on neutral community model. Bacitracin, fosmidomycin and multidrug ARGs were predominant in both PE and CI pipes. Both pipe materials and NOM regulated the biofilm antibiotic resistome. Plasmid was the major MGE co-existing with ARGs, facilitating ARG horizontal transfer. Pathogens (Achromobacter xylosoxidans and Ralstonia pickettii) carried multiple ARGs (qacEdelta1, OXA-22 and aadA) and MGEs (integrase, plasmid and transposase), which deserved more attention. Microbial community contributed more to ARG change than MGEs. Structure equation model (SEM) demonstrated that turbidity and ammonia affected ARGs by directly mediating Shannon diversity and MGEs. These findings might provide a technical guidance for controlling pathogens and ARGs from the point of pipe material and NOM in drinking water.}, }
@article {pmid39259403, year = {2024}, author = {Visperas, A and Cui, K and Alam, MM and Subramanian, S and Butsch, E and Klika, AK and Samia, AC and Piuzzi, NS}, title = {Diamond-like carbon (DLC) surface treatment decreases biofilm burden by S. aureus on titanium alloy in vitro- a pilot study.}, journal = {European journal of orthopaedic surgery &amp; traumatology : orthopedie traumatologie}, volume = {}, number = {}, pages = {}, pmid = {39259403}, issn = {1432-1068}, abstract = {PURPOSE: Periprosthetic joint infection is a complication of total joint arthroplasty with treatment costs over $1.6 billion dollars per year in the US with high failure rates. Therefore, generation of coatings that can prevent infection is paramount. Diamond-like carbon (DLC) is an ideal coating for implants as they are wear-resistant, corrosion-resistant, inert, and have a low friction coefficient. The purpose of this study was to test the efficacy of DLC surface treatment in prevention of biofilm on titanium discs infected with Staphylococcus aureus in vitro.<br><br>METHODS: Titanium alloy discs (n&#x2009;=&#x2009;4 non-coated and n&#x2009;=&#x2009;4 DLC-coated) were infected with 5&#x2009;&#xd7;&#x2009;10[5] colony-forming units (CFU) of S. aureus for 2 weeks then analysed via crystal violet and scanning electron microscopy (SEM).<br><br>RESULTS: Crystal violet analysis yielded differences in the appearance of biofilm on implant surface where DLC-coated had a clumpier appearance but no difference in biofilm quantification. Interestingly, this clumpy appearance did lead to differences in SEM biofilm coverage where significantly less biofilm coverage was found on DLC-coated discs (81.78% vs. 54.17%, p&#x2009;<&#x2009;0.003).<br><br>CONCLUSION: DLC-coated titanium alloy implants may have preventative properties in S. aureus infection. Observing differences in biofilm coverage does warrant additional testing including CFU titration and biofilm kinetics with eventual use in an animal model of periprosthetic joint infection.}, }
@article {pmid39257244, year = {2024}, author = {Rajagopal, GK and Raorane, CJ and Ravichandran, V and Rajasekharan, SK}, title = {Synergy of Histone Acetyltransferase Inhibitor (HATi) with Quercetin Inhibits Biofilm Formation in Candida tropicalis.}, journal = {Letters in applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/lambio/ovae085}, pmid = {39257244}, issn = {1472-765X}, abstract = {Histone acetyltransferase inhibitors (HATi) are mechanism-based inhibitors that show promise in the treatment of several illnesses, including diabetes, hyperlipidemia, cancer, and Alzheimer's disease. The work emphasizes the significance of HATi as a possible treatment strategy against Candida species biofilms. Here, in this study, we found that combining a HATi, anacardic acid, and quercetin, a known flavonoid, significantly prevented biofilm formation by C. tropicalis. We further show that C. tropicalis exhibited a considerable downregulation of drug-resistance gene expression (CDR1 and MDR1) when co-administrated. Additionally, in silico studies revealed that the anacardic acid (AA) interacts strongly with a histone acetyltransferase, Rtt109, which may account for the observed biofilm inhibitory effect. In conclusion, the study illustrates how HATi may be used to potentiate the inhibitory action of phytoactives or antifungals against drug-resistant yeast infections.}, }
@article {pmid39256439, year = {2024}, author = {de Sousa, DV and Maia, PVS and Eltink, E and de Moura Guimarães, L}, title = {Biomolecules in Pleistocene fossils from tropical cave indicate fossil biofilm.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {21071}, pmid = {39256439}, issn = {2045-2322}, support = {432075/2018-6//Conselho Nacional das Funda&#xe7;&#xf5;es Estaduais de Amparo &#xe0; Pesquisa/ ; 0936-21-52799//Funda&#xe7;&#xe3;o de Amparo &#xe0; Ci&#xea;ncia e Tecnologia do Estado de Pernambuco/ ; 102032/2024-6//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; }, mesh = {*Fossils ; *Biofilms ; *Spectrum Analysis, Raman ; *Caves/microbiology ; Animals ; Tooth/microbiology/chemistry ; Brazil ; }, abstract = {Finding biomolecules in fossils is a challenging task due to their degradation over time from physical, chemical, and biological factors. The primary hypothesis for explaining the presence of biomolecules in fossilized bones tissues suggests their survival in the fossilization process. In contrast, some of these biomolecules could either derive from bacteria biofilm, thus without a direct relationship with the fossil record or could be an artifact from measurement procedures. Raman spectroscopy studies across various fossil ages and environments have detected multiple bands ranging from 1200 to 1800 cm[-1] associative of organic compounds. However, the significance of these bands remains elusive. Our research aims to address this issue through a deep Raman spectroscopy investigation on Pleistocene teeth from Tayassu and Smilodon populator. These fossils were obtained from a well-preserved stratigraphic succession in Toca de Cima do Pilão cave, near the National Park of Serra da Capivara in semiarid Brazil. We propose two hypotheses to explain the presence of organic compounds related to 1200 to 1800 cm[-1] Raman spectral range in fossil tissues: (i) these bands are biological signatures of preserved fossil biomolecules, or (ii) they are exogenous biological signatures associated with the bacterial biofilm formation during post-depositional processes. Our results align with the latter hypothesis, followed by biofilm degradation. However, the specific mechanisms involved in the natural biofilm degradation in fossil records remain unexplored in this study. In our case, the formation of biofilm on fossil bones is attributed to the oligotrophic conditions of the cave sediment matrix. We present a comprehensive model to elucidate the existence of biofilm on fossilized tissues, emphasizing the pivotal role of post-depositional processes, especially water action, in the cave environment. As the fossils were discovered in a cave setting, post-depositional processes significantly contribute to the formation of the biofilm matrix. Although our study provides insights into biofilm formation, further research is needed to delve into the specific mechanisms driving natural biofilm degradation in fossils.}, }
@article {pmid39255667, year = {2024}, author = {Mei, Z and Wang, F and Fu, Y and Liu, Y and Hashsham, SA and Wang, Y and Harindintwali, JD and Dou, Q and Virta, M and Jiang, X and Deng, Y and Zhang, T and Tiedje, JM}, title = {Biofilm enhanced the mitigations of antibiotics and resistome in sulfadiazine and trimethoprim co-contaminated soils.}, journal = {Journal of hazardous materials}, volume = {479}, number = {}, pages = {135721}, doi = {10.1016/j.jhazmat.2024.135721}, pmid = {39255667}, issn = {1873-3336}, abstract = {Reducing antibiotic levels in soil ecosystems is vital to curb the dissemination of antimicrobial resistance genes (ARGs) and mitigate global health threats. However, gaps persist in understanding how antibiotic resistome can be suppressed during antibiotic degradation. Herein, we investigate the efficacy of a biochar biofilm incorporating antibiotics-degrading bacterial strain (Arthrobacter sp. D2) to mitigate antibiotic resistome in non-manured and manure-amended soils with sulfadiazine (SDZ) and trimethoprim (TMP) contamination. Results show that biofilm enhanced SDZ degradation by 83.0% within three days and increased TMP attenuation by 55.4% over 60 days in non-manured soils. In the non-manured black soil, the relative abundance of ARGs increased initially after biofilm inoculation. However, by day 30, it decreased by 20.5% compared to the controls. Moreover, after 7 days, biofilm reduced TMP by 38.5% in manured soils and decreased the total ARG abundance by 19.0%. Thus, while SDZ degradation did not increase sulfonamide resistance genes, TMP dissipation led to a proliferation of insertion sequences and related TMP resistance genes. This study underscores the importance of antibiotic degradation in reducing related ARGs while cautioning against the potential proliferation and various ARGs transfer by resistant microorganisms.}, }
@article {pmid39254872, year = {2024}, author = {Amer, AM and Charnock, C and Nguyen, S}, title = {Novel Teixobactin Analogues Show Promising In Vitro Activity on Biofilm Formation by Staphylococcus aureus and Enterococcus faecalis.}, journal = {Current microbiology}, volume = {81}, number = {10}, pages = {349}, pmid = {39254872}, issn = {1432-0991}, mesh = {*Biofilms/drug effects ; *Enterococcus faecalis/drug effects/physiology/growth &amp; development ; *Staphylococcus aureus/drug effects/physiology ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Microbial Sensitivity Tests ; *Depsipeptides/pharmacology/chemistry ; }, abstract = {The treatment of infections caused by biofilm-forming organisms is challenging. The newly discovered antibiotic teixobactin shows activity against a wide range of biofilm-forming bacteria. However, the laborious and low-yield chemical synthesis of teixobactin complicates its further development for clinical application. The use of more easily synthesized teixobactin analogues may offer promise in this regard. In this article, three newly developed analogues were tested for efficacy against Staphylococcus aureus and Enterococcus faecalis. Minimum inhibitory and -bactericidal concentrations were investigated. MIC values for S. aureus and E. faecalis ranged from 0.5-2 and 2-4 μg/mL, respectively. Moreover, the ability of the analogues to prevent biofilm formation and to inactivate bacterial cells in already established S. aureus biofilm on medical grade materials (PVC and PTFE) used in the production of infusion tubing and catheters were also tested. The analogues showed an ability to prevent biofilm formation and inactivate bacterial cells in established biofilms at concentrations as low as 1-2 μg/mL. Confocal laser scanning microscopy showed that the most promising analogue (TB3) inactivated S. aureus cells in a preformed biofilm and gave a reduction in biovolume. The relative ease of synthesis of the analogues and their in vitro efficacy, makes them promising candidates for pharmaceutical development.}, }
@article {pmid39252055, year = {2024}, author = {Firouzjaei, MD and Halaji, M and Yaghoubi, S and Hendizadeh, P and Salehi, M and Mohammadi, M and Pournajaf, A}, title = {Inducible clindamycin-resistant and biofilm formation in the Staphylococcus aureus isolated from healthcare worker's anterior nasal carriage.}, journal = {BMC research notes}, volume = {17}, number = {1}, pages = {252}, pmid = {39252055}, issn = {1756-0500}, mesh = {Humans ; *Biofilms/drug effects/growth &amp; development ; *Clindamycin/pharmacology ; *Health Personnel ; *Anti-Bacterial Agents/pharmacology ; *Microbial Sensitivity Tests ; *Staphylococcus aureus/drug effects/isolation &amp; purification/physiology/genetics ; *Methicillin-Resistant Staphylococcus aureus/drug effects/isolation &amp; purification/genetics/physiology ; *Staphylococcal Infections/microbiology/epidemiology ; *Carrier State/microbiology ; Iran ; Male ; Adult ; Female ; Erythromycin/pharmacology ; Drug Resistance, Multiple, Bacterial/genetics ; Drug Resistance, Bacterial/genetics ; }, abstract = {OBJECTIVE: The purpose of this study is a new update on the resistance profile, Macrolide-Lincosamide-Streptogramin B resistance mechanisms and biofilm formation in the Staphylococcus aureus isolated from health care workers (HCWs) nasal carriage at a children's teaching hospital in Babol (Northern Iran).<br><br>RESULTS: A total of 143 non-repetitive nasal swab samples were collected from volunteers, where 53.8% (n; 77/143) were HCWs, 33.6% (n; 48/143) medical students, and 12.6% (n; 18/143) resident students. The prevalence of nasal carriers of S. aureus was 22.4% (n; 32/143), among them, 40.6% (n; 13/32) were identified as methicillin-resistant Staphylococcus aureus (MRSA(carriers. Antimicrobial susceptibility testing showed that erythromycin (68.8%, n; 22/32) and ciprofloxacin (15.6%, n; 5/32) had the highest and lowest resistance rate, respectively. The frequency of resistance genes in the strains was as follows; ermC (n; 17/32, 53.1%), ermA (n; 11/32, 34.4%), ermB (n; 6/32, 18.7%), ereA (n; 3/32, 9.4%). Moreover, 50.0% (n; 16/32), 28.1% (n; 9/32) and 21.8% (n; 7/32) of isolates were strongly, weakly and moderately biofilm producer, respectively. Macrolides-lincosamides-streptogramins B (MLSB) antibiotic resistance among S. aureus isolates from HCWs nasal carriage have found significant prevalence rates throughout the globe. It is crucial to remember that the development of biofilms and MLS B antibiotic resistance are both dynamic processes.}, }
@article {pmid39251105, year = {2024}, author = {Sun, X and Xiao, F and Su, Y and Li, Z and Yu, X and Parales, RE and Li, L}, title = {Cyclic di-GMP incorporates the transcriptional factor FleQ03 in Pseudomonas syringae MB03 to elicit biofilm-dependent resistance in response to Caenorhabditis elegans predation.}, journal = {Journal of invertebrate pathology}, volume = {}, number = {}, pages = {108189}, doi = {10.1016/j.jip.2024.108189}, pmid = {39251105}, issn = {1096-0805}, abstract = {Bacteria usually form biofilms as a defense mechanism against predation by bacterivorous nematodes. In this context, the second messenger c-di-GMP from the wild-type Pseudomonas syringae MB03 actuates the transcriptional factor FleQ03 to elicit biofilm-dependent nematicidal activity against Caenorhabditis elegans N2. P. syringae MB03 cells exhibited nematicidal activity and c-di-GMP content in P. syringae MB03 cells was increased after feeding to nematodes. Expression of a diguanylate cyclase (DGC) gene in P. syringae MB03 resulted in an increased c-di-GMP content, biofilm yield and nematicidal activity, whereas converse effects were obtained when expressing a phosphodiesterase (PDE) gene. Molecular docking and isothermal titration calorimetry assays verified the affinity activity between c-di-GMP and the FleQ03 protein. The disruption of the fleQ03 gene in P. syringae MB03, while increasing c-di-GMP content, significantly diminished both biofilm formation and nematicidal activity. Interestingly, P. syringae MB03 formed a full-body biofilm around the worms against predation, probably extending from the tail to the head, whereas it was not observed in the fleQ03 gene disrupted cells. Thus, we hypothesized that c-di-GMP incorporated FleQ03 to reinforce bacterial biofilm and biofilm-dependent pathogenicity in response to C. elegans predation, providing insights into a possible means of resisting bacterivorous nematodes by bacteria in natural ecosystems.}, }
@article {pmid39249569, year = {2024}, author = {Ruhal, R and Sahu, A and Koujalagi, T and Das, A and Prasanth, H and Kataria, R}, title = {Biofilm-specific determinants of enterococci pathogen.}, journal = {Archives of microbiology}, volume = {206}, number = {10}, pages = {397}, pmid = {39249569}, issn = {1432-072X}, support = {NA//VIT University/ ; NA//VIT University/ ; NA//VIT University/ ; NA//VIT University/ ; NA//VIT University/ ; NA//VIT University/ ; }, mesh = {*Biofilms/growth &amp; development ; Enterococcus faecalis/genetics/physiology ; Enterococcus/physiology/genetics/metabolism ; Humans ; Enterococcus faecium/physiology/genetics ; Bacterial Proteins/genetics/metabolism ; Bacterial Adhesion ; Gram-Positive Bacterial Infections/microbiology ; Adhesins, Bacterial/metabolism/genetics ; Gene Expression Regulation, Bacterial ; }, abstract = {Amongst all Enterococcus spp., E. faecalis and E. faecium are most known notorious pathogen and their biofilm formation has been associated with endocarditis, oral, urinary tract, and wound infections. Biofilm formation involves a pattern of initial adhesion, microcolony formation, and mature biofilms. The initial adhesion and microcolony formation involve numerous surface adhesins e.g. pili Ebp and polysaccharide Epa. The mature biofilms are maintained by eDNA, It's worth noting that phage-mediated dispersal plays a prominent role. Further, the involvement of peptide pheromones in regulating biofilm maintenance sets it apart from other pathogens and facilitating the horizontal transfer of resistance genes. The role of fsr based regulation by regulating gelE expression is also discussed. Thus, we provide a concise overview of the significant determinants at each stage of Enterococcus spp. biofilm formation. These elements could serve as promising targets for antibiofilm strategies.}, }
@article {pmid39248307, year = {2024}, author = {Bi, Y and Chen, X and Luo, F and Wang, X and Chen, X and Yao, J and Shao, Z}, title = {Magnetic silk fibroin nanospheres loaded with amphiphilic polypeptides and antibiotics for biofilm eradication.}, journal = {Biomaterials science}, volume = {}, number = {}, pages = {}, doi = {10.1039/d4bm01065e}, pmid = {39248307}, issn = {2047-4849}, abstract = {The eradication of established biofilms is a highly challenging task, due to the protective barrier effect of extracellular polymeric substances (EPS) and the presence of persister cells. Both increased drug permeability and elimination of persister cells are essential for the eradication of biofilms. Here, magnetic silk fibroin nanospheres loaded with antibiotics and host defense peptide (HDP) mimics (MPSN/S@P) were developed to demonstrate a new strategy for biofilm eradication. As an HDP mimic, an amphiphilic polypeptide containing 90% L-lysine and 10% L-valine (Lys90Val10) was selected for loading onto magnetic silk fibroin nanospheres via electrostatic interactions. Lys90Val10 exhibited excellent antibacterial activities against both planktonic and persister cells of Staphylococcus aureus (S. aureus). As a representative of the hydrophobic drug, spiramycin (SPM) was conveniently embedded into the β-sheet domain during the self-assembly process of silk fibroin. The sustained release of SPM during biofilm eradication enhanced the antibacterial efficacy of MPSN/S@P. The antibacterial test demonstrated that the extract from the MPSN/S@P suspension can kill both planktonic and persister cells of S. aureus, as well as inhibiting biofilm formation. Importantly, with the assistance of magnetic guidance and photothermal effects derived from Fe3O4 nanoparticles (Fe3O4 NPs), over 92% of bacteria in the biofilm were killed by MPSN/S@P, indicating the successful eradication of mature biofilms. The simple preparation method, integration of photothermal and magnetic responsiveness, and persister cell killing functions of MPSN/S@P provide an accessible strategy and illustrative paradigm for efficient biofilm eradication.}, }
@article {pmid39247681, year = {2024}, author = {Cordery, C and Craddock, J and Malý, M and Basavaraja, K and Webb, JS and Walsh, MA and Tews, I}, title = {Control of phosphodiesterase activity in the regulator of biofilm dispersal RbdA from Pseudomonas aeruginosa.}, journal = {RSC chemical biology}, volume = {}, number = {}, pages = {}, pmid = {39247681}, issn = {2633-0679}, abstract = {The switch between planktonic and biofilm lifestyle correlates with intracellular concentration of the second messenger bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP). While bacteria possess cyclase and phosphodiesterase enzymes to catalyse formation or hydrolysis of c-di-GMP, both enzymatic domains often occur in a single protein. It is tacitly assumed that one of the two enzymatic activities is dominant, and that additional domains and protein interactions enable responses to environmental conditions and control activity. Here we report the structure of the phosphodiesterase domain of the membrane protein RbdA (regulator of biofilm dispersal) in a dimeric, activated state and show that phosphodiesterase activity is controlled by the linked cyclase. The phosphodiesterase region around helices α5/α6 forms the dimer interface, providing a rationale for activation, as this region was seen in contact with the cyclase domain in an auto-inhibited structure previously described. Kinetic analysis supports this model, as the activity of the phosphodiesterase alone is lower when linked to the cyclase. Analysis of a computed model of the RbdA periplasmatic domain reveals an all-helical architecture with a large binding pocket that could accommodate putative ligands. Unravelling the regulatory circuits in multi-domain phosphodiesterases like RbdA is important to develop strategies to manipulate or disperse bacterial biofilms.}, }
@article {pmid39247326, year = {2024}, author = {de Souza, BM and Braga, AS and Vertuan, M and Sassaki, S and Araújo, TT and Santos, PSDS and Buzalaf, MAR and Magalhães, AC}, title = {Influence of irradiated dentin, biofilm and different artificial saliva formulations on root dentin demineralization.}, journal = {Heliyon}, volume = {10}, number = {16}, pages = {e36334}, pmid = {39247326}, issn = {2405-8440}, abstract = {The aim of this study was evaluated the influence of radiation as well as of new formulations of artificial saliva on the development of root dentin lesions. Bovine root samples were divided into: irradiated (70 Gy) dentin or not; the type of biofilm (from irradiated patient-experimental or non-irradiated patient-control) and the type of artificial saliva (for the condition irradiated dentin/biofilm from irradiated patient): Control Artificial Saliva (inorganic); Control Saliva + 1 mg/ml hemoglobin; Control Saliva +0.1 mg/ml cystatin; Control Saliva + hemoglobin + cystatin; Bioextra (positive control) and deionized water (DiW, negative control) (n = 12/group). Biofilm was produced using human biofilm and McBain saliva (0.2 % of sucrose, 37[o] C and 5 % CO2); the treatments were done 1x/day, for 5 days. Colony-forming units (CFU) counting was performed; demineralization was quantified by transversal microradiography. Two-way ANOVA/Bonferroni or Sidak test for the comparison between biofilm x dentin and ANOVA/Tukey or Kruskal-Wallis/Dunn for comparing artificial saliva were done (p < 0.05). The type of biofilm had no influence on CFU and demineralization. Sound dentin under control biofilm presented the lowest Lactobacillus ssp. and Streptococcus mutans CFU and the lowest mean mineral loss (R) (25.6 ± 2.2; 23.7 ± 2.9 %) compared to irradiated dentin (26.1 ± 2.8; 28.1 ± 3.3, p < 0.004) for both types of biofilms (experimental and control, respectively). Bioextra was the only artificial saliva that reduced R (10.8 ± 2.5 %) and Lesion Depth (LD) (35 ± 15 μm) compared to DiW (17.3 ± 3.3 %, 81 ± 18 μm, p < 0.0001). Irradiation has impact on caries development; the experimental saliva were unable to reduce its occurrence.}, }
@article {pmid39246828, year = {2024}, author = {Erb, IK and Suarez, C and Frank, EM and Bengtsson-Palme, J and Lindberg, E and Paul, CJ}, title = {Escherichia coli in urban marine sediments: interpreting virulence, biofilm formation, halotolerance, and antibiotic resistance to infer contamination or naturalization.}, journal = {FEMS microbes}, volume = {5}, number = {}, pages = {xtae024}, pmid = {39246828}, issn = {2633-6685}, abstract = {Marine sediments have been suggested as a reservoir for pathogenic bacteria, including Escherichia coli. The origins, and properties promoting survival of E. coli in marine sediments (including osmotolerance, biofilm formation capacity, and antibiotic resistance), have not been well-characterized. Phenotypes and genotypes of 37 E. coli isolates from coastal marine sediments were characterized. The isolates were diverse: 30 sequence types were identified that have been previously documented in humans, livestock, and other animals. Virulence genes were found in all isolates, with more virulence genes found in isolates sampled from sediment closer to the effluent discharge point of a wastewater treatment plant. Antibiotic resistance was demonstrated phenotypically for one isolate, which also carried tetracycline resistance genes on a plasmid. Biofilm formation capacity varied for the different isolates, with most biofilm formed by phylogroup B1 isolates. All isolates were halotolerant, growing at 3.5% NaCl. This suggests that the properties of some isolates may facilitate survival in marine environments and can explain in part how marine sediments can be a reservoir for pathogenic E. coli. As disturbance of sediment could resuspend bacteria, this should be considered as a potential contributor to compromised bathing water quality at nearby beaches.}, }
@article {pmid39246292, year = {2024}, author = {Shao, L and Li, T and Yang, S and Ma, L and Cai, B and Jia, Q and Jiang, H and Bai, T and Li, Y}, title = {The prebiotic effects of fructooligosaccharides enhance the growth characteristics of Staphylococcus epidermidis and enhance the inhibition of Staphylococcus aureus biofilm formation.}, journal = {International journal of cosmetic science}, volume = {}, number = {}, pages = {}, doi = {10.1111/ics.13020}, pmid = {39246292}, issn = {1468-2494}, support = {1021ZK230016013//Shandong Freda Biotech Co., Ltd., and the Collaborative Innovation Center of Fragrance Flavour and Cosmetics/ ; }, abstract = {OBJECTIVE: Oligosaccharides have been shown to enhance the production of short chain fatty acids (SCFAs) by gut probiotics and regulate gut microbiota, to improve intestinal health. Recent research indicates that oligosaccharides may also positively impact skin microbiota by selectively promoting the growth of skin commensal bacteria and inhibiting pathogenic bacteria. However, the specific metabolic and regulatory mechanisms of skin commensal bacteria in response to oligosaccharides remain unclear. This study aims to explore the influence of four oligosaccharides on the growth and metabolism of Staphylococcus epidermidis and further identify skin prebiotics that can enhance its probiotic effects on the skin.<br><br>METHODS: Fructooligosaccharides (FOS), isomaltooligosaccharide (IMO), galactooligosaccharides (GOS) and inulin were compared in terms of their impact on cell proliferation, SCFAs production of S. epidermidis CCSM0287 and the biofilm inhibition effect of their fermentation supernatants on Staphylococcus aureus CCSM0424. Furthermore, the effect of FOS on S. epidermidis CCSM0287 was analysed by the transcriptome analysis.<br><br>RESULTS: All four oligosaccharides effectively promoted the growth of S. epidermidis CCSM0287 cells, increased the production of SCFAs, with FOS demonstrating the most significant effect. Analysis of the SCFAs indicated that S. epidermidis CCSM0287 predominantly employs oligosaccharides to produce acetic acid and isovaleric acid, differing from the SCFAs produced by gut microbiota. Among the four oligosaccharides, the addition of 2% FOS fermentation supernatant significantly inhibited S. aureus CCSM0424 biofilm formation. Furthermore, RNA sequencing revealed 162 differentially expressed genes (84 upregulated and 78 downregulated) of S. epidermidis CCSM0287 upon FOS treatment compared with glucose treatment. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis highlighted differences in the amino acid synthesis pathway, particularly in terms of arginine biosynthesis.<br><br>CONCLUSION: FOS promotes cell proliferation, increases the SCFA production of S. epidermidis CCSM0287 and enhance the inhibition of S. aureus biofilm formation, suggesting that FOS serves as a potential prebiotic for strain S. epidermidis CCSM0287.}, }
@article {pmid39246244, year = {2024}, author = {Saravanan, V and Gopalakrishnan, V and Mahendran, MIMS and Vaithianathan, R and Srinivasan, S and Boopathy, V and Krishnamurthy, S}, title = {Biofilm mediated integrin activation and directing acceleration of colorectal cancer.}, journal = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica}, volume = {}, number = {}, pages = {}, doi = {10.1111/apm.13466}, pmid = {39246244}, issn = {1600-0463}, abstract = {Bacterial biofilm plays a vital role in influencing several diseases, infections, metabolic pathways and communication channels. Biofilm influence over colorectal cancer (CRC) has been a booming area of research interest. The virulence factors of bacterial pathogen have a high tendency to induce metabolic pathway to accelerate CRC. The bacterial species biofilm may induce cancer through regulating the major signalling pathways responsible for cell proliferation, differentiation, survival and growth. Activation of cancer signals may get initiated from the chronic infections through bacterial biofilm species. Integrin mediates in the activation of major pathway promoting cancer. Integrin-mediated signals are expected to be greatly influenced by biofilm. Integrins are identified as an important dimer, whose dysfunction may alter the signalling cascade specially focusing on TGF-β, PI3K/Akt/mToR, MAPK and Wnt pathway. Along with biofilm shield, the tumour gains greater resistance from radiation, chemotherapy and also from other antibiotics. The biofilm barrier is known to cause challenges for CRC patients undergoing treatment.}, }
@article {pmid39245418, year = {2024}, author = {Li, L and Xiong, Y and Zhang, Y and Yan, Y and Zhao, R and Yang, F and Xie, M}, title = {Biofilm-camouflaged Prussian blue synergistic mitochondrial mass enhancement for Alzheimer's disease based on Cu[2+] chelation and photothermal therapy.}, journal = {Journal of controlled release : official journal of the Controlled Release Society}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jconrel.2024.09.009}, pmid = {39245418}, issn = {1873-4995}, abstract = {Alzheimer's disease (AD) is one of the most common neurodegenerative diseases characterized by cognitive and memory impairment. Metal ion imbalance and Mitochondrial dysfunction, leading to abnormal aggregation of β-amyloid protein (Aβ), are key factors in the pathogenesis of AD. Therefore, we designed a composite nanometer system of red blood cell (RBC) membranes-encapsulated Prussian blue nanoparticles (PB/RBC). Prussian blue nanoparticles (PBNPs) can chelate Cu[2+] and reduce reactive oxygen species (ROS). The RBC membranes are a kind of natural long-lasting circulating carrier. At the same time, through NIR irradiation, the excellent photothermal ability of PBNPs can also temporarily open the blood-brain barrier (BBB), enhance the transmission efficiency of PB/RBC across the BBB, and depolymerize the formed Aβ deposits, thereby achieving the optimal therapeutic effect. In vitro and in vivo studies demonstrated that PB/RBC could inhibit Cu[2+]-induced Aβ monomers aggregation, eliminate the deposition of Aβ plaques, improve the quality of mitochondria, restore the phagocytic function of microglia, alleviate neuroinflammation in APP/PS1 mice, and repair memory damage. In conclusion, our biofilm-camouflaged nano-delivery system provides significant neuroprotection by inhibiting Cu[2+]-induced Aβ monomers aggregation, photothermally depolymerizing Aβ fibrils and reducing the level of ROS, thus effectively ameliorating and treating AD.}, }
@article {pmid39244811, year = {2024}, author = {Maggio, F and Rossi, C and Serio, A and Chaves-Lopez, C and Casaccia, M and Paparella, A}, title = {Anti-biofilm mechanisms of action of essential oils by targeting genes involved in quorum sensing, motility, adhesion, and virulence: A review.}, journal = {International journal of food microbiology}, volume = {426}, number = {}, pages = {110874}, doi = {10.1016/j.ijfoodmicro.2024.110874}, pmid = {39244811}, issn = {1879-3460}, abstract = {Biofilms are a critical factor for food safety, causing important economic losses. Among the novel strategies for controlling biofilms, essential oils (EOs) can represent an environmentally friendly approach, able to act both on early and mature stages of biofilm formation. This review reports the anti-biofilm mechanisms of action of EOs against five pathogenic bacterial species known for their biofilm-forming ability. These mechanisms include disturbing the expression of genes related to quorum sensing (QS), motility, adhesion, and virulence. Biofilms and QS are interconnected processes, and EOs interfere with the communication system (e.g. regulating the expression of agrBDCA, luxR, luxS, and pqsA genes), thus influencing biofilm formation. In addition, QS is an important mechanism that regulates gene expression related to bacterial survival, virulence, and pathogenicity. Similarly, EOs also influence the expression of many virulence genes. Moreover, EOs exert their effects modulating the genes associated with bacterial adhesion and motility, for example those involved in curli (csg), fimbriae (fim, lpf), and flagella (fla, fli, flh, and mot) production, as well as the ica genes responsible for synthetizing polysaccharide intercellular adhesin. This review provides a comprehensive framework on the topic for a better understanding of EOs biofilm mechanisms of action.}, }
@article {pmid39244761, year = {2024}, author = {Cui, Y and Wang, D and Zhang, L and Qu, X}, title = {Research progress on the regulatory mechanism of biofilm formation in probiotic lactic acid bacteria.}, journal = {Critical reviews in food science and nutrition}, volume = {}, number = {}, pages = {1-15}, doi = {10.1080/10408398.2024.2400593}, pmid = {39244761}, issn = {1549-7852}, abstract = {Probiotic lactic acid bacteria (LAB) must undergo three key stages of testing, including food processing, storage, and gastrointestinal tract environment, their beneficial effects could exert. The biofilm formation of probiotic LAB is helpful for improving their stress resistances, survival rates, and colonization abilities under adverse environmental conditions, laying an important foundation for their probiotic effects. In this review, the formation process, the composition and function of basic components of probiotic LAB biofilm have been summarized. This review focuses on the regulatory mechanism of probiotic LAB biofilm formation. In addition, the characteristics and related mechanisms of probiotics in biofilm state have been analyzed to guide the application of probiotic LAB biofilms in the field of health and food. The biofilm formation of LAB is an extremely complex process involving multiple regulatory factors. Besides quorum sensing (QS), other regulatory factors are not yet fully understood. The probiotic LAB in biofilm state exhibit superior survival rate, adhesion performance, and immunomodulation ability, attribute to various metabolic processes, including stress response, exopolysaccharide (EPS) metabolism, amino acid and protein metabolisms, etc. The understanding about regulatory mechanism of biofilm formation of different probiotic species and strains will accelerate the development and application of probiotics products.}, }
@article {pmid39244528, year = {2024}, author = {Feng, R and Chen, Y and Chen, T and Hu, Z and Peng, T}, title = {DUF1127-containing protein and ProQ had opposite effects on biofilm formation in Vibrio alginolyticus.}, journal = {BMC microbiology}, volume = {24}, number = {1}, pages = {330}, pmid = {39244528}, issn = {1471-2180}, support = {42276158//National Natural Science Foundation of China/ ; 2024A1515010759//Guang dong Natural Science Foundation-General Project/ ; KYY24053//Initial Funding of Jiangsu University of Technology/ ; }, mesh = {*Biofilms/growth &amp; development ; *Vibrio alginolyticus/genetics/physiology/metabolism ; *Bacterial Proteins/genetics/metabolism ; *Gene Expression Regulation, Bacterial ; *Oxidative Stress ; RNA-Binding Proteins/genetics/metabolism ; Virulence/genetics ; Gene Deletion ; Reactive Oxygen Species/metabolism ; }, abstract = {The RNA binding protein is crucial for gene regulation at the post transcription level. In this study, functions of the DUF1127-containing protein and ProQ, which are RNA-binding proteins, were revealed in Vibrio alginolyticus. DUF1127 deletion increased the ability of biofilm formation, whereas ProQ deletion reduced the amount of biofilm. Moreover, extracellular proteinase secretion was significantly reduced in the DUF1127 deletion strain. ProQ, not DUF1127-containing protein, can help the cell to defense oxidative stress. Deletion of DUF1127 resulted in a higher ROS level in the cell, however, ProQ deletion showed no difference. RNA-seq unveiled the expression of genes involved in extracellular protease secretion were significantly downregulated and biofilm synthesis-related genes, such as rbsB and alsS, were differentially expressed in the DUF1127 deletion strain. ProQ affected the expression of genes involved in biofilm synthesis (flgC and flgE), virulence (betB and hutG), and oxidative stress. Moreover, the DUF1127-containing and ProQ affected the mRNA levels of various regulators, such as LysR and BetI. Overall, our study revealed that the DUF1127-containing protein and ProQ have crucial functions on biofilm formation in V. alginolyticus.}, }
@article {pmid39244368, year = {2024}, author = {Yao, S and Yang, H and Zhang, M and Xian, J and Zhou, R and Jin, Y and Huang, J and Wu, C}, title = {Sucrose contributed to the biofilm formation of Tetragenococcus halophilus and changed the biofilm structure.}, journal = {Food microbiology}, volume = {124}, number = {}, pages = {104616}, doi = {10.1016/j.fm.2024.104616}, pmid = {39244368}, issn = {1095-9998}, mesh = {*Biofilms/growth &amp; development ; *Sucrose/metabolism ; Polysaccharides, Bacterial/metabolism ; Enterococcaceae/genetics/metabolism/physiology ; Bacterial Proteins/genetics/metabolism ; Monosaccharides/metabolism ; Gene Expression Regulation, Bacterial ; Freeze Drying ; }, abstract = {Based on the previous research results that the addition of sucrose in the medium improved the biofilm formation of Tetragenococcus halophilus, the influence of sucrose on biofilm formation was explored. Moreover, the influence of exogenous expression of related genes sacA and galE from T. halophilus on the biofilm formation of L. lactis NZ9000 was investigated. The results showed that the addition of sucrose in the medium improved the biofilm formation, the resistance of biofilm cells to freeze-drying stress, and the contents of exopolysaccharides (EPS) and eDNA in the T. halophilus biofilms. Meanwhile, the addition of sucrose in the medium changed the monosaccharide composition of EPS and increased the proportion of glucose and galactose in the monosaccharide composition. Under 2.5% (m/v) salt stress condition, the expression of gene sacA promoted the biofilm formation and the EPS production of L. lactis NZ9000 with the sucrose addition in the medium and changed the EPS monosaccharide composition. The expression of gene galE up-regulated the proportion of rhamnose, galactose, and arabinose in the monosaccharide composition of EPS, and down-regulated the proportion of glucose and mannose. This study will provide a theoretical basis for regulating the biofilm formation of T. halophilus, and provide a reference for the subsequent research on lactic acid bacteria biofilms.}, }
@article {pmid39244358, year = {2024}, author = {Yi, Y and Chen, M and Coldea, TE and Yang, H and Zhao, H}, title = {Soy protein hydrolysates induce menaquinone-7 biosynthesis by enhancing the biofilm formation of Bacillus subtilis natto.}, journal = {Food microbiology}, volume = {124}, number = {}, pages = {104599}, doi = {10.1016/j.fm.2024.104599}, pmid = {39244358}, issn = {1095-9998}, mesh = {*Bacillus subtilis/metabolism/genetics/physiology ; *Biofilms/growth &amp; development ; *Vitamin K 2/analogs &amp; derivatives/metabolism ; *Fermentation ; *Protein Hydrolysates/metabolism ; *Soybean Proteins/metabolism ; Bacterial Proteins/metabolism/genetics ; Quorum Sensing ; }, abstract = {Menaquinone-7 (MK-7) is a form of vitamin K2 with health-beneficial effects. A novel fermentation strategy based on combining soy protein hydrolysates (SPHs) with biofilm-based fermentation was investigated to enhance menaquinone-7 (MK-7) biosynthesis by Bacillus subtilis natto. Results showed the SPHs increased MK-7 yield by 199.4% in two-stage aeration fermentation as compared to the SP-based medium in submerged fermentation, which was related to the formation of robust biofilm with wrinkles and the enhancement of cell viability. Moreover, there was a significant correlation between key genes related to MK-7 and biofilm synthesis, and the quorum sensing (QS) related genes, Spo0A and SinR, were downregulated by 0.64-fold and 0.39-fold respectively, which promoted biofilm matrix synthesis. Meanwhile, SPHs also enhanced the MK-7 precursor, isoprene side chain, supply, and MK-7 assembly efficiency. Improved fermentation performances of bacterial cells during fermentation were attributed to abundant oligopeptides (Mw < 1 kDa) and moderate amino acids, particularly Arg, Asp, and Phe in SPHs. All these results revealed that SPHs were a potential and superior nitrogen source for MK-7 production by Bacillus subtilis natto.}, }
@article {pmid39244072, year = {2024}, author = {Hou, S and Li, Y and Chen, Q and Yang, J and Zhao, P and Zhao, Y}, title = {Mechano-triggered eradication of dentinal tubule biofilm via in situ generation of nanoscale sonosensitizer by the tailored irrigation formulation.}, journal = {International journal of pharmaceutics}, volume = {}, number = {}, pages = {124655}, doi = {10.1016/j.ijpharm.2024.124655}, pmid = {39244072}, issn = {1873-3476}, abstract = {The efficient elimination of bacteria within the dentinal tubules has been hindered by the poor deposition and short residence of disinfecting agents. Meanwhile, the current irrigant (e.g., NaClO, 5.25 %) shows severe adverse effects on the surrounding soft tissues because of its inherent high irritancy. To address this issue, this work reports an in situ generated sonosensitizer to handle the biofilm in dentinal tubules with minimal adverse effects. The production of nanoscale sonosensitizer involves the concurrent delivery of H2O2 (0.01 %), ferrocene derivative (Fc), and indocyanine green (ICG). With ultrasound treatment, the reaction between H2O2 and Fc liberated Fe[3+] that further complexed with ICG to generate the nanoscale sonosensitizer in situ, followed by singlet oxygen production for potent disinfecting action. Because the above cascade reactions occur within the confined dentinal tubules, the generated ICG-Fe[3+] nanosensitizer would show prolonged retention therein. The anti-bacterial potency of nanosensitizer was demonstrated in petrodish and ex vivo biofilm models. Meanwhile, the transmission electron microscope imaging of biofilm and cytotoxicity assay in L929 fibroblast cells proved the superiority of nanosensitizer against NaClO regarding adverse effects. The current work opens new avenues of biofilm elimination in dentinal tubules, showing a high translation potential.}, }
@article {pmid39243653, year = {2024}, author = {Yan, Z and Chen, Y and Su, P and Liu, S and Jiang, R and Wang, M and Zhang, L and Lu, G and Yuan, S}, title = {Microbial carbon metabolism patterns of microplastic biofilm in the vertical profile of urban rivers.}, journal = {Journal of environmental management}, volume = {370}, number = {}, pages = {122422}, doi = {10.1016/j.jenvman.2024.122422}, pmid = {39243653}, issn = {1095-8630}, abstract = {Microplastics (MPs) can provide a unique niche for microbiota in waters, thus regulating the nutrients and carbon cycling. Following the vertical transport of MPs in waters, the compositions of attached biofilm may be dramatically changed. However, few studies have focused on the related ecological function response, including the carbon metabolism. In this study, we investigated the microbial carbon metabolism patterns of attached biofilm on different MPs in the vertical profile of urban rivers. The results showed that the carbon metabolism capacity of biofilm on the degradable polylactic acid (PLA) MPs was higher than that in the non-degradable polyethylene terephthalate (PET) MPs. In the vertical profile, the carbon metabolism rates of biofilm on two MPs both decreased with water depth, being 0.74 and 0.91 folds in bottom waters of that in surface waters. Specifically, the utilization of polymers, carbohydrate, and amine of PLA biofilm was significantly inhibited in the bottom waters, which were not altered on the PET. Compared with surface waters, the microbial metabolism function index of PLA biofilm was inhibited in deep waters, but elevated in the PET biofilm. In addition, the water quality parameters (e.g., nutrients) in the vertical profile largely shaped carbon metabolism patterns. These findings highlight the distinct carbon metabolism patterns in aquatic environments in the vertical profile, providing new insights into the effects of MPs on global carbon cycle.}, }
@article {pmid39242535, year = {2024}, author = {Attrah, M and Schärer, MR and Esposito, M and Gionchetta, G and Bürgmann, H and Lens, PNL and Fenner, K and van de Vossenberg, J and Robinson, SL}, title = {Disentangling abiotic and biotic effects of treated wastewater on stream biofilm resistomes enables the discovery of a new planctomycete beta-lactamase.}, journal = {Microbiome}, volume = {12}, number = {1}, pages = {164}, pmid = {39242535}, issn = {2049-2618}, support = {109070/WT_/Wellcome Trust/United Kingdom ; Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung, 186531 (ANTIVERSA as part of biodeversa+, European Biodiversity Partnership)//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung/ ; Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung, 186531 (ANTIVERSA as part of biodeversa+, European Biodiversity Partnership)//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung/ ; 200021L_201006//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung/ ; PZPGP2_209124//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung/ ; }, mesh = {*Biofilms/drug effects ; *Wastewater/microbiology ; *beta-Lactamases/genetics ; *Rivers/microbiology ; *Metagenomics ; Microbiota/drug effects ; Bacteria/genetics/classification/drug effects/isolation &amp; purification ; Anti-Bacterial Agents/pharmacology ; Planctomycetales/genetics/drug effects ; Metagenome ; Bacterial Proteins/genetics/metabolism ; }, abstract = {BACKGROUND: Environmental reservoirs of antibiotic resistance pose a threat to human and animal health. Aquatic biofilms impacted by wastewater effluent (WW) are known environmental reservoirs for antibiotic resistance; however, the relative importance of biotic factors and abiotic factors from WW on the abundance of antibiotic resistance genes (ARGs) within aquatic biofilms remains unclear. Additionally, experimental evidence is limited within complex aquatic microbial communities as to whether genes bearing low sequence similarity to validated reference ARGs are functional as ARGs.<br><br>RESULTS: To disentangle the effects of abiotic and biotic factors on ARG abundances, natural biofilms were previously grown in flume systems with different proportions of stream water and either ultrafiltered or non-ultrafiltered WW. In this study, we conducted deep shotgun metagenomic sequencing of 75 biofilm, stream, and WW samples from these flume systems and compared the taxonomic and functional microbiome and resistome composition. Statistical analysis revealed an alignment of the resistome and microbiome composition and a significant association with experimental treatment. Several ARG classes exhibited an increase in normalized metagenomic abundances in biofilms grown with increasing percentages of non-ultrafiltered WW. In contrast, sulfonamide and extended-spectrum beta-lactamase ARGs showed greater abundances in biofilms grown in ultrafiltered WW compared to non-ultrafiltered WW. Overall, our results pointed toward the dominance of biotic factors over abiotic factors in determining ARG abundances in WW-impacted stream biofilms and suggested gene family-specific mechanisms for ARGs that exhibited divergent abundance patterns. To investigate one of these specific ARG families experimentally, we biochemically characterized a new beta-lactamase from the Planctomycetota (Phycisphaeraceae). This beta-lactamase displayed activity in the cleavage of cephalosporin analog despite sharing a low sequence identity with known ARGs.<br><br>CONCLUSIONS: This discovery of a functional planctomycete beta-lactamase ARG is noteworthy, not only because it was the first beta-lactamase to be biochemically characterized from this phylum, but also because it was not detected by standard homology-based ARG tools. In summary, this study conducted a metagenomic analysis of the relative importance of biotic and abiotic factors in the context of WW discharge and their impact on both known and new ARGs in aquatic biofilms. Video Abstract.}, }
@article {pmid39242261, year = {2024}, author = {Carmona-Orozco, ML and Echeverri, F}, title = {Corrigendum to "Induction of biofilm in extended-spectrum beta-lactamase Staphylococcus aureus with drugs commonly used in pharmacotherapy" [Microb Pathog 195 (2024) 106863 1-11].}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106911}, doi = {10.1016/j.micpath.2024.106911}, pmid = {39242261}, issn = {1096-1208}, }
@article {pmid39241550, year = {2024}, author = {Guo, Z and Ge, M and Ruan, Z and Ma, Y and Chen, Y and Lin, H}, title = {2D Janus carrier-enabled trojan horse: Gallium delivery for the sequential therapy of biofilm associated infection.}, journal = {Biomaterials}, volume = {313}, number = {}, pages = {122761}, doi = {10.1016/j.biomaterials.2024.122761}, pmid = {39241550}, issn = {1878-5905}, abstract = {Biofilm-associated infections (BAIs) continue to pose a major challenge in the medical field. Nanomedicine, in particular, promises significant advances in combating BAIs through the introduction of a variety of nanomaterials and nano-antimicrobial strategies. However, studies to date have primarily focused on the removal of the bacterial biofilm and neglect the subsequent post-biofilm therapeutic measures for BAIs, rendering pure anti-biofilm strategies insufficient for the holistic recovery of affected patients. Herein, we construct an emerging dual-functional composite nanosheet (SiHx@Ga) that responds to pHs fluctuation in the biofilm microenvironment to enable a sequential therapy of BAIs. In the acidic environment of biofilm, SiHx@Ga employs the self-sensitized photothermal Trojan horse strategy to effectively impair the reactive oxygen species (ROS) defense system while triggering oxidative stress and lipid peroxidation of bacteria, engendering potent antibacterial and anti-biofilm effects. Surprisingly, in the post-treatment phase, SiHx@Ga adsorbs free pathogenic nucleic acids released after biofilm destruction, generates hydrogen with ROS-scavenging and promotes macrophage polarization to the M2 type, effectively mitigating damaging inflammatory burst and promoting tissue healing. This well-orchestrated strategy provides a sequential therapy of BAIs by utilizing microenvironmental variations, offering a conceptual paradigm shift in the field of nanomedicine anti-infectives.}, }
@article {pmid39241141, year = {2024}, author = {Yarov, YY and Tkachenko, IM and Skripnikov, PM and Hurzhii, OV and Kozak, RV}, title = {Results of microbiological study of dental biofilm in generalized periodontitis against the background of different body reactivity.}, journal = {Wiadomosci lekarskie (Warsaw, Poland : 1960)}, volume = {77}, number = {7}, pages = {1415-1419}, doi = {10.36740/WLek202407117}, pmid = {39241141}, issn = {0043-5147}, mesh = {Humans ; *Biofilms/growth &amp; development ; *Periodontitis/microbiology ; Female ; Male ; Adult ; Middle Aged ; }, abstract = {OBJECTIVE: Aim: To study the spectrum, frequency of isolation and level of colonization of dental biofilm with microorganisms in generalized periodontitis against the background of different body reactivity.<br><br>PATIENTS AND METHODS: Materials and Methods: 216 people with the diagnosis of generalized periodontitis. Depending on the state of reactivity of the organism, the patients were divided into 3 groups: with normo-, hyper- and with hyporeaction. The patients underwent patch surgery. After the surgery, dental biofilm was taken. Microbiological studies included the isolation and species identification of dental biofilm microorganisms, the results of quantitative studies of microflora: the level of colonization was expressed in colony-forming units per 1 ml (CFU/ml); the frequency of microorganisms isolation was expressed in absolute numbers. Statistical processing of the obtained digital data was performed using the computer program Statistica 8.0.<br><br>RESULTS: Results: The studies have shown that in different states of the body's reactivityi n patients with generalized periodontitis after flap surgery, different quantitative and qualitative composition of the microflora of the dental biofilm is determined. In case of normal body reactivity, there are predominantly aerobic-anaerobic associations with a wide range and quantitative predominance of aerobic microflora; in case of impaired (hyper- and hypo-) reactivity, there are predominantly aerobic-anaerobic associations with an expansion of the spectrum, frequency of isolation and level of colonization of facultative and obligate anaerobes.<br><br>CONCLUSION: Conclusions: The identified differences in the quantitative and qualitative composition of the microflora of the dental biofilm indicate the key role of the body's reactivity in the studied processes.}, }
@article {pmid39240091, year = {2024}, author = {Dramé, I and Rossez, Y and Krzewinski, F and Charbonnel, N and Ollivier-Nakusi, L and Briandet, R and Dague, E and Forestier, C and Balestrino, D}, title = {FabR, a regulator of membrane lipid homeostasis, is involved in Klebsiella pneumoniae biofilm robustness.}, journal = {mBio}, volume = {}, number = {}, pages = {e0131724}, doi = {10.1128/mbio.01317-24}, pmid = {39240091}, issn = {2150-7511}, abstract = {Biofilm is a dynamic structure from which individual bacteria and micro-aggregates are released to subsequently colonize new niches by either detachment or dispersal. Screening of a transposon mutant library identified genes associated with the alteration of Klebsiella pneumoniae biofilm including fabR, which encodes a transcriptional regulator involved in membrane lipid homeostasis. An isogenic ∆fabR mutant formed more biofilm than the wild-type (WT) strain and its trans-complemented strain. The thick and round aggregates observed with ∆fabR were resistant to extensive washes, unlike those of the WT strain. Confocal microscopy and BioFlux microfluidic observations showed that fabR deletion was associated with biofilm robustness and impaired erosion over time. The genes fabB and yqfA associated with fatty acid metabolism were significantly overexpressed in the ∆fabR strain, in both planktonic and biofilm conditions. Two monounsaturated fatty acids, palmitoleic acid (C16:1) and oleic acid (C18:1), were found in higher proportion in biofilm cells than in planktonic forms, whereas heptadecenoic acid (C17:1) and octadecanoic acid, 11-methoxy (C18:0-OCH3) were found in higher proportion in the planktonic lifestyle. The fabR mutation induced variations in the fatty acid composition, with no clear differences in the amounts of saturated fatty acids (SFA) and unsaturated fatty acids for the planktonic lifestyle but lower SFA in the biofilm form. Atomic force microscopy showed that deletion of fabR is associated with decreased K. pneumoniae cell rigidity in the biofilm lifestyle, as well as a softer, more elastic biofilm with increased cell cohesion compared to the wild-type strain.IMPORTANCEKlebsiella pneumoniae is an opportunistic pathogen responsible for a wide range of nosocomial infections. The success of this pathogen is due to its high resistance to antibiotics and its ability to form biofilms. The molecular mechanisms involved in biofilm formation have been largely described but the dispersal process that releases individual and aggregate cells from mature biofilm is less well documented while it is associated with the colonization of new environments and thus new threats. Using a multidisciplinary approach, we show that modifications of bacterial membrane fatty acid composition lead to variations in the biofilm robustness, and subsequent bacterial detachment and biofilm erosion over time. These results enhance our understanding of the genetic requirements for biofilm formation in K. pneumoniae that affect the time course of biofilm development and the embrittlement step preceding its dispersal that will make it possible to control K. pneumoniae infections.}, }
@article {pmid39238019, year = {2024}, author = {Abdel-Fatah, SS and Mohammad, NH and Elshimy, R and Mosallam, FM}, title = {Impeding microbial biofilm formation and Pseudomonas aeruginosa virulence genes using biologically synthesized silver Carthamus nanoparticles.}, journal = {Microbial cell factories}, volume = {23}, number = {1}, pages = {240}, pmid = {39238019}, issn = {1475-2859}, mesh = {*Biofilms/drug effects ; *Pseudomonas aeruginosa/drug effects/genetics ; *Metal Nanoparticles/chemistry ; *Silver/pharmacology/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Microbial Sensitivity Tests ; Virulence/drug effects ; Virulence Factors/genetics/metabolism ; Plant Extracts/pharmacology/chemistry ; Bacterial Proteins/metabolism/genetics ; }, abstract = {Long-term antibiotic treatment results in the increasing resistance of bacteria to antimicrobials drugs, so it is necessary to search for effective alternatives to prevent and treat pathogens that cause diseases. This study is aimed for biological synthesis of silver Carthamus nanoparticles (Ag-Carth-NPs) to combat microbial biofilm formation and Pseudomonas aeruginosa virulence genes. Ag-Carth-NPs are synthesized using Carthamus tenuis aqueous extract as environmentally friendly method has no harmful effect on environment. General factorial design is used to optimize Ag-Carth-NPs synthesis using three variables in three levels are Carthamus extract concentration, silver nitrate concentration and gamma radiation doses. Analysis of response data indicates gamma radiation has a significant effect on Ag-Carth-NPs production. Ag-Carth-NPs have sharp peak at λ max 425 nm, small and spherical particles with size 20.0 ± 1.22 nm, high stability up to 240 day with zeta potential around - 43 ± 0.12 mV, face centered cubic crystalline structure and FT-IR spectroscopy shows peak around 620 cm[-1] that corresponding to AgNPs that stabilized by C. tenuis extract functional moiety. The antibacterial activity of Ag-Carth-NPs against pathogenic bacteria and fungi was determined using well diffusion method. The MIC values of Ag-Carth-NPs were (6.25, 6.25, 3.126, 25, 12.5, 12.5, 25 and 12.5 µg/ml), MBC values were (12.5, 12.5, 6.25, 50, 25, 25, 50 and 25 µg/ml) and biofilm inhibition% were (62.12, 68.25, 90.12, 69.51, 70.61, 71.12, 75.51 and 77.71%) against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Candida tropicalis and Candida albicans respectively. Ag-Carth-NPs has bactericidal efficacy and significantly reduced the swarming, swimming motility, pyocyanin and protease production of P. aeruginosa. Furthermore, P. aeruginosa ToxA gene expression was significantly down regulated by 81.5%, while exoU reduced by 78.1%, where lasR gene expression reduction was 68%, while the reduction in exoU was 66% and 60.1% decrease in lasB gene expression after treatment with Ag-Carth-NPs. This activity is attributed to effect of Ag-Carth-NPs on cell membrane integrity, down regulation of virulence gene expression, and induction of general and oxidative stress in P. aeruginosa. Ag-Carth-NPs have no significant cytotoxic effects on normal human cell (Hfb4) but have IC50 at 5.6µg/mL against of HepG-2 cells. Limitations of the study include studies with low risks of silver nanoparticles for in vitro antimicrobial effects and its toxicity.}, }
@article {pmid39237859, year = {2024}, author = {Rostamani, M and Bakht, M and Rahimi, S and Alizadeh, SA and Anari, RK and Khakpour, M and Javadi, A and Fardsanei, F and Nikkhahi, F}, title = {Phenotypic and genotypic determination of resistance to common disinfectants among strains of Acinetobacter baumannii producing and non-producing biofilm isolated from Iran.}, journal = {BMC microbiology}, volume = {24}, number = {1}, pages = {323}, pmid = {39237859}, issn = {1471-2180}, abstract = {BACKGROUND: Nosocomial infections are a global problem in hospitals all around the world. It is considered a major health problem, especially in developing countries. The increase in the patient's stay in hospitals has increased the mortality rate, and consequently, the costs drastically increase. The main purpose of using disinfectants in the hospital environment is to reduce the risk of nosocomial infections. Ethylene diamine tetra acetic acid (EDTA) causes lysis and increases susceptibility to antimicrobial agents in the planktonic form of bacteria. This substance affects the permeability of the outer membrane of bacteria. It also prevents the formation of biofilms by bacteria.<br><br>MATERIALS AND METHODS: In the current study, 120 isolates of Acinetobacter baumannii (A. baumannii) were confirmed by phenotypic and genotypic methods. Antibiogram was performed and then the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of isolates against 5% sodium hypochlorite, ethanol %70, sayasept-HP 2%, chlorhexidine 2%, dettol 4/8% were evaluated. In addition, the disinfectant effect was re-evaluated with the mixture of EDTA solution. All isolates were examined for biofilm presence by crystal violet staining method in triplicates and repeated three times for each strain. Also for all isolates detection of efflux pump genes (Qac-E, qacE-&#x394;1, SUG-E) by PCR technique was done.<br><br>RESULTS: Antibiogram results of A. baumannii showed that 6.7% were Multi-drug-resistant (MDR), and 89.2% were Extensively drug-resistant (XDR) isolates. The highest effect of disinfectants was related to 5% sodium hypochlorite, and the least effect was 70% ethanol. EDTA increases the efficacy of selected disinfectants significantly. The highest prevalence of the efflux pump genes was related to SUG-E (95%) and Qac-E (91.7%), and, the qacE-&#x394;1 gene with 12.5%. The biofilm production rate was 91.3% among all isolates.<br><br>CONCLUSION: The best and safest way to disinfect hospital floors and surfaces is to choose the right disinfectants, and learn how to use them properly. In this study, a mixture of disinfectants and EDTA had a significant effect on bactericidal activity. it was found that improper use of disinfectants, especially the use of sub-inhibitory dilutions, increases the resistance of bacteria to disinfectants.}, }
@article {pmid39237802, year = {2024}, author = {Biswas, A and A, JM and Lewis, SA and Raja, S and Paul, A and Ghosal, K and Mahmood, S and Ansari, MD}, title = {Design and Evaluation of Microemulsion-Based Drug Delivery Systems for Biofilm-Based Infection in Burns.}, journal = {AAPS PharmSciTech}, volume = {25}, number = {7}, pages = {203}, pmid = {39237802}, issn = {1530-9932}, mesh = {*Biofilms/drug effects ; *Emulsions ; *Burns/drug therapy/microbiology ; *Pseudomonas aeruginosa/drug effects ; *Drug Delivery Systems/methods ; *Anti-Bacterial Agents/administration &amp; dosage/pharmacology ; Particle Size ; Drug Liberation ; Surface-Active Agents/chemistry ; Polysorbates/chemistry ; Tea Tree Oil/administration &amp; dosage/chemistry/pharmacology ; Chemistry, Pharmaceutical/methods ; Humans ; }, abstract = {Normal skin is the first line of defense in the human body. A burn injury makes the skin susceptible to bacterial infection, thereby delaying wound healing and ultimately leading to sepsis. The chances of biofilm formation are high in burn wounds due to the presence of avascular necrotic tissue. The most common pathogen to cause burn infection and biofilm is Pseudomonas aeruginosa. The purpose of this study was to create a microemulsion (ME) formulation for topical application to treat bacterial burn infection. In the present study, tea tree oil was used as the oil phase, Tween 80 and transcutol were used as surfactants, and water served as the aqueous phase. Pseudo ternary phase diagrams were used to determine the design space. The ranges of components as suggested by the design were chosen, optimization of the microemulsion was performed, and in vitro drug release was assessed. Based on the characterization studies performed, it was found that the microemulsion were formulated properly, and the particle size obtained was within the desired microemulsion range of 10 to 300 nm. The I release study showed that the microemulsion followed an immediate release profile. The formulation was further tested based on its ability to inhibit biofilm formation and bacterial growth. The prepared microemulsion was capable of inhibiting biofilm formation.}, }
@article {pmid39236969, year = {2024}, author = {Aramli, N and Safarkar, R and Shiralipour, A and Sadeghi, Z}, title = {Biofilm formation, antibiotic-resistance and clonal relatedness among clinical isolates of Acinetobacter baumannii.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106916}, doi = {10.1016/j.micpath.2024.106916}, pmid = {39236969}, issn = {1096-1208}, abstract = {In this work, the antibiotic resistance, biofilm formation capability, and clonal relatedness of 50 A. baumannii isolates collected from three hospitals in Ardabil city, Iran, were evaluated. Antibiotic sensitivity and biofilm formation of isolates were determined by disk diffusion and microtiter-plate methods, respectively. Molecular typing of isolates was also performed using repetitive sequence-based PCR (REP-PCR). The majority of isolates were resistant to cephems, aminoglycosides, and carbapenems, with 80% classified as multi-drug resistant (MDR). While, only isolates collected from blood and tracheal were resistant to colistin. Additionally, 42 isolates (84%) had biofilm formation capability. According to rep-PCR results, 34 isolates showed similar banding patterns, while 16 isolates had unique banding patterns. Finally, based on the molecular analysis, there was a direct relationship between biofilm formation and the antibiotic resistance of isolates. In other words, MDR isolates had a higher ability to form biofilm.}, }
@article {pmid39236967, year = {2024}, author = {Haranahalli Nataraj, B and Nayakvadi, S and Dhali, A and Shome, R and Prakash, K and Revanasiddappa, ST}, title = {Evaluation of virulence determinants and cell surface properties associated with biofilm formation in Methicillin-Resistant Staphylococcus aureus (MRSA) and Extended Spectrum Beta-Lactamase (ESBL) Escherichia coli from livestock and poultry origin.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106905}, doi = {10.1016/j.micpath.2024.106905}, pmid = {39236967}, issn = {1096-1208}, abstract = {Antibiotic resistance poses a persistent threat to modern medicine due to the emergence of novel antibiotic-resistant strains. Therefore, a timely understanding of antibiotic resistance and the virulence biology of pathogenic bacteria, particularly those of public health significance, is crucial for implementing effective mitigation strategies. This study aimed to investigate the virulence profiles of ten S. aureus isolates (NDa to NDj) and ten E. coli isolates (ND1 to ND10) originating from livestock and poultry, and to assess how various cell surface properties and biofilm formation abilities influence antibiotic resistance phenotypes. Antibiotic resistance profiling through phenotypic (AST) and genotypic methods (PCR) confirmed that NDa to NDe were methicillin-resistant S. aureus (MRSA) and ND1 to ND5 were extended-spectrum β-lactamase (ESBL) producing E. coli isolates. Virulence properties such as hemolytic activity, coagulase activity, and nuclease activity were found to be independent of the antibiotic resistance phenotype in S. aureus. In contrast, biofilm formation phenotype was observed to influence antibiotic resistance phenotypes, with MRSA and ESBL E. coli isolates demonstrating higher biofilm formation potency. Chemical and enzymatic analysis of S. aureus and E. coli biofilms revealed proteins and polysaccharides as major components, followed by nucleic acids. Furthermore, cell surface properties such as auto-aggregation and hydrophobicity were notably higher in isolates with strong to medium biofilm-forming capabilities (ESBL and MRSA isolates), corroborated by genomic confirmation of various genes associated with biofilm, adhesion, and colonization. In conclusion, this study highlights that surface hydrophobicity and biofilm formation ability of MRSA (NDa to NDe) and ESBL E. coli (ND1 to ND5) isolates may influence antibiotic resistance phenotypes.}, }
@article {pmid39236594, year = {2024}, author = {Aniba, R and Dihmane, A and Raqraq, H and Ressmi, A and Nayme, K and Timinouni, M and Barguigua, A}, title = {Molecular and phenotypic characterization of biofilm formation and antimicrobial resistance patterns of uropathogenic staphylococcus haemolyticus isolates in Casablanca, Morocco.}, journal = {Diagnostic microbiology and infectious disease}, volume = {110}, number = {4}, pages = {116483}, doi = {10.1016/j.diagmicrobio.2024.116483}, pmid = {39236594}, issn = {1879-0070}, abstract = {This study aimed to establish the correlation between antibiotic resistance and biofilm formation by Staphylococcus haemolyticus and to examine the impact of sub-inhibitory concentrations of antibiotics (sub-MICs) on biofilm formation. Antibiotic susceptibility testing was conducted using the disk diffusion method, and biofilm formation was determined using Congo red agar and microtiter plate methods. Antibiotic resistance and biofilm-associated genes were detected using polymerase chain reaction. The majority of the twenty-one S. haemolyticus isolates were multidrug-resistant, methicillin-resistant (MRSH) and biofilm producers, including 43 % of moderate biofilm producers. A significant correlation was observed between MRSH and MSSH isolates in terms of biofilm production. Vancomycin, gentamicin, and ciprofloxacin at their sub-MICs tended to promote biofilm formation. The eno gene was present in 76.2 % of strains, followed by aap, and atlE. This study revealed a strong correlation between the biofilm-forming ability and antibiotic resistance in S. haemolyticus, which underlines a crucial public health issue.}, }
@article {pmid39235742, year = {2025}, author = {Giaouris, E}, title = {Comparing Gene Expression Between Planktonic and Biofilm Cells of Foodborne Bacterial Pathogens Through RT-qPCR.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2852}, number = {}, pages = {143-158}, pmid = {39235742}, issn = {1940-6029}, mesh = {*Biofilms/growth &amp; development ; *Plankton/genetics ; Gene Expression Regulation, Bacterial ; Food Microbiology ; Gene Expression Profiling/methods ; Real-Time Polymerase Chain Reaction/methods ; Bacteria/genetics ; Listeria monocytogenes/genetics/physiology ; Reverse Transcriptase Polymerase Chain Reaction/methods ; }, abstract = {Like most microorganisms, important foodborne pathogenic bacteria, such as Salmonella enterica, Listeria monocytogenes, and several others as well, can attach to surfaces, of either abiotic or biotic nature, and create biofilms on them, provided the existence of supportive environmental conditions (e.g., permissive growth temperature, adequate humidity, and nutrient presence). Inside those sessile communities, the enclosed bacteria typically present a gene expression profile that differs from the one that would be displayed by the same cells growing planktonically in liquid media (free-swimming cells). This altered gene expression has important consequences on cellular physiology and behavior, including stress tolerance and induction of virulence. In this chapter, the methodology to use reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to monitor and comparatively quantify expression changes in preselected genes of bacteria between planktonic and biofilm growth modes is presented.}, }
@article {pmid39235741, year = {2025}, author = {Dubois-Brissonnet, F}, title = {Characterization of Bacterial Membrane Fatty Acid Profiles for Biofilm Cells.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2852}, number = {}, pages = {135-141}, pmid = {39235741}, issn = {1940-6029}, mesh = {*Biofilms/growth &amp; development ; *Fatty Acids/metabolism ; *Cell Membrane/metabolism ; Bacteria/metabolism ; Phospholipids/metabolism ; Membrane Fluidity ; }, abstract = {When submitted to environmental stresses, bacteria can modulate its fatty acid composition of membrane phospholipids in order to optimize membrane fluidity. Characterization of bacterial membrane fatty acid profiles is thus an interesting indicator of cellular physiological state. The methodology described here aims to improve the recovering of biofilm cells for the characterization of their fatty acid profiles. The saponification reagent is directly applied on the whole biofilm before the removal of cells from the inert surface. In this way, maximum of the cells and their fatty acids can be recovered from the deepest layers of the biofilm.}, }
@article {pmid39233097, year = {2024}, author = {Higashihira, S and Simpson, SJ and Arnold, CJ and Deckard, ER and Meneghini, RM and Greenfield, EM and Buller, LT}, title = {Biofilm Formation is Durably Prevented on Pre-Fabricated Antibiotic Cement Spacers Compared to Cobalt Chrome and Polyethylene.}, journal = {The Journal of arthroplasty}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.arth.2024.08.046}, pmid = {39233097}, issn = {1532-8406}, abstract = {BACKGROUND: A two-stage revision remains the standard for managing chronic periprosthetic joint infection (PJI). Despite multiple spacer options, whether a particular one better resists biofilm formation remains unclear. Prefabricated polymethylmethacrylate (PMMA) articulating spacers containing antibiotics and a proprietary pore structure were developed to increase antibiotic elution characterized by a rapid burst phase for the initial 1 to 2 days and an extended slow-release phase for > 28 days. This in vitro study determined whether biofilm formation is prevented during the initial rapid burst phase and/or the slow-release phase.<br><br>METHODS: S. aureus-Xen36 was incubated in 1.5 ml of Luria-Bertani broth with PMMA discs with the proprietary pore structure either with or without gentamycin and vancomycin, or with 'Hoffman style' positive-control discs (ultra-high molecular weight polyethylene (UHMWPE) or cobalt-chrome). Non-adherent bacteria were removed by three Phosphate Buffered Saline rinses every 20 to 24 hours. Planktonic bacterial growth in the culture broth and biofilm formation on the discs were measured by Colony Forming Unit (CFU) counting and resazurin reduction assays. Experiments were repeated > 4 times.<br><br>RESULTS: No detectable planktonic bacterial growth or biofilm formation occurred in cultures containing PMMA with antibiotics (&#x2264; 15 CFUs/disc), whereas biofilms formed on PMMA without antibiotics, UHMWPE, and cobalt-chrome (1x10[7] to 4x10[8] CFUs/disc, P < 0.0001). Biofilm formation was confirmed by a 100-fold decrease in sensitivity to vancomycin. To determine whether the antibiotic slow-release phase is sufficient to block biofilm formation, PMMA discs with antibiotics were pre-eluted for 14 days with multiple saline changes prior to bacterial inoculation. After antibiotic elution, still no detectable biofilms formed on PMMA discs with antibiotics (&#x2264; 15 CFUs/disc, P <0.0001).<br><br>CONCLUSION: Antibiotic release during both the initial and slow-release phases prevented biofilm formation on PMMA with the proprietary pore structure. This may translate into improved infection eradication rates clinically.}, }
@article {pmid39226944, year = {2024}, author = {Yang, Z and Li, Z and Zhu, K and Zhou, J and Lin, H and Zhou, J}, title = {Pre-anoxic electro-stimulation enhanced simultaneous nitrification-denitrification in single-stage electrolysis-integrated sequencing batch biofilm reactor.}, journal = {Bioresource technology}, volume = {412}, number = {}, pages = {131412}, doi = {10.1016/j.biortech.2024.131412}, pmid = {39226944}, issn = {1873-2976}, abstract = {Simultaneous nitrification-denitrification (SND) is a promising nitrogen removal process. However, total nitrogen (TN) removal is limited due to unsatisfactory denitrification. This study demonstrated that short-time (1 h) pre-anoxic electro-stimulation significantly enhanced SND efficiency in the aerobic phase by promoting the proliferation of mixotrophic and heterotrophic denitrifiers. SND and TN removal efficiencies at the optimal electric current (EC) (0.02 A) were 85.6 % and 93.9 %, which were 39.1 % and 17.2 % higher than control. Microbial community analysis indicated that the abundance of mixotrophic and heterotrophic denitrifiers significantly increased. H2 generated in the electro-stimulation process induced the proliferation of mixotrophic denitrifiers. The weak EC (0.02 A) promoted the activity and growth of heterotrophic denitrifiers by accelerating electron transfer. They concurrently mediated heterotrophic denitrification to enhance SND efficiency. PICRUSt2 analysis revealed that the abundance of denitrifying genes dramatically surged. This study provides new insights into applying electrolysis to achieve advanced SND while minimizing electricity consumption.}, }
@article {pmid39226538, year = {2024}, author = {Özkul, G and Kehribar, E&#x15e; and Ahan, RE and Şeker, U&#xd6;&#x15e;}, title = {An Antibiotic-Degrading Engineered Biofilm Platform to Combat Environmental Antibiotic Resistance.}, journal = {ACS biomaterials science &amp; engineering}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsbiomaterials.4c01074}, pmid = {39226538}, issn = {2373-9878}, abstract = {The presence of antibiotics in natural water bodies is a growing problem regarding the occurrence of antibiotic resistance among various species. This is mainly caused by the excessive use of medical and veterinary antibiotics as well as the lack of effective treatment processes for eliminating residual antibiotics from wastewaters. In this study, we introduce a genetically engineered biomaterial as a solution for the effective degradation of one of the dominantly found antibiotics in natural water bodies. Our biomaterial harnesses laccase-type enzymes, which are known to attack specific types of antibiotics, i.e., fluoroquinolone-type synthetic antibiotics, and as a result degradation occurs. The engineered biomaterial is built using Escherichia coli biofilm protein CsgA as a scaffold, which is fused separately to two different laccase enzymes with the SpyTag-SpyCatcher peptide-protein duo. The designed biofilm materials were successful in degrading ciprofloxacin, as demonstrated with the data obtained from mass spectrometry analysis and cell viability assays.}, }
@article {pmid39226040, year = {2024}, author = {Dong, Q and Chang, Y and Goodwin, PH and Liu, Q and Xu, W and Xia, M and Zhang, J and Sun, R and Xu, S and Wu, C and Wu, K and Yang, L}, title = {Double-Wing Motif Protein is a Novel Biofilm Regulatory Factor of the Plant Disease Biocontrol Agent, Bacillus subtilis.}, journal = {Journal of agricultural and food chemistry}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.jafc.4c02192}, pmid = {39226040}, issn = {1520-5118}, abstract = {Transposon mutagenesis screening of Bacillus subtilis YB-1471, a novel rhizosphere biocontrol agent of Fusarium crown rot (FCR) of wheat, resulted in the identification of orf04391, linked to reduced biofilm formation. The gene encodes a protein possessing a putative tertiary structure of a "double-wing" DNA-binding domain. Expression of orf04391 increased during biofilm development in stationary cultures and during rapid growth in shaking cultures. An orf04391 deletion strain showed reduced biofilm production related to lower levels of the extracellular matrix, and the mutant also had reduced sporulation, adhesion, root colonization, and FCR biocontrol efficiency. Transcriptome analysis of YB-1471 and Δorf04391 in stationary culture showed that the loss of orf04391 resulted in altered expression of numerous genes, including sinI, an initiator of biofilm formation. DNA binding was shown with his-tagged Orf04391 binding to the sinIR operon in vivo and in vitro. Orf04391 appears to be a transcriptional regulator of biofilm formation in B. subtilis through the Spo0A-SinI/SinR pathway.}, }
@article {pmid39225712, year = {2024}, author = {Chekli, Y and Thiriet-Rupert, S and Caillet, C and Quilès, F and Le Cordier, H and Deshayes, E and Bardiaux, B and Pédron, T and Titecat, M and Debarbieux, L and Ghigo, JM and Francius, G and Duval, JFL and Beloin, C}, title = {Biophysical insights into sugar-dependent medium acidification promoting YfaL protein-mediated Escherichia coli self-aggregation, biofilm formation and acid stress resistance.}, journal = {Nanoscale}, volume = {}, number = {}, pages = {}, doi = {10.1039/d4nr01884b}, pmid = {39225712}, issn = {2040-3372}, abstract = {The ability of bacteria to interact with their environment is crucial to form aggregates and biofilms, and develop a collective stress resistance behavior. Despite its environmental and medical importance, bacterial aggregation is poorly understood and mediated by few known adhesion structures. Here, we identified a new role for a surface-exposed Escherichia coli protein, YfaL, which can self-recognize and induce bacterial autoaggregation. This process occurs only under acidic conditions generated during E. coli growth in the presence of fermentable sugars. These findings were supported by electrokinetic and atomic force spectroscopy measurements, which revealed changes in the electrostatic, hydrophobic, and structural properties of YfaL-decorated cell surface upon sugar consumption. Furthermore, YfaL-mediated autoaggregation promotes biofilm formation and enhances E. coli resistance to acid stress. The prevalence and conservation of YfaL in environmental and clinical E. coli suggest strong evolutionary selection for its function inside or outside the host. Overall, our results emphasize the importance of environmental parameters such as low pH as physicochemical cues influencing bacterial adhesion and aggregation, affecting E. coli and potentially other bacteria's resistance to environmental stress.}, }
@article {pmid39224216, year = {2024}, author = {Gong, F and Xin, S and Liu, X and He, C and Yu, X and Pan, L and Zhang, S and Gao, H and Xu, J}, title = {Multiple biological characteristics and functions of intestinal biofilm extracellular polymers: friend or foe?.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1445630}, pmid = {39224216}, issn = {1664-302X}, abstract = {The gut microbiota is vital to human health, and their biofilms significantly impact intestinal immunity and the maintenance of microbial balance. Certain pathogens, however, can employ biofilms to elude identification by the immune system and medical therapy, resulting in intestinal diseases. The biofilm is formed by extracellular polymorphic substances (EPS), which shield microbial pathogens from the host immune system and enhance its antimicrobial resistance. Therefore, investigating the impact of extracellular polysaccharides released by pathogens that form biofilms on virulence and defence mechanisms is crucial. In this review, we provide a comprehensive overview of current pathogenic biofilm research, deal with the role of extracellular polymers in the formation and maintenance of pathogenic biofilm, and elaborate different prevention and treatment strategies to provide an innovative approach to the treatment of intestinal pathogen-based diseases.}, }
@article {pmid39222779, year = {2024}, author = {Basak, P and Dastidar, DG and Ghosh, D and Chakraborty, T and Sau, S and Chakrabarti, G}, title = {Staphylococcus aureus major cell division protein FtsZ assembly is inhibited by silibinin, a natural flavonolignan that also blocked bacterial growth and biofilm formation.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {135252}, doi = {10.1016/j.ijbiomac.2024.135252}, pmid = {39222779}, issn = {1879-0003}, abstract = {The bacterial cell division protein FtsZ has been considered a potential therapeutic target due to its rapid treadmilling that induces cellular wall construction in bacteria. The current study discovered a novel antimicrobial compound, silibinin, a natural flavonolignan and its impact on the recombinant S. aureus FtsZ (SaFtsZ). Silibinin inhibited S. aureus Newman growth in a dose-dependent manner. The IC50 and MIC values for silibinin were 75 μM and 200 μM, respectively. It had no cytotoxicity against HEK293 cells in vitro. Silibinin also enlarged the bacterial cell morphology by ~40 folds and showed antibiofilm property. It perturbed the S. aureus membrane potential both at IC50 conc. and at MIC conc. Further, it inhibited both the polymerization and GTPase activity of SaFtsZ. It did not inhibit tubulin assembly, a eukaryotic FtsZ homolog. A fluorescence quenching study yielded the Kd value for SaFtsZ-Silibinin interaction and binding stoichiometry 0.857 ± 0.188 μM and 1:1, respectively. Both in silico study and competition assay indicated that silibinin binds at the GTP binding site on SaFtsZ. The Ki value for the silibinin-mediated inhibition of SaFtsZ was 8.8 μM. Therefore, these findings have comprehensively shown the antimicrobial behavior of silibinin on S. aureus Newman cells targeting SaFtsZ.}, }
@article {pmid39221168, year = {2024}, author = {Coenye, T and Ahonen, M and Anderson, S and Cámara, M and Chundi, P and Fields, M and Foidl, I and Gnimpieba, EZ and Griffin, K and Hinks, J and Loka, AR and Lushbough, C and MacPhee, C and Nater, N and Raval, R and Slater-Jefferies, J and Teo, P and Wilks, S and Yung, M and ,  and Webb, JS}, title = {Global challenges and microbial biofilms: Identification of priority questions in biofilm research, innovation and policy.}, journal = {Biofilm}, volume = {8}, number = {}, pages = {100210}, pmid = {39221168}, issn = {2590-2075}, abstract = {Priority question exercises are increasingly used to frame and set future research, innovation and development agendas. They can provide an important bridge between the discoveries, data and outputs generated by researchers, and the information required by policy makers and funders. Microbial biofilms present huge scientific, societal and economic opportunities and challenges. In order to identify key priorities that will help to advance the field, here we review questions from a pool submitted by the international biofilm research community and from practitioners working across industry, the environment and medicine. To avoid bias we used computational approaches to group questions and manage a voting and selection process. The outcome of the exercise is a set of 78 unique questions, categorized in six themes: (i) Biofilm control, disruption, prevention, management, treatment (13 questions); (ii) Resistance, persistence, tolerance, role of aggregation, immune interaction, relevance to infection (10 questions); (iii) Model systems, standards, regulatory, policy education, interdisciplinary approaches (15 questions); (iv) Polymicrobial, interactions, ecology, microbiome, phage (13 questions); (v) Clinical focus, chronic infection, detection, diagnostics (13 questions); and (vi) Matrix, lipids, capsule, metabolism, development, physiology, ecology, evolution environment, microbiome, community engineering (14 questions). The questions presented are intended to highlight opportunities, stimulate discussion and provide focus for researchers, funders and policy makers, informing future research, innovation and development strategy for biofilms and microbial communities.}, }
@article {pmid39219609, year = {2024}, author = {Leynaud, V and Jousserand, NP and Lucas, MN and Cavalié, L and Motta, JP and Oswald, &#xc9; and Lavoué, R}, title = {Adjunctive intravesical EDTA-tromethamine treatment of a biofilm-associated recurrent Escherichia coli cystitis in a dog.}, journal = {The Canadian veterinary journal = La revue veterinaire canadienne}, volume = {65}, number = {9}, pages = {886-893}, pmid = {39219609}, issn = {0008-5286}, mesh = {Dogs ; Animals ; *Dog Diseases/drug therapy/microbiology ; Female ; *Cystitis/veterinary/drug therapy/microbiology ; *Edetic Acid/therapeutic use/administration &amp; dosage ; *Biofilms/drug effects ; *Escherichia coli Infections/veterinary/drug therapy ; *Anti-Bacterial Agents/therapeutic use/administration &amp; dosage ; Administration, Intravesical ; Escherichia coli/drug effects ; Recurrence ; }, abstract = {A 15-month-old spayed female greater Swiss mountain dog was brought to our clinic because of relapsing episodes of urinary tract infection, present since her adoption at 2 mo of age. A diagnosis of chronic bacterial cystitis associated with an invasive, biofilm-forming uropathogenic Escherichia coli was made with bladder-wall histology and fluorescent in situ hybridization analysis. Local treatment with EDTA-tromethamine (EDTA-Tris) infusions along with parenteral cefquinome and prophylactic measures (Type-A proanthocyanidins and probiotics) coincided with clinical and bacterial remission. The dog has been free of clinical signs of urinary tract infection for >4 y. Biofilm-forming uropathogenic E. coli can cause chronic, recurrent cystitis due to low antibiotic efficacy and should be considered in cases of recurrent cystitis in dogs, especially in the absence of identified predisposing factors. This case report describes the diagnostic and therapeutic options that were used to manage a case of this type. Key clinical message: Fluorescent in situ hybridization analysis may be considered in the diagnosis of chronic bacterial cystitis in dogs, and intravesical instillations of EDTA-Tris may be helpful in managing such cases.}, }
@article {pmid39218889, year = {2024}, author = {He, W and Ma, P and Li, L and Wang, D and Li, X and Wen, X and Zuo, Y and Guo, Q and Zhang, Y and Cheng, R and Wang, Z}, title = {Efficacy and safety of preventing catheter-associated urinary tract infection by inhibiting catheter bacterial biofilm formation: a multicenter randomized controlled trial.}, journal = {Antimicrobial resistance and infection control}, volume = {13}, number = {1}, pages = {96}, pmid = {39218889}, issn = {2047-2994}, support = {31072238, 31172441, 31372562, 81170650//National Natural Science Foundation of China/ ; }, mesh = {Humans ; *Biofilms/growth &amp; development ; *Urinary Tract Infections/prevention &amp; control/microbiology ; *Catheter-Related Infections/prevention &amp; control/microbiology ; Female ; Male ; Middle Aged ; Double-Blind Method ; Urinary Catheters/adverse effects/microbiology ; Urinary Catheterization/adverse effects ; Aged ; Adult ; China ; Bandages ; Cross Infection/prevention &amp; control ; }, abstract = {BACKGROUND: Catheter-associated urinary tract infection (CAUTI) remains the most significant challenge among hospital-acquired infections (HAIs), yet still unresolved. The present study aims to evaluate the preventive effectiveness of JUC Spray Dressing (name of U.S. FDA and CE certifications, while the medical device name in China is Long-acting Antimicrobial Material) alone for CAUTI without combining with antibiotics and to evaluate the impact of bacterial biofilm formation on CAUTI results on the inserted catheters of patients.<br><br>METHODS: In this multicenter, randomized, double-blind study, we enrolled adults who suffered from acute urinary retention (AUR) and required catheterization in 6 hospitals in China. Participants were randomly allocated 1:1 according to a random number table to receive JUC Spray Dressing (JUC group) or normal saline (placebo group). The catheters were pretreated with JUC Spray Dressing or normal saline respectively before catheterization. Urine samples and catheter samples were collected after catheterization by trial staff for further investigation.<br><br>RESULTS: From April 2012 to April 2020, we enrolled 264 patients and randomly assigned them to the JUC group (n&#x2009;=&#x2009;132) and the placebo group (n&#x2009;=&#x2009;132). Clinical symptoms and urine bacterial cultures showed the incidence of CAUTI of the JUC group was significantly lower than the placebo group (P&#x2009;<&#x2009;0.01). In addition, another 30 patients were enrolled to evaluate the biofilm formation on catheters after catheter insertion in the patients' urethra (10 groups, 3 each). The results of scanning electron microscopy (SEM) showed that bacterial biofilm formed on the 5th day in the placebo group, while no bacterial biofilm formed on the 5th day in the JUC group. In addition, no adverse reactions were reported using JUC Spray Dressing.<br><br>CONCLUSION: Continued indwelling urinary catheters for 5 days resulted in bacterial biofilm formation, and pretreatment of urethral catheters with JUC Spray Dressing can prevent bacterial biofilm formation by forming a physical antimicrobial film, and significantly reduce the incidence of CAUTI. This is the first report of a study on inhibiting bacterial biofilm formation on the catheters in CAUTI patients.}, }
@article {pmid39218719, year = {2024}, author = {Rogers, ME and de Pablos, LM and Sunter, JD}, title = {Gels and cells: the Leishmania biofilm as a space and place for parasite transmission.}, journal = {Trends in parasitology}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.pt.2024.08.001}, pmid = {39218719}, issn = {1471-5007}, abstract = {Leishmania make an abundant glycoprotein and proteophosphoglycan-rich gel, called the promastigote secretory gel, in the anterior midgut of their sand fly vector. This gel is a multi-faceted virulence factor which promotes the survival and transmission of the parasites between hosts. Here, we present the case that Leishmania parasites embedded in the promastigote secretory gel should be redefined as a biofilm as it shares striking similarities in biogenesis, form, and function with biofilms of other unicellular organisms. We believe that this reinterpretation will stimulate new hypotheses and avenues of research to improve our understanding of the developmental programme of Leishmania and the interaction these parasites and other kinetoplastids have with their insect hosts.}, }
@article {pmid39218374, year = {2024}, author = {Janus, A and Deepa, PM and Vergis, J and Rajasekhar, R and Habeeb, BP and Bipin, KC and Vinu David, P and Anand, LF and Ratish, RL and Shyma, VH and Vijayakumar, K}, title = {Unravelling the Complex Mechanisms of Multidrug Resistance in Bovine Mastitis Pathogens: Insights into Antimicrobial Resistance Genes, Biofilm Dynamics, and Efflux Systems.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106902}, doi = {10.1016/j.micpath.2024.106902}, pmid = {39218374}, issn = {1096-1208}, abstract = {Mastitis remains a paramount economic threat to dairy livestock, with antibiotic resistance severely compromising treatment efficacy. This study provides an in-depth investigation into the multidrug resistance (MDR) mechanisms in bacterial isolates from bovine mastitis, emphasizing the roles of antimicrobial resistance genes (ARGs), biofilm formation, and active efflux systems. A total of 162 Staphylococci, eight Escherichia coli, and seven Klebsiella spp. isolates were obtained from 215 milk samples of clinical and subclinical mastitis cases. Antibiotic susceptibility testing identified Twenty Staphylococci (12.35%), six E. coli (75%) and seven Klebsiella (100%) identified as MDR displaying significant resistance to β-lactams and tetracyclines The Multiple Antibiotic Resistance (MAR) index of these isolates ranged from 0.375 to 1.0, highlighting extensive resistance. Notably, 29 of the 33 MDR isolates produced biofilms on Congo red agar, while all exhibited biofilm formation in the Microtitre Plate assay. Critical ARGs (blaZ, blaTEM, blaCTX-M, tetM, tetA, tetB, tetC, strA/B, aadA) and efflux pump genes (acrB, acrE, acrF, emrB, norB) regulating active efflux were identified. This pioneering study elucidates the synergistic contribution of ARGs, biofilm production, and efflux pump activity to MDR in bovine mastitis pathogens. To our knowledge, this comprehensive study is the first of its kind, offering novel insights into the complex resistance mechanisms. The findings underscore the imperative need for advanced antibiotic stewardship and strategic interventions in dairy farming to curb the rise of antibiotic-resistant infections, thereby protecting both animal and public health.}, }
@article {pmid39218364, year = {2024}, author = {Xue, Y and Cheng, Y and Wang, Q and Zhao, R and Han, X and Zhu, J and Bai, L and Li, G and Zhang, H and Liang, H}, title = {Simultaneous removal of ammonia nitrogen, sulfamethoxazole, and antibiotic resistance genes in self-corrosion microelectrolysis-enhanced counter-diffusion biofilm system.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131399}, doi = {10.1016/j.biortech.2024.131399}, pmid = {39218364}, issn = {1873-2976}, abstract = {A self-corrosion microelectrolysis (SME)-enhanced membrane-aerated biofilm reactor (eMABR) was developed for the removal of pollutants and reduction of antibiotic resistance genes (ARGs). Fe[2+] and Fe[3+] formed iron oxides on the biofilm, which enhanced the adsorption and redox process. SME can induce microorganisms to secrete more extracellular proteins and up-regulate the expression of ammonia monooxygenase (AMO) (0.92 log2). AMO exposed extra binding sites (ASP-69) for antibiotics, weakening the competition between NH4[+]-N and sulfamethoxazole (SMX). The NH4[+]-N removal efficiency in the S-eMABR (adding SMX and IC) increased by 44.87 % compared to the S-MABR (adding SMX). SME increased the removal performance of SMX by approximately 1.45 times, down-regulated the expressions of sul1 (-1.69 log2) and sul2 (-1.30 log2) genes, and controlled their transfer within the genus. This study provides a novel strategy for synergistic reduction of antibiotics and ARGs, and elucidates the corresponding mechanism based on metatranscriptomic and molecular docking analyses.}, }
@article {pmid39217929, year = {2024}, author = {Duan, R and Zhang, S and Jiang, S and Zhang, S and Song, Y and Luo, M and Lu, J}, title = {Glufosinate-ammonium increased nitrogen and phosphorus content in water and shaped microbial community in epiphytic biofilm of Hydrilla verticillata.}, journal = {Journal of hazardous materials}, volume = {479}, number = {}, pages = {135674}, doi = {10.1016/j.jhazmat.2024.135674}, pmid = {39217929}, issn = {1873-3336}, abstract = {Glufosinate-ammonium (GLAM) can be released into adjacent water bodies with rainfall runoff and return water from farmland irrigation. However, impacts of GLAM on aquatic organisms remain unclear. In this study, changes in water quality, plant physiological parameters and epiphytic microbial community were investigated in wetlands with Hydrilla verticillata exposed to GLAM for 24 days. We found GLAM addition damaged cell and reduced chlorophyll a content in Hydrilla verticillata leaves, and increased ammonium and phosphorus in water (p < 0.001). The α-diversity increased in bacterial community but decreased in eukaryotic community with GLAM exposure. Neutral community models explained 62.3 % and 55.0 % of the variance in bacterial and eukaryotic communities, respectively. Many GLAM micro-biomarkers were obtained, including some clades from Proteobacteria, Bacteroidete, Actinobacteriota, Phragmoplastophyta, Annelida and Arthropoda. Redundancy analysis revealed that GLAM concentration was positively correlated to Flavobacterium, Gomphonema and Closterium but negatively to Methyloglobulus and Methylocystis. Network analysis revealed that 15 mg/L GLAM disturbed the interactions among phytoplankton, protozoa, metazoan and bacteria and reduced the stability of the microbial communities compared to 8 mg/L GLAM. GLAM shaped the nitrogen and phosphorus cycle related bacterial genes. This study highlights that herbicides are non-neglectable factors affecting the efficiency of aquatic ecological restoration in agricultural areas to control agricultural non-point source pollution.}, }
@article {pmid39216701, year = {2024}, author = {Li, Q and Zhao, W and Cui, S and Gadow, SI and Qin, Y and Li, YY}, title = {Synergetic association of hydroxyapatite-mediated biofilm and suspended sludge enhances resilience of partial nitrification/anammox (PN/A) system treating high-strength anaerobic membrane bioreactor (AnMBR) permeate.}, journal = {Bioresource technology}, volume = {412}, number = {}, pages = {131391}, doi = {10.1016/j.biortech.2024.131391}, pmid = {39216701}, issn = {1873-2976}, abstract = {A single-stage partial nitrification/anammox (PN/A) system with biocarriers was used to treat the permeate from an anaerobic membrane reactor (AnMBR) processing organic fraction of municipal solid wastes. The suitable Ca/P ratio and high pH in the AnMBR permeate facilitated hydroxyapatite (HAP) formation, enhancing the biofilm attachment and the settleability of suspended sludge. This maintained sufficient biomass and a stable microbial structure after flushing to mitigate the free nitrous acid inhibition. Robust anammox bacteria in the biofilm and ammonia-oxidizing bacteria in the suspended sludge ensured that the PN/A system achieved an 87.3 % nitrogen removal efficiency at an influent NH4[+]-N concentration of 1802 mg/L. This study demonstrates that AnMBR permeate with high Ca, P and NH4[+]-N content is suitable for single-stage PN/A system with biocarriers due to the high resilience enhanced by HAP, offering a reference for the treatment of high-strength AnMBR permeate.}, }
@article {pmid39216664, year = {2024}, author = {Huang, Y and Hu, T and Lin, B and Ke, Y and Li, J and Ma, J}, title = {Microplastics-biofilm interactions in biofilm-based wastewater treatment processes: A review.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {}, number = {}, pages = {124836}, doi = {10.1016/j.envpol.2024.124836}, pmid = {39216664}, issn = {1873-6424}, abstract = {Microplastics, pervasive contaminants from plastic, present significant challenges to wastewater treatment processes. This review critically examines the interactions between microplastics and biofilm-based treatment technologies, specifically focusing on the concepts of "biofilm on microplastics" and "microplastics in biofilm". It discusses the implications of these interactions in contaminant removal and process performance. Advanced characterization techniques, including morphological characterization, chemical composition analysis, and bio-information analysis, are assessed to elucidate the complex interplay between microplastics and biofilms within biofilters, biological aerated filters (BAFs), rotating biological contactors (RBCs), and moving bed biofilm reactors (MBBRs). This review synthesizes current research findings, highlighting that microplastics can either hinder or enhance the treatment processes, contingent on their concentration, physicochemical properties, and the specific biofilm technology employed. The insights gained from this review are essential for developing strategies to mitigate the adverse effects of microplastics and for optimizing the design and operation of wastewater treatment.}, }
@article {pmid39216533, year = {2024}, author = {Yoshida, S and Inaba, H and Nomura, R and Nakano, K and Matsumoto-Nakano, M}, title = {Role of fimbriae variations in Porphyromonas gulae biofilm formation.}, journal = {Journal of oral biosciences}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.job.2024.08.003}, pmid = {39216533}, issn = {1880-3865}, abstract = {OBJECTIVES: Porphyromonas gulae is a major causative agent of periodontal disease in companion animals that possesses various virulence factors, including fimbriae, lipopolysaccharides, and proteases. P. gulae fimbriae are classified into three genotypes (A, B, and C) based on their nucleotide sequences. Type C fimbrial isolates have been reported to be more virulent than other fimA types, suggesting that different fimA types may aid in the regulation of periodontal pathogenesis. Detailed findings regarding the ability of P. gulae to form biofilms have yet to be reported. Here, we investigated the contributions of fimbrial genotypes in P. gulae biofilm formation.<br><br>METHODS: P. gulae and P. gingivalis biofilms were generated on plates and analyzed using confocal laser microscopy. Additionally, the biofilms formed were assessed by staining with crystal violet. Furthermore, the physical strength of P. gulae biofilms was examined by ultrasonication.<br><br>RESULTS: Biofilms formed by P. gulae type C were denser than those formed by types A and B. Moreover, the amount of biofilm formed by type C strains was significantly greater than that formed by type A and B strains, which was similar to the biofilms formed by P. gingivalis with type II fimbriae. Additionally, the physical strength of the type C biofilm was significantly greater than that of the other strains.<br><br>CONCLUSIONS: These results suggest that FimA variation may coordinate for biofilm formation. This is the first report on the observation and characterization of P. gulae biofilm formation.}, }
@article {pmid39214208, year = {2024}, author = {Kar, A and Saha, P and De, R and Bhattacharya, S and Mukherjee, SK and Hossain, ST}, title = {Unveiling the role of PA0730.1 sRNA in Pseudomonas aeruginosa virulence and biofilm formation: Exploring rpoS and mucA regulation.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {135130}, doi = {10.1016/j.ijbiomac.2024.135130}, pmid = {39214208}, issn = {1879-0003}, abstract = {Small RNA (sRNA) in bacteria serve as the key messengers in regulating genes associated with quorum sensing controlled bacterial virulence. This study was aimed to unveil the regulatory role of sRNA PA0730.1 on the expression of various traits of Pseudomonas aeruginosa linked to pathogenicity, with special emphasis on the growth, colony morphology, cell motility, biofilm formation, and the expression of diverse virulence factors. PA0730.1 sRNA was found to be upregulated both during planktonic stationary growth phase and at biofilm state of P. aeruginosa PAO1. PA0730.1 deleted strain showed significant growth retardation with increased doubling time. Overexpression of PA0730.1 led to enhanced motility and biofilm formation, while the ∆PA0730.1 strain displayed significant inhibition in motility and biofilm formation. Furthermore, PA0730.1 was found to regulate the synthesis of selected virulence factors of P. aeruginosa. These observations in PA0730.1[+] and ∆PA0730.1 were found to be correlated with the PA0730.1-mediated repression of transcription regulators, mucA and rpoS, both at transcriptional and translational levels. The results suggest that PA0730.1 sRNA might be a promising target for developing new drug to counter P. aeruginosa pathogenesis, and could also help in RNA oligonucleotide based therapeutic research for formulating a novel therapeutant.}, }
@article {pmid39214178, year = {2024}, author = {Cao, Q and Zhang, C and Zhang, J and Zhang, J and Zheng, Z and Liu, H}, title = {Enhanced microbial electrosynthesis performance with 3-D algal electrodes under high CO2 sparging: Superior biofilm stability and biocathode-plankton interactions.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131381}, doi = {10.1016/j.biortech.2024.131381}, pmid = {39214178}, issn = {1873-2976}, abstract = {Microbial electrosynthesis (MES) shows great promise for converting CO2 into high-value chemicals. However, cathode biofilm erosion by high CO2 sparging and the unclear role of plankton in MES hinders the continuous improvement of its performance. This study aims to enhance biofilm resistance and improve interactions between bio-cathode and plankton by upgrading waste algal biomass into 3-D porous algal electrode (PAE) with rough surface. Results showed that the acetate synthesis of PAE under 20 mL/min CO2 sparging (PAE-20) was up to 3330.61 mol/m[3], 4.63 times that of carbon felt under the same conditions (CF-20). The microbial loading of PAE-20 biofilm was twice that of CF-20. Furthermore, higher cumulative abundance of functional microorganisms was observed in plankton of PAE-20 (55 %), compared to plankton of CF-20 (14 %), and enhanced biocathode-plankton interactions significantly suppressed acetate consumption. Thus, this efficient and sustainable 3-D electrode advances MES technology and offers new perspectives for waste biomass recycling.}, }
@article {pmid39214043, year = {2024}, author = {Anoy, MMI and Hill, EA and Garcia, MR and Kim, WJ and Beliaev, AS and Beyenal, H}, title = {A directional electrode separator improves anodic biofilm current density in a well-mixed single-chamber bioelectrochemical system.}, journal = {Enzyme and microbial technology}, volume = {180}, number = {}, pages = {110502}, doi = {10.1016/j.enzmictec.2024.110502}, pmid = {39214043}, issn = {1879-0909}, abstract = {In this study, a directional electrode separator (DES) was designed and incorporated into a single-chamber bioelectrochemical system (BES) to reduce migration and reoxidation of hydrogen. This issue arises when H2, generated at the cathode, travels to the anode where anodic biofilms use H2. To test the feasibility of our design, a 3D-printed BES reactor equipped with a DES was inoculated with anaerobic digestor granules and operated under fed-batch conditions using fermented corn stover effluent. The DES equipped reactor achieved significantly higher current densities (∼53 A/m[2]) compared to a conventional single-chamber BES without a separator (∼16 A/m[2]), showing a 3.3 times improvement. Control abiotic electrochemical experiments revealed that the DES exhibited significantly higher proton conductivity (456±127 µS/mm) compared to a proton exchange membrane (67±21 µS/mm) with a statistical significance of P=0.03. The DES also effectively reduced H2 migration to the anode by 21-fold relative to the control. Overall, incorporating a DES in a single-chamber BES enhanced anodic current density by reducing H2 migration to the anode.}, }
@article {pmid39214032, year = {2024}, author = {Qu, Q and Zhang, X and Muhire, J and Yang, A and Xie, M and Xiong, R and Cheng, W and Pei, D and Huang, C}, title = {Biomimetic triggered release from hydroxyethyl cellulose @ Prussian blue microparticles for tri-modality biofilm removal.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {244}, number = {}, pages = {114184}, doi = {10.1016/j.colsurfb.2024.114184}, pmid = {39214032}, issn = {1873-4367}, abstract = {Human health is under growing threat from the increasing incidence of bacterial infections. Through their antimicrobial mechanisms, bacteria use appropriate strategies to overcome the antimicrobial effects of antibiotics. The enhanced effects of synergistic strategies on drug-resistant bacteria and biofilms have led to increasing interest in these approaches in recent years. Herein, biomimetic hydroxyethyl cellulose @ Prussian blue microparticles (HEC@PB MPs) generated by the gas-shearing method show a synergistic antibacterial property induced by antibiotic-, photothermal- and photodynamic- effect. MPs, as tri-modality antibacterial agents, exhibit ideal antibacterial activity and biofilm removal effect, and their mode of action on bacteria was investigated. Additionally, a drug release concept encouraged by the ROS-driven breakdown of cellulose, as seen in brown-rot fungi, was introduced. It combines ROS-responsive HEC and photodynamic PB and is likely to fit a niche in many applications.}, }
@article {pmid39212539, year = {2024}, author = {Goltermann, L and Shahryari, S and Rybtke, M and Tolker-Nielsen, T}, title = {Microbial Primer: The catalytic biofilm matrix.}, journal = {Microbiology (Reading, England)}, volume = {170}, number = {8}, pages = {}, doi = {10.1099/mic.0.001497}, pmid = {39212539}, issn = {1465-2080}, mesh = {*Biofilms/growth &amp; development ; *Bacteria/genetics/metabolism ; Extracellular Matrix/metabolism ; Bacterial Physiological Phenomena ; }, abstract = {The extracellular matrix of microbial biofilms has traditionally been viewed as a structural scaffold that retains the resident bacteria in the biofilm. Moreover, a role of the matrix in the tolerance of biofilms to antimicrobials and environmental stressors was recognized early in biofilm research. However, as research progressed it became apparent that the biofilm matrix can also be involved in processes such as bacterial migration, genetic exchange, ion capture and signalling. More recently, evidence has accumulated that the biofilm matrix can also have catalytic functions. Here we review foundational research on this fascinating catalytic role of the biofilm matrix.}, }
@article {pmid39211930, year = {2024}, author = {Paseban, K and Noroozi, S and Gharehcheloo, R and Haddadian, A and Falahi Robattorki, F and Dibah, H and Amani, R and Sabouri, F and Ghanbarzadeh, E and Hajrasouiha, S and Azari, A and Rashidian, T and Mirzaie, A and Pirdolat, Z and Salarkia, M and Shahrava, DS and Safaeinikjoo, F and Seifi, A and Sadat Hosseini, N and Saeinia, N and Bagheri Kashtali, A and Ahmadiyan, A and Mazid Abadi, R and Sadat Kermani, F and Andalibi, R and Chitgarzadeh, A and Tavana, AA and Piri Gharaghie, T}, title = {Preparation and optimization of niosome encapsulated meropenem for significant antibacterial and anti-biofilm activity against methicillin-resistant Staphylococcus aureus isolates.}, journal = {Heliyon}, volume = {10}, number = {16}, pages = {e35651}, doi = {10.1016/j.heliyon.2024.e35651}, pmid = {39211930}, issn = {2405-8440}, abstract = {BACKGROUND: One of the targeted drug delivery systems is the use of nanocarriers, and one of these drug delivery systems is niosome. Niosome have a nano-vesicular structure and are composed of non-ionic surfactants. Objective: In this study, various niosome-encapsulated meropenem formulations were prepared. Subsequently, their antibacterial and anti-biofilm activities were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) strains.<br><br>METHODS: The physicochemical properties of niosomal formulations were characterized using a field scanning electron microscope, X-Ray diffraction, Zeta potential, and dynamic light scattering. Antibacterial and anti-biofilm activities were evaluated using broth microdilution and minimum biofilm inhibitory concentration, respectively. In addition, biofilm gene expression analysis was performed using quantitative Real-Time PCR. To evaluate biocompatibility, the cytotoxicity of niosome-encapsulated meropenem in a normal human diploid fibroblast (HDF) cell line was investigated using an MTT assay.<br><br>RESULTS: An F1 formulation of niosome-encapsulated meropenem with a size of 51.3&#xa0;&#xb1;&#xa0;5.84&#xa0;nm and an encapsulation efficiency of 84.86&#xa0;&#xb1;&#xa0;3.14&#xa0;% was achieved. The synthesized niosomes prevented biofilm capacity with a biofilm growth inhibition index of 69&#xa0;% and significantly downregulated icaD, FnbA, Ebps, and Bap gene expression in MRSA strains (p&#xa0;<&#xa0;0.05). In addition, the F1 formulation increased antibacterial activity by 4-6 times compared with free meropenem. Interestingly, the F1 formulation of niosome-encapsulated meropenem indicated cell viability >90&#xa0;% at all tested concentrations against normal HDF cells. The results of the present study indicate that niosome-encapsulated meropenem increased antibacterial and anti-biofilm activities without profound cytotoxicity in normal human cells, which could prove useful as a good drug delivery system.}, }
@article {pmid39211795, year = {2024}, author = {Liu, L and Li, H and Ma, C and Liu, J and Zhang, Y and Xu, D and Xiong, J and He, Y and Yang, H and Chen, H}, title = {Effect of anti-biofilm peptide CRAMP-34 on the biofilms of Acinetobacter lwoffii derived from dairy cows.}, journal = {Frontiers in cellular and infection microbiology}, volume = {14}, number = {}, pages = {1406429}, doi = {10.3389/fcimb.2024.1406429}, pmid = {39211795}, issn = {2235-2988}, mesh = {*Biofilms/drug effects/growth &amp; development ; Animals ; Cattle ; Female ; *Acinetobacter/drug effects/genetics ; *Anti-Bacterial Agents/pharmacology ; China ; Mastitis, Bovine/microbiology/drug therapy ; Bacterial Adhesion/drug effects ; Gene Expression Profiling ; Microbial Sensitivity Tests ; Acinetobacter Infections/microbiology ; }, abstract = {Dairy mastitis is one of the most common diseases in dairy farming, and the formation of pathogenic bacteria biofilms may be an important reason why traditional antibiotic therapy fails to resolve some cases of dairy mastitis. We isolated and identified three strains of A. lwoffii were with strong biofilm forming ability from dairy cow mastitis samples from Chongqing dairy farms in China. In order to investigate the effect of novel anti-biofilm peptide CRAMP-34 on A.lwoffii biofilms, the anti-biofilm effect was evaluated by crystal violet staining, biofilms viable bacteria counting and confocal laser scanning microscopy (CLSM). In addition, transcriptome sequencing analysis, qRT-PCR and phenotypic verification were used to explore the mechanism of its action. The results showed that CRAMP-34 had a dose-dependent eradicating effect on A. lwoffii biofilms. Transcriptome sequencing analysis showed that 36 differentially expressed genes (11 up-regulated and 25 down-regulated) were detected after the intervention with the sub-inhibitory concentration of CRAMP-34. These differentially expressed genes may be related to enzyme synthesis, fimbriae, iron uptake system, capsular polysaccharide and other virulence factors through the functional analysis of differential genes. The results of subsequent bacterial motility and adhesion tests showed that the motility of A.lwoffii were enhanced after the intervention of CRAMP-34, but there was no significant change in adhesion. It was speculated that CRAMP-34 may promote the dispersion of biofilm bacteria by enhancing the motility of biofilm bacteria, thereby achieving the effect of eradicating biofilms. Therefore, these results, along with our other previous findings, suggest that CRAMP-34 holds promise as a new biofilm eradicator and deserves further research and development.}, }
@article {pmid39210732, year = {2024}, author = {Mourão, A and Serrano, I and Cunha, E and Tavares, L and Lourenço, A and Oliveira, M}, title = {In vitro efficacy of lavender oil, otological gel and gentamicin to eradicate biofilm produced by Pseudomonas aeruginosa.}, journal = {Veterinary dermatology}, volume = {}, number = {}, pages = {}, doi = {10.1111/vde.13294}, pmid = {39210732}, issn = {1365-3164}, support = {UIDB/00276/2020//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e a Tecnologia/ ; LA/P/0059/2020//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e a Tecnologia/ ; }, abstract = {BACKGROUND: Otitis externa (OE) is one of the most frequently diagnosed dermatological diseases in dogs, having a multifactorial aetiology. Among the bacterial agents associated with canine OE, Pseudomonas aeruginosa is of special concern owing to its frequent multidrug resistance profile and ability to form biofilms related to the infection's chronicity and recurrence.<br><br>OBJECTIVES: The main objective of this study was to evaluate and compare the antibiofilm activity of two innovative antimicrobials-an otological gel containing a synthetic antimicrobial peptide and Lavandula angustifolia essential oil-with gentamicin (a conventional antibiotic) using biofilm-producing P. aeruginosa isolates obtained from dogs with OE.<br><br>MATERIALS AND METHODS: The biofilm eradication capacity of gentamicin, otological gel and lavender oil was determined against a collection of 12 P.&#x2009;aeruginosa biofilm-producers among 35 clinical isolates obtained from the ear canals of dogs with OE. Also, the antimicrobial activity of the otological gel against P.&#x2009;aeruginosa biofilms was assessed in an in&#xa0;vitro model of dog cerumen.<br><br>RESULTS: Lavender oil showed the best effectiveness after 30&#x2009;min of contact, eradicating 58.3% (seven of 12) of the isolates, and gentamicin showed full eradication (12 of 12) after 24&#x2009;h. The otological gel acted more slowly than the lavender oil; yet at 24&#x2009;h, the antibiofilm capacity of both compounds was similar, with no significant difference between them. It also was found that triglycerides from synthetic cerumen earwax had antipseudomonal activity and, when combined with the otological gel, led to the full eradication of P.&#x2009;aeruginosa.<br><br>The results of this in&#xa0;vitro study indicate that lavender oil and the otological gel may be effective topical treatments for canine OE promoted by P.&#x2009;aeruginosa biofilm-producers, as alternatives to gentamicin.}, }
@article {pmid39210155, year = {2024}, author = {Ashraf, N and Anas, A and Sukumaran, V and James, J and Bilutheth, MN and Chekkillam, AR and Jasmin, C and Raj K, D and Babu, I}, title = {Biofilm-forming bacteria associated with corals secrete melanin with UV-absorption properties.}, journal = {World journal of microbiology &amp; biotechnology}, volume = {40}, number = {10}, pages = {313}, pmid = {39210155}, issn = {1573-0972}, support = {MLP2013//Council of Scientific and Industrial Research, India/ ; BT/PR30688/BIC/101/1139/2018//Department of Biotechnology, Ministry of Science and Technology, India/ ; }, mesh = {*Anthozoa/microbiology ; Animals ; *Melanins/metabolism ; *Bacteria/classification/metabolism/isolation &amp; purification/genetics ; *Biofilms/growth &amp; development ; India ; Ultraviolet Rays ; RNA, Ribosomal, 16S/genetics ; Coral Reefs ; Phylogeny ; Microbiota ; }, abstract = {Corals are colonized by a plethora of microorganisms, and their diversity plays a significant role in the health and resilience of corals when they face oxidative stress leading to bleaching. In the current study, we examined 238 bacteria isolated from five different coral species (Acropora hyacinthus, Pocillopora damicornis, Podabacea crustacea, Porites lobata, and Pavona venosa) collected from the coral reef ecosystems of Kavaratti, Lakshadweep Islands, India. We found that bacteria such as Psychrobacter sp., Halomonas sp., Kushneria sp., Staphylococcus sp., Bacillus sp., Brachybacterium sp., Citrobacter sp., and Salinicola sp. were commonly present in the corals. On the other hand, Qipengyuania sp., Faucicola sp., Marihabitans sp., Azomonas sp., Atlantibacter sp., Cedecea sp., Krasalinikoviella sp., and Aidingimonas sp. were not previously reported from the corals. Among the bacterial isolates, a significant number showed high levels of biofilm formation (118), UV absorption (119), and melanin production (127). Considering these properties, we have identified a combination of seven bacteria from the genera Halomonas sp., Psychrobacter sp., Krasalinikoviella sp., and Micrococcus sp. as a potential probiotic consortium for protecting corals from oxidative stress. Overall, this study provides valuable insights into the coral microbiome and opens up possibilities for microbiome-based interventions to protect these crucial ecosystems in the face of global environmental challenges.}, }
@article {pmid39209232, year = {2024}, author = {Dorner, M and Behrens, S}, title = {Biochar as ammonia exchange biofilm carrier for enhanced aerobic nitrification in activated sludge.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131374}, doi = {10.1016/j.biortech.2024.131374}, pmid = {39209232}, issn = {1873-2976}, abstract = {The effects of biochar on aerobic nitrification in activated sludge was investigated in sequencing batch reactors. Biochar-amended reactors exhibited 87-94 % lower ammonia in effluent and 16-71 % greater removal of total Kjeldahl nitrogen compared to control reactors. Quantitative qPCR analyzes revealed that the relative abundance of ammonia oxidizing bacteria (amoA/16S rRNA genes) was greater in biochar than control reactors. AOB were enriched on biochar surfaces, with biochar particles having up to 12.1 times greater relative abundance of AOB compared to suspended biomass. Biochar's maximum ammonia sorption capacity of 4.4 mg N/g at pH 7 decreased with decreasing pH. Using a pH-sensitive fluorescent probe we show that biofilms growing on biochar surfaces maintain a pH of > 6.7 despite reactor acidification by nitrification. Microbial colonization of biochar in activated sludge creates a pH-sheltered environment that sustains biochar's ammonia sorption capacity, resulting in enrichment of AOB on biochar particles and improved nitrification.}, }
@article {pmid39208563, year = {2024}, author = {Guo, Q and Liu, B and Guo, X and Yan, P and Cao, B and Liu, R and Liu, X}, title = {Characterization and application of LysSGF2 and HolSGF2 as potential biocontrol agents against planktonic and biofilm cells of common pathogenic bacteria.}, journal = {International journal of food microbiology}, volume = {425}, number = {}, pages = {110848}, doi = {10.1016/j.ijfoodmicro.2024.110848}, pmid = {39208563}, issn = {1879-3460}, abstract = {Antimicrobial resistance represents a global health emergency, necessitating the introduction of novel antimicrobial agents. In the present study, lysozyme and holin from Shigella flexneri 1.1868 phage SGF2, named LysSGF2 and HolSGF2, respectively, were cloned, expressed, and characterized. LysSGF2 and HolSGF2 showed lytic activities against S. flexneri 1.1868 cells at 4-55 °C and pH 3.1-10.3. LysSGF2 exhibited antimicrobial activity against five gram-negative and two gram-positive bacteria. HolSGF2 showed antimicrobial activity against four gram-negative and one gram-positive species. The antibacterial activities of LysSGF2 and HolSGF2 were determined in liquid beverages, including bottled water and milk. The relative lytic activity of LysSGF2 combined with HolSGF2 against the tested bacteria was approximately 46-77 % in water. Furthermore, the combination markedly decreased the viable counts of tested bacteria by approximately 3-5 log CFU/mL. LysSGF2 and HolSGF2 could efficiently remove biofilms on polystyrene, glass, and stainless-steel. The efficacy of the LysSGF2 and HolSGF2 combination against the tested bacteria on polystyrene was 58-71 %. Combination treatment effectively killed biofilm cells formed on stainless-steel and glass by 1-4 log CFU/mL. ese results indicate that LysSGF2 and HolSGF2 can successfully control both the planktonic and biofilm cells of common pathogenic bacteria, suggesting that the combined or single use of LysSGF2 and HolSGF2 may be of great value in food processing.}, }
@article {pmid39207160, year = {2024}, author = {Shen, L and Zhang, J and Chen, Y and Rao, L and Wang, X and Zhao, H and Wang, B and Xiao, Y and Yu, J and Xu, Y and Shi, J and Han, W and Song, Z and Yu, F}, title = {Correction for Shen et al., "Small-Molecule Compound CY-158-11 Inhibits Staphylococcus aureus Biofilm Formation".}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0198424}, doi = {10.1128/spectrum.01984-24}, pmid = {39207160}, issn = {2165-0497}, }
@article {pmid39205249, year = {2024}, author = {Soro, O and Kigen, C and Nyerere, A and Gachoya, M and Georges, M and Odoyo, E and Musila, L}, title = {Characterization and Anti-Biofilm Activity of Lytic Enterococcus Phage vB_Efs8_KEN04 against Clinical Isolates of Multidrug-Resistant Enterococcus faecalis in Kenya.}, journal = {Viruses}, volume = {16}, number = {8}, pages = {}, doi = {10.3390/v16081275}, pmid = {39205249}, issn = {1999-4915}, support = {PAU/ADM/PAUSTI/9/2022//African Union Commission/ ; JKU/ADM/10B//AFRICA-ai-JAPAN Project Innovation Research Funds/ ; }, mesh = {*Biofilms/growth &amp; development/drug effects ; *Enterococcus faecalis/virology/drug effects ; Kenya ; *Bacteriophages/physiology/genetics/isolation &amp; purification/classification ; *Drug Resistance, Multiple, Bacterial ; *Genome, Viral ; *Host Specificity ; Humans ; Anti-Bacterial Agents/pharmacology ; Gram-Positive Bacterial Infections/microbiology ; Sewage/virology ; }, abstract = {Enterococcus faecalis (E. faecalis) is a growing cause of nosocomial and antibiotic-resistant infections. Treating drug-resistant E. faecalis requires novel approaches. The use of bacteriophages (phages) against multidrug-resistant (MDR) bacteria has recently garnered global attention. Biofilms play a vital role in E. faecalis pathogenesis as they enhance antibiotic resistance. Phages eliminate biofilms by producing lytic enzymes, including depolymerases. In this study, Enterococcus phage vB_Efs8_KEN04, isolated from a sewage treatment plant in Nairobi, Kenya, was tested against clinical strains of MDR E. faecalis. This phage had a broad host range against 100% (26/26) of MDR E. faecalis clinical isolates and cross-species activity against Enterococcus faecium. It was able to withstand acidic and alkaline conditions, from pH 3 to 11, as well as temperatures between -80 °C and 37 °C. It could inhibit and disrupt the biofilms of MDR E. faecalis. Its linear double-stranded DNA genome of 142,402 bp contains 238 coding sequences with a G + C content and coding gene density of 36.01% and 91.46%, respectively. Genomic analyses showed that phage vB_Efs8_KEN04 belongs to the genus Kochikohdavirus in the family Herelleviridae. It lacked antimicrobial resistance, virulence, and lysogeny genes, and its stability, broad host range, and cross-species lysis indicate strong potential for the treatment of Enterococcus infections.}, }
@article {pmid39204439, year = {2024}, author = {Apaza Ticona, L and Martínez Noguerón, A and Sánchez Sánchez-Corral, J and Montoto Lozano, N and Ortega Domenech, M}, title = {Anti-Inflammatory, Antibacterial, Anti-Biofilm, and Anti-Quorum Sensing Activities of the Diterpenes Isolated from Clinopodium bolivianum.}, journal = {Pharmaceutics}, volume = {16}, number = {8}, pages = {}, doi = {10.3390/pharmaceutics16081094}, pmid = {39204439}, issn = {1999-4923}, abstract = {This study reports for the first time the isolation of four diterpenoid compounds: 15-Hydroxy-12-oxo-abietic acid (1), 12α-hydroxyabietic acid (2), (-)-Jolkinolide E (3), and 15-Hydroxydehydroabietic acid (4) from Clinopodium bolivianum (C. bolivianum). The findings demonstrate that both the dichloromethane/methanol (DCMECB) extract of C. bolivianum and the isolated compounds exhibit significant anti-inflammatory (inhibition of NF-κB activation), antibacterial (primarily against Gram-positive bacteria), and anti-biofilm (primarily against Gram-negative bacteria) activities. Among the isolated diterpenes, compounds 3 and 4 showed notable anti-inflammatory effects, with IC50 values of 17.98 μM and 23.96 μM for compound 3, and 10.79 μM and 17.37 μM for compound 4, in the HBEC3-KT and MRC-5 cell lines. Regarding their antibacterial activity, compounds 3 and 4 were particularly effective, with MIC values of 0.53-1.09 μM and 2.06-4.06 μM, respectively, against the S. pneumoniae and S. aureus Gram-positive bacteria. Additionally, these compounds demonstrated significant anti-biofilm and anti-quorum sensing activities, especially against Gram-negative bacteria (H. influenzae and L. pneumophila). We also explain how compound 3 (BIC = 1.50-2.07 μM, Anti-QS = 0.31-0.64 μM) interferes with quorum sensing due to its structural homology with AHLs, while compound 4 (BIC = 4.65-7.15 μM, Anti-QS = 1.21-2.39 μM) destabilises bacterial membranes due to the presence and position of its hydroxyl groups. These results support the traditional use of C. bolivianum against respiratory infections caused by both Gram-positive and Gram-negative bacteria. Furthermore, given the increasing antibiotic resistance and biofilm formation by these bacteria, there is a pressing need for the development of new, more active compounds. In this context, compounds 3 and 4 isolated from C. bolivianum offer promising potential for the development of a library of new, more potent, and selective drugs.}, }
@article {pmid39204321, year = {2024}, author = {MubarakAli, D and Saravanakumar, K and Ganeshalingam, A and Santosh, SS and De Silva, S and Park, JU and Lee, CM and Cho, SH and Kim, SR and Cho, N and Thiripuranathar, G and Park, S}, title = {Recent Progress in Multifunctional Stimuli-Responsive Combinational Drug Delivery Systems for the Treatment of Biofilm-Forming Bacterial Infections.}, journal = {Pharmaceutics}, volume = {16}, number = {8}, pages = {}, doi = {10.3390/pharmaceutics16080976}, pmid = {39204321}, issn = {1999-4923}, support = {2022R1I1A1A01067464//National Research Foundation (NRF) of Korea/ ; NRF-2022R1F1A1063364//Ministry of Education, Science, and Technology, Republic of Korea/ ; K413000//Korea Basic Science Institute/ ; G22202201282201//Korea Institute of Marine Science &amp; Technology Promotion (KIMST), funded by the Ministry of Oceans and Fisheries/ ; }, abstract = {Drug-resistant infectious diseases pose a substantial challenge and threat to medical regimens. While adaptive laboratory evolution provides foresight for encountering such situations, it has inherent limitations. Novel drug delivery systems (DDSs) have garnered attention for overcoming these hurdles. Multi-stimuli responsive DDSs are particularly effective due to their reduced background leakage and targeted drug delivery to specific host sites for pathogen elimination. Bacterial infections create an acidic state in the microenvironment (pH: 5.0-5.5), which differs from normal physiological conditions (pH: 7.4). Infected areas are characterized by the overexpression of hyaluronidase, gelatinase, phospholipase, and other virulence factors. Consequently, several effective stimuli-responsive DDSs have been developed to target bacterial pathogens. Additionally, biofilms, structured communities of bacteria encased in a self-produced polymeric matrix, pose a significant challenge by conferring resistance to conventional antimicrobial treatments. Recent advancements in nano-drug delivery systems (nDDSs) show promise in enhancing antimicrobial efficacy by improving drug absorption and targeting within the biofilm matrix. nDDSs can deliver antimicrobials directly to the biofilm, facilitating more effective eradication of these resilient bacterial communities. Herein, this review examines challenges in DDS development, focusing on enhancing antibacterial activity and eradicating biofilms without adverse effects. Furthermore, advances in immune system modulation and photothermal therapy are discussed as future directions for the treatment of bacterial diseases.}, }
@article {pmid39203688, year = {2024}, author = {Seručnik, M and Dogsa, I and Zadravec, LJ and Mandic-Mulec, I and Žnidaršič-Plazl, P}, title = {Development of a Microbioreactor for Bacillus subtilis Biofilm Cultivation.}, journal = {Micromachines}, volume = {15}, number = {8}, pages = {}, doi = {10.3390/mi15081037}, pmid = {39203688}, issn = {2072-666X}, abstract = {To improve our understanding of Bacillus subtilis growth and biofilm formation under different environmental conditions, two versions of a microfluidic reactor with two channels separated by a polydimethylsiloxane (PDMS) membrane were developed. The gas phase was introduced into the channel above the membrane, and oxygen transfer from the gas phase through the membrane was assessed by measuring the dissolved oxygen concentration in the liquid phase using a miniaturized optical sensor and oxygen-sensitive nanoparticles. B. subtilis biofilm formation was monitored in the growth channels of the microbioreactors, which were designed in two shapes: one with circular extensions and one without. The volumes of these microbioreactors were (17 ± 4) μL for the reactors without extensions and (28 ± 4) μL for those with extensions. The effect of microbioreactor geometry and aeration on B. subtilis biofilm growth was evaluated by digital image analysis. In both microbioreactor geometries, stable B. subtilis biofilm formation was achieved after 72 h of incubation at a growth medium flow rate of 1 μL/min. The amount of oxygen significantly influenced biofilm formation. When the culture was cultivated with a continuous air supply, biofilm surface coverage and biomass concentration were higher than in cultivations without aeration or with a 100% oxygen supply. The channel geometry with circular extensions did not lead to a higher total biomass in the microbioreactor compared to the geometry without extensions.}, }
@article {pmid39203579, year = {2024}, author = {Wint, WY and Miyanohara, M and Terada-Ito, C and Yamada, H and Ryo, K and Murata, T}, title = {Effects of Sucrose and Farnesol on Biofilm Formation by Streptococcus mutans and Candida albicans.}, journal = {Microorganisms}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/microorganisms12081737}, pmid = {39203579}, issn = {2076-2607}, abstract = {Candida albicans (C. albicans) and Streptococcus mutans (S. mutans) are frequently detected in the plaque biofilms of children with early childhood caries. This study investigated the effects of sucrose and farnesol on biofilm formation by the oral pathogens S. mutans and C. albicans, including their synergistic interactions. Biofilm formation dynamics were monitored using the Cell Index (CI). The CI for S. mutans increased in the brain-heart infusion medium, peaking at 10 h; however, the addition of sucrose reduced the CI. For C. albicans yeast cells, the CI increased at sucrose concentrations > 0.5%, peaking at 2 h. Mixed cultures of S. mutans and C. albicans yeast cells showed significantly higher CI values in the presence of sucrose, suggesting a synergistic effect on biofilm formation. Farnesol consistently suppressed biofilm formation by C. albicans yeast cells, even in the presence of sucrose, and higher farnesol concentrations resulted in greater inhibition. Regarding C. albicans hyphal cells, sucrose did not enhance biofilm formation, whereas farnesol significantly reduced biofilm formation at all concentrations tested. These findings elucidate the complex roles of sucrose and farnesol in biofilm formation by S. mutans and C. albicans and emphasize the potential of farnesol as an effective oral biofilm inhibitor.}, }
@article {pmid39203542, year = {2024}, author = {Wang, X and Wu, Y and Chen, M and Fu, C and Xu, H and Li, L}, title = {Different Roles of Dioxin-Catabolic Plasmids in Growth, Biofilm Formation, and Metabolism of Rhodococcus sp. Strain p52.}, journal = {Microorganisms}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/microorganisms12081700}, pmid = {39203542}, issn = {2076-2607}, support = {22076102//National Natural Science Foundation of China/ ; 21876100//National Natural Science Foundation of China/ ; 2023KJ005//Youth Innovation Team Project of Higher School in Shandong Province/ ; }, abstract = {Microorganisms harbor catabolic plasmids to tackle refractory organic pollutants, which is crucial for bioremediation and ecosystem health. Understanding the impacts of plasmids on hosts provides insights into the behavior and adaptation of degrading bacteria in the environment. Here, we examined alterations in the physiological properties and gene expression profiles of Rhodococcus sp. strain p52 after losing two conjugative dioxin-catabolic megaplasmids (pDF01 and pDF02). The growth of strain p52 accelerated after pDF01 loss, while it decelerated after pDF02 loss. During dibenzofuran degradation, the expression levels of dibenzofuran catabolic genes on pDF01 were higher compared to those on pDF02; accordingly, pDF01 loss markedly slowed dibenzofuran degradation. It was suggested that pDF01 is more beneficial to strain p52 under dibenzofuran exposure. Moreover, plasmid loss decreased biofilm formation, especially after pDF02 loss. Transcriptome profiling revealed different pathways enriched in upregulated and downregulated genes after pDF01 and pDF02 loss, indicating different adaptation mechanisms. Based on the transcriptional activity variation, pDF01 played roles in transcription and anabolic processes, while pDF02 profoundly influenced energy production and cellular defense. This study enhances our knowledge of the impacts of degradative plasmids on native hosts and the adaptation mechanisms of hosts, contributing to the application of plasmid-mediated bioremediation in contaminated environments.}, }
@article {pmid39203493, year = {2024}, author = {Saoudi, B and Bariz, K and Saci, S and Belounis, Y and Ait Issad, H and Abbaci, M and Mustapha, MA and Nabti, EH and Alenazy, R and Alhussaini, MS and Alyahya, AAI and Alqasmi, M and Alhumaidi, MS and Almufarriji, FM and Houali, K}, title = {Enhancing Antibiotic Efficacy and Combating Biofilm Formation: Evaluating the Synergistic Potential of Origanum vulgare Essential Oil against Multidrug-Resistant Gram-Negative Bacteria.}, journal = {Microorganisms}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/microorganisms12081651}, pmid = {39203493}, issn = {2076-2607}, abstract = {Multidrug-resistant (MDR) Gram-negative bacteria remain a global public health issue due to the barrier imposed by their outer membrane and their propensity to form biofilms. It is becoming imperative to develop new antibacterial strategies. In this context, this study aims to evaluate the antibacterial efficacy of Origanum vulgare essential oil (OEO), alone and in combination with antibiotics, as well as its antibiofilm action against multidrug-resistant Gram-negative strains. OEO components were identified by gas chromatography-mass spectrometry (GC-MS), and antibacterial activity was assessed using the agar diffusion test and the microdilution method. Interactions between OEO and antibiotics were examined using the checkerboard method, while antibiofilm activity was analyzed using the crystal violet assay. Chemical analysis revealed that carvacrol was the major compound in OEO (61.51%). This essential oil demonstrated activity against all the tested strains, with inhibition zone diameters (IZDs) reaching 32.3 ± 1.5 mm. The combination of OEO with different antibiotics produced synergistic and additive effects, leading to a reduction of up to 98.44% in minimum inhibitory concentrations (MICs). In addition, this essential oil demonstrated an ability to inhibit and even eradicate biofilm formation. These results suggest that OEO could be exploited in the development of new molecules, combining its metabolites with antibiotics.}, }
@article {pmid39203430, year = {2024}, author = {Gilmore, A and Badham, M and Rudisin, W and Ashton, N and Williams, D}, title = {A Bead Biofilm Reactor for High-Throughput Growth and Translational Applications.}, journal = {Microorganisms}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/microorganisms12081588}, pmid = {39203430}, issn = {2076-2607}, support = {W81XWH-20-1-0378//Congressionally Directed Medical Research Programs/ ; }, abstract = {Bacteria in natural ecosystems such as soil, dirt, or debris preferentially reside in the biofilm phenotype. When a traumatic injury, such as an open fracture, occurs, these naturally dwelling biofilms and accompanying foreign material can contaminate the injury site. Given their high tolerance of systemic levels of antibiotics that may be administered prophylactically, biofilms may contribute to difficult-to-treat infections. In most animal models, planktonic bacteria are used as initial inocula to cause infection, and this might not accurately mimic clinically relevant contamination and infection scenarios. Further, few approaches and systems utilize the same biofilm and accompanying substrate throughout the experimental continuum. In this study, we designed a unique reactor to grow bacterial biofilms on up to 50 silica beads that modeled environmental wound contaminants. The data obtained indicated that the reactor system repeatably produced mature Staphylococcus aureus and Pseudomonas aeruginosa biofilms on the silica beads, with an average of 5.53 and 6.21 log10 colony-forming units per mm[2], respectively. The bead substrates are easily manipulable for in vitro or in vivo applications, thus improving translatability. Taken together, the bead biofilm reactor presented herein may be a useful system for repeatably growing established biofilms on silica beads that could be used for susceptibility testing and as initial inocula in future animal models of trauma-related injuries.}, }
@article {pmid39203407, year = {2024}, author = {Li, X and Ding, W and Li, Z and Yan, Y and Tong, Y and Xu, J and Li, M}, title = {vB_CacS-HV1 as a Novel Pahexavirus Bacteriophage with Lytic and Anti-Biofilm Potential against Cutibacterium acnes.}, journal = {Microorganisms}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/microorganisms12081566}, pmid = {39203407}, issn = {2076-2607}, support = {2022-KF-08//Open Project of the State Key Laboratory of Plateau Ecology and Agriculture/ ; 2022-NK-107//National Science and Technology Achievement Transformation Special Project - Pre-subsidy - Rural Affairs Department/ ; }, abstract = {Acne vulgaris is a prevalent chronic inflammatory skin disease, most common in adolescence and often persisting into adulthood, leading to severe physical and psychological impacts. The primary etiological factor is Cutibacterium acnes infection. The overuse of antibiotics for acne treatment over recent decades has led to the emergence of antibiotic-resistant Cutibacterium acnes strains. In this study, we isolated and characterized a novel bacteriophage, vB_CacS-HV1, from saliva samples. The average nucleotide identity analysis indicated that vB_CacS-HV1 is a new species within the Pahexavirus genus, enhancing our understanding of this underexplored group. vB_CacS-HV1 demonstrates favorable stability, lacks potentially harmful genetic elements (virulence factors, antibiotic resistance genes, transposons, and integrases), and exhibits potent lytic and anti-biofilm activities against Cutibacterium acnes at low concentrations. These advantages highlight vB_CacS-HV1's potential as a promising antibacterial agent that could possibly be complementary to antibiotics or other treatments for acne therapy.}, }
@article {pmid39203365, year = {2024}, author = {Principi, N and Esposito, S}, title = {Biofilm Production and Its Implications in Pediatrics.}, journal = {Microorganisms}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/microorganisms12081522}, pmid = {39203365}, issn = {2076-2607}, abstract = {Biofilms, aggregates of bacteria enclosed in a self-produced matrix, have been implicated in various pediatric respiratory infections, including acute otitis media (AOM), otitis media with effusion (OME), adenoiditis, protracted bacterial bronchitis, and pulmonary exacerbations in cystic fibrosis. These infections are prevalent in children and often associated with biofilm-producing pathogens, leading to recurrent and chronic conditions. Biofilms reduce antibiotic efficacy, contributing to treatment failure and disease persistence. This narrative review discusses biofilm production by respiratory pathogens such as Streptococcus pneumoniae, non-typeable Haemophilus influenzae, Pseudomonas aeruginosa, and Staphylococcus aureus. It examines their mechanisms of biofilm formation, antibiotic resistance, and the challenges they present in clinical treatment. Various antibiofilm strategies have shown promise in vitro and in animal studies, including the use of N-acetylcysteine, enzymes like dispersin B, and agents disrupting quorum sensing and biofilm matrix components. However, their clinical application, particularly in children, remains limited. Traditional treatments for biofilm-associated diseases have not significantly evolved, even with biofilm detection. The transition from experimental findings to clinical practice is complex and requires robust clinical trials and standardized biofilm detection protocols. Addressing biofilms in pediatric respiratory infections is crucial for improving treatment outcomes and managing recurrent and chronic diseases effectively.}, }
@article {pmid39203351, year = {2024}, author = {Liang, J and Zheng, X and Ning, T and Wang, J and Wei, X and Tan, L and Shen, F}, title = {Revealing the Viable Microbial Community of Biofilm in a Sewage Treatment System Using Propidium Monoazide Combined with Real-Time PCR and Metagenomics.}, journal = {Microorganisms}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/microorganisms12081508}, pmid = {39203351}, issn = {2076-2607}, support = {42307051//National Natural Science Foundation of China/ ; 2022M713416//China Postdoctoral Science Foundation/ ; CAAS-ZDRW202306//Special Fund for Basic Scientific Research of Central Public Welfare Institutes/ ; }, abstract = {Microbial community composition, function, and viability are important for biofilm-based sewage treatment technologies. Most studies of microbial communities mainly rely on the total deoxyribonucleic acid (DNA) extracted from the biofilm. However, nucleotide materials released from dead microorganisms may interfere with the analysis of viable microorganisms and their metabolic potential. In this study, we developed a protocol to assess viability as well as viable community composition and function in biofilm in a sewage treatment system using propidium monoazide (PMA) coupled with real-time quantitative polymerase chain reaction (qPCR) and metagenomic technology. The optimal removal of PMA from non-viable cells was achieved by a PMA concentration of 4 μM, incubation in darkness for 5 min, and exposure for 5 min. Simultaneously, the detection limit can reach a viable bacteria proportion of 1%, within the detection concentration range of 10[2]-10[8] CFU/mL (colony forming unit/mL), showing its effectiveness in removing interference from dead cells. Under the optimal conditions, the result of PMA-metagenomic sequencing revealed that 6.72% to 8.18% of non-viable microorganisms were influenced and the composition and relative abundance of the dominant genera were changed. Overall, this study established a fast, sensitive, and highly specific biofilm viability detection method, which could provide technical support for accurately deciphering the structural composition and function of viable microbial communities in sewage treatment biofilms.}, }
@article {pmid39203113, year = {2024}, author = {Išljamović, M and Bonvin, D and Milojević, M and Stojanović, S and Spasić, M and Stojković, B and Janošević, P and Otašević, S and Ebersold, MM}, title = {Antifungal Effect of Poly(methyl methacrylate) with Farnesol and Undecylenic Acid against Candida albicans Biofilm Formation.}, journal = {Materials (Basel, Switzerland)}, volume = {17}, number = {16}, pages = {}, doi = {10.3390/ma17163936}, pmid = {39203113}, issn = {1996-1944}, support = {No. 2014.0040/Serbia///Swiss Government Excellence Scholarship/ ; }, abstract = {The control of Candida albicans biofilm formation on dentures made of poly(methyl methacrylate) (PMMA) is an important challenge due to the high resistance to antifungal drugs. Interestingly, the natural compounds undecylenic acid (UDA) and farnesol (FAR) both prevent C. albicans biofilm formation and could have a synergetic effect. We therefore modified PMMA with a combination of UDA and FAR (UDA+FAR), aiming to obtain the antifungal PMMA_UDA+FAR composites. Equal concentrations of FAR and UDA were added to PMMA to reach 3%, 6%, and 9% in total of both compounds in composites. The physico-chemical properties of the composites were characterized by Fourier-transform infrared spectroscopy and water contact angle measurement. The antifungal activity of the composites was tested on both biofilm and planktonic cells with an XTT test 0 and 6 days after the composites' preparation. The effect of the UDA+FAR combination on C. albicans filamentation was studied in agar containing 0.0125% and 0.4% UDA+FAR after 24 h and 48 h of incubation. The results showed the presence of UDA and FAR on the composite and decreases in the water contact angle and metabolic activity of both the biofilm and planktonic cells at both time points at non-toxic UDA+FAR concentrations. Thus, the modification of PMMA with a combination of UDA+FAR reduces C. albicans biofilm formation on dentures and could be a promising anti-Candida strategy.}, }
@article {pmid39202995, year = {2024}, author = {Bugyna, L and Bilská, K and Boháč, P and Pribus, M and Bujdák, J and Bujdáková, H}, title = {Anti-Biofilm Effect of Hybrid Nanocomposite Functionalized with Erythrosine B on Staphylococcus aureus Due to Photodynamic Inactivation.}, journal = {Molecules (Basel, Switzerland)}, volume = {29}, number = {16}, pages = {}, doi = {10.3390/molecules29163917}, pmid = {39202995}, issn = {1420-3049}, support = {EU Next Generation EU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V01-00105//Government Office of the Slovak Republic/ ; APVV-21- 0302//Slovak Research and Development Agency/ ; APVV-22-0150//Slovak Research and Development Agency/ ; VEGA 1/0240/23//Ministry of Education, Research, Development and Youth/ ; }, mesh = {*Biofilms/drug effects ; *Nanocomposites/chemistry ; *Staphylococcus aureus/drug effects ; *Erythrosine/pharmacology/chemistry ; Polyurethanes/chemistry/pharmacology ; Anti-Bacterial Agents/pharmacology/chemistry ; Photosensitizing Agents/pharmacology/chemistry ; Silicates/chemistry/pharmacology ; Photochemotherapy/methods ; Polyelectrolytes ; }, abstract = {Resistant biofilms formed by Staphylococcus aureus on medical devices pose a constant medical threat. A promising alternative to tackle this problem is photodynamic inactivation (PDI). This study focuses on a polyurethane (PU) material with an antimicrobial surface consisting of a composite based on silicate, polycation, and erythrosine B (EryB). The composite was characterized using X-ray diffraction and spectroscopy methods. Anti-biofilm effectiveness was determined after PDI by calculation of CFU mL[-1]. The liquid PU precursors penetrated a thin silicate film resulting in effective binding of the PU/silicate composite and the PU bulk phases. The incorporation of EryB into the composite matrix did not significantly alter the spectral properties or photoactivity of the dye. A green LED lamp and laser were used for PDI, while irradiation was performed for different periods. Preliminary experiments with EryB solutions on planktonic cells and biofilms optimized the conditions for PDI on the nanocomposite materials. Significant eradication of S. aureus biofilm on the composite surface was achieved by irradiation with an LED lamp and laser for 1.5 h and 10 min, respectively, resulting in a 10,000-fold reduction in biofilm growth. These results demonstrate potential for the development of antimicrobial polymer surfaces for modification of medical materials and devices.}, }
@article {pmid39202793, year = {2024}, author = {Fehlhofer, J and Ries, J and Nickel, FT and Rothhammer, V and Schwab, S and Kesting, M and Buchbender, M}, title = {Correction: Fehlhofer et al. Expression of Inflammatory Mediators in Biofilm Samples and Clinical Association in Multiple Sclerosis Patients in Remission-A Pilot Study. Life 2024, 14, 367.}, journal = {Life (Basel, Switzerland)}, volume = {14}, number = {8}, pages = {}, doi = {10.3390/life14080932}, pmid = {39202793}, issn = {2075-1729}, abstract = {References [...].}, }
@article {pmid39201405, year = {2024}, author = {Ruiz-Mazón, L and Ramírez-Rico, G and de la Garza, M}, title = {Lactoferrin Affects the Viability of Bacteria in a Biofilm and the Formation of a New Biofilm Cycle of Mannheimia haemolytica A2.}, journal = {International journal of molecular sciences}, volume = {25}, number = {16}, pages = {}, doi = {10.3390/ijms25168718}, pmid = {39201405}, issn = {1422-0067}, support = {992577//Conahcyt/ ; CB-A1-S-8989//Conahcyt/ ; }, mesh = {*Biofilms/drug effects/growth &amp; development ; *Mannheimia haemolytica/drug effects/physiology ; *Lactoferrin/pharmacology ; Animals ; Microbial Viability/drug effects ; Cattle ; Virulence Factors/metabolism ; Sheep ; }, abstract = {Respiratory diseases in ruminants are responsible for enormous economic losses for the dairy and meat industry. The main causative bacterial agent of pneumonia in ovine is Mannheimia haemolytica A2. Due to the impact of this disease, the effect of the antimicrobial protein, bovine lactoferrin (bLf), against virulence factors of this bacterium has been studied. However, its effect on biofilm formation has not been reported. In this work, we evaluated the effect on different stages of the biofilm. Our results reveal a decrease in biofilm formation when bacteria were pre-incubated with bLf. However, when bLf was added at the start of biofilm formation and on mature biofilm, an increase was observed, which was visualized by greater bacterial aggregation and secretion of biofilm matrix components. Additionally, through SDS-PAGE, a remarkable band of ~80 kDa was observed when bLf was added to biofilms. Therefore, the presence of bLf on the biofilm was determined through the Western blot and Microscopy techniques. Finally, by using Live/Dead staining, we observed that most of the bacteria in a biofilm with bLf were not viable. In addition, bLf affects the formation of a new biofilm cycle. In conclusion, bLf binds to the biofilm of M. haemolytica A2 and affects the viability of bacteria and the formation a new biofilm cycle.}, }
@article {pmid39200500, year = {2024}, author = {Liu, Y and Liu, Y and Hao, L and Cao, J and Jiang, L and Yi, H}, title = {Metabolomic Approaches to Study the Potential Inhibitory Effects of Plantaricin Q7 against Listeria monocytogenes Biofilm.}, journal = {Foods (Basel, Switzerland)}, volume = {13}, number = {16}, pages = {}, doi = {10.3390/foods13162573}, pmid = {39200500}, issn = {2304-8158}, support = {32172180//National Natural Science Foundation of China/ ; ZR2020KC009//Key Program of Natural Science Foundation of Shandong Province in China/ ; }, abstract = {Listeria monocytogenes is a serious pathogen and can exacerbate harmful effects through the formation of biofilm. Inhibition of or reduction in L. monocytogenes biofilm is a promising strategy to control L. monocytogenes in the food industry. In our previous study, it was found that plantaricin Q7 produced by Lactiplantibacillus plantarum Q7 could inhibit and reduce L. monocytogenes biofilm, but the specific mechanism remains unclear. In this study, the inhibitive and reduced activity of plantaricin Q7 on L. monocytogenes biofilm was investigated by metabolomics. The results showed that plantaricin Q7 inhibited the synthesis of L. monocytogenes biofilm mainly through purine metabolism and glycerol phospholipid metabolism, and the key differential metabolites included acetylcholine and hypoxanthine with a decrease in abundance from 5.80 to 4.85. In addition, plantaricin Q7 reduced the formed L. monocytogenes biofilm by purine metabolism and arginine biosynthesis, and the main differential metabolites were N-acetylglutamate and D-ribose-1-phosphate with a decrease in abundance from 6.21 to 4.73. It was the first report that purine metabolism and amino acid metabolism were the common metabolic pathway for plantaricin Q7 to inhibit and reduce L. monocytogenes biofilm, which could be potential targets to control L. monocytogenes biofilm. A putative metabolic pathway for L. monocytogenes biofilm inhibition and reduction by plantaricin Q7 was proposed. These findings provided a novel strategy to control L. monocytogenes biofilm in food processing.}, }
@article {pmid39200422, year = {2024}, author = {Wei, J and Zhang, X and Ismael, M and Zhong, Q}, title = {Anti-Biofilm Effects of Z102-E of Lactiplantibacillus plantarum against Listeria monocytogenes and the Mechanism Revealed by Transcriptomic Analysis.}, journal = {Foods (Basel, Switzerland)}, volume = {13}, number = {16}, pages = {}, doi = {10.3390/foods13162495}, pmid = {39200422}, issn = {2304-8158}, support = {2024A1515012695//Guangdong Basic and Applied Basic Research Foundation/ ; 31972046//National Natural Science Foundation of China/ ; 2020B1212060059//Science and Technology Projects of Guangdong Province/ ; }, abstract = {Lactic acid bacteria (LAB) are the most common probiotics, and they present excellent inhibitory effects on pathogenic bacteria. This study aimed to explore the anti-biofilm potential of the purified active substance of Lactiplantibacillus plantarum, named Z102-E. The effects of Z102-E on Listeria monocytogenes were investigated in detail, and a transcriptomic analysis was conducted to reveal the anti-biofilm mechanism. The results indicated that the sub-MIC of Z102-E (3.2, 1.6, and 0.8 mg/mL) decreased the bacterial growth and effectively reduced the self-aggregation, surface hydrophobicity, sugar utilization, motility, biofilm formation, AI-2 signal molecule, contents of extracellular polysaccharides, and extracellular protein of L. monocytogenes. Moreover, the inverted fluorescence microscopy observation confirmed the anti-biofilm effect of Z102-E. The transcriptomic analysis indicated that 117 genes were up-regulated and 214 were down-regulated. Z102-E regulated the expressions of genes related to L. monocytogenes quorum sensing, biofilm formation, etc. These findings suggested that Z102-E has great application potential as a natural bacteriostatic agent.}, }
@article {pmid39200087, year = {2024}, author = {Mishra, A and Tabassum, N and Aggarwal, A and Kim, YM and Khan, F}, title = {Artificial Intelligence-Driven Analysis of Antimicrobial-Resistant and Biofilm-Forming Pathogens on Biotic and Abiotic Surfaces.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/antibiotics13080788}, pmid = {39200087}, issn = {2079-6382}, support = {RS-2023-00241461//Ministry of Education/ ; 2023 (202315350001)//Pukyong National University/ ; }, abstract = {The growing threat of antimicrobial-resistant (AMR) pathogens to human health worldwide emphasizes the need for more effective infection control strategies. Bacterial and fungal biofilms pose a major challenge in treating AMR pathogen infections. Biofilms are formed by pathogenic microbes encased in extracellular polymeric substances to confer protection from antimicrobials and the host immune system. Biofilms also promote the growth of antibiotic-resistant mutants and latent persister cells and thus complicate therapeutic approaches. Biofilms are ubiquitous and cause serious health risks due to their ability to colonize various surfaces, including human tissues, medical devices, and food-processing equipment. Detection and characterization of biofilms are crucial for prompt intervention and infection control. To this end, traditional approaches are often effective, yet they fail to identify the microbial species inside biofilms. Recent advances in artificial intelligence (AI) have provided new avenues to improve biofilm identification. Machine-learning algorithms and image-processing techniques have shown promise for the accurate and efficient detection of biofilm-forming microorganisms on biotic and abiotic surfaces. These advancements have the potential to transform biofilm research and clinical practice by allowing faster diagnosis and more tailored therapy. This comprehensive review focuses on the application of AI techniques for the identification of biofilm-forming pathogens in various industries, including healthcare, food safety, and agriculture. The review discusses the existing approaches, challenges, and potential applications of AI in biofilm research, with a particular focus on the role of AI in improving diagnostic capacities and guiding preventative actions. The synthesis of the current knowledge and future directions, as described in this review, will guide future research and development efforts in combating biofilm-associated infections.}, }
@article {pmid39200075, year = {2024}, author = {Jantaruk, P and Teerapo, K and Charoenwutthikun, S and Roytrakul, S and Kunthalert, D}, title = {Anti-Biofilm and Anti-Inflammatory Properties of the Truncated Analogs of the Scorpion Venom-Derived Peptide IsCT against Pseudomonas aeruginosa.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/antibiotics13080775}, pmid = {39200075}, issn = {2079-6382}, support = {R2565B051, PHD/0050/2559//Naresuan University (NU) and National Science, Research and Innovation Fund (NSRF), and The Royal Golden Jubilee Ph.D. (RGJ-PHD) Program Scholarship,/ ; }, abstract = {Pseudomonas aeruginosa is an opportunistic pathogen in humans and a frequent cause of severe nosocomial infections and fatal infections in immunocompromised individuals. Its ability to form biofilms has been the main driving force behind its resistance to almost all conventional antibiotics, thereby limiting treatment efficacy. In an effort to discover novel therapeutic agents to fight P. aeruginosa-associated biofilm infections, the truncated analogs of scorpion venom-derived peptide IsCT were synthesized and their anti-biofilm properties were examined. Among the investigated peptides, the IsCT-Δ6-8 peptide evidently showed the most potential anti-P. aeruginosa biofilm activity and the effect was not due to bacterial growth inhibition. The IsCT-Δ6-8 peptide also exhibited inhibitory activity against the production of pyocyanin, an important virulence factor of P. aeruginosa. Furthermore, the IsCT-Δ6-8 peptide significantly suppressed the production of inflammatory mediators nitric oxide and interleukin-6 in P. aeruginosa LPS-induced macrophages. Due to its low cytotoxicity to mammalian cells, the IsCT-Δ6-8 peptide emerges as a promising candidate with significant anti-biofilm and anti-inflammatory properties. These findings highlight its potential application in treating P. aeruginosa-related biofilm infections.}, }
@article {pmid39200043, year = {2024}, author = {Manuschai, J and Sotozono, M and Takenaka, S and Kornsombut, N and Takahashi, R and Saito, R and Nagata, R and Ida, T and Noiri, Y}, title = {In Vitro Inhibitory Effect of Silver Diamine Fluoride Combined with Potassium Iodide against Mixed-Species Biofilm Formation on Human Root Dentin.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/antibiotics13080743}, pmid = {39200043}, issn = {2079-6382}, support = {JP21H03117B//Japan society for the promotion of science/ ; 21K16990//Japan society for the promotion of science/ ; }, abstract = {Applying a saturated potassium iodide (KI) solution immediately after silver diamine fluoride (SDF) application may affect the inhibitory effects of SDF on biofilm formation. This study compared the efficacy of 38% SDF with and without KI on preventing mixed-species biofilm formation on human root dentin surfaces and assessed ion incorporation into root dentin. The biofilms, composed of Streptococcus mutans, Lactobacillus rhamnosus, and Actinomyces naeslundii, were grown on specimen surfaces treated with either SDF or SDF + KI. After 24 h, the biofilms were evaluated using scanning electron microscopy, live/dead staining, adenosine triphosphate (ATP) assays, colony-forming unit (CFU) counts, and quantitative polymerase chain reaction. A Mann-Whitney U test was used to compare the results between the groups. Ion incorporation was assessed using an electron probe microanalyzer. The relative ATP content in the SDF + KI group was significantly higher than that in the SDF group (p < 0.05). However, biofilm morphology and the logarithmic reduction in CFUs and bacterial DNA were comparable across the groups. The SDF + KI treatment resulted in less silver and fluoride ion incorporation than that yielded by SDF alone. The inhibitory effects of SDF and SDF + KI on mixed-species biofilm formation were almost equivalent, although KI application affected the ion incorporation.}, }
@article {pmid39200019, year = {2024}, author = {Santiago, MB and Tanimoto, MH and Ambrosio, MALV and Veneziani, RCS and Bastos, JK and Sabino-Silva, R and Martins, CHG}, title = {The Antibacterial Potential of Brazilian Red Propolis against the Formation and Eradication of Biofilm of Helicobacter pylori.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/antibiotics13080719}, pmid = {39200019}, issn = {2079-6382}, support = {2017/04138-8//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de S&#xe3;o Paulo/ ; Finance code 001//Coordena&#xe7;&#xe3;o de Aperfeicoamento de Pessoal de N&#xed;vel Superior/ ; 307974/2019-7 and 409157/2022-8 and 384347/2023-1//National Council for Scientific and Technological Development/ ; }, abstract = {Helicobacter pylori is associated with gastrointestinal diseases, and its treatment is challenging due to antibiotic-resistant strains, necessitating alternative therapies. Brazilian red propolis (BRP), known for its diverse bioactive compounds with pharmaceutical properties, was investigated for its anti-H. pylori activity, focusing on biofilm formation inhibition and eradication. BRP was tested against H. pylori (ATCC 43526) using several assays: time-kill, nucleotide leakage, biofilm formation inhibition (determining the minimum inhibitory concentration of biofilm of 50%-MICB50, and cell viability), and biofilm eradication (determining the minimum eradication concentration of biofilm of 99.9%-MBEC). Standardization of H. pylori biofilm formation was also conducted. In the time-kill assay, BRP at 50 µg/mL eliminated all H. pylori cells after 24 h. The nucleotide leakage assay showed no significant differences between control groups and BRP-treated groups at 25 µg/mL and 50 µg/mL. H. pylori formed biofilms in vitro at 10[9] CFU/mL after 72 h. The MICB50 of BRP was 15.6 µg/mL, and at 500, 1000, and 2000 µg/mL, BRP eradicated all bacterial cells. The MBEC was 2000 µg/mL. These findings suggest that BRP has promising anti-H. pylori activity, effectively inhibiting and eradicating biofilms. Further studies are necessary to elucidate BRP's mechanisms of action against H. pylori.}, }
@article {pmid39199989, year = {2024}, author = {Chakraborty, S and Baindara, P and Sharma, P and Jose T, A and V, K and Manoharan, R and Mandal, SM}, title = {Anti-Biofilm Action of Cineole and Hypericum perforatum to Combat Pneumonia-Causing Drug-Resistant P. aeruginosa.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/antibiotics13080689}, pmid = {39199989}, issn = {2079-6382}, abstract = {Hospital-acquired antibiotic-resistant pneumonia is one of the major causes of mortality around the world that pose a catastrophic threat. Pseudomonas aeruginosa is one of the most significant opportunistic pathogens responsible for hospital-acquired pneumonia and gained resistance to the majority of conventional antibiotics. There is an urgent need for antibiotic alternatives to control drug-resistant pneumonia and other related respiratory infections. In the present study, we explored the antibacterial potential of cineole in combination with homeopathic medicines against biofilm-forming drug-resistant P. aeruginosa. Out of 26 selected and screened homeopathic medicines, Hypericum Perforatum (HyPer) was found to eradicate biofilm-forming drug-resistant P. aeruginosa most effectively when used in combination with cineole. Interestingly, the synergistic action of HyPer and cineole was also found to be similarly effective against planktonic cells of P. aeruginosa. Further, the potential synergistic killing mechanisms of cineole and HyPer were determined by analyzing zeta membrane potential, outer membrane permeability, and DNA release from P. aeruginosa cells upon treatment with cineole and HyPer. Additionally, molecular docking analysis revealed strong binding affinities of hypericin (an active ingredient of HyPer) with the PqsA (a quorum sensing protein) of P. aeruginosa. Overall, our findings revealed the potential synergistic action of cineole and HyPer against biofilm-forming drug-resistant P. aeruginosa. Cineole and HyPer could be used in combination with other bronchodilators as inhalers to control the biofilm-forming drug-resistant P. aeruginosa.}, }
@article {pmid39199988, year = {2024}, author = {Vintilă, C and Coșeriu, RL and Mare, AD and Ciurea, CN and Togănel, RO and Simion, A and Cighir, A and Man, A}, title = {Biofilm Formation and Antibiotic Resistance Profiles in Carbapenemase-Producing Gram-Negative Rods-A Comparative Analysis between Screening and Pathological Isolates.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/antibiotics13080687}, pmid = {39199988}, issn = {2079-6382}, abstract = {(1) Background: Carbapenem-resistant (CR) bacteria pose a significant global public health challenge due to their ability to evade treatment with beta-lactam antibiotics, including carbapenems. This study investigates the biofilm-forming capabilities of CR clinical bacterial isolates and examines the impact of serum on biofilm formation. Additionally, the study evaluates the resistance profiles and genetic markers for carbapenemase production. (2) Methods: Bacterial isolates were collected from the microbiology laboratory of Mures County Clinical Hospital between October 2022 and September 2023. Pharyngeal and rectal swabs were screened for carbapenem-resistant bacteria using selective media. Lower respiratory tract samples were also analyzed for CR Gram-negative bacteria. The isolates were tested for their ability to form biofilms in the presence and absence of fetal bovine serum at 24 and 48 h. Carbapenemase production was detected phenotypically and confirmed via PCR for relevant genes. (3) Results: Out of 846 screened samples, 4.25% from pharyngeal swabs and 6.38% from rectal swabs tested positive for CR bacteria. Acinetobacter baumannii and Klebsiella pneumoniae were the most common species isolated. Biofilm formation varied significantly between clinical isolates and standard strains, with clinical isolates generally showing higher biofilm production. The presence of serum had no significant effect on biofilm formation in Klebsiella spp., but stimulated biofilm formation for Acinetobacter spp. Carbapenemase genes blaKPC, blaOXA-48-like, and blaNDM were detected in various isolates, predominantly in Klebsiella spp., but were not the main determinants of carbapenem resistance, at least in screening isolates. (4) Conclusions: This study highlights the variability in biofilm formation among CR clinical isolates and underscores the differences between the bacteria found as carriage versus infection. Both bacterial species and environmental factors variably influence biofilm formation. These insights are crucial for the development of effective treatment and infection control strategies in clinical settings.}, }
@article {pmid39199987, year = {2024}, author = {David, A and Tahrioui, A and Tareau, AS and Forge, A and Gonzalez, M and Bouffartigues, E and Lesouhaitier, O and Chevalier, S}, title = {Pseudomonas aeruginosa Biofilm Lifecycle: Involvement of Mechanical Constraints and Timeline of Matrix Production.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/antibiotics13080688}, pmid = {39199987}, issn = {2079-6382}, abstract = {Pseudomonas aeruginosa is an opportunistic pathogen causing acute and chronic infections, especially in immunocompromised patients. Its remarkable adaptability and resistance to various antimicrobial treatments make it difficult to eradicate. Its persistence is enabled by its ability to form a biofilm. Biofilm is a community of sessile micro-organisms in a self-produced extracellular matrix, which forms a scaffold facilitating cohesion, cell attachment, and micro- and macro-colony formation. This lifestyle provides protection against environmental stresses, the immune system, and antimicrobial treatments, and confers the capacity for colonization and long-term persistence, often characterizing chronic infections. In this review, we retrace the events of the life cycle of P. aeruginosa biofilm, from surface perception/contact to cell spreading. We focus on the importance of extracellular appendages, mechanical constraints, and the kinetics of matrix component production in each step of the biofilm life cycle.}, }
@article {pmid39199983, year = {2024}, author = {Artesani, L and Ciociola, T and Vismarra, A and Bacci, C and Conti, S and Giovati, L}, title = {Activity of Synthetic Peptide KP and Its Derivatives against Biofilm-Producing Escherichia coli Strains Resistant to Cephalosporins.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/antibiotics13080683}, pmid = {39199983}, issn = {2079-6382}, support = {Bando di Ateneo 2021 per la ricerca co-funded by MUR-Italian Ministry of Universities and Research - D.M. 737/2021 - PNR - PNRR - NextGenerationEU.//University of Parma/ ; }, abstract = {Bacterial resistance to β-lactam antibiotics, particularly new generation cephalosporins, is a major public health concern. In Escherichia coli, resistance to these antibiotics is mainly mediated by extended-spectrum β-lactamases (ESBL), which complicates a range of health-threatening infections. These infections may also be biofilm-related, making them more difficult to treat because of the higher tolerance to conventional antibiotics and the host immune response. In this study, we tested as potential new drug candidates against biofilm-forming ESBL-producing E. coli four antimicrobial peptides previously shown to have antifungal properties. The peptides proved to be active in vitro at micromolar concentrations against both sensitive and ESBL-producing E. coli strains, effectively killing planktonic cells and inhibiting biofilm formation. Quantitative fluorescence intensity analysis of three-dimensional reconstructed confocal laser scanning microscopy (CLSM) images of mature biofilm treated with the most active peptide showed significant eradication and a reduction in viable bacteria, while scanning electron microscopy (SEM) revealed gross morphological alterations in treated bacteria. The screening of the investigated peptides for antibacterial and antibiofilm activity led to the selection of a leading candidate to be further studied for developing new antimicrobial drugs as an alternative treatment against microbial infections, primarily associated with biofilms.}, }
@article {pmid39198733, year = {2024}, author = {Crossman, L and Sims, L and Dean, R and Felgate, H and Calvo, TD and Hill, C and McNamara, I and Webber, MA and Wain, J}, title = {Sticking together: independent evolution of biofilm formation in different species of staphylococci has occurred multiple times via different pathways.}, journal = {BMC genomics}, volume = {25}, number = {1}, pages = {812}, pmid = {39198733}, issn = {1471-2164}, mesh = {*Biofilms/growth &amp; development ; *Staphylococcus/genetics/physiology ; Phylogeny ; Bacterial Proteins/genetics/metabolism ; Evolution, Molecular ; }, abstract = {BACKGROUND: Staphylococci cause a wide range of infections, including implant-associated infections which are difficult to treat due to the presence of biofilms. Whilst some proteins involved in biofilm formation are known, the differences in biofilm production between staphylococcal species remains understudied. Currently biofilm formation by Staphylococcus aureus is better understood than other members of the genus as more research has focused on this species.<br><br>RESULTS: We assembled a panel of 385 non-aureus Staphylococcus isolates of 19 species from a combination of clinical sources and reference strains. We used a high-throughput crystal violet assay to assess the biofilm forming ability of all strains and assign distinct biofilm formation categories. We compared the prevalence of Pfam domains between the categories and used machine learning to identify amino acid 20-mers linked to biofilm formation. This identified some domains within proteins already linked to biofilm formation and important domains not previously linked to biofilm formation in staphylococci. RT-qPCR confirmed the expression of selected genes predicted to encode important domains within biofilms in Staphylococcus epidermidis. The prevalence and distribution of biofilm associated domains showed a link to phylogeny, suggesting different Staphylococcus species have independently evolved different mechanisms of biofilm production.<br><br>CONCLUSIONS: This work has identified different routes to biofilm formation in diverse species of Staphylococcus and suggests independent evolution of biofilm has occurred multiple times across the genus. Understanding the mechanisms of biofilm formation in any given species is likely to require detailed study of relevant strains and the ability to generalise across the genus may be limited.}, }
@article {pmid39198017, year = {2024}, author = {Mnisi, TJ and Matotoka, MM and Masoko, P}, title = {Antioxidant, antibacterial and anti-biofilm activities of selected indigenous plant species against nosocomial bacterial pathogens.}, journal = {Letters in applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/lambio/ovae080}, pmid = {39198017}, issn = {1472-765X}, abstract = {Biofilms are responsible for over 60% of nosocomial infections. The focus of this study was to investigate the antioxidant, antibacterial, antibiofilm, and anti-motility activities of Gardenia volkensii, Carissa bispinosa, Peltophorum africanum and Senna petersiana. Antioxidant activity was evaluated using free radical (DPPH) scavenging and ferric reducing power assays. Antibacterial and antibiofilm activities were evaluated using the broth micro-dilution and the crystal violet assays respectively. Anti-motility was evaluated using anti-swarming activities and the brine shrimp lethality assay was used for cytotoxicity. G. volkensii and C. bispinosa acetone extracts had low EC50 values of 9.59 and 9.99 μg ml-1on the free-radical scavenging activity respectively. All the plant extracts demonstrated broad-spectrum antibacterial activity against Klebsiella pneumoniae, Pseudomonasa aeruginosa, Escherichia coli and Enterococcus faecalis and Staphylococcus aureus (MIC < 0.63 mg ml 1). The initial cell adherence stage of P. aeruginosa and E. coli was the most susceptible stage where sub-MICs resulted in inhibitions >50%. P. africanum had the least cytotoxic effects. All extracts had anti-motility activity against P. aeruginosa and E. coli. This study showed that not only do the plants have strong antibacterial activity but had noteworthy inhibition (>50%) of initial cell adherence and may be suitable candidates for the treatment of nosocomial pathogens.}, }
@article {pmid39197770, year = {2024}, author = {Yang, Y and Zhu, Y and Gan, D and Cai, X and Li, X and Liu, X and Xia, S}, title = {Enhancing biofilm formation with powder carriers for efficient nitrogen and phosphorus removal.}, journal = {The Science of the total environment}, volume = {951}, number = {}, pages = {175812}, doi = {10.1016/j.scitotenv.2024.175812}, pmid = {39197770}, issn = {1879-1026}, abstract = {This study assesses the improvement in nitrogen and phosphorus removal from wastewater achieved through the integration of zeolite and attapulgite carrier materials into the activated sludge (AS) process. It was found that the addition of these materials significantly enhanced the processing performance of the reactor. Specifically, the use of zeolite and attapulgite powders increased sludge particle sizes to averages of 231.56 μm and 219.62 μm, respectively. This facilitated micro-granule formation, substantially improving the settling characteristics of the sludge and boosting the activity and proliferation of essential microbes. Illumina MiSeq sequencing demonstrated significant accumulations of DGAOs (Candidatus_Competibacter) and DPAOs (Candidatus_Accumulibacter). Furthermore, these carriers augmented the protein content in extracellular polymers, enhancing the hydrophobicity of the sludge and promoting aggregation. Comparative analysis based on the extended Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory indicated a preferential adhesion affinity of sludge for zeolite compared to attapulgite, attributed primarily to Lewis acid-base and electric double-layer interactions. These findings underscore zeolite's enhanced efficacy in biomass fixation and suggest significant potential for the technological advancement of wastewater treatment plants.}, }
@article {pmid39197692, year = {2024}, author = {Zhou, Y and Chang, J and Zhang, M and Li, X and Yang, W and Hu, L and Zhou, D and Ni, B and Lu, R and Zhang, Y}, title = {VPA0198, a GGDEF domain-containing protein, affects motility, biofilm formation, and virulence of Vibrio parahaemolyticus and is regulated by quorum sensing associated regulators.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106882}, doi = {10.1016/j.micpath.2024.106882}, pmid = {39197692}, issn = {1096-1208}, abstract = {Cyclic di-GMP (c-di-GMP), a ubiquitous secondary messenger in bacteria, affects multiple bacterial behaviors including motility and biofilm formation. c-di-GMP is synthesized by diguanylate cyclase harboring a GGDEF domain and degraded by phosphodiesterase harboring an either EAL or HD-GYP domain. Vibrio parahaemolyticus, the leading cause of seafood-associated gastroenteritis, harbors more than 60 genes involved in c-di-GMP metabolism. However, roles of most of these genes including vpa0198, which encodes a GGDEF-domain containing protein, are still completely unknown. AphA and OpaR are the master quorum sensing (QS) regulators operating at low (LCD) and high cell density (HCD), respectively. QsvR integrates into QS to control gene expression via direct regulation of AphA and OpaR. In this study, we showed that deletion of vpa0198 remarkably reduced c-di-GMP production and biofilm formation, whereas promoted the swimming motility of V. parahaemolyticus. Overexpression of VPA0198 in the vpa0198 mutant strain significantly reduced the swimming and swarming motility and enhanced the biofilm formation ability of V. parahaemolyticus. In addition, transcription of vpa0198 was under the collective regulation of AphA, OpaR and QsvR. AphA activated the transcription of vpa0198 at LCD, whereas QsvR and OpaR coordinately and directly repressed vpa0198 transcription at HCD, thereby leading to a cell density-dependent expression of vpa0198. Therefore, this work expanded the knowledge of synthetic regulatory mechanism of c-di-GMP in V. parahaemolyticus.}, }
@article {pmid39197659, year = {2024}, author = {Wang, X and Zhang, J and Li, L and Zhu, Y and Zhang, Y and Ni, M and Ding, Y and Huang, Y and Pan, Y}, title = {Formation mechanism of high biofilm phosphorus storage capacity and its effect on phosphorus uptake-release and carbon source consumption.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131363}, doi = {10.1016/j.biortech.2024.131363}, pmid = {39197659}, issn = {1873-2976}, abstract = {Phosphorus recovery from wastewater is an effective method to alleviate the shortage of phosphorus resources. The biofilm phosphorus recovery process can realize simultaneous removal and enrichment of phosphorus in wastewater. In this study, a sequencing batch biofilm reactor was constructed to study the rapid phosphorus release and slow phosphorus release stages in the phosphorus recovery cycle. The relationship between high biofilm phosphorus storage capacity (Pbiofilm), phosphorus recovery solution concentration, phosphorus uptake-release behavior and carbon source consumption were explored. The increase in phosphorus recovery solution concentration promotes the elevation of Pbiofilm, which, conversely promotes phosphorus release in the next recovery cycle. In addition, the distinct phosphorus uptake-release characteristics of extracellular polymeric substances and cells were illustrated. This study provides a theoretical foundation to elevate the phosphorus recovery efficiency and reduce carbon source consumption in biofilm phosphorus recovery process.}, }
@article {pmid39197632, year = {2024}, author = {Huang, B and Xiao, F and Chen, Z and Hu, T and Qiu, R and Wang, W and You, W and Su, X and Hu, W and Wang, Z}, title = {Coaxial electrospun nanofiber accelerates infected wound healing via engineered probiotic biofilm.}, journal = {International journal of biological macromolecules}, volume = {279}, number = {Pt 1}, pages = {135100}, doi = {10.1016/j.ijbiomac.2024.135100}, pmid = {39197632}, issn = {1879-0003}, abstract = {Bacterial infection is the primary cause of delayed wound healing. Infected wounds suffer from a series of harmful factors in the harsh wound microenvironment (WME), greatly damaging their potential for tissue regeneration. Herein, a novel probiotic biofilm-based antibacterial strategy is proposed through experimentation. Firstly, a series of coaxial polycaprolactone (PCL) / silk fibroin (SF) nanofiber films (termed as PSN-n, n = 0.5, 1.0, 1.5, and 2.0, respectively) are prepared by coaxial electrospinning and their physiochemical properties are comprehensively characterized. Afterward, the PSN-1.5 is selected and co-cultured with L. paracasei to allow the formation of probiotic biofilm. The probiotic biofilm-loaded PSN-1.5 nanofiber film (termed as PSNL-1.5) exhibits relatively good broad-spectrum antibacterial activity, biocompatibility, and enhanced pro-regenerative capability by immunoregulation of M2 macrophage. A wound healing assay is performed using an S. aureus-infected skin defect model. The application effect of PSNL-1.5 is significantly better than that of a commercial nano‑silver burn &amp; scald dressing (Anson®), revealing huge potential for clinical translation. This study is of significant novelty in demonstrating the antibacterial and pro-regenerative abilities of probiotic biofilms. The product of this study will be extensively used for treating infected wounds or other wounds.}, }
@article {pmid39197623, year = {2024}, author = {Zhou, J and Li, K and Ramasamy, P}, title = {Chitosan-collagen biopolymer biofilm derived from cephalopod gladius; Evaluation of osteogenesis, angiogenesis and wound healing for tissue engineering application.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {135078}, doi = {10.1016/j.ijbiomac.2024.135078}, pmid = {39197623}, issn = {1879-0003}, abstract = {Chitosan (Ch) and acid-soluble collagen (ASC) from Doryteuthis singhalensis gladius were isolated to test their osteogenic, angiogenic, and wound healing capabilities in male Wistar rats. The results of the study showed that the ASC yield was 18.58 %, the total protein content was 86.43 % ± 0.18 %, and the amino acid composition was as follows: glycine, 15.68 %; proline, 13.84 %. A, B, I, II, and III show FT-IR amide regional bands at 3392, 2959, 1652, 1471, and 1237 cm[-1] respectively. The electrophoretic pattern of ASC validated its molecular weights of 105 kDa and 96 kDa. The [1]H NMR spectra showed pure singles at 1.99 ppm, and the UV-Vis spectrum showed a particular absorbance between 238 and 220 nm. The DSC showed two endothermic peaks: one with an To value of 119.72 °C and TP of 126.28 °C, and the other with 147.42 °C and 148.47 °C. Initially, we fabricated Ch and ASC biofilms at an 8.5:1.5 ratio for tissue engineering applications. A cellular-level study demonstrated good biocompatibility and enhanced osteoblastic differentiation of collagen chitosan films (CChF). Additionally, the biofilm exhibited increased angiogenic potency, as observed in the chick embryo chorioallantoic membrane (CAM) assay. The experimental animal model demonstrated that in wound healing, the CChF treated rats (95.75 ± 2.28 %) had a greater decrease in the diameter of the wound than the control rats (22.25 ± 2.45 %), followed by the CF (collagen film) treated rats (63.25 ± 2.08 %) and ChF (chitosan film) (52.67 ± 1.58 %). Rats treated with CChF had 48.82 ± 1.25 mg/g of hydroxyproline in NFGT and 75.25 ± 1.56 mg/g of overall protein. The higher hydroxyproline levels in the CChF-treated groups corroborated these histopathological findings. These results imply that by promoting the development of scars, inflammation, and proliferation, CChF accelerates the healing process.}, }
@article {pmid39196492, year = {2024}, author = {Ünal, N and Kiymaci, ME and Savluk, M and Erdogan, H and Seker, E}, title = {Determination of antibacterial and anti-biofilm activities of Terpinen-4-ol loaded polydopamine nanoparticles against Staphylococcus aureus isolates from cows with subclinical mastitis.}, journal = {Veterinary research communications}, volume = {}, number = {}, pages = {}, pmid = {39196492}, issn = {1573-7446}, support = {Project No:221O176//The Scientific and Technological Research Council of T&#xfc;rkiye (TUBITAK)/ ; Project No:221O176//The Scientific and Technological Research Council of T&#xfc;rkiye (TUBITAK)/ ; Project No:221O176//The Scientific and Technological Research Council of T&#xfc;rkiye (TUBITAK)/ ; Project No:221O176//The Scientific and Technological Research Council of T&#xfc;rkiye (TUBITAK)/ ; }, abstract = {Mastitis in cows is one of the most important diseases that give rise to economic losses in dairy farms. Increasing antimicrobial resistance in Staphylococcus aureus, one of the most common causes of mastitis, is a significant health problem. Due to the problems encountered in treating infections caused by resistant strains, developing alternative treatment methods, such as Nanomaterial systems and natural agents, are important. The essential oil of Melaleuca alternifolia is used as an antibacterial and the primary active component is terpinen-4-ol. This study aimed to investigate the antibacterial and anti-biofilm activity of terpinen-4-ol and terpinen-4-ol loaded polydopamine (T-PDA) nanoparticles against S. aureus isolates, which were resistant to at least one group of antibiotics isolated from milk samples of subclinical mastitis cows. The S. aureus strains were identified by biochemical tests and verified with the API Staph kit. The antibiotic susceptibility of the isolates was determined by the disc diffusion method. The broth microdilution method determined the antimicrobial activities of the terpinen-4-ol and T-PDA nanoparticles, and anti-biofilm activities were assessed using the modified crystal violet method. All of the isolates were resistant to benzylpenicillin and susceptible to trimethoprim/sulfamethoxazole. Multi-antibiotic resistance was detected in the 11 S. aureus isolates used in this study. For the terpinen-4-ol and T-PDA nanoparticles, MIC values were determined in the range of 0.125-0.5% (µL/mL) and 0.125-0.25% (µL/mL), respectively. None of the isolates formed biofilms. As a result, it was found that the antibacterial efficacy of the T- PDA nanoparticles was higher against nine of the S. aureus isolates than against the terpinen-4-ol.}, }
@article {pmid39195716, year = {2024}, author = {Díaz, LKC and Berná, A and Boltes, K}, title = {Bioelectroremediation of a Real Industrial Wastewater: The Role of Electroactive Biofilm and Planktonic Cells through Enzymatic Activities.}, journal = {Toxics}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/toxics12080614}, pmid = {39195716}, issn = {2305-6304}, support = {PID2021-128700OB-I00//Ministerio de Ciencia e Innovaci&#xf3;n/ ; P2018/EMT-4341//Comunidad de Madrid/ ; }, abstract = {Bioelectrochemical processes are emerging as one of the most efficient and sustainable technologies for wastewater treatment. Their application for industrial wastewater treatment is still low due to the high toxicity and difficulty of biological treatment for industrial effluents. This is especially relevant in pharmaceutical industries, where different solvents, active pharma ingredients (APIs), extreme pH, and salinity usually form a lethal cocktail for the bacterial community in bioreactors. This work evaluates the impact of the anode architecture on the detoxification performance and analyzes, for the first time, the profile of some key bioremediation enzymes (catalase and esterase) and reactive oxygen species (ROS) during the operation of microbial electrochemical cells treating real pharmaceutical wastewater. Our results show the existence of oxidative stress and loss of cell viability in planktonic cells, while the electrogenic bacteria that form the biofilm maintain their biochemical machinery intact, as observed in the bioelectrochemical response. Monitorization of electrical current flowing in the bioelectrochemical system showed how electroactive biofilm, after a short adaptation period, started to degrade the pharma effluent. The electroactive biofilms are responsible for the detoxification of this type of industrial wastewater.}, }
@article {pmid39195076, year = {2024}, author = {Christian, N and Burden, D and Emam, A and Brenk, A and Sperber, S and Kalu, M and Cuadra, G and Palazzolo, D}, title = {Effects of E-Liquids and Their Aerosols on Biofilm Formation and Growth of Oral Commensal Streptococcal Communities: Effect of Cinnamon and Menthol Flavors.}, journal = {Dentistry journal}, volume = {12}, number = {8}, pages = {}, doi = {10.3390/dj12080232}, pmid = {39195076}, issn = {2304-6767}, support = {Not Applicable//Debusk College of Osteopathic Medicine and Muhlenberg College Intramural Funds/ ; }, abstract = {(1) Background: The rise in electronic cigarette (E-cigarette) popularity, especially among adolescents, has prompted research to investigate potential effects on health. Although much research has been carried out on the effect on lung health, the first site exposed to vaping-the oral cavity-has received relatively little attention. The aims of this study were twofold: to examine the effects of E-liquids on the viability and hydrophobicity of oral commensal streptococci, and the effects of E-cigarette-generated aerosols on the biomass and viability of oral commensal streptococci. (2) Methods: Quantitative and confocal biofilm analysis, live-dead staining, and hydrophobicity assays were used to determine the effect on oral commensal streptococci after exposure to E-liquids and/or E-cigarette-generated aerosols. (3) Results: E-liquids and flavors have a bactericidal effect on multispecies oral commensal biofilms and increase the hydrophobicity of oral commensal streptococci. Flavorless and some flavored E-liquid aerosols have a bactericidal effect on oral commensal biofilms while having no effect on overall biomass. (4) Conclusions: These results indicate that E-liquids/E-cigarette-generated aerosols alter the chemical interactions and viability of oral commensal streptococci. Consequently, the use of E-cigarettes has the potential to alter the status of disease and health in the oral cavity and, by extension, affect systemic health.}, }
@article {pmid39193978, year = {2024}, author = {Muslim, SN and Muslem, WH and Alwan, BH and Rasool, KH}, title = {Evaluation of L-Asparaginase Purified from Pseudomonas Fluorescens as Inhibitor for Biofilm Producers in Dental Decays.}, journal = {Clinical laboratory}, volume = {70}, number = {8}, pages = {}, doi = {10.7754/Clin.Lab.2024.240112}, pmid = {39193978}, issn = {1433-6510}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Pseudomonas fluorescens/drug effects/isolation &amp; purification ; *Asparaginase/pharmacology/isolation &amp; purification ; Humans ; *Dental Caries/microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Anti-Bacterial Agents/pharmacology ; }, abstract = {BACKGROUND: This study aimed to assess Pseudomonas fluorescens-purified L-Asparaginase's effectiveness as a broad-spectrum inhibitor of biofilm producers in dental decays.<br><br>METHODS: The 16S rRNA sequence was used to build a phylogenetic tree to calculate the evolutionary distance between the isolated bacterial strain SW3 and other species. The evolutionary history was inferred by using the neighbor-joining approach.<br><br>RESULTS: The bacteria were identified from dental decays, including Staphylococcus aureus, Streptococcus mutans, Streptococcus oralis, and Streptococcus mitis. Each one of these isolates showed different degrees of biofilm development. Purified L-Asparaginase inhibited the most potent Gram-positive biofilm-forming bacteria (biofilm producers) with higher inhibition percentages against Streptococcus oralis and Streptococcus mitis, 65 - 73.8 % and 54.7 - 63%, respectively. The inhibition percentages increased with increasing concentration and reached up to 74 - 81% with Streptococcus oralis and 66 - 74% with Streptococcus mitis, while SW3 bacteria showed (100%). This strain was suggested SW3 (Pseudomonas spp.). Pseudomonas fluorescens bacterial strain isolated from rhizosphere soil produced extracellular L-Asparaginase when grown on as a substrate. L-Asparaginase was purified to homogeneity by using ammonium sulfate at 60% saturation, followed by gel filtration chromatography on a sephadex G-100 column, with a recovery yield of 49% and a purification fold of 2.22.<br><br>CONCLUSIONS: L-Asparaginase had a promising use for removing and avoiding biofilm growth, implying that it might be used in the dental industry in the future.}, }
@article {pmid39193785, year = {2024}, author = {Alves, GDSG and de Oliveira, AMP and Roseno, ACB and Ribeiro, NP and Alves, MDS and Sampaio, C and do Prado, RL and Pessan, JP and Monteiro, DR}, title = {Interkingdom biofilm of Streptococcus pyogenes and Candida albicans: establishment of an in vitro model and dose-response validation of antimicrobials.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-13}, doi = {10.1080/08927014.2024.2395390}, pmid = {39193785}, issn = {1029-2454}, abstract = {Although Streptococcus pyogenes and Candida albicans may colonize tonsillar tissues, the interaction between them in mixed biofilms has been poorly explored. This study established an interkingdom biofilm model of S. pyogenes and C. albicans and verified the dose-response validation of antimicrobials. Biofilms were formed on microplates, in the presence or absence of a conditioning layer of human saliva, using Brain Heart Infusion (BHI) broth or artificial saliva (AS) as a culture medium, and with variations in the microorganism inoculation sequence. Biofilms grown in AS showed higher mass than those grown in BHI broth, and an opposite trend was observed for metabolism. The number of S. pyogenes colonies was lower in AS. Amoxicillin and nystatin showed dose-dependent effects. The inoculation of the two species at the same time, without prior exposure to saliva, and using BHI broth would be the model of choice for future studies assessing the effects of antimicrobials on dual S. pyogenes/C. albicans biofilms.}, }
@article {pmid39193397, year = {2024}, author = {Wang, Z and Lu, X and Zheng, M and Hu, Z and Batstone, D and Yuan, Z and Hu, S}, title = {Quadrupling the capacity of post aerobic digestion treating anaerobically digested sludge using a moving-bed biofilm (MBBR) configuration.}, journal = {Water research X}, volume = {24}, number = {}, pages = {100240}, doi = {10.1016/j.wroa.2024.100240}, pmid = {39193397}, issn = {2589-9147}, abstract = {Wastewater treatment plants produce large amounts of sludge requiring stabilization before safe disposal. Traditional biological stabilization approaches are cost-effective but generally require either an extended retention time (10-40 days), or elevated temperatures (40-80 °C) for effective pathogens inactivation. This study overcomes these limitations via a novel acidic aerobic digestion process, leveraging an acid-tolerant ammonia-oxidizing bacterium (AOB) Candidatus Nitrosoglobus. To retain this novel but slowly growing AOB, we proposed the first-ever application of a classical wastewater configuration-moving bed biofilm reactor (MBBR)-for sludge treatment. The AOB in biofilm maintains acidic pH and high nitrite levels in sludge, generating free nitrous acid in situ to expedite sludge stabilization. This process was tested in two laboratory-scale aerobic digesters processing full-scale anaerobically digested sludge. At an ambient temperature of 20 °C, pathogens were reduced to levels well below the threshold specified for the highest stabilization level (Class A), within a retention time of 3.5 days. A high volatile solids reduction of 27.4 ± 5.2% was achieved. Through drastically accelerating stabilization and enhancing reduction, this process substantially saves capital and operational costs for sludge disposal.}, }
@article {pmid39191399, year = {2024}, author = {Ando, K and Miyahara, S and Hanada, S and Fukuda, K and Saito, M and Sakai, A and Maruo, A and Zenke, Y}, title = {Effective biofilm eradication in MRSA isolates with aminoglycoside-modifying enzyme genes using high-concentration and prolonged gentamicin treatment.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0064724}, doi = {10.1128/spectrum.00647-24}, pmid = {39191399}, issn = {2165-0497}, abstract = {UNLABELLED: Bone and soft tissue infections caused by biofilm-forming bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), remain a significant clinical challenge. While the control of local infection is necessary, systemic treatment is also required, and biofilm eradication is a critical target for successful management. Topical antibiotic treatments, such as antibiotic-loaded bone cement (ALBC), have been used for some time, and continuous local antibiotic perfusion therapy, a less invasive method, has been developed by our group. However, the optimal antibiotics and concentrations for biofilms of clinical isolates are still not well understood. We examined the efficacy of high concentrations of gentamicin against MRSA biofilms and the role of gentamicin resistance genes in biofilm eradication. We collected 101 MRSA samples from a hospital in Japan and analyzed their gene properties, including methicillin and gentamicin resistance, and their minimum biofilm eradication concentration (MBEC) values. Our results showed that high concentrations of gentamicin are effective against MRSA biofilms and that even concentrations lower than the MBEC value could eliminate biofilms after prolonged exposure. We also identified three aminoglycoside/gentamicin resistance genes [aac(6')-aph(2″), aph(3')-III, and ant(4')-IA] and found that the presence or absence of these genes may inform the selection of treatments. It was also found that possession of the aac(6')-aph(2″) gene correlated with the minimum inhibitory concentration/MBEC values of gentamicin. Although this study provides insight into the efficacy of gentamicin against MRSA biofilms and the role of gentamicin resistance genes, careful selection of the optimal treatment strategy is needed for clinical application.<br><br>IMPORTANCE: Our analysis of 101 MRSA clinical isolates has provided valuable insights that could enhance treatment selection for biofilm infections in orthopedics. We found that high concentrations of gentamicin were effective against MRSA biofilms, and even prolonged exposure to concentrations lower than the minimum biofilm eradication concentration (MBEC) value could eliminate biofilms. The presence of the aac(6')-aph(2&#x2033;) gene, an aminoglycoside resistance gene, was found to correlate with the minimum inhibitory concentration (MIC) and MBEC values of gentamicin, providing a potential predictive tool for treatment susceptibility. These results suggest that extended high concentrations of local gentamicin treatment could effectively eliminate MRSA biofilms in orthopedic infections. Furthermore, testing for gentamicin MIC or the possession of the aac(6')-aph(2&#x2033;) gene could help select treatment, including topical gentamicin administration and surgical debridement.}, }
@article {pmid39190939, year = {2024}, author = {Wen, J and Dan, Y and Liu, X and Li, H}, title = {Promoting microalgal biofilm formation by crushed oyster shell-hydroxyapatite layer on micropatterned aluminum coating for heavy metal ions removal.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {243}, number = {}, pages = {114168}, doi = {10.1016/j.colsurfb.2024.114168}, pmid = {39190939}, issn = {1873-4367}, abstract = {Microalgal biomass has shown inspiring potential for the heavy metal removal from wastewater, and forming microalgal biofilm is one of the sustainable methods for the microalgal biomass production. Here we report the formation of microalgal biofilm by accelerated colonization of typical algae Chlorella on thermal sprayed aluminum (Al) coatings with biologically modified surfaces. Micro-patterning surface treatment of the Al coatings promotes the attachment of Chlorella from 6.31 % to 17.51 %. Further enhanced algae attachment is achieved through liquid flame spraying a bioactive crushed oyster shell-hydroxyapatite (CaCO3-HA) composite top layer on the micropatterned coating, reaching 46.03-49.62 % of Chlorella attachment ratio after soaking in Chlorella suspension for 5 days. The rapidly formed microalgal biofilm shows an adsorption ratio of 95.43 % and 85.23 % for low concentration Zn[2+] and Cu[2+] in artificial seawater respectively within 3 days. Quick interaction has been realized between heavy metal ions and the negatively-charged extracellular polymeric substances (EPS) matrix existing in the biofilm. Fourier transform infrared spectroscopy (FTIR) results indicate that both carboxyl and phosphoryl groups of biofilms are crucial in the adsorption of Cu[2+] and the adsorption of Zn[2+] is due to the hydroxyl and phosphate groups. Meanwhile, the biofilm could act as a barrier to protect Chlorella against the attack of the heavy metal ions with relatively low concentrations in aqueous solution. The route of quick cultivating microalgal biofilm on marine structures through constructing biological layer on their surfaces would give insight into developing new techniques for removing low concentration heavy metal ions from water for environmental bioremediation.}, }
@article {pmid39189769, year = {2024}, author = {Wang, L and Wang, X and Wu, H and Wang, H and Lu, Z}, title = {Interspecies synergistic interactions mediated by cofactor exchange enhance stress tolerance by inducing biofilm formation.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0088424}, doi = {10.1128/msystems.00884-24}, pmid = {39189769}, issn = {2379-5077}, abstract = {UNLABELLED: Metabolic exchange plays a crucial role in shaping microbial community interactions and functions, including the exchange of small molecules such as cofactors. Cofactors are fundamental to enzyme catalytic activities; however, the role of cofactors in microbial stress tolerance is unclear. Here, we constructed a synergistic consortium containing two strains that could efficiently mineralize di-(2-ethylhexyl) phthalate under hyperosmotic stress. Integration of transcriptomic analysis, metabolic profiling, and a genome-scale metabolic model (GEM) facilitated the discovery of the potential mechanism of microbial interactions. Multi-omics analysis revealed that the vitamin B12-dependent methionine-folate cycle could be a key pathway for enhancing the hyperosmotic stress tolerance of synergistic consortium. Further GEM simulations revealed interspecies exchange of S-adenosyl-L-methionine and riboflavin, cofactors needed for vitamin B12 biosynthesis, which was confirmed by in vitro experiments. Overall, we proposed a new mechanism of bacterial hyperosmotic stress tolerance: bacteria might promote the production of vitamin B12 to enhance biofilm formation, and the species collaborate with each other by exchanging cofactors to improve consortium hyperosmotic stress tolerance. These findings offer new insights into the role of cofactors in microbial interactions and stress tolerance and are potentially exploitable for environmental remediation.<br><br>IMPORTANCE: Metabolic interactions (also known as cross-feeding) are thought to be ubiquitous in microbial communities. Cross-feeding is the basis for many positive interactions (e.g., mutualism) and is a primary driver of microbial community assembly. In this study, a combination of multi-omics analysis and metabolic modeling simulation was used to reveal the metabolic interactions of a synthetic consortium under hyperosmotic stress. Interspecies cofactor exchange was found to promote biofilm formation under hyperosmotic stress. This provides a new perspective for understanding the role of metabolic interactions in microbial communities to enhance environmental adaptation, which is significant for improving the efficiency of production activities and environmental bioremediation.}, }
@article {pmid39188729, year = {2024}, author = {Suban, S and Yemini, S and Shor, A and Waldman Ben-Asher, H and Yaron, O and Karako-Lampert, S and Sendersky, E and Golden, SS and Schwarz, R}, title = {A cyanobacterial sigma factor F controls biofilm-promoting genes through intra- and intercellular pathways.}, journal = {Biofilm}, volume = {8}, number = {}, pages = {100217}, pmid = {39188729}, issn = {2590-2075}, abstract = {Cyanobacteria frequently constitute integral components of microbial communities known as phototrophic biofilms, which are widespread in various environments. Moreover, assemblages of these organisms, which serve as an expression platform, simplify harvesting the biomass, thereby holding significant industrial relevance. Previous studies of the model cyanobacterium Synechococcus elongatus PCC 7942 revealed that its planktonic growth habit results from a biofilm-suppression mechanism that depends on an extracellular inhibitor, an observation that opens the door to investigating cyanobacterial intercellular communication. Here, we demonstrate that the RNA polymerase sigma factor SigF1, is required for this biofilm-suppression mechanism whereas the S. elongatus paralog SigF2 is not involved in biofilm regulation. Comprehensive transcriptome analyses identified distinct regulons under the control of each of these sigma factors. sigF1 inactivation substantially lowers transcription of genes that code for the primary pilus subunit and consequently prevents pilus assembly. Moreover, additional data demonstrate absence of the biofilm inhibitor from conditioned medium of the sigF1 mutant, further validating involvement of the pilus assembly complex in secretion of the biofilm inhibitor. Consequently, expression is significantly upregulated for the ebfG-operon that encodes matrix components and the genes that encode the corresponding secretion system, which are repressed by the biofilm inhibitor in the wild type. Thus, this study uncovers a basic regulatory component of cyanobacterial intercellular communication, a field that is in its infancy. Elevated expression of biofilm-promoting genes in a sigF1 mutant supports an additional layer of regulation by SigF1 that operates via an intracellular mechanism.}, }
@article {pmid39185371, year = {2024}, author = {Mashal, S and Siddiqua, A and Ullah, N and Baloch, R and Khan, M and Hasnain, SZU and Imran Aziz, M and Huseynov, E and Selakovic, D and Rosic, G and Makhkamov, T and Yuldashev, A and Islamov, S and Abdullayeva, N and Khujanazarov, U and Amin, A}, title = {Bioactive plant waste components targeting oral bacterial pathogens as a promising strategy for biofilm eradication.}, journal = {Frontiers in chemistry}, volume = {12}, number = {}, pages = {1406869}, pmid = {39185371}, issn = {2296-2646}, abstract = {The significance of this study lies in its exploration of bioactive plant extracts as a promising avenue for combating oral bacterial pathogens, offering a novel strategy for biofilm eradication that could potentially revolutionize oral health treatments. Oral bacterial infections are common in diabetic patients; however, due to the development of resistance, treatment options are limited. Considering the excellent antimicrobial properties of phenolic compounds, we investigated them against isolated oral pathogens using in silico and in vitro models. We performed antibiogram studies and minimum inhibitory concentration (MIC), antibiofilm, and antiquorum sensing activities covering phenolic compounds. Bacterial strains were isolated from female diabetic patients and identified by using 16S rRNA sequencing as Pseudomonas aeruginosa, Bacillus chungangensis, Bacillus paramycoides, and Paenibacillus dendritiformis. Antibiogram studies confirmed that all strains were resistant to most tested antibiotics except imipenem and ciprofloxacin. Molecular docking analysis revealed the significant interaction of rutin, quercetin, gallic acid, and catechin with transcription regulator genes 1RO5, 4B2O, and 5OE3. All tested molecules followed drug-likeness rules except rutin. The MIC values of the tested compounds varied from 0.0625 to 0.5 mg/mL against clinical isolates. Significant antibiofilm activity was recorded in the case of catechin (73.5% ± 1.6% inhibition against B. paramycoides), cinnamic acid (80.9% ± 1.1% inhibition against P. aeruginosa), and vanillic acid and quercetin (65.5% ± 1.7% and 87.4% ± 1.4% inhibition, respectively, against B. chungangensis) at 0.25-0.125 mg/mL. None of the phenolic compounds presented antiquorum sensing activity. It was, therefore, concluded that polyphenolic compounds may have the potential to be used against oral bacterial biofilms, and further detailed mechanistic investigations should be performed.}, }
@article {pmid39185188, year = {2024}, author = {Walton, B and Abbondante, S and Marshall, ME and Dobruchowska, JM and Alvi, A and Gallagher, LA and Vallikat, N and Zhang, Z and Wozniak, DJ and Yu, EW and Boons, GJ and Pearlman, E and Rietsch, A}, title = {A biofilm-tropic Pseudomonas aeruginosa bacteriophage uses the exopolysaccharide Psl as receptor.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2024.08.12.607380}, pmid = {39185188}, issn = {2692-8205}, abstract = {Bacteria in nature can exist in multicellular communities called biofilms. Biofilms also form in the course of many infections. Pseudomonas aeruginosa infections frequently involve biofilms, which contribute materially to the difficulty to treat these infections with antibiotic therapy. Many biofilm-related characteristics are controlled by the second messenger, cyclic-di-GMP, which is upregulated on surface contact. Among these factors is the exopolysaccharide Psl, which is a critically important component of the biofilm matrix. Here we describe the discovery of a P. aeruginosa bacteriophage, which we have called Clew-1, that directly binds to and uses Psl as a receptor. While this phage does not efficiently infect planktonically growing bacteria, it can disrupt P. aeruginosa biofilms and replicate in biofilm bacteria. We further demonstrate that the Clew-1 can reduce the bacterial burden in a mouse model of P. aeruginosa keratitis, which is characterized by the formation of a biofilm on the cornea. Due to its reliance on Psl for infection, Clew-1 does not actually form plaques on wild-type bacteria under standard in vitro conditions. This argues that our standard isolation procedures likely exclude bacteriophage that are adapted to using biofilm markers for infection. Importantly, the manner in which we isolated Clew-1 can be easily extended to other strains of P. aeruginosa and indeed other bacterial species, which will fuel the discovery of other biofilm-tropic bacteriophage and expand their therapeutic use.}, }
@article {pmid39184815, year = {2024}, author = {Green, HD and Van Horn, GT and Williams, T and Eberly, A and Morales, GH and Mann, R and Hauter, IM and Hadjifrangiskou, M and Schmitz, JE}, title = {Intra-strain colony biofilm heterogeneity in uropathogenic Escherichia coli and the effect of the NlpI lipoprotein.}, journal = {Biofilm}, volume = {8}, number = {}, pages = {100214}, doi = {10.1016/j.bioflm.2024.100214}, pmid = {39184815}, issn = {2590-2075}, abstract = {Biofilm growth facilitates the interaction of uropathogenic Escherichia coli (UPEC) with the host environment. The extracellular polymeric substances (EPS) of UPEC biofilms are composed prominently of curli amyloid fiber and cellulose polysaccharide. When the organism is propagated as a colony biofilm on agar media, these macromolecules can generate pronounced macroscopic structures. Moreover, curli/cellulose associate tightly with Congo red, generating a characteristic pink-to-red staining pattern when the media is supplemented with this dye. Among different clinical isolates of UPEC, changes in the abundance of curli/cellulose can lead to diverse colony biofilm phenotypes on a strain-by-strain basis. Nevertheless, for any given isolate, these phenotypes are classically homogenous throughout the colony biofilm. Here, we report that a subset of clinical UPEC isolates display heterogenous 'peppermint' colony biofilms, with distinct pale and red subpopulations. Through isolation of these subpopulations and whole genome sequencing, we demonstrate various emergent mutations associated with the phenomenon, including within the gene encoding the outer membrane lipoprotein nlpI. Deletion of nlpI within independent strain-backgrounds increased biofilm rugosity, while its overexpression induced the peppermint phenotype. Upregulation of EPS-associated proteins and transcripts was likewise observed in the absence of nlpI. Overall, these results demonstrate that EPS elaboration in UPEC is impacted by nlpI. More broadly, this phenomenon of intra-strain colony biofilm heterogeneity may be leveraged as a tool to identify additional members within the broad collection of genes that regulate or otherwise affect biofilm formation.}, }
@article {pmid39184814, year = {2024}, author = {Chen, N and Li, Y and Liang, X and Qin, K and Zhang, Y and Wang, J and Wu, Q and Gupta, TB and Ding, Y}, title = {Bacterial extracellular vesicle: A non-negligible component in biofilm life cycle and challenges in biofilm treatments.}, journal = {Biofilm}, volume = {8}, number = {}, pages = {100216}, doi = {10.1016/j.bioflm.2024.100216}, pmid = {39184814}, issn = {2590-2075}, abstract = {Bacterial biofilms, especially those formed by pathogens, have been increasingly impacting human health. Bacterial extracellular vesicle (bEV), a kind of spherical membranous structure released by bacteria, has not only been reported to be a component of the biofilm matrix but also plays a non-negligible role in the biofilm life cycle. Nevertheless, a comprehensive overview of the bEVs functions in biofilms remains elusive. In this review, we summarize the biogenesis and distinctive features characterizing bEVs, and consolidate the current literature on their functions and proposed mechanisms in the biofilm life cycle. Furthermore, we emphasize the formidable challenges associated with vesicle interference in biofilm treatments. The primary objective of this review is to raise awareness regarding the functions of bEVs in the biofilm life cycle and lay the groundwork for the development of novel therapeutic strategies to control or even eliminate bacterial biofilms.}, }
@article {pmid39184655, year = {2024}, author = {S, MP and John, J and K, P and Prasad, K and Fahad Ismail, TM and Sivakumar, S and Sivakumar, K and Flora, J and Kumar Sivabalan, P and Wase, P}, title = {Biofilm Formation on Denture Base Material Reinforced With a Novel Organic Material.}, journal = {Cureus}, volume = {16}, number = {7}, pages = {e65232}, doi = {10.7759/cureus.65232}, pmid = {39184655}, issn = {2168-8184}, abstract = {BACKGROUND: Microcrystalline cellulose (MCC) is a novel organic material developed by one of the authors in this study. When MCC was incorporated with conventionally available denture base resin, it demonstrated increased flexural strength and flexural modulus. However, it was speculated that because the material is organic, it can promote the growth of Candida. The purpose of this study is to evaluate the Candida albicans biofilm formation on polymethyl methacrylate (PMMA) denture base resin incorporated with MCC.<br><br>MATERIALS AND METHODS: MCC is an organic material extracted from the oil palm empty fruit bunch (OPEFB). The growth of C. albicans and biofilm formation in three test groups were compared by biofilm assay and imaging techniques like microscopy (by safranin staining) and scanning electron microscopy. The three test groups were comprised of MCC-reinforced PMMA containing OPEFB fibers of 50-micrometer thickness at 5% weight reinforcement, conventionally and commercially available heat cure PMMA, and an empty well to assess any discrepancies from the environment.<br><br>RESULTS: The test groups showed increased biofilm formation by C. albicans compared to commercially and conventionally available heat cure PMMA. Reinforcement with MCC showed higher biofilm formation of 1.43 times higher compared to conventional PMMA. Biofilms formed by Candida albicans on MCC-reinforced PMMA appeared heterogeneous in structure, comprised of yeast cells and hyphae, surrounded by a higher density of polysaccharide extracellular matrix material compared to that of conventionally available heat cure PMMA.<br><br>CONCLUSION: Biofilm formation is increased in denture base resin incorporated with MCC. More investigation is warranted to study the antifungal efficacy of the addition of antifungal agents to the reinforced denture base resin.}, }
@article {pmid39182887, year = {2024}, author = {Ma, W and Yang, Y and Wang, W and Qv, J and Jia, J and Ren, X}, title = {Fabrication of N-halamine/MWPPy-ZnO hybrids based cellulose nanofibril composite films with improved UV-protective, antibacterial, and biofilm control functions.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {135023}, doi = {10.1016/j.ijbiomac.2024.135023}, pmid = {39182887}, issn = {1879-0003}, abstract = {The design and fabrication of synergistic hybrid antibacterial materials is a promising approach for achieving effective sterilization while compensating for the deficiency of a single component. Despite being highly effective biocidal components, the poor UV light stability of some N-halamines limits their applications. This study was conducted to address this issue by the rational integration of cyclic N-halamine precursor (PGHAPA) with microwaved zinc oxide (MWPPy-ZnO) nanoparticles via covalent bonds and the preparation of cellulose nanofibrils based antibacterial composite films after chlorination (CNF/MWPPy-ZnO-PGHAPA-Cl). The proposed films offered tight lamellar structure, considerable thermal stability and better mechanical properties. The results from the FT-IR and XPS experiments provided the evidence of chemical reactions among the PGHAPA, MWPPy-ZnO, and CNF film. Notably, the CNF/MWPPy-ZnO-PGHAPA-Cl films showed improved UV stability with a chlorine content of up to 0.16 % after 24 h of irradiation, which was much greater than that of the CNF/PGHAPA-Cl films. Furthermore, the CNF/MWPPy-ZnO-PGHAPA-Cl films displayed rapid bactericidal activity, inactivating all the contacted Staphylococcus aureus and Escherichia coli O157:H7 strains within 5 min, along with prominent biofilm disruption, indicating great potential for daily food packaging applications.}, }
@article {pmid39182856, year = {2024}, author = {A, J and Deepa, PM and Vergis, J and Rajasekhar, R and Habeeb, BP and David, PV and Bipin, KC and Anand, LF and Vijayakumar, K}, title = {Green synthesized silver nanoparticles from Ocimum sanctum: A potent inhibitor of biofilm forming ability and efflux pumps in bacteria causing bovine mastitis.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106883}, doi = {10.1016/j.micpath.2024.106883}, pmid = {39182856}, issn = {1096-1208}, abstract = {Therapeutic management of mastitis faces significant challenges due to multidrug resistance. In the present study, multi-drug-resistant (MDR) Staphylococcus spp, Klebsiella pneumoniae, and Escherichia coli were isolated from bovine clinical mastitis cases and the phenotypic and genotypic multidrug resistance profiling was carried out. Silver nanoparticles (AgNPs) were biosynthesized using Ocimum sanctum leaf extracts and characterized via UV Vis absorption, Fourier Transform Infrared Spectroscopy, X-ray diffraction studies, Energy dispersive spectroscopy and Electron Microscopy. The determined minimum inhibitory concentration and minimum bactericidal concentration of the AgNPs against the recovered MDR isolates were 62.5μg/ml and 125 μg/ml respectively. At a concentration of 50 μg/ml, the AgNPs demonstrated biofilm inhibitory activities of 80.35 % for MDR E. coli, 71.29 % for S. aureus and 60.18 % for MDR K. pneumoniae. Post-treatment observations revealed notable differences in biofilm formation across bacterial isolates. Furthermore, AgNP treatment led to significant downregulation of expression of the efflux pump genes acrB, acrE, acrF, and emrB in Gram-negative isolates and norB in Staphylococci isolates. This research underscores the potential for the development of an eco-friendly antimicrobial alternative in the form of green synthesized silver nanoparticles to combat drug resistance offering potential antibiofilm and efflux pump inhibitory activities.}, }
@article {pmid39182787, year = {2024}, author = {Zheng, X and Zhang, W and Wu, Y and Wu, J and Chen, Y and Long, M}, title = {Biodegradation of organosulfur with extra carbon source: Insights into biofilm formation and bacterial metabolic processes.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {175758}, doi = {10.1016/j.scitotenv.2024.175758}, pmid = {39182787}, issn = {1879-1026}, abstract = {Organosulfur compounds are prevalent in wastewater, presenting challenges for biodegradation, particularly in low-carbon environments. Supplementing additional carbon sources not only provides essential nutrients for microbial growth but also serves as regulators, influencing adaptive changes in biofilm and enhancing the survival of microorganisms in organosulfur-induced stress bioreactors. This study aims to elucidate the biodegradation of organosulfur under varying carbon source levels, placing specific emphasis on functional bacteria and metabolic processes. It has been observed that higher levels of carbon supplementation led to significantly improved total sulfur (TS) removal efficiencies, exceeding 83 %, and achieve a high organosulfur CH3SH removal efficiency of ~100 %. However, in the reactor with no external carbon source added, the oxidation end-product SO4[2-] accumulated significantly, surpassing 120 mEq/m[2]-day. Furthermore, the TB-EPS concentration consistently increasedwith the ascending glucose concentration. The analysis of bacterial community reveals the enrichment of functional bacteria involved in sulfur metabolism and biofilm formation (e.g. Ferruginibacter, Rhodopeudomonas, Gordonia, and Thiobacillus). Correspondingly, the gene expressions related to the pathway of organosulfur to SO4[2-] were notably enhanced (e.g. MTO increased by 27.7 %). In contrast, extra carbon source facilitated the transfer of organosulfur into amino acids in sulfur metabolism and promoted assimilation. These metabolic insights, coupled with kinetic transformation results, further validate distinct sulfur pathways under different carbon source conditions. The intricate interplay between bacteria growth regulation, pollutant biodegradation, and microbial metabolites underscores a complex network relationship that significantly contributes to efficient operation of bioreactors.}, }
@article {pmid39181904, year = {2024}, author = {Udayagiri, H and Sana, SS and Dogiparthi, LK and Vadde, R and Varma, RS and Koduru, JR and Ghodake, GS and Somala, AR and Boya, VKN and Kim, SC and Karri, RR}, title = {Phytochemical fabrication of ZnO nanoparticles and their antibacterial and anti-biofilm activity.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {19714}, pmid = {39181904}, issn = {2045-2322}, mesh = {*Zinc Oxide/chemistry/pharmacology ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Biofilms/drug effects ; *Metal Nanoparticles/chemistry ; *Escherichia coli/drug effects ; *Microbial Sensitivity Tests ; *Klebsiella pneumoniae/drug effects ; Plant Extracts/chemistry/pharmacology ; Phytochemicals/pharmacology/chemistry ; X-Ray Diffraction ; Spectroscopy, Fourier Transform Infrared ; }, abstract = {The synthesis of metal nanoparticles through bio-reduction is environmentally benign and devoid of impurities, which is very important for biological applications. This method aims to improve ZnO nanoparticle's antibacterial and anti-biofilm activity while reducing the amount of hazardous chemicals used in nanoparticle production. The assembly of zinc oxide nanoparticles (ZnO NPs) is presented via bio-reduction of an aqueous zinc nitrate solution using Echinochloacolona (E. colona) plant aqueous leaf extract comprising various phytochemical components such as phenols, flavonoids, proteins, and sugars. The synthesized nano ZnO NPs are characterized by UV-visible spectrophotometer (UV-vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (X-RD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental composition by energy-dispersive x-ray spectroscopy (EDX). The formation of biosynthesized ZnO nanoparticles was confirmed by the absorbance at 360-370 nm in the UV-vis spectrum. The average crystal size of the particles was found to be 15.8 nm, as calculated from XRD. SEM and TEM analysis of prepared ZnO NPs confirmed the spherical and hexagonal shaped nanoparticles. ZnO NPs showed antibacterial activity against Escherichia coli and Klebsiella pneumoniae with the largest zone of inhibition (ZOI) of 17 and 18 mm, respectively, from the disc diffusion method. Furthermore, ZnO NPs exhibited significant anti-biofilm activity in a dose-dependent manner against selected bacterial strains, thus suggesting that ZnO NPs can be deployed in the prevention of infectious diseases and also used in food preservation.}, }
@article {pmid39181514, year = {2024}, author = {Wang, T and Han, X and Cheng, Y and Yang, J and Bai, L and Zeng, W and Wang, H and Cheng, N and Zhang, H and Li, G and Liang, H}, title = {Insights into the azo dye decolourisation and denitrogenation in micro-electrolysis enhanced counter-diffusion biofilm system.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131333}, doi = {10.1016/j.biortech.2024.131333}, pmid = {39181514}, issn = {1873-2976}, abstract = {In this study, electron transport pathways were activated and diversified by coupling counter-diffusion biofilms with micro-electrolysis for Alizarin yellow R (AYR) denitrogenation. Due to the binding of AYR to two residues of EC 4.1.3.36 with higher binding energy, the expression of EC 4.1.3.36 was down-regulated, causing the EC 3.1.2.28 and EC 2.5.1.74 for menaquinone synthesis (redox mediator) undetectable in Membrane aerated biofilm reactors (MABR). Spontaneous electron generation in the micro electrolysis-coupled MABR (ME-MABR) significantly activated two enzymes. Activated menaquinone up-regulated decolourisation related genes expression in ME-MABR, including azoR (2.12 log2), NQO1 (2.97 log2), wrbA (0.45 log2), and ndh (0.47 log2). The diversified electron flow pathways also promoted the nitrogen metabolism coding genes up-regulation, accelerating further inorganic nitrogen denitrogenation after AYR mineralisation. Compared to MABR, the decolourisation, mineralisation, and denitrogenation in ME-MABR increased by 25.80 %, 16.53 %, and 13.32 %, respectively. This study provides new insights into micro-electrolysis enhanced removal of AYR.}, }
@article {pmid39181432, year = {2024}, author = {Lu, C and Zhang, YY and Peng, SM and Gu, M and Wong, HM}, title = {Effects of graphene oxide and graphene quantum dots on enhancing CPP-ACP anti-caries ability of enamel lesion in a biofilm-challenged environment.}, journal = {Journal of dentistry}, volume = {}, number = {}, pages = {105319}, doi = {10.1016/j.jdent.2024.105319}, pmid = {39181432}, issn = {1879-176X}, abstract = {OBJECTIVE: To investigate the anticaries effects of graphene oxide (GO) and graphene quantum dots (GQDs) combined with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on enamel in a biofilm-challenged environment.<br><br>MATERIAL AND METHODS: GO and GQDs were synthesised using citric acid. The antibiofilm and biofilm inhibition effects for Streptococcus mutans were evaluated by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and colony-forming units (CFU). Remineralisation ability was determined by assessing mineral loss, calcium-to-phosphorus ratio, and surface morphology. To create a biofilm-challenged environment, enamel blocks were immersed in S. mutans to create the lesion and then subjected to artificial saliva/biofilm cycling for 7 days. Anticaries effects of GO, GQDs, GQDs@CPP-ACP, GO@CPP-ACP, and CPP-ACP were determined by broth pH and mineral changes after 7-day pH cycling. Biocompatibility was tested using a Cell Counting Kit-8 (CCK8) assay for human gingival fibroblasts (HGF-1).<br><br>RESULTS: GQDs and GO presented significant antibiofilm and biofilm inhibition effects compared to the CPP-ACP and control groups (P<0.05). The enamel covered by GQDs and GO showed better crystal structure formation and less mineral loss (P<0.05) than that covered by CPP-ACP alone. After 7 days in the biofilm-challenged environment, the GO@CPP-ACP group showed less lesion depth than the CPP-ACP and control groups (P<0.05). GO and GQDs showed good biocompatibility compared to the control group by CCK8 (P>0.05) within 3 days.<br><br>CONCLUSION: GO and GQDs could improve the anti-caries effects of CPP-ACP, and CPP-ACP agents with GO or GQDs could be a potential option for enamel lesion management.<br><br>CLINICAL SIGNIFICANCE: GO and GQDs have demonstrated the potential to significantly enhance the anticaries effects of CPP-ACP. Incorporating these nanomaterials into CPP-ACP formulations could provide innovative and effective options for the management of enamel lesions, offering improved preventive and therapeutic strategies in dental care.}, }
@article {pmid39180785, year = {2024}, author = {Aniba, R and Dihmane, A and Raqraq, H and Ressmi, A and Nayme, K and Timinouni, M and Barguigua, A}, title = {Exploring staphylococcus in urinary tract infections: A systematic review and meta-analysis on the epidemiology, antibiotic resistance and biofilm formation.}, journal = {Diagnostic microbiology and infectious disease}, volume = {110}, number = {4}, pages = {116470}, doi = {10.1016/j.diagmicrobio.2024.116470}, pmid = {39180785}, issn = {1879-0070}, abstract = {This study aimed to determine the epidemiology, biofilm formation and antibiotic resistance of staphylococci collected worldwide in the context of UTIs. This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Forty studies from 23 countries were selected for quantitative review. Electronic databases (PubMed, Scopus, Google Scholar, and Web of Sciences) were searched for articles published between 2010 and 2024 on the epidemiology, biofilm formation, and antibiotic resistance of uropathogenic staphylococci. Strict inclusion and exclusion standards were applied during the review of the articles. Forty articles were included in this systematic review. The prevalence of uropathogenic staphylococci varies from country to country, with the pooled prevalence of S. aureus and coagulase-negative staphylococci (CoNS) being 8.71 % (95 %CI: 6.145-11.69) and 13.17 % (95 %CI: 8.08-19.27) respectively. Among CoNS isolates, S. epidermidis was the most common with 19.3 % (95 %CI: 5.88-38.05). The prevalence of methicillin-resistant S. aureus isolates increased significantly from 23 % in 2010-2015 to 47 % in 2021-2024 (p = 0.03). S. haemolyticus is the most antibiotic-resistant species in CoNS, with 45 % of isolates resistant to methicillin, 33 % to gentamicin, and 29 % to tetracycline. Eighty-eight S. aureus strains were biofilm producers, including 35 % moderate biofilm producers and 48 % strong biofilm producers. The combined frequencies of icaA, clfA and fnbpA were 100, 99, and 89 %, respectively. The development of antibiotic resistance and biofilm formation by staphylococci involved in UTIs explains the need for periodic regional surveillance of these infections, which poses a serious public health problem.}, }
@article {pmid39179305, year = {2024}, author = {Reigh, EL}, title = {STAPH: The Biofilm.}, journal = {Annals of allergy, asthma &amp; immunology : official publication of the American College of Allergy, Asthma, &amp; Immunology}, volume = {133}, number = {3}, pages = {284-285}, doi = {10.1016/j.anai.2024.04.012}, pmid = {39179305}, issn = {1534-4436}, mesh = {*Biofilms ; Humans ; Staphylococcus aureus ; Staphylococcal Infections ; }, }
@article {pmid39178800, year = {2024}, author = {Kuriki, N and Asahi, Y and Okamoto, M and Noiri, Y and Ebisu, S and Machi, H and Suzuki, M and Hayashi, M}, title = {Synergistic effects of arginine and fluoride on human dental biofilm control.}, journal = {Journal of dentistry}, volume = {149}, number = {}, pages = {105307}, doi = {10.1016/j.jdent.2024.105307}, pmid = {39178800}, issn = {1879-176X}, abstract = {OBJECTIVES: The aim of this study was to quantitatively and comprehensively investigate the combined effects of arginine and fluoride on the suppression of pathogenicity using an in situ biofilm model and next-generation sequencing (NGS).<br><br>METHODS: Using the in situ model, dental biofilms were formed and the viable bacterial counts and arginine activity in the arginine- and fluoride-containing dentifrice and control groups were measured. We also compared their effects on the bacterial microbiota and predictive functional factors in the control, arginine (arg), and arginine + fluoride (argF) groups using NGS analysis.<br><br>RESULTS: Compared to the control treatment, the use of 8 % arginine and 1450 ppm fluoride toothpaste resulted in significantly high oral NH4[+] concentrations without affecting the number of viable bacteria (P < 0.05). NGS analysis revealed that the oral microbiota of the control, arg, and argF groups were significantly different. Heat map analysis of the predicted functional factors revealed that the arg group had different properties from the other groups and activated specific substrate metabolic pathways; contrastingly, argF treatment inhibited the activity of these pathways and prevented an increase in the abundance of bacterial genera that utilize substrates such as sucrose, suggesting the synergistic effect of arginine and fluoride.<br><br>CONCLUSIONS: This study indicates that the combination of arginine and fluoride has a synergistic effect on the bacterial microbiota and pathogenicity of dental biofilms compared with arginine alone.<br><br>CLINICAL SIGNIFICANCE: Our findings suggest that the combination of arginine and fluoride could be used as an effective prebiotic and may inhibit the growth of bacteria associated with dental diseases.}, }
@article {pmid39178688, year = {2024}, author = {Jia, D and Zou, Y and Zhang, Y and Xu, H and Yang, W and Zheng, X and Zhang, Y and Yu, Q}, title = {A self-supplied hydrogen peroxide and nitric oxide-generating nanoplatform enhances the efficacy of chemodynamic therapy for biofilm eradication.}, journal = {Journal of colloid and interface science}, volume = {678}, number = {Pt A}, pages = {20-29}, doi = {10.1016/j.jcis.2024.08.148}, pmid = {39178688}, issn = {1095-7103}, abstract = {Bacterial biofilms present a profound challenge to global public health, often resulting in persistent and recurrent infections that resist treatment. Chemodynamic therapy (CDT), leveraging the conversion of hydrogen peroxide (H2O2) to highly reactive hydroxyl radicals (•OH), has shown potential as an antibacterial approach. Nonetheless, CDT struggles to eliminate biofilms due to limited endogenous H2O2 and the protective extracellular polymeric substances (EPS) within biofilms. This study introduces a multifunctional nanoplatform designed to self-supply H2O2 and generate nitric oxide (NO) to overcome these hurdles. The nanoplatform comprises calcium peroxide (CaO2) for sustained H2O2 production, a copper-based metal-organic framework (HKUST-1) encapsulating CaO2, and l-arginine (l-Arg) as a natural NO donor. When exposed to the acidic microenvironment within biofilms, the HKUST-1 layer decomposes, releasing Cu[2+] ions and l-Arg, and exposing the CaO2 core to initiate a cascade of reactions producing reactive species such as H2O2, •OH, and superoxide anions (•O2[-]). Subsequently, H2O2 catalyzes l-Arg to produce NO, which disperses the biofilm and reacts with •O2[-] to form peroxynitrite, synergistically eradicating bacteria with •OH. In vitro assays demonstrated the nanoplatform's remarkable antibiofilm efficacy against both Gram-positive Methicillin-resistant Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa, significantly reducing bacterial viability and EPS content. In vivo mouse model experiments validated the nanoplatform's effectiveness in eliminating biofilms and promoting infected wound healing without adverse effects. This study represents a breakthrough in overcoming traditional CDT limitations by integrating self-supplied H2O2 with NO's biofilm-disrupting capabilities, offering a promising therapeutic strategy for biofilm-associated infection.}, }
@article {pmid39178662, year = {2024}, author = {Her, E and Han, S and Ha, SD}, title = {Development of poly(lactic acid)-based natural antimicrobial film incorporated with caprylic acid against Salmonella biofilm contamination in the meat industry.}, journal = {International journal of food microbiology}, volume = {425}, number = {}, pages = {110871}, doi = {10.1016/j.ijfoodmicro.2024.110871}, pmid = {39178662}, issn = {1879-3460}, abstract = {Using a solvent-casting method, a poly(lactic acid) (PLA) film incorporated with caprylic acid (CA) was developed as an active packaging against Salmonella enterica ser. Typhimurium and S. enteritidis to reduce the risk of microbial contamination during distribution and storage of meat. According to the minimum inhibitory concentration (MIC) test results of the natural antimicrobial, CA was introduced at 0.6, 1.2, 2.4, and 4.8 % (v/v) into neat PLA. The biofilm inhibitory effect and antimicrobial efficacy of CA-PLA film against both Salmonella strains, as well as the intermolecular interactions and barrier properties of CA-PLA film, were evaluated. Biofilm formation was reduced to below the detection limit (<1.0 log CFU/cm[2]) for both S. typhimurium and S. enteritidis when co-cultured overnight with 4.8 % CA-PLA film. The 4.8 % CA-PLA film achieved maximum log reductions of 2.58 and 1.65 CFU/g for S. typhimurium and 2.59 and 1.76 CFU/g for S. enteritidis on inoculated chicken breast and beef stored at 25 °C overnight, respectively, without any quality (color and texture) losses. CA maintained its typical chemical structure in the film, as confirmed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra. Furthermore, film surface morphology observations by field emission scanning electron microscopy (FESEM) showed that CA-PLA film was smoother than neat PLA film. No significant (P > 0.05) changes were observed for water vapor permeability and oxygen permeability by the addition of CA into PLA film, suggesting that CA-PLA film is a promising strategy for active packaging to control Salmonella contamination in the meat industry.}, }
@article {pmid39176452, year = {2024}, author = {Berking, BB and Rijpkema, SJ and Zhang, BHE and Sait, A and Amatdjais-Groenen, H and Wilson, DA}, title = {Biofilm Disruption from within: Light-Activated Molecular Drill-Functionalized Polymersomes Bridge the Gap between Membrane Damage and Quorum Sensing-Mediated Cell Death.}, journal = {ACS biomaterials science &amp; engineering}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsbiomaterials.4c01177}, pmid = {39176452}, issn = {2373-9878}, abstract = {Bacterial biofilms represent an escalating global health concern with the proliferation of drug resistance and hospital-acquired infections annually. Numerous strategies are under exploration to combat biofilms and preempt the development of antibacterial resistance. Among these, mechanical disruption of biofilms and enclosed bacteria presents a promising avenue, aiming to induce membrane permeabilization and consequent lethal damage. Herein, we introduce a hemithioindigo (HTI) motor activated by visible light, capable of disrupting sessile bacteria when integrated into a polymeric vesicle carrier. Under visible light, bacteria exhibited a notable outer membrane permeability, reduced membrane fluidity, and diminished viability following mechanical drilling. Moreover, various genetic responses pertaining to the cell envelope were examined via qRT-PCR, alongside the activation of a self-lysis mechanism associated with phage stress, which was coupled with increases in quorum sensing, demonstrating a potential self-lysis cascade from within. The multifaceted mechanisms of action, coupled with the energy efficiency of mechanical damage, underscore the potential of this system in addressing the challenges posed by pathogenic biofilms.}, }
@article {pmid39174958, year = {2024}, author = {Hashim, A and Kheir El Din, NH and El-Khazragy, N and Almalahy, HG}, title = {Comparison of the efficacy of Er,Cr:YSGG laser on oral biofilm removal from implant surfaces with various application times for the treatment of peri-implantitis defects: ex vivo study.}, journal = {BMC oral health}, volume = {24}, number = {1}, pages = {980}, pmid = {39174958}, issn = {1472-6831}, mesh = {Humans ; *Biofilms ; Decontamination/methods ; *Dental Implants/microbiology ; Dental Plaque/microbiology/therapy ; *Lasers, Solid-State/therapeutic use ; *Peri-Implantitis/microbiology/therapy ; Surface Properties ; }, abstract = {PURPOSE: The major struggle in peri-implantitis therapy is the availability of successful decontamination of the infected implant surface. The main hypothesis of this study was the Er,Cr: YSGG laser decontamination efficacy investigation on the infected implant surfaces with various peri-implantitis defects. The primary objective of this study was to decide the efficacy of Er,Cr:YSGG laser as a decontamination tool at various peri-implantitis simulating defects. The secondary objective was to compare the efficacy of the Er,Cr: YSGG laser on oral biofilm removal between two protocols the first protocol (4 cycles at 2.5 min) and the second protocol (5 cycles at 5 min) at various peri-implantitis simulating defects.<br><br>MATERIALS AND METHODS: A total of 3 subjects whose plaque biofilms formed in-vivo on twenty-four tested implants were divided into four tested groups. Two native implants were tested as controls.The in vitro defect model was computer-aided designed and printed into a 3D-printed model with various anulations in peri-implant infrabony defects, which were 15,30,60,and 90 degrees.<br><br>RESULTS: Both Er, Cr: YSGG decontamination protocols at 50&#xa0;mJ (1.5 W/30&#xa0;Hz), 50% air, and 40% water were effective at reducing the total implant surface area/ biofilm ratio (%), but the second protocol had a markedly greater reduction in the duration of application (5 cycles at 5&#xa0;min) than did the first protocol (4 cycles at 2.5&#xa0;min).<br><br>CONCLUSION: The Er, Cr: YSGG laser is an effective decontamination device in various peri-implantitis defects. The second protocol(5 cycles at 5&#xa0;min) with greater application time and circles is more effective than the first one. The defect angulation influence the decontamination capability in peri-implantitis therapy.<br><br>Clinicians anticipate that the exploration of suitable therapeutic modalities for peri-implantitis therapy is limited by the obvious heterogeneity of the available evidence in the literature and need for a pre-clinical theoretical basis setup. The major challenges associated with peri-implantitis therapy include the successful decontamination of the infected implant surface, the absence of any damage to the treated implant surface with adequate surface roughness, and the biocompatibility of the implant surface, which allows osteoblastic cells to grow on the treated surface and is the key for successful re-osseointegration. Therefore, these are the expected empirical triads that need to be respected for successful peri-implantitis therapy. Failure of one of the triads represents a peri-implantitis therapeutic failure. The Er, Cr: YSGG laser is regarded as one of the expected devices for achieving the required triad.<br><br>TRIAL REGISTRATION: "Efficacy of Er,Cr YSGG Laser in Treatment of Peri-implantitis".<br><br>CLINICALTRIALS: gov ID NCT05137821. First Posted date: 30 -11-2021.}, }
@article {pmid39173960, year = {2024}, author = {Hou, Z and Dong, W and Wang, H and Zhao, Z and Li, Y and Liu, H and Shi, K and Liang, Q and Peng, Y}, title = {Rapid start-up of mainstream partial denitrification /anammox and enhanced nitrogen removal through inoculation of precultured biofilm for treating low-strength municipal sewage.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131320}, doi = {10.1016/j.biortech.2024.131320}, pmid = {39173960}, issn = {1873-2976}, abstract = {This study investigated the rapid start-up of mainstream partial denitrification coupled with anammox (PD/A) and nitrogen removal performance by inoculating precultured PD/A biofilm. The results showed mainstream PD/A in the anaerobic-anoxic-aerobic (A[2]O) process was rapidly established within 30 days. Nitrogen removal efficiency (NRE) improved by 23.8 % contrasted to the traditional A[2]O process. The mass balance showed that anammox contribution to total nitrogen (TN) removal were maintained at 37.9 %∼55.7 %, and reducing hydraulic retention time (HRT) strengthened simultaneously denitrification and anammox activity. The microbial community showed that the dominant bacteria such as denitrifying bacteria (DNBs) and glycogen accumulating organisms (GAOs) both in biofilm and flocculent sludge (floc), integrating with anammox bacteria (AnAOB) in biofilm might lead to enhanced nitrogen removal. Overall, this study offered a fast start-up strategy of mainstream PD/A with enhanced nitrogen removal, which are valuable for upgradation and renovation of existed municipal wastewater treatment plants (WWTPs).}, }
@article {pmid39173494, year = {2024}, author = {Hemmati, YB and Bahrami, R and Pourhajibagher, M}, title = {Assessing the physico-mechanical, anti-bacterial, and anti-demineralization properties of orthodontic resin composite containing different concentrations of photoactivated zinc oxide nanoparticles on Streptococcus mutans biofilm around ceramic and metal orthodontic brackets: An ex vivo study.}, journal = {International orthodontics}, volume = {22}, number = {4}, pages = {100901}, doi = {10.1016/j.ortho.2024.100901}, pmid = {39173494}, issn = {1879-680X}, abstract = {BACKGROUND AND PURPOSE: The aim of this study was to evaluate the physico-mechanical, anti-bacterial, and anti-demineralization properties of orthodontic resin composite containing photoactivated zinc oxide nanoparticles (ZnONPs) on Streptococcus mutans biofilm around ceramic and metal brackets.<br><br>MATERIAL AND METHODS: Following the minimum inhibitory concentration (MIC) determination for ZnONPs, shear bond strength (SBS) was tested for composites containing different concentrations of ZnONPs. The chosen concentration was used to evaluate the microleakage, anti-bacterial, and anti-demineralization properties.<br><br>RESULTS: Adding 50&#x3bc;g/mL of ZnONPs to the orthodontic composite did not negatively affect its physico-mechanical properties. ZnONPs (50&#x3bc;g/mL)-mediated aPDT and 0.2% chlorhexidine significantly (P=0.000) reduced S.&#xa0;mutans biofilms compared to the phosphate-buffered saline (PBS) groups (metal/PBS=7.47&#xb1;0.7&#xd7;10[6], and ceramic/PBS=7.47&#xb1;0.7&#xd7;10[6]), with the lowest colony count observed in these groups (metal/chlorhexidine=1.06&#xb1;0.4&#xd7;10[5], ceramic/chlorhexidine=1&#xb1;0.2&#xd7;10[5], metal/ZnONPs-mediated aPDT=1.33&#xb1;0.3&#xd7;10[5], and ceramic/ZnONPs-mediated aPDT=1.2&#xb1;0.3&#xd7;10[5]). Sodium fluoride varnish and ZnONPs-mediated aPDT showed the highest efficacy in anti-demineralization and significantly improving the enamel surface microhardness compared to the artificial saliva, especially in ceramic bracket groups (524.17&#xb1;42.78N and 441.00&#xb1;29.48N, 394.17&#xb1;46.83N, P=0.000, and P=0.003, respectively).<br><br>CONCLUSION: ZnONPs (50&#x3bc;g/mL)-mediated aPDT effectively inhibited S.&#xa0;mutans biofilm and promoted anti-demineralization without adverse effects on the physico-mechanical properties of the composite resin. These results suggest the potential of this method in preventing white spot lesions during orthodontic treatment.}, }
@article {pmid39170400, year = {2024}, author = {Rossetti, AP and Perpetuini, G and Tofalo, R}, title = {Sniffing the wine differences: The role of Starmerella bacillaris biofilm-detached cells.}, journal = {Heliyon}, volume = {10}, number = {15}, pages = {e35692}, pmid = {39170400}, issn = {2405-8440}, abstract = {This study investigated the impact of 10 strains of Starmerella bacillaris, co-inoculated as planktonic or biofilm-detached cells with Saccharomyces cerevisiae, on the volatilome of a red wine. The wines produced with St. bacillaris biofilm-detached cells exhibited a greater concentration of glycerol and a lower quantity of ethanol than the other wines. Furthermore, these wines exhibited elevated levels of higher alcohols, organic acids, esters, terpenes, and norisoprenoids. Based on the odor activity value and relative odor contribution, isoamyl acetate, ethyl octanoate, ethyl isobutanoate, and methyl decanoate were the main aroma components of wines made with planktonic cells. The main compounds characterizing the wines obtained with biofilm-detached cells were: phenethyl alcohol, β-damascenone, citronellol, β-ionone, and nerol. The sensory analysis revealed that the wines produced with biofilm-detached cells had higher scores for mouth-feel, spicy, floral, and raspberry notes than the others. The present study provides evidence that St. bacillaris biofilm-detached cells released specific volatile compounds in red wines.}, }
@article {pmid39169973, year = {2024}, author = {Sultan, AM and Mahmoud, NM}, title = {Detection of resistance integrons among biofilm and non-biofilm producing clinical isolates of Pseudomonas aeruginosa.}, journal = {Germs}, volume = {14}, number = {1}, pages = {11-19}, pmid = {39169973}, issn = {2248-2997}, abstract = {INTRODUCTION: Integrons are genetic systems that may confer antibiotic resistance to Pseudomonas aeruginosa. Biofilm formation can facilitate gene exchange and can accelerate the development of antibiotic resistance. The aim of this work was to assess the distribution of resistance integrons including class 1, 2 and 3 among biofilm- and non-biofilm producing clinical strains of P. aeruginosa. We also aimed to investigate the relationship between the existence of these integrons and the isolates' resistance patterns.<br><br>METHODS: Specimens were obtained from patients showing evidence of infection. P. aeruginosa isolates were identified using conventional techniques, while disk diffusion test was used to detect their antimicrobial susceptibilities. Biofilm formation was detected by the tissue culture plate technique, while classes of integrons were detected by polymerase chain reaction.<br><br>RESULTS: Out of 106 P. aeruginosa isolates, 55.7% were class 1 integron-positive while 19.8% were class 2 integron-positive. However, class 3 integrons were not detected. Significant associations were found between class 1 integrons and resistance toward amikacin, gentamicin, cefepime, ceftazidime and ciprofloxacin. Class 2 integrons were associated with amikacin, ceftazidime and cefepime resistance. Of pseudomonal isolates, 61.3% were biofilm producing. Biofilm production was associated significantly with the existence of class 1 integrons (p<0.001) and class 2 integrons (p=0.039).<br><br>CONCLUSIONS: About two thirds of isolated strains harbored resistance integrons, which emphasized their significance in our locality. The frequencies of class 1 and 2 integrons were significantly higher among biofilm forming isolates. Ongoing surveillance and infection control strategies are necessary to limit spread of integrons.}, }
@article {pmid39169088, year = {2024}, author = {Zacher, AT and Mirza, K and Thieme, L and Nietzsche, S and Senft, C and Schwarz, F}, title = {Biofilm formation of Staphylococcus aureus on various implants used for surgical treatment of destructive spondylodiscitis.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {19364}, pmid = {39169088}, issn = {2045-2322}, mesh = {*Biofilms/growth &amp; development ; *Staphylococcus aureus/physiology/drug effects ; Humans ; *Discitis/microbiology/surgery ; *Titanium ; *Prostheses and Implants/microbiology ; Staphylococcal Infections/microbiology ; Polymers/chemistry ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Bacterial Adhesion ; Bone Cements ; Benzophenones ; Polyethylene Glycols/chemistry ; Ketones ; }, abstract = {The incidence of spondylodiscitis has witnessed a significant increase in recent decades. Surgical intervention becomes necessary in case of bone destruction to remove infected tissue and restore spinal stability, often involving the implantation of a cage. Despite appropriate treatment, relapses occur in up to 20 percent of cases, resulting in substantial economic and social burdens. The formation of biofilm has been identified as a major contributor to relapse development. Currently, there is no consensus among German-speaking spinal surgeons or in the existing literature regarding the preferred choice of material to minimize relapse rates. Thus, the objective of this study is to investigate whether certain materials used in spinal implants exhibit varying degrees of susceptibility to bacterial attachment, thereby providing valuable insights for improving treatment outcomes.Eight cages of each PEEK, titanium-coated PEEK (Ti-PEEK), titanium (Ti), polyetherketoneketone (PEKK), tantalum (Ta) and antibiotic-loaded bone cement were incubated with 20% human plasma for 24 h. Subsequently, four implants were incubated with S. aureus for 24 h or 48 h each. The biofilm was then removed by sonication and the attained solution plated for Colony Forming Units (CFU) counting. Scanning electron microscopy was used to confirm bacterial attachment. The CFUs have been compared directly and in relation to the cages surface area. The surface area of the implants was PEEK 557 mm[2], Ti-PEEK 472 mm[2], Ti 985 mm[2], PEKK 594 mm[2], Ta 706 mm[2], bone cement 123 mm[2]. The mean CFU count per implant and per mm[2] surface area after 24 h and after 48 h was calculated. Bone cement was found to have significantly more CFUs per mm[2] surface area than the other materials tested. When comparing the CFU count per implant, bone cement was statistically significantly more prone to biofilm formation than PEEK after 48 h. There was no statistical significance between the other materials when comparing both CFU count per mm[2] surface area and CFU count per implant. The electron microscopic analysis showed the attachment of the bacteria, as well as production of extracellular polymeric substances (EPS) as a sign for beginning biofilm formation. Antibiotic-loaded bone cement has shown statistically significantly more bacterial attachment than the other examined materials. No difference was found between the other materials regarding bacterial attachment after 24 h and 48 h. Proposed hypotheses for further studies include testing whether differences become apparent after longer incubation or with different pathogens involved in the pathogenesis of pyogenic spondylodiscitis.}, }
@article {pmid39168436, year = {2024}, author = {Qi, R and Qian, C and Wang, Y}, title = {Biofilm formation on MgFe-LDH@quartz sand as novel wetland substrate under varied C/N ratios for BDE-47 removal.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {}, number = {}, pages = {124779}, doi = {10.1016/j.envpol.2024.124779}, pmid = {39168436}, issn = {1873-6424}, abstract = {Layered double hydroxide (LDH)-coated substrates could enhance the removal of various wastewater-born pollutants. However, research on biofilms attached to LDH-coatings and their synergistic purification effects on strongly hydrophobic persistent organic pollutants (POPs) remains limited. This study aims to investigate biofilm formation on MgFe-LDH@quartz sand and its effectiveness in removing tetrabromodiphenyl ether (BDE-47), an emerging halogenated POP in municipal wastewater. Under different C/N ratios (3, 5, and 10), BDE-47 removal rates ranged from 28.0% to 41.6% after 72 h. The optimal performance was achieved with LDH coating at C/N=5, when substrate biofilm reached its highest extracelluar polymer substances (EPS) content, dehydrogenase activity and relative hydrophobicity. Moreover, distinct distribution patterns of EPS components' fluorescence peaks were observed in the LDH-coating treatment using three dimensional excitation-emission matrix (3D-EEM). While substrate adsorption was the primary mechanism for BDE-47 removal, accounting for 59.6% to 83.4% of the total, biofilm adsorption and degradation contributed a relatively lower amount, ranging from 11.5% to 21.4%, and were more dependent on the C/N ratio. Notably, the maximum carrying capacity of protein predicted by the logistic growth model exhibited a strong positive correlation with the total BDE-47 removal rate (R[2]=0.82, p<0.05), highlighting the importance of biofilm extracelluar proteins.}, }
@article {pmid39167960, year = {2024}, author = {Nasu, T and Maeda, S}, title = {Escherichia coli persisters in biofilm can perform horizontal gene transfer by transformation.}, journal = {Biochemical and biophysical research communications}, volume = {738}, number = {}, pages = {150549}, doi = {10.1016/j.bbrc.2024.150549}, pmid = {39167960}, issn = {1090-2104}, abstract = {Persisters represent a subset of cells that exhibit transient tolerance to antimicrobials. These persisters can withstand sudden exposure to antimicrobials, even as the majority of normal cells perish. In this study, we have demonstrated the capacity of ampicillin-tolerant and alkali-tolerant persisters to execute horizontal gene transfer via in situ transformation within biofilms. Air-solid biofilms, comprising two Escherichia coli populations each with a distinct plasmid, were formed on agar media. They were treated with lethal doses of ampicillin or NaOH for 24 h, followed by a 1-min glass-ball roll. This process led to a high frequency of horizontal plasmid transfer (10[-7]-10[-6] per cell) from dead cells to surviving persisters within the biofilms. Plasmid transfer was DNase-sensitive and also occurred by adding purified plasmid DNA to plasmid-free biofilms, demonstrating a transformation mechanism. This marks the first evidence of persisters' novel ability for horizontal gene transfer, via transformation.}, }
@article {pmid39168903, year = {2024}, author = {Evangeline, WP and Rajalakshmi, E and Mahalakshmi, S and Ramya, V and Devkiran, B and Saranya, E and Ramya, M}, title = {Impact of eugenol on biofilm development in Shigella flexneri 1457: a plant terpenoid based-approach to inhibit food-borne pathogen.}, journal = {Archives of microbiology}, volume = {206}, number = {9}, pages = {384}, pmid = {39168903}, issn = {1432-072X}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Shigella flexneri/drug effects/genetics/growth &amp; development/physiology ; *Eugenol/pharmacology ; *Anti-Bacterial Agents/pharmacology ; Quorum Sensing/drug effects ; Microbial Sensitivity Tests ; Dysentery, Bacillary/drug therapy/microbiology ; Terpenes/pharmacology ; }, abstract = {Shigella flexneri is a gram-negative bacterium responsible for shigellosis and bacterial dysentery. Despite using various synthetic antimicrobial agents and antibiotics, their efficacy is limited, prompting concerns over antibiotic resistance and associated health risks. This study investigated eugenol, a polyphenol with inherent antioxidant and antibacterial properties, as a potential alternative treatment. We aimed to evaluate eugenol's antibacterial effects and mechanisms of action against S. flexneri and its impact on biofilm formation. We observed significant growth suppression of S. flexneri with eugenol concentrations of 8-10 mM (98.29%). Quantitative analysis using the Crystal Violet assay demonstrated a marked reduction in biofilm formation at 10 mM (97.01 %). Assessment of Cell Viability and morphology via Fluorescence-Activated Cell Sorting and Scanning Electron Microscopy confirmed these findings. Additionally, qPCR analysis revealed the downregulation of key genes responsible for adhesion (yebL), quorum sensing (rcsC, sdiA), and EPS production (s0482) associated with bacterial growth and biofilm formation. The present study suggests eugenol could offer a promising alternative to conventional antibiotics for treating shigellosis caused by S. flexneri.}, }
@article {pmid39166876, year = {2024}, author = {de Palma, TH and Powers, C and McPartland, MJ and Mark Welch, J and Ramsey, M}, title = {Essential genes for Haemophilus parainfluenzae survival and biofilm growth.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0067424}, doi = {10.1128/msystems.00674-24}, pmid = {39166876}, issn = {2379-5077}, abstract = {Haemophilus parainfluenzae (Hp) is a Gram-negative, highly prevalent, and abundant commensal in the human oral cavity, and an infrequent extraoral opportunistic pathogen. Hp occupies multiple niches in the oral cavity, including the supragingival plaque biofilm. Little is known about how Hp interacts with its neighbors in healthy biofilms nor its mechanisms of pathogenesis as an opportunistic pathogen. To address this, we identified the essential genome and conditionally essential genes in in vitro biofilms aerobically and anaerobically. Using transposon insertion sequencing (TnSeq) with a highly saturated mariner transposon library in two strains, the ATCC33392 type-strain (Hp 392) and oral isolate EL1 (Hp EL1), we show that the essential genomes of Hp 392 and Hp EL1 are composed of 395 (20%) and 384 (19%) genes, respectively. The core essential genome, consisting of 341 (17%) essential genes conserved between both strains, was composed of genes associated with genetic information processing, carbohydrate, protein, and energy metabolism. We also identified conditionally essential genes for aerobic and anaerobic biofilm growth, which were associated with carbohydrate and energy metabolism in both strains. RNAseq analysis determined that most genes upregulated during anaerobic growth are not essential for Hp 392 anaerobic survival. The completion of this library and analysis under these conditions gives us a foundational insight into the basic biology of H. parainfluenzae in differing oxygen conditions, similar to its in vivo habitat. This library presents a valuable tool for investigation into conditionally essential genes for an organism that lives in close contact with many microbial species in the human oral habitat.IMPORTANCEHaemophilus parainfluenzae is a highly abundant human commensal microbe, present in most healthy individuals where it colonizes the mouth. H. parainfluenzae correlates with good oral health and may play a role in preservation of healthy host status. Also, H. parainfluenzae can cause opportunistic infections outside of the oral cavity. To date, little is known about how H. parainfluenzae colonizes the human host, despite being such a frequent and abundant part of our human microbiome. Here, we demonstrate the creation and use of a powerful tool, a TnSeq library, used to identify genes necessary for both the outright growth of this organism and also genes conditionally essential for growth in varying oxygen status which it can encounter in the human host. This tool and these data serve as a foundation for further study of this relatively unknown organism that may play a role in preserving human health.}, }
@article {pmid39166556, year = {2024}, author = {Casarin, RCV and Silva, RVCD and Paz, HES and Stolf, CS and Carvalho, LM and Noronha, MF and Sallum, AW and Monteiro, MF}, title = {Metatranscriptomic analysis shows functional alterations in subgingival biofilm in young smokers with periodontitis: a pilot study.}, journal = {Journal of applied oral science : revista FOB}, volume = {32}, number = {}, pages = {e20240031}, doi = {10.1590/1678-7757-2024-0031}, pmid = {39166556}, issn = {1678-7765}, mesh = {Humans ; *Biofilms ; Pilot Projects ; Male ; Female ; Adult ; *Smoking/adverse effects ; Periodontitis/microbiology ; Case-Control Studies ; Young Adult ; Gene Expression Profiling ; Gingiva/microbiology ; Transcriptome ; }, abstract = {OBJECTIVE: This study aimed to assess the influence of smoking on the subgingival metatranscriptomic profile of young patients affected by stage III/IV and generalized periodontal disease.<br><br>METHODOLOGY: In total, six young patients, both smokers and non-smokers (n=3/group), who were affected by periodontitis were chosen. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for case-control reporting were followed. Periodontal clinical measurements and subgingival biofilm samples were collected. RNA was extracted from the biofilm and sequenced via Illumina HiSeq. Differential expression analysis used Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and differentially expressed genes were identified using the Sleuth package in R, with a statistical cutoff of &#x2264;0.05.<br><br>RESULTS: This study found 3351 KEGGs in the subgingival biofilm of both groups. Smoking habits altered the functional behavior of subgingival biofilm, resulting in 304 differentially expressed KEGGs between groups. Moreover, seven pathways were modulated: glycan degradation, galactose metabolism, glycosaminoglycan degradation, oxidative phosphorylation, peptidoglycan biosynthesis, butanoate metabolism, and glycosphingolipid biosynthesis. Smoking also altered antibiotic resistance gene levels in subgingival biofilm by significantly overexpressing genes related to beta-lactamase, permeability, antibiotic efflux pumps, and antibiotic-resistant synthetases.<br><br>CONCLUSION: Due to the limitations of a small sample size, our data suggest that smoking may influence the functional behavior of subgingival biofilm, modifying pathways that negatively impact the behavior of subgingival biofilm, which may lead to a more virulent community.}, }
@article {pmid39165955, year = {2024}, author = {Malekahmadi, S and Yousefnezhadazizi, A and Askaripour, H}, title = {Simulation of anaerobic biodegradation process in a tubular bioreactor with a biofilm layer: Steady-state and unsteady-state conditions.}, journal = {Heliyon}, volume = {10}, number = {15}, pages = {e35397}, pmid = {39165955}, issn = {2405-8440}, abstract = {In this paper, anaerobic biodegradation process in a tubular bioreactor with an inner biofilm layer for steady-state and unsteady-state conditions are simulated. The effects of various parameters including bioreactor diameter, fraction of active biomass transferred to liquid phase, and residence time of the liquid on bioreactor performance are examined. Simulations indicate that decreasing diameter of bioreactor leads to increasing degree of conversion of the substrate in liquid phase and decreasing dimensionless concentration of the substrate in biofilm. With an increase in the fraction of active biomass transferred to liquid, substrate concentrations in liquid and biofilm slightly vary. Increased residence time of the liquid phase results in the degree of conversion of substrate goes up, but substrate concentration in biofilm lowers a little. In addition, it is found that biomass concentration of liquid phase is boosted with decreased bioreactor diameter and increased residence time of liquid. A proportional-integral controller is designed and the tuned parameters of K P = - 0.131 and K I = 0.02 are obtained using genetic algorithm. It is observed that controller regulate well the degree of conversion of the substrate within 120 s for both servo and regulatory modes.}, }
@article {pmid39162860, year = {2024}, author = {Wang, D and Liu, N and Qiao, M and Xu, C}, title = {Gallic acid as biofilm inhibitor can improve transformation efficiency of Ruminiclostridium papyrosolvens.}, journal = {Biotechnology letters}, volume = {}, number = {}, pages = {}, pmid = {39162860}, issn = {1573-6776}, support = {LZ24C010001//Zhejiang Provincial Natural Science Foundation of China/ ; 32170053//National Natural Science Foundation of China/ ; 2022LFR065//Science Development Foundation of Zhejiang A&amp;F University/ ; }, abstract = {Ruminiclostridium papyrosolvens is an anaerobic, mesophilic, and cellulolytic clostridia, promising consolidated bioprocessing (CBP) candidate for producing renewable green chemicals from cellulose, but its genetic transformation has been severely impeded by extracellular biofilm. Here, we analyzed the effects of five different inhibitors with gradient concentrations on R. papyrosolvens growth and biofilm formation. Gallic acid was proved to be a potent inhibitor of biofilm synthesis of R. papyrosolvens. Furthermore, the transformation efficiency of R. papyrosolvens was significantly increased when the cells were treated by the gallic acid, and the mutant strain was successfully obtained by the improved transformation method. Thus, inhibition of biofilm formation of R. papyrosolvens by using gallic acid will contribute to its genetic transformation and efficient metabolic engineering.}, }
@article {pmid39162544, year = {2024}, author = {Chen, KZM and Vu, LM and Vollmer, AC}, title = {Cultivation in long-term simulated microgravity is detrimental to pyocyanin production and subsequent biofilm formation ability of Pseudomonas aeruginosa.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0021124}, doi = {10.1128/spectrum.00211-24}, pmid = {39162544}, issn = {2165-0497}, abstract = {UNLABELLED: Pseudomonas aeruginosa forms aggregates known as biofilms. Previous studies have shown that when P. aeruginosa is cultivated in space, thicker and structurally different biofilms are formed than from those grown on Earth. We investigated how microgravity, simulated in a laboratory setting, influenced the growth, colonization, and virulence potentials of a P. aeruginosa PA14 wild-type strain, as well as two surface attachment-defective (sad) mutants altered at crucial biofilm-forming steps: flgK and pelA. Using high-aspect ratio rotating-wall vessel (HARV) bioreactors, P. aeruginosa bacteria were grown to stationary phase under prolonged (6 days) exposure to simulated microgravity or normal gravity conditions. After the exposure, the capacity of the culture to form biofilms was measured. Additionally, pigment (pyocyanin) formed by each culture during the incubation was extracted and quantified. We demonstrate that the first prolonged exposure to low-shear modeled microgravity (LSMMG) and without nutrient replenishment significantly diminishes wild-type P. aeruginosa PA14 biofilm formation abilities after exposure and pyocyanin production during exposure, while the mutant strains exhibit differing outcomes for both properties.<br><br>IMPORTANCE: Given plans for humans to engage in prolonged space travel, we investigated biofilm and pigment/virulence factor formation in Pseudomonas aeruginosa when cultivated in microgravity. These bacteria are opportunistic pathogens in immunocompromised individuals. Previous studies of space travelers have shown some immune system diminutions. Hence, our studies shed some light on how prolonged cultivation of bacteria in simulated microgravity conditions affect their growth characteristics.}, }
@article {pmid39162533, year = {2024}, author = {Liu, H and Chen, H and Ma, Z and Zhang, Y and Zhang, S and Zhao, D and Yao, Z and Zhou, T and Wang, Z}, title = {Plumbagin enhances antimicrobial and anti-biofilm capacities of chlorhexidine against clinical Klebsiella pneumoniae while reducing resistance mutations.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0089624}, doi = {10.1128/spectrum.00896-24}, pmid = {39162533}, issn = {2165-0497}, abstract = {With the widespread misuse of disinfectants, the clinical susceptibility of Klebsiella pneumoniae (K. pneumoniae) to chlorhexidine (CHX) has gradually diminished, posing significant challenges to clinical disinfection and infection control. K. pneumoniae employs overexpression of efflux pumps and the formation of thick biofilms to evade the lethal effects of CHX. Plumbagin (PLU) is a natural plant extract that enhances membrane permeability and reduces proton motive force. In this study, we elucidated the synergistic antimicrobial activity of PLU in combination with CHX, effectively reducing the MIC of CHX against K. pneumoniae to 1 µg/mL and below. Crucially, through crystal violet staining and confocal laser scanning microscopy live/dead staining, we discovered that PLU significantly enhances the anti-biofilm capability of CHX. Mechanistically, experiments involving membrane permeability, alkaline phosphatase leakage, reactive oxygen species, and RT-qPCR suggest that the combination of PLU and CHX improves the permeability of bacterial inner and outer membranes, promotes bacterial oxidative stress, and inhibits oqxA/B efflux pump expression. Furthermore, we conducted surface disinfection experiments on medical instruments to simulate clinical environments, demonstrating that the combination effectively reduces bacterial loads by more than 3 log10 CFU/mL. Additionally, results from resistance mutation frequency experiments indicate that combined treatment reduces the generation of resistant mutants within the bacterial population. In summary, PLU can serve as an adjuvant, enhancing the anti-biofilm capability of CHX and reducing the occurrence of resistance mutations, thereby extending the lifespan of CHX.IMPORTANCEAs disinfectants are extensively and excessively utilized worldwide, clinical pathogens are progressively acquiring resistance against these substances. However, high concentrations of disinfectants can lead to cross-resistance to antibiotics, and concurrent use of different disinfectants can promote bacterial resistance mutations and facilitate the horizontal transfer of resistance genes, which poses significant challenges for clinical treatment. Compared with the lengthy process of developing new disinfectants, enhancing the effectiveness of existing disinfectants with natural plant extracts is important and meaningful. CHX is particularly common and widely used compared with other disinfectants. Meanwhile, Klebsiella pneumoniae, as a clinically significant pathogen, exhibits high rates of resistance and pathogenicity. Previous studies and our data indicate a significant decrease in the sensitivity of clinical K. pneumoniae to CHX, highlighting the urgent need for novel strategies to address this issue. In light of this, our research is meaningful.}, }
@article {pmid39160249, year = {2024}, author = {Ahmady-Asbchin, S and Akbari Nasab, M and Gerente, C}, title = {Heavy metals biosorption in unary, binary, and ternary systems onto bacteria in a moving bed biofilm reactor.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {19168}, pmid = {39160249}, issn = {2045-2322}, mesh = {*Metals, Heavy/metabolism ; *Bioreactors/microbiology ; *Biofilms/growth &amp; development ; Biodegradation, Environmental ; Nickel/metabolism/chemistry ; Cadmium/metabolism ; Bacillus/metabolism ; Phylogeny ; Hydrogen-Ion Concentration ; Bacteria/metabolism ; Adsorption ; Lead/metabolism ; Temperature ; }, abstract = {Toxic and heavy metals cause direct and indirect damage to the environment and ultimately to humans. This study involved the isolation of indigenous bacteria from heavy metal-contaminated environments that have the ability to bioabsorb heavy metals such as cadmium, nickel, and lead. The bioabsorption process was optimized by varying parameters such as temperature, metal concentration, number of bacteria, pH, and more. The bacterial isolates were investigated in terms of morphology, biochemistry, and phylogeny, with 12 strains chosen in the initial stage and one strain chosen in the final stage. It should be remembered that the metal uptake capacity of all isolates was approximately calculated. A box and reactor were designed to house these optimized microorganisms. Based on biochemical, morphological, and molecular results, the isolated strain was found to be closely related to the Bacillus genus. In the first five steps of testing, the ideal pH for removing lead alone, lead with cadmium, lead with nickel, and lead ternary (with cadmium and nickel) by Bacillus bacteria was found to be 7, 6, 5.5, and 6.5, respectively. The absorption efficiencies for single lead (unary), lead together with nickel, cadmium (binary), and ternary (lead with cadmium and nickel) were found to be 0.36, 0.25, 0.22, and 0.21 mmol/g, respectively. The ideal temperature for lead removal was around 30 °C. The adsorption isotherm for each lead metal in different states was found to be similar to the Langmuir isotherm, indicating that the surface absorption process is a single-layer process. The kinetics of the process follow the second-order kinetic model. The amount of Bacillus bacteria biomass obtained during this process was approximately 1.5 g per liter.}, }
@article {pmid39159773, year = {2024}, author = {Biswas, T and Ahmed, M and Mondal, S}, title = {Mixed species biofilm: structure, challenge and its intricate involvement in hospital associated infections.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106866}, doi = {10.1016/j.micpath.2024.106866}, pmid = {39159773}, issn = {1096-1208}, abstract = {Hospital associated infections or healthcare associated infections (HAIs) are a major threat to healthcare and medical management, mostly because of their recalcitrant nature. The primary cause of these HAIs is bacterial associations, especially the interspecies interactions. In interspecies interactions, more than one species co-exists in a common platform of extracellular polymeric substances (EPS), establishing a strong interspecies crosstalk and thereby lead to the formation of mixed species biofilms. In this process, the internal microenvironment and the surrounding EPS matrix of the biofilms ensure the protection of the microorganisms and allow them to survive under antagonistic conditions. The communications between the biofilm members as well as the interactions between the bacterial cells and the matrix polymers, also aid in the rigidity of the biofilm structure and allow the microorganisms to evade both the host immune response and a wide range of anti-microbials. Therefore, to design a treatment protocol for HAIs is difficult and it has become a growing point of concern. This review therefore first aims to discuss the role of microenvironment, molecular structure, cell-cell communication, and metabolism of mixed species biofilms in manifestation of HAIs. In addition, we discuss the electrochemical properties of mixed-species biofilms and their mechanism in developing drug resistance. Then we focus on the most dreaded bacterial HAI including oral and gut multi-species infections, catheter-associated urinary tract infections, surgical site infections, and ventilator-associated pneumonia. Further, we highlight the challenges to eradication of the mixed species biofilms and the current and prospective future strategies for the treatment of mixed species-associated HAI. Together, the review presents a comprehensive understanding of mixed species biofilm-mediated infections in clinical scenario, and summarizes the current challenge and prospect of therapeutic strategies against HAI.}, }
@article {pmid39159772, year = {2024}, author = {Carmona-Orozco, ML and Echeverri, F}, title = {Induction of biofilm in extended-spectrum beta-lactamase Staphylococcus aureus with drugs commonly used in pharmacotherapy.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106863}, doi = {10.1016/j.micpath.2024.106863}, pmid = {39159772}, issn = {1096-1208}, abstract = {Staphylococcus aureus is a bacterial pathogen that causes bloodstream infections, pneumonia, and skin abscesses and is the primary pathogen responsible for medical devices associated with biofilm infections, accounting for approximately 70% of cases. Therefore, the World Health Organization (WHO) has designated this microorganism as a top priority due to its role in causing over 20,000 bacteremia-related deaths in the US each year. The issue of pathogen resistance to antibiotics, mainly by a biofilm, further complicates these infections since biofilms render the bacterial colony impervious to antibiotics. However, many natural and synthetic substances also induce bacterial biofilm formation. Therefore, we investigated whether the most common active pharmaceutical ingredients (APIs) could induce biofilm formation in two clinical isolates of extended-spectrum beta-lactamase Staphylococcus aureus, one of them also methicillin-resistant (A2M) and two medical devices. We detected biofilm inducers, inhibitors, and destabilizers. Microbial strain, medical devices, API structure, and concentration influenced the modulatory effects of biofilm. In all devices tested, including microplates, FR18 duodenal probe, and respiratory probe, the clinic isolate methicillin-resistant S. aureus A2M exhibited lower susceptibility to biofilm formation than S. aureus A1. The anti-inflammatory acetaminophen, the hypocholesterolemic lovastatin, and the diuretic hydrochlorothiazide all induced biofilm. However, verapamil, an antihypertensive, and cetirizine, an antihistamine, inhibited biofilm on S. aureus A2M, while propranolol, another antihypertensive, inhibited biofilm on S. aureus A1. Additionally, diclofenac, an analgesic, and cetirizine destabilized the biofilm, resulting in more free bacteria and possibly making them more susceptible to external agents such as antibiotics. Nonetheless, further epidemiologic analyses and in vivo assays are needed to confirm these findings and to establish a correlation between drug use, the onset of bacterial infections in patients, and the use of medical devices. This work provides information about the probable clinical implications of drugs in patients using medical devices or undergoing surgical procedures. Inhibitory APIs could also be used as drug repurposing or templates to design new, more potent biofilm inhibitors.}, }
@article {pmid39159744, year = {2024}, author = {Magalhães, TC and Lopes, AG and Ferreira, GF and Denadai, &#xc2;ML and da Silva, JG and Dos Santos, RL and Munchow, EA and de Carvalho, FG}, title = {In vitro assessment of NaF/Chit supramolecular complex: colloidal stability, antibacterial activity and enamel protection against S. mutans biofilm.}, journal = {Journal of dentistry}, volume = {}, number = {}, pages = {105316}, doi = {10.1016/j.jdent.2024.105316}, pmid = {39159744}, issn = {1879-176X}, abstract = {OBJECTIVES: This study assessed the effect of NaF/Chit suspensions on enamel and on S. mutans biofilm, simulating application of a mouthrinse.<br><br>METHODS: The NaF/Chit particle suspensions were prepared at molar ratio [NaF]/Chitmon]&#x2248;0.68 at nominal concentrations of 0.2% and 0.05% NaF and characterized by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering and zeta potential. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured. The S. mutans biofilm was formed for 7 days on eighty human enamel blocks that were divided into eight groups (n=10/group): i) 0.05% NaF solution; ii) 0.31% Chit solution; iii) NaF/Chit(R=0.68) suspension at 0.05% NaF; iv) 1.0% HAc solution (Control); v) 0.2% NaF solution; vi) 1.25% Chit solution; vii) NaF/Chit(R=0.68) suspension at 0.2% NaF; viii) 0.12% chlorhexidine digluconate. The substances were applied daily for 90s. S. mutans cell counts (CFU/mL) were performed, and the Knoop microhardness (KHN) of enamel samples were measured before and after biofilm formation. The KHN and CFU/mL data were analyzed by repeated measure ANOVA and Tukey's test (&#x3b1;&#x202f;=&#x202f;0.05).<br><br>RESULTS: Interactions between NaF and Chit were evidenced in solid state by FTIR spectra. The NaF/Chit complexes showed spontaneous microparticle formation and colloidal stability. The MIC and MBC ranged from 0.65-1.31 mg/mL. The NaF/Chit(R=0.68) suspension at 0.2%NaF Group showed lower CFU/mL values than other groups. The NaF/Chit(R=0.68) suspensions Groups had the highest KHN values after biofilm formation.<br><br>CONCLUSIONS: The NaF/Chit(R=0.68) complexes exhibited an antibacterial effect against S. mutans biofilm and reduced the enamel hardness loss.<br><br>CLINICAL SIGNIFICANCE: The NaF/Chit(R=0.68) suspensions showed potential to be used as a mouthrinse for caries prevention.}, }
@article {pmid39160204, year = {2024}, author = {Nahum, Y and Gross, N and Cerrone, A and Matouš, K and Nerenberg, R}, title = {Effect of biofilm physical characteristics on their susceptibility to antibiotics: impacts of low-frequency ultrasound.}, journal = {NPJ biofilms and microbiomes}, volume = {10}, number = {1}, pages = {70}, pmid = {39160204}, issn = {2055-5008}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Anti-Bacterial Agents/pharmacology ; *Tobramycin/pharmacology ; *Pseudomonas aeruginosa/drug effects/physiology ; Microbial Sensitivity Tests ; Microbial Viability/drug effects ; Ultrasonic Waves ; }, abstract = {Biofilms are highly resistant to antimicrobials, often causing chronic infections. Combining antimicrobials with low-frequency ultrasound (LFU) enhances antimicrobial efficiency, but little is known about the underlying mechanisms. Biofilm physical characteristics, which depend on factors such as growth conditions and age, can have significant effects on inactivation efficiency. In this study, we investigated the susceptibility of Pseudomonas aeruginosa biofilms to tobramycin, with and without LFU treatment. The biofilms were grown under low and high fluid shear to provide different characteristics. Low-shear biofilms exhibited greater thickness, roughness, and porosity and lower density, compared to high-shear biofilms. The biofilm matrix of the high-shear biofilms had a three times higher protein-to-polysaccharide ratio, suggesting greater biofilm stiffness. This was supported by microrheology measurements of biofilm creep compliance. For the low-shear biofilms without LFU, the viability of the biofilms in their inner regions was largely unaffected by the antibiotic after a 2-hour treatment. However, when tobramycin was combined with LFU, the inactivation for the entire biofilm increased to 80% after 2 h. For the high-shear biofilms without LFU, higher LFU intensities were needed to achieve similar inactivation results. Microrheology measurements revealed that changes in biofilm inactivation profiles were closely related to changes in biofilm mechanical properties. Modeling suggests that LFU changes antibiotic diffusivity within the biofilm, probably due to a "decohesion" effect. Overall, this research suggests that biofilm physical characteristics (e.g., compliance, morphology) are linked to antimicrobial efficiency. LFU weakens the biofilm while increasing its diffusivity for antibiotics.}, }
@article {pmid39158270, year = {2024}, author = {Nairn, BL and Lima, BP and Chen, R and Yang, JQ and Wei, G and Chumber, AK and Herzberg, MC}, title = {Effects of fluid shear stress on oral biofilm formation and composition and the transcriptional response of Streptococcus gordonii.}, journal = {Molecular oral microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/omi.12481}, pmid = {39158270}, issn = {2041-1014}, support = {R01 DE025618/DE/NIDCR NIH HHS/United States ; K08 DE027705/DE/NIDCR NIH HHS/United States ; R03 DE031337/DE/NIDCR NIH HHS/United States ; 2236497//National Science Foundation/ ; }, abstract = {Biofilms are subjected to many environmental pressures that can influence community structure and physiology. In the oral cavity, and many other environments, biofilms are exposed to forces generated by fluid flow; however, our understanding of how oral biofilms respond to these forces remains limited. In this study, we developed a linear rocker model of fluid flow to study the impact of shear forces on Streptococcus gordonii and dental plaque-derived multispecies biofilms. We observed that as shear forces increased, S. gordonii biofilm biomass decreased. Reduced biomass was largely independent of overall bacterial growth. Transcriptome analysis of S. gordonii biofilms exposed to moderate levels of shear stress uncovered numerous genes with differential expression under shear. We also evaluated an ex vivo plaque biofilm exposed to fluid shear forces. Like S. gordonii, the plaque biofilm displayed decreased biomass as shear forces increased. Examination of plaque community composition revealed decreased diversity and compositional changes in the plaque biofilm exposed to shear. These studies help to elucidate the impact of fluid shear on oral bacteria and may be extended to other bacterial biofilm systems.}, }
@article {pmid39156801, year = {2024}, author = {Naziri, Z and Hajihasani, A and Derakhshandeh, A}, title = {Investigation of antibiotic resistance, virulence genes, and biofilm formation of Escherichia coli isolated from sheep feces in Shiraz industrial slaughterhouse, South of Iran.}, journal = {Iranian journal of veterinary research}, volume = {25}, number = {1}, pages = {25-32}, pmid = {39156801}, issn = {1728-1997}, abstract = {BACKGROUND: With the increase in human population, the consumption of livestock products such as sheep meat has also increased. Sheep are the reservoir and shedder of Escherichia coli that can be transmitted to humans. Aims: Characterization of fecal E. coli isolated from sheep in slaughterhouse.<br><br>METHODS: Stool specimens were collected from 30 apparently healthy sheep from different flocks in Shiraz industrial slaughterhouse. The resistance of E. coli isolates against 10 antibiotics was determined by disk diffusion method. The presence of three major extended spectrum beta-lactamase (ESBL) genes and five tetracycline resistance genes as well as seven virulence genes were investigated by polymerase chain reaction (PCR) technique. Using the microtiter plate method, the biofilm formation ability of E. coli isolates was investigated.<br><br>RESULTS: The highest frequency of resistance was to amoxicillin (100%) followed by tetracycline (25%). All E. coli isolates were susceptible to gentamicin and nitrofurantoin, and only one isolate was resistant to the tested third-generation cephalosporins. Multidrug resistance phenotype was observed in 16.7% of the isolates. bla TEM (25%) was the most prevalent ESBL gene and tetA (62.5%) was the most prevalent tetracycline resistance gene in the isolates. crl, csgA, fimH, and bcsA genes were present in all isolates, and the prevalence of papC and afa genes was 95.8% and 83.3%, respectively. In total, 62.5% of the isolates were biofilm producers.<br><br>CONCLUSION: According to the concept of One Health, the presence of virulent antibiotic-resistant biofilm producing strains of E. coli in sheep is a risk to public health.}, }
@article {pmid39155946, year = {2024}, author = {Godart, GA and Elwasila, SM and Durvasula, RV}, title = {A rare case of candida osteomyelitis of the mandible associated with osteoradionecrosis and biofilm formation.}, journal = {IDCases}, volume = {37}, number = {}, pages = {e02029}, pmid = {39155946}, issn = {2214-2509}, abstract = {Candida osteomyelitis, in general, is a relatively rare manifestation compared to its bacterial counterparts. The mandible's involvement is rarer, lacking established management and fewer guidelines. Herein, we aim to illustrate the significant challenge in treatment, namely due to the persistent and resistant nature of Candida albicans-associated biofilm. A multidisciplinary approach involving adjunctive use of antifungals with surgical interventions is typically necessary and feasible in this case. However, surgical interventions may not always be possible in challenging instances in which the patient may be structurally (including osteoradionecrosis) and vascularly compromised, raising questions about the feasibility of standard-of-care as well as the success of alternative therapies aimed at disrupting biofilm formation. Clinicians should maintain a high index of suspicion for complicating, deep-seated Candidiasis in at-risk populations and endeavor to treat as aggressively as possible to limit recurrent disease owing to persistence.}, }
@article {pmid39155705, year = {2024}, author = {Tan, S and Huang, Y and Yang, H and Zhang, S and Tang, X}, title = {Microbial communities and denitrification mechanisms of pyrite autotrophic denitrification coupled with three-dimensional biofilm electrode reactor.}, journal = {Water environment research : a research publication of the Water Environment Federation}, volume = {96}, number = {8}, pages = {e11107}, doi = {10.1002/wer.11107}, pmid = {39155705}, issn = {1554-7531}, support = {21806126//National Natural Science Foundation of China/ ; WUT.2019IVB031//Fundamental Research Funds for the Central Universities/ ; }, mesh = {*Denitrification ; *Biofilms ; *Bioreactors ; *Electrodes ; *Sulfides/metabolism/chemistry ; Autotrophic Processes ; Iron/metabolism ; Bacteria/metabolism/classification/genetics ; Nitrates/metabolism ; Microbiota ; }, abstract = {Denitrification is of great significance for low C/N wastewater treatment. In this study, pyrite autotrophic denitrification (PAD) was coupled with a three-dimensional biofilm electrode reactor (BER) to enhance denitrification. The effect of current on denitrification was extensively studied. The nitrate removal of the PAD-BER increased by 14.90% and 74.64% compared to the BER and the PAD, respectively. In addition, the electron utilization, extracellular polymeric substances secretion, and denitrification enzyme activity (NaR and NiR) were enhanced in the PAD-BER. The microbial communities study displayed that Dokdonella, Hydrogenophaga, Nitrospira, and Terrimonas became the main genera for denitrification. Compared with the PAD and the BER, the abundance of the key denitrification genes narG, nirK, nirS, and nosZ were all boosted in the PAD-BER. This study indicated that the enhanced autotrophic denitrifiers and denitrification genes were responsible for the improved denitrification in the PAD-BER. PRACTITIONER POINTS: PAD-BER displayed higher nitrate removal, EPS, NAR, and NIR activity. The three types of denitrification (HD, HAD, and PAD) and their contribution percentage in the PAD-BER were analyzed. HAD was dominant among the three denitrification processes in PAD-BER. Microbial community composition and key denitrification genes were tested to reveal the denitrification mechanisms.}, }
@article {pmid39155413, year = {2024}, author = {Yang, K and Wang, L and Chen, J and Wang, Z and Li, J and Chen, X and Fu, S and Hai, L and Deng, L and He, D}, title = {H2O2-Activatable Liposomal Nanobomb Capable of Generating Hypoxia-Irrelevant Alkyl Radicals by Photo-Triggered Cascade Reaction for High-Performance Elimination of Biofilm Bacteria.}, journal = {Advanced healthcare materials}, volume = {}, number = {}, pages = {e2402136}, doi = {10.1002/adhm.202402136}, pmid = {39155413}, issn = {2192-2659}, support = {22375061//National Natural Science Foundation of China/ ; 21775036//National Natural Science Foundation of China/ ; 22005343//National Natural Science Foundation of China/ ; 2021SK2053//Key Research and Development Program of Hunan Province/ ; 2022RC1164//Science and Technology Innovation Program of Hunan Province/ ; 22A0031//Research Foundation of Education Department of Hunan Province/ ; 2022JJ30379//Natural Science Foundation of Hunan Province/ ; ZDSYS20220606101604009//Shenzhen Science and Technology Program/ ; }, abstract = {High H2O2 levels are widely present at the infection sites or in the biofilm microenvironment. Herein, hemin with peroxidase-like catalytic activity and its substrate, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), are simultaneously introduced into a liposomal nanoparticle containing thermosensitive 2,2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIBI)-loaded bovine serum albumin (BAG), rationally constructing an H2O2-activatable liposomal nanobomb (Lipo@BHA) for combating biofilm-associated bacterial infections with high performance. In the presence of H2O2, hemin can catalyze the conversion of ABTS into its oxidized form (ABTS·[+]) with strong near-infrared (NIR) absorption, which produces photonic hyperpyrexia to cause the decomposition of AIBI into oxygen-independent alkyl radicals (·R) and nitrogen (N2) microbubbles. The former not only directly damage bacterial cells but also significantly accelerates the oxidization of ABTS to ABTS·[+] for augmenting photothermal-triggered generation of ·R. Interestingly, the released N2 can induce transient cavitation to rupture lysosomal nanoparticle and improve the biofilm permeability, thereby enhancing the antibiofilm effect of Lipo@BHA. The proposed Lipo@BHA exhibits satisfactory multi-mode combination antibacterial properties. Through endogenous H2O2-activated cascade reaction, Lipo@BHA achieves remarkable hypoxia-irrelevant ·R therapy of biofilm-associated wound infections with low cytotoxicity and good in vivo biosafety. Therefore, this work presents a versatile H2O2-activatable cascade ·R generation strategy for biofilm-specific therapeutic applications.}, }
@article {pmid39154385, year = {2024}, author = {Li, Z and Wang, Q and Lei, Z and Zheng, H and Zhang, H and Huang, J and Ma, Q and Li, F}, title = {Biofilm formation and microbial interactions in moving bed-biofilm reactors treating wastewater containing pharmaceuticals and personal care products: A review.}, journal = {Journal of environmental management}, volume = {368}, number = {}, pages = {122166}, doi = {10.1016/j.jenvman.2024.122166}, pmid = {39154385}, issn = {1095-8630}, abstract = {The risk of pharmaceuticals and personal care products (PPCPs) has been paid more attention after the outbreak of COVID-19, threatening the ecology and human health resulted from the massive use of drugs and disinfectants. Wastewater treatment plants are considered the final stop to restrict PPCPs from wide spreading into the environment, but the performance of conventional treatment is limited due to their concentrations and characteristics. Previous studies have shown the unreplaceable capability of moving bed-biofilm reactor (MBBR) as a cost-effective method with layered microbial structure for treating wastewater even with toxic compounds. The biofilm community and microbial interactions are essential for the MBBR process in completely degrading or converting types of PPCPs to secondary metabolites, which still need further investigation. This review starts with discussing the initiation of MBBR formation and its influencing parameters according to the research on MBBRs in the recent years. Then the efficiency of MBBRs and the response of biofilm after exposure to PPCPs are further addressed, followed by the bottlenecks proposed in this field. Some critical approaches are also recommended for mitigating the deficiencies of MBBRs based on the recently published publications to reduce the environmental risk of PPCPs. Finally, this review provides fundamental information on PPCPs removal by MBBRs with the main focus on microbial interactions, promoting the MBBRs to practical application in the real world of wastewater treatment.}, }
@article {pmid39153696, year = {2024}, author = {Xu, H and Yang, XL and Zhang, ZH and Xia, YG and Song, HL}, title = {External circuit loading mode regulates anode biofilm electrochemistry and pollutants removal in microbial fuel cells.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131300}, doi = {10.1016/j.biortech.2024.131300}, pmid = {39153696}, issn = {1873-2976}, abstract = {This study investigated the effects of different external circuit loading mode on pollutants removal and power generation in microbial fuel cells (MFC). The results indicated that MFC exhibited distinct characteristics of higher maximum power density (Pmax) (named MFC-HP) and lower Pmax (named MFC-LP). And the capacitive properties of bioanodes may affect anodic electrochemistry. Reducing external load to align with the internal resistance increased Pmax of MFC-LP by 54.47 %, without no obvious effect on MFC-HP. However, intermittent external resistance loading (IER) mitigated the biotoxic effects of sulfamethoxazole (SMX) (a persistent organic pollutant) on chemical oxygen demand (COD) and NH4[+]-N removal and maintained high Pmax (424.33 mW/m[2]) in MFC-HP. Meanwhile, IER mode enriched electrochemically active bacteria (EAB) and environmental adaptive bacteria Advenella, which may reduce antibiotic resistance genes (ARGs) accumulation. This study suggested that the external circuit control can be effective means to regulate electrochemical characteristics and pollutants removal performance of MFC.}, }
@article {pmid39153576, year = {2024}, author = {Dias, GR and Freitas-Silva, J and de Carvalho, MM and Ramos, VFDS and Muricy, G and Rodrigues, JCF and Costa, BRFV and de Oliveira, BFR and Laport, MS}, title = {Bioemulsifier from sponge-associated bacteria reduces staphylococcal biofilm.}, journal = {Microbial pathogenesis}, volume = {195}, number = {}, pages = {106856}, doi = {10.1016/j.micpath.2024.106856}, pmid = {39153576}, issn = {1096-1208}, abstract = {Biofilm formation is a major health concern and studies have been pursued to find compounds able to prevent biofilm establishment and remove pre-existing biofilms. While biosurfactants (BS) have been well-known for possessing antibiofilm activities, bioemulsifiers (BE) are still scarcely explored for this purpose. The present study aimed to evaluate the bioemulsifying properties of cell-free supernatants produced by Bacillaceae and Vibrio strains isolated from marine sponges and investigate their antiadhesive and antibiofilm activities against different pathogenic Gram-positive and Gram-negative bacteria. The BE production by the marine strains was confirmed by the emulsion test, drop-collapsing, oil-displacement, cell hydrophobicity and hemolysis assays. Notably, Bacillus cereus 64BHI1101 displayed remarkable emulsifying activity and the ultrastructure analysis of its BE extract (BE64-1) revealed the presence of structures typically observed in macromolecules composed of polysaccharides and proteins. BE64-1 showed notable antiadhesive and antibiofilm activities against Staphylococcus aureus, with a reduction of adherence of up to 100 % and a dispersion of biofilm of 80 %, without affecting its growth. BE64-1 also showed inhibition of Staphylococcus epidermidis and Escherichia coli biofilm formation and adhesion. Thus, this study provides a starting point for exploring the antiadhesive and antibiofilm activities of BE from sponge-associated bacteria, which could serve as a valuable tool for future research to combat S. aureus biofilms.}, }
@article {pmid39153575, year = {2024}, author = {Sikdar, B and Mukherjee, S and Bhattacharya, R and Raj, A and Roy, A and Banerjee, D and Gangopadhyay, G and Roy, S}, title = {The anti-quorum sensing and biofilm inhibitory potential of Piper betle L. leaf extract and prediction of the roles of the potent phytocompounds.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106864}, doi = {10.1016/j.micpath.2024.106864}, pmid = {39153575}, issn = {1096-1208}, abstract = {The leaves of Piper betle L., known as betel leaf, have immense medicinal properties. It possesses potent antimicrobial efficacies and can be a valuable tool to combat drug-resistant microorganisms. Quorum sensing (QS) inhibition is one of the best strategies to combat drug resistance. The present study investigates the anti-quorum sensing and biofilm inhibitory potential of Piper betle L. leaf extract against two bacterial strains, Chromobacterium violaceum and Pseudomonas aeruginosa. The extract produced substantial QS-inhibition zones in a biosensor strain of C. violaceum (CV026), indicating interference with quorum-sensing signals. The Results demonstrated significant inhibition in biofilm formation and different QS-regulated virulence factors (violacein, exopolysaccharides, pyocyanin, pyoverdine, elastase) in both C. violaceum and P. aeruginosa at sub-MIC concentrations of the extract and tetracycline, an antibiotic with known anti-QS activity. The quantitative real-time PCR (qRT-PCR) revealed decreased gene expression in different QS-related genes in C. violaceum (cviI, cviR, and vioA) and P. aeruginosa (lasI, lasR, lasB, rhlI, rhlR, and rhlA) strains after treatment. Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified the significant phytocompounds, mainly derivatives of chavicol and eugenol, in the extract. Of these compounds, chavicol acetate (affinity: -7.00 Kcal/mol) and acetoxy chavicol acetate (affinity: -7.87 Kcal/mol) showed the highest potential to bind with the CviR and LasR protein, respectively, as evident from the in-silico molecular docking experiment. The findings of this endeavour highlight the promising role of Piper betle L. as a source of natural compounds with anti-quorum sensing properties against pathogenic bacteria, opening avenues for developing novel therapeutic agents to combat bacterial infections.}, }
@article {pmid39153098, year = {2024}, author = {Estrada-Arriaga, EB and Montero-Farías, R and Morales-Morales, C and García-Sánchez, L and Falcón-Rojas, A and Garzón-Zúñiga, MA and Gutierrez-Macias, T}, title = {Performance of a pilot-scale microbial electrolysis cell coupled with biofilm-based reactor for household wastewater treatment: simultaneous pollutant removal and hydrogen production.}, journal = {Bioprocess and biosystems engineering}, volume = {}, number = {}, pages = {}, pmid = {39153098}, issn = {1615-7605}, abstract = {The septic tank is the most commonly used decentralized wastewater treatment systems for household wastewater treatment in on-site applications. The removal rate of various pollutants is lower in different septic tank configurations. The integration of a microbial electrolysis cells (MEC) into septic tank or biofilm-based reactors can be a green and sustainable technology for household wastewater treatment and energy production. In this study, a 50-L septic tank was converted into a 50-L MEC coupled with biofilm-based reactor for simultaneous household wastewater treatment and hydrogen production. The biofilm-based reactor was integrated by an anaerobic packed-bed biofilm reactor (APBBR) and an aerobic moving bed biofilm reactor (aeMBBR). The MEC/APBBR/aeMBBR was evaluated at different organic loading rates (OLRs) by applying voltage of 0.7 and 1.0 V. Result showed that the increase of OLRs from 0.2 to 0.44 kg COD/m[3] d did not affect organic matter removals. Nutrient and solids removal decreased with increasing OLR up to 0.44 kg COD/m[3] d. Global removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total nitrogen (TN), ammoniacal nitrogen (NH4[+]), total phosphorus (TP) and total suspended solids (TSS) removal ranged from 81 to 84%, 84 to 85%, 53 to 68%, 88 to 98%, 11 to 30% and 76 to 88% respectively, was obtained in this study. The current density generated in the MEC from 0 to 0.41 A/m[2] contributed to an increase in hydrogen production and pollutants removal. The maximum volumetric hydrogen production rate obtained in the MEC was 0.007 L/L[.]d (0.072 L/d). The integration of the MEC into biofilm-based reactors applying a voltage of 1.0 V generated different bioelectrochemical nitrogen and phosphorus transformations within the MEC, allowing a simultaneous denitrification-nitrification process with phosphorus removal.}, }
@article {pmid39150420, year = {2024}, author = {Xue, Y and Zhang, C and Li, S and Zhou, Q and Zhou, X and Zhang, Y}, title = {Enhanced denitrification by graphene oxide-modified cathode for the secondary effluent of wastewater treatment plants in three-dimensional biofilm electrode reactors.}, journal = {Water science and technology : a journal of the International Association on Water Pollution Research}, volume = {89}, number = {12}, pages = {3192-3207}, pmid = {39150420}, issn = {0273-1223}, support = {No. 2020YFD1100102//Key Technologies Research and Development Program/ ; }, mesh = {*Graphite/chemistry ; *Denitrification ; *Biofilms ; *Electrodes ; *Bioreactors ; *Waste Disposal, Fluid/methods ; *Wastewater/chemistry ; Nitrogen/chemistry ; Water Purification/methods ; }, abstract = {In this study, a novel three-dimensional biofilm electrode reactor (3D-BER) with a graphene oxide (GO)-modified cathode was developed to enhance the denitrification performance of secondary effluent from wastewater treatment plants (SEWTPs). The effects of different hydraulic retention times (HRTs) and currents on the 3D-BER were explored. The results indicated that at the optimal HRT of 4 h and current of 350 mA/m[2], the 3D-BER with GO-modified cathode had a higher denitrification rate (2.40 ± 0.1 mg TN/L/h) and less accumulation of intermediate products, especially with 3.34% total nitrogen (TN) molar conversion to N2O. The GO-modified cathode offered a large biocompatible specific surface area and enhanced the conductivity, which favored microbial growth and increased electron transfer efficiency and extracellular enzyme activities. Moreover, the activity of nitrite reductase increased more than that of nitrate reductase to accelerate nitrite reduction, thus facilitating the denitrification process. The proposed 3D-BER provided an effective solution to elevate tertiary denitrification in the SEWTP.}, }
@article {pmid39149593, year = {2024}, author = {Bai, X and Peng, W and Tang, Y and Wang, Z and Guo, J and Song, F and Yang, H and Huang, C}, title = {An NIR-propelled janus nanomotor with enhanced ROS-scavenging, immunomodulating and biofilm-eradicating capacity for periodontitis treatment.}, journal = {Bioactive materials}, volume = {41}, number = {}, pages = {271-292}, doi = {10.1016/j.bioactmat.2024.07.014}, pmid = {39149593}, issn = {2452-199X}, abstract = {Periodontitis is an inflammatory disease caused by bacterial biofilms, which leads to the destruction of periodontal tissue. Current treatments, such as mechanical cleaning and antibiotics, struggle to effectively address the persistent biofilms, inflammation, and tissue damage. A new approach involves developing a Janus nanomotor (J-CeM@Au) by coating cerium dioxide-doped mesoporous silica (CeM) with gold nanoparticles (AuNPs). This nanomotor exhibits thermophoretic motion when exposed to near-infrared (NIR) laser light due to the temperature gradient produced by the photothermal effects of asymmetrically distributed AuNPs. The NIR laser provides the energy for propulsion and activates the nanomotor's antibacterial properties, allowing it to penetrate biofilms and kill bacteria. Additionally, the nanomotor's ability to scavenge reactive oxygen species (ROS) can modulate the immune response and create a regenerative environment, promoting the healing of periodontal tissue. Overall, this multifunctional nanomotor offers a promising new approach for treating periodontitis by simultaneously addressing biofilm management and immune modulation with autonomous movement.}, }
@article {pmid39149462, year = {2024}, author = {Fleeman, R and Iv, RB and Cella, E and Azarian, T and Rendueles, O}, title = {Diverse polysaccharide production and biofilm formation abilities of clinical Klebsiella pneumoniae.}, journal = {Research square}, volume = {}, number = {}, pages = {}, doi = {10.21203/rs.3.rs-4630973/v1}, pmid = {39149462}, issn = {2693-5015}, abstract = {Klebsiella pneumoniae infections have become a growing threat for human health. The lack of understanding of the relationship between antibiotic resistance, mucoviscosity, and biofilm formation in clinical isolates impedes our abilities to effectively predict K. pneumoniae infection outcomes. These traits are also associated with fitness in natural populations and more specifically within a host. The Multidrug-Resistant Organism Repository and Surveillance Network offers a unique opportunity into the genetic and phenotypic variabilities in the K. pneumoniae isolates encountered in the clinics today. To this end, we compared the genetic profiles of these isolates with the phenotypic biofilm formation abilities, percent mucoviscosity, and growth rates. We found most isolates formed limited biofilm, although a select group of isolates could form extremely robust biofilms. Variation in biofilm formation could not be explained by difference in growth rate, suggesting specific genetic and physical determinants. Interestingly, the most mucoid strains in the populations were lacking the genetic element regulating the mucoid phenotype and three of these isolates were able to form robust biofilms. There was a significant phenotype-genotype correlation with decreased biofilm formation and an insertion sequence in the transcriptional activator of the type III fimbrial system. Finally, confocal microscopy highlighted the structural and spatial heterogeneity of biofilm among the most robust biofilm formers not detected by traditional methods. The combination of phenotypic, genomic and image analyses allowed us to reveal an unexpected phenotypic diversity and an intricate relation between growth, mucoviscosity and specific virulence-associated genetic determinants.}, }
@article {pmid39149421, year = {2024}, author = {Chao, Y and Mørch, M and Håkansson, AP and Shannon, O}, title = {Biofilm-dispersed pneumococci induce elevated leukocyte and platelet activation.}, journal = {Frontiers in cellular and infection microbiology}, volume = {14}, number = {}, pages = {1405333}, doi = {10.3389/fcimb.2024.1405333}, pmid = {39149421}, issn = {2235-2988}, mesh = {*Biofilms/growth &amp; development ; Humans ; *Streptococcus pneumoniae/immunology ; *Platelet Activation ; *Neutrophils/immunology ; Monocytes/immunology/microbiology ; Pneumococcal Infections/microbiology/immunology ; Blood Platelets/microbiology ; Leukocytes/immunology ; Flow Cytometry ; Adult ; Female ; Male ; }, abstract = {INTRODUCTION: Streptococcus pneumoniae (the pneumococcus) effectively colonizes the human nasopharynx, but can migrate to other host sites, causing infections such as pneumonia and sepsis. Previous studies indicate that pneumococci grown as biofilms have phenotypes of bacteria associated with colonization whereas bacteria released from biofilms in response to changes in the local environment (i.e., dispersed bacteria) represent populations with phenotypes associated with disease. How these niche-adapted populations interact with immune cells upon reaching the vascular compartment has not previously been studied. Here, we investigated neutrophil, monocyte, and platelet activation using ex vivo stimulation of whole blood and platelet-rich plasma with pneumococcal populations representing distinct stages of the infectious process (biofilm bacteria and dispersed bacteria) as well as conventional broth-grown culture (planktonic bacteria).<br><br>METHODS: Flow cytometry and ELISA were used to assess surface and soluble activation markers for neutrophil and monocyte activation, platelet-neutrophil complex and platelet-monocyte complex formation, and platelet activation and responsiveness.<br><br>RESULTS: Overall, we found that biofilm-derived bacteria (biofilm bacteria and dispersed bacteria) induced significant activation of neutrophils, monocytes, and platelets. In contrast, little to no activation was induced by planktonic bacteria. Platelets remained functional after stimulation with bacterial populations and the degree of responsiveness was inversely related to initial activation. Bacterial association with immune cells followed a similar pattern as activation.<br><br>DISCUSSION: Differences in activation of and association with immune cells by biofilm-derived populations could be an important consideration for other pathogens that have a biofilm state. Gaining insight into how these bacterial populations interact with the host immune response may reveal immunomodulatory targets to interfere with disease development.}, }
@article {pmid39149420, year = {2024}, author = {Zhang, Z and Pan, Y and Hussain, W and Chen, G and Li, E}, title = {BBSdb, an open resource for bacterial biofilm-associated proteins.}, journal = {Frontiers in cellular and infection microbiology}, volume = {14}, number = {}, pages = {1428784}, doi = {10.3389/fcimb.2024.1428784}, pmid = {39149420}, issn = {2235-2988}, mesh = {*Biofilms/growth &amp; development ; *Bacterial Proteins/genetics/metabolism ; Bacteria/genetics/metabolism/classification ; Transcriptome ; Proteome ; Escherichia coli/genetics/metabolism ; Computational Biology/methods ; }, abstract = {Bacterial biofilms are organized heterogeneous assemblages of microbial cells encased within a self-produced matrix of exopolysaccharides, extracellular DNA and proteins. Over the last decade, more and more biofilm-associated proteins have been discovered and investigated. Furthermore, omics techniques such as transcriptomes, proteomes also play important roles in identifying new biofilm-associated genes or proteins. However, those important data have been uploaded separately to various databases, which creates obstacles for biofilm researchers to have a comprehensive access to these data. In this work, we constructed BBSdb, a state-of-the-art open resource of bacterial biofilm-associated protein. It includes 48 different bacteria species, 105 transcriptome datasets, 21 proteome datasets, 1205 experimental samples, 57,823 differentially expressed genes (DEGs), 13,605 differentially expressed proteins (DEPs), 1,930 'Top 5% differentially expressed genes', 444 'Threshold-based DEGs' and a predictor for prediction of biofilm-associated protein. In addition, 1,781 biofilm-associated proteins, including annotation and sequences, were extracted from 942 articles and public databases via text-mining analysis. We used E. coli as an example to represent how to explore potential biofilm-associated proteins in bacteria. We believe that this study will be of broad interest to researchers in field of bacteria, especially biofilms, which are involved in bacterial growth, pathogenicity, and drug resistance. Availability and implementation: The BBSdb is freely available at http://124.222.145.44/#!/.}, }
@article {pmid39149263, year = {2024}, author = {Williams, I and Tuckerman, JS and Peters, DI and Bangs, M and Williams, E and Shin, IJ and Kaspar, JR}, title = {A Strain of Streptococcus mitis Inhibits Biofilm Formation of Caries Pathogens via Abundant Hydrogen Peroxide Production.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2024.08.06.606862}, pmid = {39149263}, issn = {2692-8205}, abstract = {Commensal oral streptococci that colonize supragingival biofilms deploy mechanisms to combat competitors within their niche. Here, we determined that Streptococcus mitis more effectively inhibited biofilm formation of Streptococcus mutans within a seven species panel. This phenotype was common amongst all assayed isolates of S. mutans , but was specific to a single strain of S. mitis , ATCC 49456. The growth inhibitory factor was not effectively carried in spent supernatants of S. mitis . However, we documented ATCC 49456 to accumulate 4-5 times more hydrogen peroxide (H 2 O 2) than other species tested, and 5-18 times more than other S. mitis strains assayed. The S. mutans biofilm formation inhibitory phenotype was reduced when grown in media containing catalase or with a S. mitis mutant of pyruvate oxidase (spxB ; pox), confirming that SpxB-dependent H 2 O 2 production was the main antagonistic factor. Addition of S. mitis within hours after S. mutans inoculation was effective at reducing biofilm biomass, but not for 24 h pre-formed biofilms. Transcriptome analysis revealed responses for both S. mitis and S. mutans , with several S. mutans differentially expressed genes following a gene expression pattern previously described, while others being unique to the interaction with S. mitis . Finally, we show that S. mitis also affected coculture biofilm formation of several other commensal streptococci. Our study shows that strains with abundant H 2 O 2 production are effective at inhibiting initial growth of caries pathogens like S. mutans , but are less effective at disrupting pre-formed biofilms and have the potential to influence the stability of other oral commensal strains.}, }
@article {pmid39148892, year = {2024}, author = {Schlichter Kadosh, Y and Muthuraman, S and Nisaa, K and Ben-Zvi, A and Karsagi Byron, DL and Shagan, M and Brandis, A and Mehlman, T and Gopas, J and Saravana Kumar, R and Kushmaro, A}, title = {Pseudomonas aeruginosa quorum sensing and biofilm attenuation by a di-hydroxy derivative of piperlongumine (PL-18).}, journal = {Biofilm}, volume = {8}, number = {}, pages = {100215}, doi = {10.1016/j.bioflm.2024.100215}, pmid = {39148892}, issn = {2590-2075}, abstract = {Bacterial communication, Quorum Sensing (QS), is a target against virulence and prevention of antibiotic-resistant infections. 16 derivatives of Piperlongumine (PL), an amide alkaloid from Piper longum L., were screened for QS inhibition. PL-18 had the best QSI activity. PL-18 inhibited the lasR-lasI, rhlR-rhlI, and pqs QS systems of Pseudomonas aeruginosa. PL-18 inhibited pyocyanin and rhamnolipids that are QS-controlled virulence elements. Iron is an essential element for pathogenicity, biofilm formation and resilience in harsh environments, its uptake was inhibited by PL-18. Pl-18 significantly reduced the biofilm biovolume including in established biofilms. PL-18-coated silicon tubes significantly inhibited biofilm formation. The transcriptome study of treated P. aeruginosa showed that PL-18 indeed reduced the expression of QS and iron homeostasis related genes, and up regulated sulfur metabolism related genes. Altogether, PL-18 inhibits QS, virulence, iron uptake, and biofilm formation. Thus, PL-18 should be further developed against bacterial infection, antibiotic resistance, and biofilm formation.}, }
@article {pmid39147521, year = {2024}, author = {Ren, F and Chen, Y and Yang, S and Zhang, Y and Liu, Y and Ma, Y and Wang, Y and Liu, Y and Dong, Q and Lu, D}, title = {Characterization of emetic Bacillus cereus biofilm formation and cereulide production in biofilm.}, journal = {Food research international (Ottawa, Ont.)}, volume = {192}, number = {}, pages = {114834}, doi = {10.1016/j.foodres.2024.114834}, pmid = {39147521}, issn = {1873-7145}, mesh = {*Bacillus cereus/metabolism/physiology ; *Biofilms/growth &amp; development ; *Depsipeptides/metabolism ; *Food Microbiology ; Microscopy, Confocal ; Animals ; Milk/microbiology ; Hot Temperature ; Extracellular Polymeric Substance Matrix/metabolism ; Foodborne Diseases/microbiology ; Food Handling/methods ; }, abstract = {Bacillus cereus is a well-known foodborne pathogen that can cause human diseases, including vomiting caused by emetic toxin, cereulide, requiring 10[5]-10[8] cells per gram to cause the disease. The bacterial cells may be eliminated during processing, but cereulide can survive in most processing techniques due to its resistance to high temperatures, extreme pH and proteolytic enzymes. Herein, we reported dynamic processes of biofilm formation of four different types and cereulide production within the biofilm. Confocal laser scanning microscopy (CLSM) images revealed that biofilms of the four different types reach each stage at different time points. Among the extracellular polymeric substances (EPS) components of the four biofilms formed by the emetic B. cereus F4810/72 strain, proteins account for the majority. In addition, there are significant differences (p < 0.05) in the EPS components at the same stage among biofilms of different types. The time point at which cereulide was first detected in the four types of biofilms was 24 h. In the biofilm of B. cereus formed in ultra-high-temperature (UHT) milk, the first peak of cereulide appeared at 72 h. The cereulide content of the biofilms formed in BHI was mostly higher than that of the biofilms formed in UHT milk. This study contributes to a better understanding of food safety issues in the industry caused by biofilm and cereulide toxin produced by B. cereus.}, }
@article {pmid39146677, year = {2024}, author = {Khalaf, MM and Gouda, M and Abou Taleb, MF and Heakal, FE and Abd El-Lateef, HM}, title = {Fabrication of smart nanogel based on carrageenan and green coffee extract as a long-term antifouling agent to improve biofilm prevention in food production.}, journal = {Food chemistry}, volume = {461}, number = {}, pages = {140719}, doi = {10.1016/j.foodchem.2024.140719}, pmid = {39146677}, issn = {1873-7072}, abstract = {This study investigates the extract of the bioactive compounds from green coffee extract (GCE) and the loading of two different concentrations of GCE (1% and 2%) onto carrageenan nanogels (CAR NGs) to compare their antibacterial and antibiofilm effects with unloaded nanogels (NGs). The bioactive compounds of GCE were characterized using GC-MS analysis. The GCE1 and GCE2 were successfully deposited onto the surface of CAR NGs. The antibacterial and antibiofilm potential of prepared NGs were conducted against some foodborne pathogens (E. coli O157, Salmonella enterica, Staphylococcus aureus, and Listeria monocytogenes). The results of GC-MS analysis indicated that there were identified 16 bioactive compounds in GCE, including caffeine (36.27%), Dodemorph (9.04%), and D-Glycero-d-ido-heptose (2.44%), contributing to its antimicrobial properties. The antibacterial coatings demonstrated a notable antimicrobial effect, showing zone of inhibition (ZOI) diameters of up to 37 mm for GCE2 loaded CAR NGs. The minimum inhibitory concentration (MIC) values for GCE2 loaded CAR NGs were 80 ppm for E. coli O157, and 120 ppm for S. enterica, S. aureus, and L. monocytogenes, achieving complete bacterial inactivation within 10-15 min of exposure. Both GCE1 and GCE2 loaded CAR NGs significantly reduced biofilm cell densities on stainless steel (SS) materials for E. coli O157, S. enterica, S. aureus, and L. monocytogenes, with reductions ranging from 60% to 95%. Specifically, biofilm densities were reduced by up to 95% for E. coli O157, 89% for S. enterica, 85% for S. aureus, and 80% for L. monocytogenes. Results of the toxicity evaluation indicated that the NGs were non-toxic and biocompatible, with predicted EC50 values proved their biocompatibility and safety. These results recommended that GCE loaded CAR NGs are promising as natural antimicrobial agents for enhancing food safety and extending shelf life. Further, the study concluded that incorporating GCE into CAR NGs is an effective strategy for developing sustainable antimicrobial coatings for the food industry and manufacturing.}, }
@article {pmid39146626, year = {2024}, author = {Pramana, A and Firmanda, A and Arnata, IW and Sartika, D and Sari, EO}, title = {Reduction of biofilm and pathogenic microorganisms using curcumin-mediated photodynamic inactivation to prolong food shelf-life.}, journal = {International journal of food microbiology}, volume = {425}, number = {}, pages = {110866}, doi = {10.1016/j.ijfoodmicro.2024.110866}, pmid = {39146626}, issn = {1879-3460}, abstract = {Pathogenic microbial contamination (bacteria and fungi) in food products during production poses a significant global health risk, leading to food waste, greenhouse gas emissions, and aesthetic and financial losses. Bacteria and fungi, by forming solid biofilms, enhance their resistance to antimicrobial agents, thereby increasing the potential for cross-contamination of food products. Curcumin molecule-mediated photodynamic inactivation (Cur-m-PDI) technology has shown promising results in sterilizing microbial contaminants and their biofilms, significantly contributing to food preservation without compromising quality. Photosensitizers (curcumin) absorb light, leading to a chemical reaction with oxygen and producing reactive oxygen species (ROS) that effectively reduce bacteria, fungi, and biofilms. The mechanism of microorganism inhibition is caused by exposure to ROS generated via the type 1 pathway involving electron transfer (such as O2•[-], H2O2, -OH•, and other radicals), the type 2 pathway involving energy transfer (such as [1]O2), secondary ROS, and weakening of antioxidant enzymes. The effectiveness of the inactivation of microorganisms is influenced by the concentration of curcumin, light (source type and energy density), oxygen availability, and duration of exposure. This article reviews the mechanism of reducing microbial food contamination and inhibiting their biofilms through Cur-m-PDI. It also highlights future directions, challenges, and considerations related to the effects of ROS in oxidizing food, the toxicity of PDI to living cells and tissues, conditions/types of food products, and the stability and degradation of curcumin.}, }
@article {pmid39145307, year = {2024}, author = {Tekedar, HC and Patel, F and Blom, J and Griffin, MJ and Waldbieser, GC and Kumru, S and Abdelhamed, H and Dharan, V and Hanson, LA and Lawrence, ML}, title = {Tad pili contribute to the virulence and biofilm formation of virulent Aeromonas hydrophila.}, journal = {Frontiers in cellular and infection microbiology}, volume = {14}, number = {}, pages = {1425624}, pmid = {39145307}, issn = {2235-2988}, mesh = {*Aeromonas hydrophila/genetics/pathogenicity/physiology ; *Biofilms/growth &amp; development ; *Fimbriae, Bacterial/genetics/metabolism ; Virulence/genetics ; Animals ; *Operon ; *Gram-Negative Bacterial Infections/microbiology ; *Fish Diseases/microbiology ; Bacterial Adhesion/genetics ; Catfishes/microbiology ; Bacterial Proteins/genetics/metabolism ; Gene Knockout Techniques ; }, abstract = {Type IV pili (T4P) are versatile proteinaceous protrusions that mediate diverse bacterial processes, including adhesion, motility, and biofilm formation. Aeromonas hydrophila, a Gram-negative facultative anaerobe, causes disease in a wide range of hosts. Previously, we reported the presence of a unique Type IV class C pilus, known as tight adherence (Tad), in virulent Aeromonas hydrophila (vAh). In the present study, we sought to functionalize the role of Tad pili in the pathogenicity of A. hydrophila ML09-119. Through a comprehensive comparative genomics analysis of 170 A. hydrophila genomes, the conserved presence of the Tad operon in vAh isolates was confirmed, suggesting its potential contribution to pathogenicity. Herein, the entire Tad operon was knocked out from A. hydrophila ML09-119 to elucidate its specific role in A. hydrophila virulence. The absence of the Tad operon did not affect growth kinetics but significantly reduced virulence in catfish fingerlings, highlighting the essential role of the Tad operon during infection. Biofilm formation of A. hydrophila ML09-119 was significantly decreased in the Tad operon deletant. Absence of the Tad operon had no effect on sensitivity to other environmental stressors, including hydrogen peroxide, osmolarity, alkalinity, and temperature; however, it was more sensitive to low pH conditions. Scanning electron microscopy revealed that the Tad mutant had a rougher surface structure during log phase growth than the wildtype strain, indicating the absence of Tad impacts the outer surface of vAh during cell division, of which the biological consequences are unknown. These findings highlight the role of Tad in vAh pathogenesis and biofilm formation, signifying the importance of T4P in bacterial infections.}, }
@article {pmid39144210, year = {2024}, author = {Wang, W and Li, Y and Lu, S and Liu, P and Han, X and Sun, W and Wang, Q and Fang, W and Jiang, W}, title = {BolA-like protein (IbaG) promotes biofilm formation and pathogenicity of Vibrio parahaemolyticus.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1436770}, pmid = {39144210}, issn = {1664-302X}, abstract = {Vibrio parahaemolyticus is a gram-negative halophilic bacterium widespread in temperate and tropical coastal waters; it is considered to be the most frequent cause of Vibrio-associated gastroenteritis in many countries. BolA-like proteins, which reportedly affect various growth and metabolic processes including flagellar synthesis in bacteria, are widely conserved from prokaryotes to eukaryotes. However, the effects exerted by BolA-like proteins on V. parahaemolyticus remain unclear, and thus require further investigation. In this study, our purpose was to investigate the role played by BolA-like protein (IbaG) in the pathogenicity of V. parahaemolyticus. We used homologous recombination to obtain the deletion strain ΔibaG and investigated the biological role of BolA family protein IbaG in V. parahaemolyticus. Our results showed that IbaG is a bacterial transcription factor that negatively modulates swimming capacity. Furthermore, overexpressing IbaG enhanced the capabilities of V. parahaemolyticus for swarming and biofilm formation. In addition, inactivation of ibaG in V. parahaemolyticus SH112 impaired its capacity for colonizing the heart, liver, spleen, and kidneys, and reduced visceral tissue damage, thereby leading to diminished virulence, compared with the wild-type strain. Finally, RNA-sequencing revealed 53 upregulated and 71 downregulated genes in the deletion strain ΔibaG. KEGG enrichment analysis showed that the two-component system, quorum sensing, bacterial secretion system, and numerous amino acid metabolism pathways had been altered due to the inactivation of ibaG. The results of this study indicated that IbaG exerts a considerable effect on gene regulation, motility, biofilm formation, and pathogenicity of V. parahaemolyticus. To the best of our knowledge, this is the first systematic study on the role played by IbaG in V. parahaemolyticus infections. Thus, our findings may lead to a better understanding of the metabolic processes involved in bacterial infections and provide a basis for the prevention and control of such infections.}, }
@article {pmid39143645, year = {2024}, author = {Al-Khafaji, NSK and Almjalawi, BSA and Ewadh, RMJ and Al-Dahmoshi, HOM and Abed, SY and Nasrolahi, A and Nwobodo, DC and Kanaan, MHG and Abdullah, SS and Saki, M}, title = {Prevalence of plasmid-mediated quinolone resistance genes and biofilm formation in different species of quinolone-resistant clinical Shigella isolates: a cross-sectional study.}, journal = {European journal of medical research}, volume = {29}, number = {1}, pages = {419}, pmid = {39143645}, issn = {2047-783X}, mesh = {Humans ; *Biofilms/drug effects/growth &amp; development ; Cross-Sectional Studies ; *Quinolones/pharmacology ; *Shigella/genetics/drug effects/isolation &amp; purification ; *Plasmids/genetics ; *Anti-Bacterial Agents/pharmacology ; *Microbial Sensitivity Tests ; Drug Resistance, Bacterial/genetics ; Prevalence ; Dysentery, Bacillary/microbiology/epidemiology/drug therapy ; Female ; }, abstract = {BACKGROUND: The purpose of this study was to look into the presence of plasmid-mediated quinolone resistance (PMQR) genes and biofilm formation in several species of clinical Shigella isolates that were resistant to quinolones.<br><br>METHODS: The stool samples of 150 patients (younger than 10 years) with diarrhea were collected in this cross-sectional study (November 2020 to December 2021). After cultivation of samples on Hektoen Enteric agar and xylose lysine deoxycholate agar, standard microbiology tests, VITEK 2 system, and polymerase chain reaction (PCR) were utilized to identify Shigella isolates. The broth microdilution method was used to determine antibiotic susceptibility. PMQR genes including qnrA, qnrB, qnrC, qnrD, qnrE, qnrS, qnrVC, qepA, oqxAB, aac(6')-Ib-cr, and crpP and biofilm formation were investigated in quinolone-resistant isolates by PCR and microtiter plate method, respectively. An enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) technique was used to determine the clonal relatedness of quinolone-resistant isolates.<br><br>RESULTS: A total of 95 Shigella isolates including S. sonnei (53, 55.8%), S. flexneri (39, 41.1%), and S. boydii (3, 3.2%) were identified. The highest resistance rates of the isolates were against ampicillin (92.6%, n&#x2009;=&#x2009;88/95). Overall, 42 of 95 (44.2%) isolates were simultaneously resistant against two or more quinolones including 26 (61.9%) S. sonnei and 16 (38.1%) S. flexneri. All isolates were multidrug-resistant (resistance to more than 3 antibiotics). The occurrence of PMQR genes was as follows: qnrS (52.4%), qnrA and aac(6')-Ib-cr (33.3%), and qnrB (19.0%). The prevalence in species was as follows: 61.5% and 37.5% (qnrS), 19.2% and 56.3% (qnrA), 38.5% and 25.0 (aac(6')-Ib-cr), and 19.2% and 18.8% (qnrB) for S. sonnei and S. flexneri, respectively. The other PMQR genes were not detected. In total, 52.8% (28/53) of quinolone-susceptible and 64.3% (27/42) of quinolone-resistant isolates were biofilm producers. Biofilm formation was not significantly different between quinolone-resistant and quinolone-susceptible isolates (P-value&#x2009;=&#x2009;0.299). Quinolone-resistant isolates showed a high genetic diversity according to the ERIC-PCR.<br><br>CONCLUSION: It seems that qnrS, qnrA, and aac(6')-Ib-cr play a significant role in the quinolone resistance among Shigella isolates in our region. Also the quinolone-resistant S. flexneri and S. sonnei isolates had a high genetic diversity. Hence, antibiotic therapy needs to be routinely revised based on the surveillance findings.}, }
@article {pmid39142478, year = {2024}, author = {Hu, D and Long, D and Xia, T and Wang, Y and Zhang, S and Wang, J and Shi, X and Wang, Y}, title = {Accelerated healing of intractable biofilm-infected diabetic wounds by trypsin-loaded quaternized chitosan hydrogels that disrupt extracellular polymeric substances and eradicate bacteria.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {134677}, doi = {10.1016/j.ijbiomac.2024.134677}, pmid = {39142478}, issn = {1879-0003}, abstract = {Complex and stubborn bacterial biofilm infections significantly hinder diabetic wound healing and threaten public health. Therefore, a dressing material that effectively clears biofilms and promotes wound healing is urgently required. Herein, we introduce a novel strategy for simultaneously dispersing extracellular polymeric substances and eradicating drug-resistant bacteria. We prepared an ultrabroad-spectrum and injectable quaternized chitosan (QCS) hydrogel loaded with trypsin, which degrades biofilm extracellular proteins. Increased temperature initiated QCS gelation to form the hydrogel, enabling the sustained release of trypsin and effective adherence of the hydrogel to irregularly shaped wounds. To reproduce clinical scenarios, biofilms formed by a mixture of Staphylococcus aureus (S. aureus), Methicillin-resistant S. aureus, and Pseudomonas aeruginosa were administered to the wounds of rats with streptozotocin-induced diabetes. Under these severe infection conditions, the hydrogel efficiently suppressed inflammation, promoted angiogenesis, and enhanced collagen deposition, resulting in accelerated healing of diabetic wounds. Notably, the hydrogel demonstrates excellent biocompatibility without cytotoxicity. In summary, we present a trypsin-loaded QCS hydrogel with tremendous clinical applications potential for the treatment of chronic infected wounds.}, }
@article {pmid39142418, year = {2024}, author = {Li, Y and Wang, Q and Chen, H and Song, C and Zheng, Y and Chai, Z and Zheng, M}, title = {Multi-stage oxic biofilm system for pilot-scale treatment of coking wastewater: Pollutants removal performance, biofilm properties and microbial community.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131271}, doi = {10.1016/j.biortech.2024.131271}, pmid = {39142418}, issn = {1873-2976}, abstract = {A multi-stage oxic biofilm system based on hydrophilic polyurethane foam was established and operated for advanced treatment of coking wastewater, in which distinct gradient variations of pollutants removal, biofilm properties and microbial community in the 5 stages were evaluated. The system rapidly achieved NH+4-N removal efficiency of 97.51 ± 2.29 % within 8 days. The biofilm growing attached on the carriers exhibited high biomass (≥10.29 g/L), which ensured sufficient microbial population. Additionally, the rising extracellular polymeric substance and declining proteins/polysaccharides ratios across stages suggested a dense-to-loose transition in the biofilm's structure, in response to the varying pollutant concentrations. The dominance of Nitrosomonas cluster in the first 3 stages and Nitrospira lineage in the following 2 stages facilitated the complete depletion of high NH+4-N concentration without NO- 2-N accumulation. Overall, the distinct biofilm property and community at each stage, shaped by the multi-stage configuration, maximized the pollutants removal efficiency.}, }
@article {pmid39142417, year = {2024}, author = {Wei, CH and Zhai, XY and Jiang, YD and Rong, HW and Zhao, LG and Liang, P and Huang, X and Ngo, HH}, title = {Simultaneous carbon, nitrogen and phosphorus removal in sequencing batch membrane aerated biofilm reactor with biofilm thickness control via air scouring aided by computational fluid dynamics.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131267}, doi = {10.1016/j.biortech.2024.131267}, pmid = {39142417}, issn = {1873-2976}, abstract = {Membrane aerated biofilm reactor (MABR) is challenged by biofilm thickness control and phosphorus removal. Air scouring aided by computational fluid dynamics (CFD) was employed to detach outer biofilm in sequencing batch MABR treating low C/N wastewater. Biofilm with 177-285 µm thickness in cycle 5-15 achieved over 85 % chemical oxygen demand (COD) and total inorganic nitrogen (TIN) removals at loading rate of 13.2 gCOD/m[2]/d and 2.64 gNH4[+]-N/m[2]/d. Biofilm rheology measurements in cycle 10-25 showed yield stress against detachment of 2.8-7.4 Pa, which were equal to CFD calculated shear stresses under air scouring flowrate of 3-9 L/min. Air scouring reduced effluent NH4[+]-N by 10 % and biofilm thickness by 78 µm. Intermittent aeration (4h off, 19.5h on) and air scouring (3 L/min, 30 s before settling) in one cycle achieved COD removal over 90 %, TIN and PO4[3-]-P removals over 80 %, showing great potential for simultaneous carbon, nitrogen and phosphorus removals.}, }
@article {pmid39143532, year = {2024}, author = {Yang, Y and Fan, L and Jiang, J and Sun, J and Xue, L and Ma, X and Kuai, L and Li, B and Li, Y}, title = {M2 macrophage-polarized anti-inflammatory microneedle patch for accelerating biofilm-infected diabetic wound healing via modulating the insulin pathway.}, journal = {Journal of nanobiotechnology}, volume = {22}, number = {1}, pages = {489}, pmid = {39143532}, issn = {1477-3155}, support = {(No. 82374444//National Natural Science Foundation of China/ ; No. RY411.33.10//Xinglin Youth Scholar of Shanghai University of Traditional Chinese Medicine/ ; (2021-2023//Youth Talent Promotion Project of China Association of Traditional Chinese Medicine/ ; CACM-2021-QNRC2-A10//Category A/ ; 2022YQ026//Health Young Talents of Shanghai Municipal Health Commission/ ; (No. 23YF1439800)//Shanghai Science and Technology Development Funds (Sailing Program)/ ; No. 2023ZZ02017//Shanghai Dermatology Research Center/ ; No. SHDC2023CRW009//Shanghai Skin Disease Hospital demonstration research ward project/ ; (No. 2022XD052)//Talent Program of Shanghai Municipal Health Commission/ ; No. 2021ZD0202003//Sci-Tech Innovation 2030-Major Project of Brain science and brain-inspired intelligence technology/ ; }, abstract = {Macrophages play a pivotal role in the healing of diabetic ulcers. The sustained elevation of glucose levels damages the insulin signaling pathway in macrophages, leading to dysfunctional macrophages that struggle to transition from pro-inflammatory (M1) to reparative (M2) states. Therefore, modulating macrophage inflammatory responses via the insulin pathway holds promise for diabetic ulcer treatment. Additionally, the presence of biofilm impedes drug penetration, and the resulting immunosuppressive microenvironment exacerbates the persistent infiltration of pro-inflammatory M1 macrophages. Therefore, we designed an array of dissolvable microneedle (denoted as NPF@MN) loaded with self-assembled nanoparticles that could deliver NPF nanoparticles, acid-sensitive NPF-releasing Protocatechualdehyde (PA) with hypoglycemic and insulin-like effects, regulating macrophage polarization to an anti-inflammatory M2 phenotype. Additionally, this study extensively examined the mechanism by which NPF@MN accelerates the healing of diabetic ulcers through the activation of the insulin signaling pathway. Through RNA-seq and GSEA analysis, we identified a reduction in the expression of pathway-related factors such as IR, IRS-1, IRS-2, and SHC. Our work presents an innovative therapeutic approach targeting the insulin pathway in diabetic ulcers and underscores its translational potential for clinical management.}, }
@article {pmid39141938, year = {2024}, author = {Shi, J and Wan, N and Yang, S and Yang, Y and Han, H}, title = {Which biofilm reactor is suitable for degradation of 2,4-dimethylphenol, focusing on bacteria, algae, or a combination of bacteria-algae?.}, journal = {Journal of hazardous materials}, volume = {478}, number = {}, pages = {135492}, doi = {10.1016/j.jhazmat.2024.135492}, pmid = {39141938}, issn = {1873-3336}, abstract = {Effectively treating phenolic substances is a crucial task in environmental protection. This study aims to determine whether bacterial-algae biofilm reactors offer superior treatment efficacy compared to traditional activated sludge and biofilm reactors. The average degradation ratios of 2,4-dimethylphenol (40, 70, 150, 300, and 230 mg/L) were found to be 98 %, 99 %, 92.1 %, 84.7 %, and 63.7 % respectively. The bacterial-algae biofilm demonstrates a higher tolerance to toxicity, assimilation ability, and efficacy recovery ability. The cell membrane of Chlorella in the bacteria-algae biofilm is not easily compromised, thus ensuring a stable pH environment. High concentrations of tightly bound extracellular polymers (TB-EPS) enhance the efficacy in treating toxic pollutants, promote the stable structure. Intact Chlorella, bacilli, and EPS were observed in bacterial-algal biofilm. The structural integrity of bacteria-algae consistently enhances its resistance to the inhibitory effects of high concentrations of phenolic compounds. Cloacibacterium, Comamonas, and Dyella were the main functional bacterial genera that facilitate the formation of bacterial-algal biofilms and the degradation of phenolic compounds. The dominant microalgal families include Aspergillaceae, Chlorellales, Chlorellaceae, and Scenedesmaceae have certain treatment effects on phenolic substances. Chlorellales and Chlorellaceae have the ability to convert NH4[+]-N. The Aspergillaceae is also capable of generating synergistic effects with Chlorellales, Chlorellaceae, and Scenedesmaceae, thereby establishing a stable bacterial-algal biofilm system.}, }
@article {pmid39141525, year = {2024}, author = {Charria-Girón, E and Zeng, H and Gorelik, TE and Pahl, A and Truong, KN and Schrey, H and Surup, F and Marin-Felix, Y}, title = {Arcopilins: A New Family of Staphylococcus aureus Biofilm Disruptors from the Soil Fungus Arcopilus navicularis.}, journal = {Journal of medicinal chemistry}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.jmedchem.4c00585}, pmid = {39141525}, issn = {1520-4804}, abstract = {Biofilms represent a key challenge in the treatment of microbial infections; for instance, Staphylococcus aureus causes chronic or fatal infections by forming biofilms on medical devices. Herein, the fungus Arcopilus navicularis was found to produce a novel family of PKS-NRPS metabolites that are able to disrupt preformed biofilms of S. aureus. Arcopilins A-F (1-6), tetramic acids, and arcopilin G (7), a 2-pyridone, were elucidated using HR-ESI-MS and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy. Their absolute configuration was established by the synthesis of MPTA-esters for 2, analysis of [1]H-[1]H coupling constants, and ROESY correlations, along with comparison with the crystal structure of 7. Arcopilin A (1) not only effectively disrupts preformed biofilms of S. aureus but also potentiates the activity of gentamicin and vancomycin up to 115- and 31-fold times, respectively. Our findings demonstrate the potential application of arcopilins for the conjugated treatment of infections caused by S. aureus with antibiotics unable to disrupt preformed biofilms.}, }
@article {pmid39140783, year = {2024}, author = {Chen, G and Fanouraki, G and Anandhi Rangarajan, A and Winkelman, BT and Winkelman, JT and Waters, CM and Mukherjee, S}, title = {Combinatorial control of Pseudomonas aeruginosa biofilm development by quorum-sensing and nutrient-sensing regulators.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0037224}, doi = {10.1128/msystems.00372-24}, pmid = {39140783}, issn = {2379-5077}, abstract = {The human pathogen Pseudomonas aeruginosa, a leading cause of hospital-acquired infections, inhabits and forms sessile antibiotic-resistant communities called biofilms in a wide range of biotic and abiotic environments. In this study, we examined how two global sensory signaling pathways-the RhlR quorum-sensing system and the CbrA/CbrB nutritional adaptation system-intersect to control biofilm development. Previous work has shown that individually these two systems repress biofilm formation. Here, we used biofilm analyses, RNA-seq, and reporter assays to explore the combined effect of information flow through RhlR and CbrA on biofilm development. We find that the ΔrhlRΔcbrA double mutant exhibits a biofilm morphology and an associated transcriptional response distinct from wildtype and the parent ΔrhlR and ΔcbrA mutants indicating codominance of each signaling pathway. The ΔrhlRΔcbrA mutant gains suppressor mutations that allow biofilm expansion; these mutations map to the crc gene resulting in loss of function of the carbon catabolite repression protein Crc. Furthermore, the combined absence of RhlR and CbrA leads to a drastic reduction in the abundance of the Crc antagonist small RNA CrcZ. Thus, CrcZ acts as the molecular convergence point for quorum- and nutrient-sensing cues. We find that in the absence of antagonism by CrcZ, Crc promotes the expression of biofilm matrix components-Pel exopolysaccharide, and CupB and CupC fimbriae. Therefore, this study uncovers a regulatory link between nutritional adaption and quorum sensing with potential implications for anti-biofilm targeting strategies.IMPORTANCEBacteria often form multicellular communities encased in an extracytoplasmic matrix called biofilms. Biofilm development is controlled by various environmental stimuli that are decoded and converted into appropriate cellular responses. To understand how information from two distinct stimuli is integrated, we used biofilm formation in the human pathogen Pseudomonas aeruginosa as a model and studied the intersection of two global sensory signaling pathways-quorum sensing and nutritional adaptation. Global transcriptomics on biofilm cells and reporter assays suggest parallel regulation of biofilms by each pathway that converges on the abundance of a small RNA antagonist of the carbon catabolite repression protein, Crc. We find a new role of Crc as it modulates the expression of biofilm matrix components in response to the environment. These results expand our understanding of the genetic regulatory strategies that allow P. aeruginosa to successfully develop biofilm communities.}, }
@article {pmid39140393, year = {2024}, author = {Basudan, S and Alqahtani, A and Alrwais, F and Almeaither, R and Auda, S and Balto, HA}, title = {Antibiofilm effect of different concentrations of silver nanoparticles combined with calcium hydroxide against Enterococcus faecalis biofilm: An ex vivo study.}, journal = {Australian endodontic journal : the journal of the Australian Society of Endodontology Inc}, volume = {}, number = {}, pages = {}, doi = {10.1111/aej.12882}, pmid = {39140393}, issn = {1747-4477}, support = {RSP-2024/179//Researchers Supporting Project, King Saud University/ ; }, abstract = {This study aimed to evaluate the antibiofilm activity of different concentrations of silver nanoparticles (AgNPs) in combination with calcium hydroxide [Ca(OH)2] against Enterococcus faecalis biofilm. On an E. faecalis biofilm on dentin discs, the following medicaments were applied for 7 days (n = 13/group): 0.005% AgNPs+Ca(OH)2, 0.01% AgNPs+Ca(OH)2, 0.02% AgNPs + Ca(OH)2, Ca(OH)2 and saline/control. Specimens were stained with LIVE/DEAD® BacLight™ dye and analysed with confocal laser scanning microscopy. Proportion of dead bacteria was calculated and analysed. There was a significant reduction in E. faecalis biofilm in all medicament groups (43.5%, 49.1%, 69.1%, 48.7%) respectively, compared with control group (2.54%) (p < 0.001). The 0.02% AgNPs + Ca(OH)2 group demonstrated the most significantly superior antibiofilm effect, with no significant difference between remaining groups. In conclusion, combining 0.02% AgNPs enhanced the antibiofilm effect of Ca(OH)2 on E. faecalis biofilm compared with lower AgNPs concentrations.}, }
@article {pmid39140129, year = {2024}, author = {Manobala, T}, title = {Peptide-based strategies for overcoming biofilm-associated infections: a comprehensive review.}, journal = {Critical reviews in microbiology}, volume = {}, number = {}, pages = {1-18}, doi = {10.1080/1040841X.2024.2390597}, pmid = {39140129}, issn = {1549-7828}, abstract = {Biofilms represent resilient microbial communities responsible for inducing chronic infections in human subjects. Given the escalating challenges associated with antibiotic therapy failures in clinical infections linked to biofilm formation, a peptide-based approach emerges as a promising alternative to effectively combat these notoriously resistant biofilms. Contrary to conventional antimicrobial peptides, which predominantly target cellular membranes, antibiofilm peptides necessitate a multifaceted approach, addressing various "biofilm-specific factors." These factors encompass Extracellular Polymeric Substance (EPS) degradation, membrane targeting, cell signaling, and regulatory mechanisms. Recent research endeavors have been directed toward assessing the potential of peptides as potent antibiofilm agents. However, to translate these peptides into viable clinical applications, several critical considerations must be meticulously evaluated during the peptide design process. This review serves to furnish an all-encompassing summary of the pivotal factors and parameters that necessitate contemplation for the successful development of an efficacious antibiofilm peptide.}, }
@article {pmid39139372, year = {2024}, author = {Diaz-Mateus, MA and Salgar-Chaparro, SJ and Tarazona, J and Farhat, H}, title = {Exploring the influence of deposit mineral composition on biofilm communities in oil and gas systems.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1438806}, pmid = {39139372}, issn = {1664-302X}, abstract = {INTRODUCTION: Inside oil and gas pipelines, native microbial communities and different solid compounds typically coexist and form mixed deposits. However, interactions between these deposits (primarily consisting of mineral phases) and microorganisms in oil and gas systems remain poorly understood. Here, we investigated the influence of magnetite (Fe3O4), troilite (FeS), and silica (SiO2) on the microbial diversity, cell viability, biofilm formation, and EPS composition of an oil-recovered multispecies consortium.<br><br>METHODS: An oilfield-recovered microbial consortium was grown for 2 weeks in separate bioreactors, each containing 10&#x2009;g of commercially available magnetite (Fe3O4), troilite (FeS), or silica (SiO2) at 40&#xb0;C&#x2009;&#xb1;&#x2009;1&#xb0;C under a gas atmosphere of 20% CO2/80% N2.<br><br>RESULTS: The microbial population formed in troilite significantly differed from those in silica and magnetite, which exhibited significant similarities. The dominant taxa in troilite was the Dethiosulfovibrio genus, whereas Sulfurospirillum dominated in magnetite and silica. Nevertheless, biofilm formation was lowest on troilite and highest on silica, correlating with the observed cell viability.<br><br>DISCUSSION: The dissolution of troilite followed by the liberation of HS[-] (H2S) and Fe[2+] into the test solution, along with its larger particle size compared to silica, likely contributed to the observed results. Confocal laser scanning microscopy revealed that the EPS of the biofilm formed in silica was dominated by eDNA, while those in troilite and magnetite primarily contained polysaccharides. Although the mechanisms of this phenomenon could not be determined, these findings are anticipated to be particularly valuable for enhancing MIC mitigation strategies currently used in oil and gas systems.}, }
@article {pmid39139360, year = {2024}, author = {Roscetto, E and Di Gennaro, D and Ascione, T and Galdiero, U and Aversa, M and Festa, E and Catania, MR and Balato, G}, title = {Antiseptics' Concentration, Combination, and Exposure Time on Bacterial and Fungal Biofilm Eradication.}, journal = {Arthroplasty today}, volume = {28}, number = {}, pages = {101468}, pmid = {39139360}, issn = {2352-3441}, abstract = {BACKGROUND: This study aims to assess the activity of solutions containing povidone-iodine (PI) and hydrogen peroxide (H2O2) alone or combined on the biofilm of microbial species in the contest of periprosthetic joint infection (PJI).<br><br>METHODS: Different antiseptic solutions were tested on 2-day-old biofilms of Gram-positive and Gram-negative bacteria and fungi at 1 and 3 minutes of exposure. The efficacy of these solutions was evaluated by measuring the biofilm metabolic activity by methoxynitrosulfophenyl-tetrazolium carboxanilide (XTT) reduction assay. The anti-biofilm effect of 5% PI and 0.3% PI&#xa0;+ 0.5% H2O2 was tested on a 5-day-old biofilm using colony-forming unit counts and an XTT reduction assay.<br><br>RESULTS: PI and H2O2 solutions showed concentration-dependent anti-biofilm activity except for E.&#xa0;faecalis. PI at 5% was the most active solution against the 2-day-old biofilm of all test microorganisms. The 0.3% PI&#xa0;+ 0.5% H&#x2082;O&#x2082; solution had a significant effect only at 3 minutes. The 5% PI and 0.3% PI&#xa0;+ 0.5% H&#x2082;O&#x2082; effect was evaluated on 5-day-old biofilms. PI at 5% produced a significant reduction in metabolic activity at both 1 and 3 minutes; 0.3% PI&#xa0;+ 0.5% H&#x2082;O&#x2082; caused a significant activity against all Gram-positive strains after 3 minutes, with a greater metabolic activity reduction than 5% PI.<br><br>CONCLUSIONS: In the case of PJI caused by Gram-positive bacteria, 0.3% PI&#xa0;+ 0.5% H&#x2082;O&#x2082; could be used for wound irrigation for 3 minutes of exposure. In the case of PJI with a different etiological agent or PJI with an unknown etiology, it is advisable to use 5% PI for 1 minute of exposure.}, }
@article {pmid39138881, year = {2024}, author = {Pathoor, NN and Ganesh, PS}, title = {Reply to "Comment on micro- and nanorobots for biofilm eradication".}, journal = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica}, volume = {}, number = {}, pages = {}, doi = {10.1111/apm.13460}, pmid = {39138881}, issn = {1600-0463}, }
@article {pmid39137519, year = {2024}, author = {Köksaldı, &#x130;&#xc7; and Avcı, E and Köse, S and Özkul, G and Kehribar, E&#x15e; and Şafak Şeker, U&#xd6;}, title = {Genetically engineered bacterial biofilm materials enhances portable whole cell sensing.}, journal = {Biosensors &amp; bioelectronics}, volume = {264}, number = {}, pages = {116644}, doi = {10.1016/j.bios.2024.116644}, pmid = {39137519}, issn = {1873-4235}, abstract = {In recent years, whole-cell biosensors (WCBs) have emerged as a potent approach for environmental monitoring and on-site analyte detection. These biosensors harness the biological apparatus of microorganisms to identify specific analytes, offering advantages in sensitivity, specificity, and real-time monitoring capabilities. A critical hurdle in biosensor development lies in ensuring the robust attachment of cells to surfaces, a crucial step for practical utility. In this study, we present a comprehensive approach to tackle this challenge via engineering Escherichia coli cells for immobilization on paper through the Curli biofilm pathway. Furthermore, incorporating a cellulose-binding peptide domain to the CsgA biofilm protein enhances cell adhesion to paper surfaces, consequently boosting biosensor efficacy. To demonstrate the versatility of this platform, we developed a WCB for copper, optimized to exhibit a discernible response, even with the naked eye. To confirm its suitability for practical field use, we characterized our copper sensor under various environmental conditions-temperature, salinity, and pH-to mimic real-world scenarios. The biosensor-equipped paper discs can be freeze-dried for deployment in on-site applications, providing a practical method for long-term storage without loss of sensitivity paper discs demonstrate sustained functionality and viability even after months of storage with 5 μM limit of detection for copper with visible-to-naked-eye signal levels. Biofilm-mediated surface attachment and analyte sensing can be independently engineered, allowing for flexible utilization of this platform as required. With the implementation of copper sensing as a proof-of-concept study, we underscore the potential of WCBs as a promising avenue for the on-site detection of a multitude of analytes.}, }
@article {pmid39137468, year = {2024}, author = {Tian, LL and Li, Y and Yang, R and Jiang, Y and He, JJ and Wang, H and Chen, LQ and Zhu, WY and Xue, T and Li, BB}, title = {Low concentrations of tetrabromobisphenol A promote the biofilm formation of methicillin-resistant Staphylococcus aureus.}, journal = {Ecotoxicology and environmental safety}, volume = {283}, number = {}, pages = {116853}, doi = {10.1016/j.ecoenv.2024.116853}, pmid = {39137468}, issn = {1090-2414}, abstract = {The effect and underlying mechanism of tetrabromobisphenol A (TBBPA), a plastic additive, on biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA USA300) remain unknown. This study first investigated the impact of different concentrations of TBBPA on the growth and biofilm formation of USA300. The results indicated that a low concentration (0.5 mg/L) of TBBPA promoted the growth and biofilm formation of USA300, whereas high concentrations (5 mg/L and 10 mg/L) of TBBPA had inhibitory effects. Further exploration revealed that the low concentration of TBBPA enhance biofilm formation by promoting the synthesis of extracellular proteins, release of extracellular DNA (eDNA), and production of staphyloxanthin. RTqPCR analysis demonstrated that the low concentration of TBBPA upregulated genes associated with extracellular protein synthesis (sarA, fnbA, fnbB, aur) and eDNA formation (atlA) and increased the expression of genes involved in staphyloxanthin biosynthesis (crtM), suggesting a potential mechanism for enhanced resistance of USA300 to adverse conditions. These findings shed light on how low concentrations of TBBPA facilitate biofilm formation in USA300 and highlight the indirect impact of plastic additives on pathogenic bacteria in terms of human health. In the future, in-depth studies about effects of plastic additives on pathogenicity of pathogenic bacteria should be conducted. CAPSULE: The protein and eDNA contents in biofilms of methicillin-resistant Staphylococcus aureus are increased by low concentrations of TBBPA.}, }
@article {pmid39135871, year = {2024}, author = {Saini, P and Ayyanna, R and Kumar, R and Bhowmick, SK and Bhaskar, V and Dey, B}, title = {Restriction of growth and biofilm formation of ESKAPE pathogens by caprine gut-derived probiotic bacteria.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1428808}, pmid = {39135871}, issn = {1664-302X}, abstract = {The accelerated rise in antimicrobial resistance (AMR) poses a significant global health risk, necessitating the exploration of alternative strategies to combat pathogenic infections. Biofilm-related infections that are unresponsive to standard antibiotics often require the use of higher-order antimicrobials with toxic side effects and the potential to disrupt the microbiome. Probiotic therapy, with its diverse benefits and inherent safety, is emerging as a promising approach to prevent and treat various infections, and as an alternative to antibiotic therapy. In this study, we isolated novel probiotic bacteria from the gut of domestic goats (Capra hircus) and evaluated their antimicrobial and anti-biofilm activities against the 'ESKAPE' group of pathogens. We performed comprehensive microbiological, biochemical, and molecular characterizations, including analysis of the 16S-rRNA gene V1-V3 region and the 16S-23S ISR region, on 20 caprine gut-derived lactic acid bacteria (LAB). Among these, six selected Lactobacillus isolates demonstrated substantial biofilm formation under anaerobic conditions and exhibited robust cell surface hydrophobicity and autoaggregation, and epithelial cell adhesion properties highlighting their superior enteric colonization capability. Notably, these Lactobacillus isolates exhibited broad-spectrum growth inhibitory and anti-biofilm properties against 'ESKAPE' pathogens. Additionally, the Lactobacillus isolates were susceptible to antibiotics listed by the European Food Safety Authority (EFSA) within the prescribed Minimum Inhibitory Concentration limits, suggesting their safety as feed additives. The remarkable probiotic characteristics exhibited by the caprine gut-derived Lactobacillus isolates in this study strongly endorse their potential as compelling alternatives to antibiotics and direct-fed microbial (DFM) feed supplements in the livestock industry, addressing the escalating need for antibiotic-free animal products.}, }
@article {pmid39135331, year = {2024}, author = {Gaihre, S and Prajapati, K and Dhungel, S and Dawadi, P and Joshi, DR and Joshi, TP}, title = {Occurrence of biofilm forming Escherichia coli in drinking water supply system in Kathmandu.}, journal = {Water environment research : a research publication of the Water Environment Federation}, volume = {96}, number = {8}, pages = {e11096}, doi = {10.1002/wer.11096}, pmid = {39135331}, issn = {1554-7531}, support = {//Nepal Academy of Science and Technology/ ; 4500406708//UNESCO and the International Development Research Center (IDRC)/ ; }, mesh = {*Biofilms ; *Escherichia coli/genetics/drug effects/physiology/isolation &amp; purification ; Nepal ; *Drinking Water/microbiology ; *Water Supply ; Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; Water Microbiology ; }, abstract = {Biofilm development in gram negative bacterial contaminants in water supply systems is linked to persistence as well as antibiotic resistance, which threatens water quality and hence the public health. This study aimed to investigate phenotypic and genetic capacity of biofilm formation by Escherichia coli isolated from supply water with their antibiotic susceptibility pattern. Altogether fifty water samples collected from a city supply water distribution scheme in Kathmandu were analyzed to assess the physicochemical and microbiological quality. Comparing Nepal's national drinking water quality standards 2022, conductivity (4%), turbidity (18%), iron (28%), and residual chlorine (8%) were found exceeding the values above the standards. Among total, 40% of water samples were contaminated with total coliform bacteria. E. coli and Citrobacter species were dominant and isolated from 20 (64.52%) and 11 (35.48%) water samples, respectively. Antibiotic susceptibility testing revealed that E. coli isolates were resistant to ampicillin (20%), nitrofurantoin (10%), and cefotaxime (10%). Citrobacter spp. (54.54%) were found multidrug resistant (MDR) while none of the isolates of E. coli were MDR. Of total, 45% of the isolates developed biofilm while testing with the Microtiter plate method. Biofilm-forming genes bcsA and csgD in E. coli isolates were detected with polymerase chain reaction (PCR) employing specific primers. bcsA and csgD genes were detected in 55% and 45% of the isolates, respectively. This study confirms the occurrences of biofilm forming and antibiotic resistant bacteria like E. coli in the drinking water supply system in Kathmandu alarming its environmental circulation and possible public health threat. Although further study is warranted, this study suggests public health and drinking water treatment interventions to mitigate the biofilm forming antibiotic resistant potential pathogens from supply water in Kathmandu, Nepal. PRACTITIONER POINTS: Forty percent of tested drinking water samples in Kathmandu were contaminated with total coliform bacteria. E. coli and half of Citrobacter spp. isolates were resistant to multiple antibiotics. bcsA and csgD genes were detected in biofilm producing E.coli isolates.}, }
@article {pmid39135304, year = {2024}, author = {Yeung, YWS and Ma, Y and Deng, Y and Khoo, BL and Chua, SL}, title = {Bacterial Iron Siderophore Drives Tumor Survival and Ferroptosis Resistance in a Biofilm-Tumor Spheroid Coculture Model.}, journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)}, volume = {}, number = {}, pages = {e2404467}, doi = {10.1002/advs.202404467}, pmid = {39135304}, issn = {2198-3844}, abstract = {Interactions between tumoral cells and tumor-associated bacteria within the tumor microenvironment play a significant role in tumor survival and progression, potentially impacting cancer treatment outcomes. In lung cancer patients, the Gram-negative pathogen Pseudomonas aeruginosa raises questions about its role in tumor survival. Here, a microfluidic-based 3D-human lung tumor spheroid-P. aeruginosa model is developed to study the bacteria's impact on tumor survival. P. aeruginosa forms a tumor-associated biofilm by producing Psl exopolysaccharide and secreting iron-scavenging pyoverdine, which is critical for establishing a bacterial community in tumors. Consequently, pyoverdine promotes cancer progression by reducing susceptibility to iron-induced death (ferroptosis), enhancing cell viability, and facilitating several cancer hallmarks, including epithelial-mesenchymal transition and metastasis. A promising combinatorial therapy approach using antimicrobial tobramycin, ferroptosis-inducing thiostrepton, and anti-cancer doxorubicin could eradicate biofilms and tumors. This work unveils a novel phenomenon of cross-kingdom cooperation, where bacteria protect tumors from death, and it paves the way for future research in developing antibiofilm cancer therapies. Understanding these interactions offers potential new strategies for combatting cancer and enhancing treatment efficacy.}, }
@article {pmid39133525, year = {2024}, author = {Scharnow, AM and Solinski, AE and Rowe, S and Drechsel, I and Zhang, H and Shaw, E and Page, JE and Wu, H and Sieber, SA and Wuest, WM}, title = {In Situ Biofilm Affinity-Based Protein Profiling Identifies the Streptococcal Hydrolase GbpB as the Target of a Carolacton-Inspired Chemical Probe.}, journal = {Journal of the American Chemical Society}, volume = {}, number = {}, pages = {}, doi = {10.1021/jacs.4c06658}, pmid = {39133525}, issn = {1520-5126}, abstract = {Natural products are important precursors for antibiotic drug design. These chemical scaffolds serve as synthetic inspiration for chemists who leverage their structures to develop novel antibacterials and chemical probes. We have previously studied carolacton, a natural product macrolactone fromSorangium cellulosum, and discovered a simplified derivative, A2, that maintained apparent biofilm inhibitory activity, although the biological target was unknown. Herein, we utilize affinity-based protein profiling (AfBPP) in situ during biofilm formation to identify the protein target using a photoexcitable cross-linking derivative of A2. From these studies, we identified glucan binding protein B (GbpB), a peptidoglycan hydrolase, as the primary target of A2. Further characterization of the interaction between A2 and GbpB, as well as PcsB, a closely related homologue from the more pathogenic S. pneumoniae, revealed binding to the catalytic CHAP (cysteine, histidine, aminopeptidase) domain. To the best of our knowledge, this is the first report of a small-molecule binder of a conserved and essential bacterial CHAP hydrolase, revealing its potential as an antibiotic target. This work also highlights A2 as a useful tool compound for streptococci and as an initial scaffold for the design of more potent CHAP binders.}, }
@article {pmid39133016, year = {2024}, author = {Albicoro, FJ and Bessho, S and Grando, K and Olubajo, S and Tam, V and Tükel, &#xc7;}, title = {Lactate promotes the biofilm-to-invasive-planktonic transition in Salmonella enterica serovar Typhimurium via the de novo purine pathway.}, journal = {Infection and immunity}, volume = {}, number = {}, pages = {e0026624}, doi = {10.1128/iai.00266-24}, pmid = {39133016}, issn = {1098-5522}, abstract = {Salmonella enterica serovar Typhimurium (S. Typhimurium) infection triggers an inflammatory response that changes the concentration of metabolites in the gut impacting the luminal environment. Some of these environmental adjustments are conducive to S. Typhimurium growth, such as the increased concentrations of nitrate and tetrathionate or the reduced levels of Clostridia-produced butyrate. We recently demonstrated that S. Typhimurium can form biofilms within the host environment and respond to nitrate as a signaling molecule, enabling it to transition between sessile and planktonic states. To investigate whether S. Typhimurium utilizes additional metabolites to regulate its behavior, our study delved into the impact of inflammatory metabolites on biofilm formation. The results revealed that lactate, the most prevalent metabolite in the inflammatory environment, impedes biofilm development by reducing intracellular c-di-GMP levels, suppressing the expression of curli and cellulose, and increasing the expression of flagellar genes. A transcriptomic analysis determined that the expression of the de novo purine pathway increases during high lactate conditions, and a transposon mutagenesis genetic screen identified that PurA and PurG, in particular, play a significant role in the inhibition of curli expression and biofilm formation. Lactate also increases the transcription of the type III secretion system genes involved in tissue invasion. Finally, we show that the pyruvate-modulated two-component system BtsSR is activated in the presence of high lactate, which suggests that lactate-derived pyruvate activates BtsSR system after being exported from the cytosol. All these findings propose that lactate is an important inflammatory metabolite used by S. Typhimurium to transition from a biofilm to a motile state and fine-tune its virulence.IMPORTANCEWhen colonizing the gut, Salmonella enterica serovar Typhimurium (S. Typhimurium) adopts a dynamic lifestyle that alternates between a virulent planktonic state and a multicellular biofilm state. The coexistence of biofilm formers and planktonic S. Typhimurium in the gut suggests the presence of regulatory mechanisms that control planktonic-to-sessile transition. The signals triggering the transition of S. Typhimurium between these two lifestyles are not fully explored. In this work, we demonstrated that in the presence of lactate, the most dominant host-derived metabolite in the inflamed gut, there is a reduction of c-di-GMP in S. Typhimurium, which subsequently inhibits biofilm formation and induces the expression of its invasion machinery, motility genes, and de novo purine metabolic pathway genes. Furthermore, high levels of lactate activate the BtsSR two-component system. Collectively, this work presents new insights toward the comprehension of host metabolism and gut microenvironment roles in the regulation of S. Typhimurium biology during infection.}, }
@article {pmid39132636, year = {2024}, author = {Rouamba, A and Badini, D and Compaoré, E and Ouédraogo, V and Kiendrebeogo, M}, title = {Lippia multiflora Leaves Extracts Enhance Cefotaxime Bactericidal Effects and Quench the Biofilm Formation in Methicillin-Resistant Staphylococcus aureus ATCC 43300.}, journal = {Avicenna journal of medical biotechnology}, volume = {16}, number = {3}, pages = {193-199}, pmid = {39132636}, issn = {2008-2835}, abstract = {BACKGROUND: The emergence of the multidrug-resistant bacteria strain has become a global world crisis. This study was designed to evaluate the antibiofilm and synergistic effects of Lippia multiflora leaf extracts on the activity of cefotaxime against the methicillin-resistant Staphylococcus aureus (S. aureus).<br><br>METHODS: The synergistic effect of methanol and dichloromethane extracts on the bactericidal activity of cefotaxime was determined by using the antibiotic susceptibility test on agar medium. The antibiofilm activity of the extracts was measured by using the crystal violet method. The antioxidant potential of the extracts was assessed by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reduction Activity Potential (FRAP) methods. The main secondary metabolites groups were analyzed by using different standard analytical tests. The total phenolics and total flavonoids were quantified spectrophotometrically.<br><br>RESULTS: The methanol extract (final concentration of 100 &#x3bc;g/ml) inhibited the formation of bacterial biofilm more than salicylic acid (p<0.05). All extracts combined with cefotaxime (20 &#x3bc;g and 200 &#x3bc;g) showed good synergistic bactericidal effect on S. aureus with inhibitory diameters of up to 40 mm. The methanol extract showed higher total phenolics (462.20&#xb1;10.90 mg EAG/g) and total flavonoids (26.20&#xb1;0.20 mg EQ/g) contents than the dichloromethane extract (96.70&#xb1;1.70 mg EAG/g and 8.00&#xb1;1.20 mg EQ/g). Moreover, the methanol extract showed a higher FRAP reducing power (353.6&#xb1;4.17 mmol EQ/g) than the dichloromethane extract (385.3&#xb1;7.01 mmol EQ/g). Qualitative phytochemical analysis showed the presence of tannins, flavonoids, terpenes and sterols in both extracts.<br><br>CONCLUSION: These data showed that L. multiflora leaves contain effective antibacterial phytomolecules for combating bacterial resistance.}, }
@article {pmid39127970, year = {2024}, author = {Chai, Y and Ma, Q and He, J and Wei, G and Huang, A}, title = {Rapid Revealing of Quorum Sensing (QS)-Regulated PLA, Biofilm and Lysine Targets of Lactiplantibacillus plantarum L3.}, journal = {Current microbiology}, volume = {81}, number = {10}, pages = {303}, pmid = {39127970}, issn = {1432-0991}, support = {No. 32260578//National Natural Science Foundation of China/ ; 202302AN360002//Yunnan Province-City Integration Project/ ; }, mesh = {*Quorum Sensing ; *Bacterial Proteins/genetics/metabolism ; *Biofilms/growth &amp; development ; *Gene Expression Regulation, Bacterial ; *Lysine/metabolism ; Lactobacillus plantarum/genetics/metabolism/physiology ; Genome, Bacterial ; Carbon-Sulfur Lyases ; }, abstract = {Quorum sensing (QS) can regulate the production of multiple functional factors in bacteria, but the process of identifying its regulatory targets is very complex and labor-intensive. In this study, an efficient and rapid method to find QS targets through prediction was used. The genome of Lactiplantibacillus plantarum (L. plantarum) L3 was sequenced and characterized, and then linked the L. plantarum L3 genome to the STRING database for QS system regulatory target prediction. A total of 3,167,484 base pairs (bps) were examined from the genome of L. plantarum L3, and 30 QS-related genes were discovered (including luxS). The STRING database prediction indicated that the 30 QS-related genes are mainly involved in the regulation of nine metabolic pathways. Furthermore, metE, metK, aroB, cysE, and birA1 were predicted to be regulatory targets of the LuxS/AI-2 QS system, and these five targets were validated based on quantitative real-time PCR and content determination. Successful elucidation of the LuxS/AI-2 QS system's key targets and regulation mechanism in L. plantarum L3 demonstrated the effectiveness of the new approach for predicting QS targets and provides a scientific basis for future work on improving regulation of functional factor production.}, }
@article {pmid39127666, year = {2024}, author = {Wang, H and Fan, Q and Wang, Y and Yi, L and Wang, Y}, title = {Multi-omics analysis reveals genes and metabolites involved in Streptococcus suis biofilm formation.}, journal = {BMC microbiology}, volume = {24}, number = {1}, pages = {297}, pmid = {39127666}, issn = {1471-2180}, support = {222300420005//Excellent Youth Foundation of He'nan Scientific Committee/ ; 232102110095//Henan Provincial Science and Technology Research Project/ ; 24IRTSTHN033//Program for Innovative Research Team (in Science and Technology) in University of Henan Province/ ; (24A230013)//Key Scientific Research Projects of Universities in Henan Province/ ; 32172852//the National Natural Science Foundation of China/ ; }, mesh = {*Streptococcus suis/genetics/metabolism ; *Biofilms/growth &amp; development ; *Metabolomics ; Metabolic Networks and Pathways/genetics ; Transcriptome ; Gene Expression Profiling ; Gene Expression Regulation, Bacterial ; Bacterial Proteins/genetics/metabolism ; Metabolome ; Multiomics ; }, abstract = {BACKGROUND: Streptococcus suis is an important zoonotic pathogen. Biofilm formation largely explains the difficulty in preventing and controlling S. suis. However, little is known about the molecular mechanism of S. suis biofilm formation.<br><br>RESULTS: In this study, transcriptomic and metabolomic analyses of S. suis in biofilm and planktonic states were performed to identify key genes and metabolites involved in biofilm formation. A total of 789 differential genes and 365 differential metabolites were identified. By integrating transcriptomics and metabolomics, five main metabolic pathways were identified, including amino acid pathway, nucleotide metabolism pathway, carbon metabolism pathway, vitamin and cofactor metabolism pathway, and aminoacyl-tRNA biosynthesis metabolic pathway.<br><br>CONCLUSIONS: These results provide new insights for exploring the molecular mechanism of S. suis biofilm formation.}, }
@article {pmid39127090, year = {2024}, author = {Swidsinski, A and Amann, R and Guschin, A and Swidsinski, S and Loening-Baucke, V and Mendling, W and Sobel, JD and Lamont, RF and Vaneechoutte, M and Baptista, PV and Bradshaw, CS and Kogan, IY and Savicheva, &#x410;M and Mitrokhin, OV and Swidsinski, NW and Sukhikh, GT and Priputnevich, TV and Apolikhina, IA and Dörffel, Y}, title = {Polymicrobial Consortia in the Pathogenesis of Biofilm Vaginosis Visualized by FISH. Historic Review Outlining the Basic Principles of the Polymicrobial Infection Theory.}, journal = {Microbes and infection}, volume = {}, number = {}, pages = {105403}, doi = {10.1016/j.micinf.2024.105403}, pmid = {39127090}, issn = {1769-714X}, }
@article {pmid39126743, year = {2024}, author = {Song, D and Wang, L and Sun, W and Zhang, Y and Xie, B and Zhao, Y and Wang, W and Wang, P and Ma, J and Cheng, W}, title = {Tourmaline triggered biofilm transformation: Boosting ultrafiltration efficiency and fouling resistance.}, journal = {Water research}, volume = {264}, number = {}, pages = {122212}, doi = {10.1016/j.watres.2024.122212}, pmid = {39126743}, issn = {1879-2448}, abstract = {Ultralow pressure filtration system, which integrates the dual functionalities of biofilm degradation and membrane filtration, has gained significant attention in water treatment due to its superior contaminant removal efficiency. However, it is a challenge to mitigate membrane biofouling while maintaining the high activity of biofilm. This study presents a novel ceramic-based ultrafiltration membrane functionalized with tourmaline nanoparticles to address this challenge. The incorporation of tourmaline nanoparticles enables the release of nutrient elements and the generation of an electric field, which enhances the biofilm activity on the membrane surface and simultaneously alleviates intrapore biofouling. The tourmaline-modified ceramic membrane (TCM) demonstrated a significant antifouling effect, with a substantial increase in water flux by 60 %. Additionally, the TCM achieved high removal efficiencies for contaminants (48.78 % in TOC, 22.28 % in UV254, and 24.42 % in TN) after 30 days of continuous operation. The fouling resistance by various constituents in natural water was individually analyzed using model compounds. The TCM with improved electronegativity and hydrophilicity exhibited superior resistance to irreversible fouling through increased electrostatic repulsion and reduced adhesion to foulants. Comprehensive characterizations and analyses, including interfacial interaction energies, redox reaction processes, and biofilm evolutions, demonstrated that the TCM can release nutrient elements to facilitate the development of functional microbial community within the biofilm, and generate reactive oxygen species (ROS) on the membrane surface to the degrade contaminants and mitigate membrane biofouling. The electric field generated by tourmaline nanoparticles can promote electron transfer in the Fe(III)/Fe(II) cycle, ensuring a stable and sustainable generation of ROS and bactericidal negative ions. These synergistic functions enhance contaminant removal and reduce irreversible fouling of the TCM. This study provides fundamental insights into the role of tourmaline-modified surfaces in enhancing membrane filtration performance and fouling resistance, inspiring the development of high-performance, anti-fouling membranes.}, }
@article {pmid39126548, year = {2024}, author = {Zaytsev, EM and Britsina, MV and Ozeretskovskaya, MN and Zaitsev, AE}, title = {Protective Activity and Safety of Experimental Acellular Pertussis Vaccines Based on Antigenic Complexes Isolated from Biofilm and Planktonic Cultures of Bordetella pertussis.}, journal = {Bulletin of experimental biology and medicine}, volume = {}, number = {}, pages = {}, pmid = {39126548}, issn = {1573-8221}, abstract = {Continued circulation of the whooping cough pathogen, even in countries with high vaccine coverage, can be related to persistence of Bordetella pertussis biofilms in the respiratory tract. The films differ from planktonic cells by increased resistance to the host immune system and antibacterial drugs. The available acellular pertussis vaccines (aPV) containing antigens isolated from planktonic cultures of B. pertussis protect from severe forms of whooping cough, but do not effectively influence circulation of virulent strains in the subclinical forms of the disease and asymptomatic carriage. It is promising to create new generation aPV based on antigens isolated from biofilm cultures of B. pertussis capable of more effectively controlling the entire infectious cycle of whooping cough, including colonization, persistence, and transmission of the pathogen. From antigenic complexes isolated from the culture medium of biofilm and planktonic cultures of the strain B. pertussis No. 317 (serotype 1.2.3), experimental aPV were made: aPV-B and aPV-P, respectively. In intracerebral infection of mice with a virulent strain of B. pertussis, aPV-B demonstrated 2.5-fold higher protective activity than aPV-P and also more effectively reduced colonization of the lungs by B. pertussis cells in mice after intranasal infection with a virulent strain. Both vaccine preparations were safe and did not cause death in mice after administration of histamine.}, }
@article {pmid39126293, year = {2024}, author = {Gallas, JA and Pelozo, LL and Corona, SAM and Shen, Y and Haapasalo, M and Sousa-Neto, MD and Souza-Gabriel, AE}, title = {Effect of pomegranate solution alone or combined with chlorhexidine against oral multispecies biofilm.}, journal = {International endodontic journal}, volume = {}, number = {}, pages = {}, doi = {10.1111/iej.14135}, pmid = {39126293}, issn = {1365-2591}, support = {//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; }, abstract = {AIM: Natural bioactive products have been tested as alternative antimicrobial agents. This study evaluated the effect of Punica granatum extract (PGE) on oral multispecies biofilms.<br><br>METHODOLOGY: Lyophilized extracts from pomegranate peel were prepared, and the punicalagin content was assessed by ultra-performance liquid chromatography (UPLC). Oral multispecies biofilms from 2 donors were grown on four collagen-coated hydroxyapatite discs. After incubation for 7&#x2009;days or 3&#x2009;weeks, the biofilms were exposed to water (control), 2% CHX, 10% PGE, 20% PGE or 30% PGE for 3&#x2009;min. The proportions of dead bacteria were assessed by the live/dead staining and confocal microscopy. After the analysis, the best PGE concentration (30%) was combined with CHX. The experimental phases were repeated using water, 2% CHX, 30% PGE and 30% PGE&#x2009;+&#x2009;2% CHX. Five random areas of the biofilm on each disc were scanned, resulting in 20 scanned areas for each group.<br><br>RESULTS: Regarding the biofilm volume, no differences were found amongst solutions (p&#x2009;=&#x2009;.111). The PGE solution killed bacteria effectively in 1-week, 2-week and 3-week-old-plaque biofilms, ranging from 37 to 55.3%, depending on the PGE concentration. The 30% PGE (a) (p&#x2009;=&#x2009;.0009) had greater antibiofilm effectiveness than 2% CHX (b), which killed bacteria in the 25.2 to 48.7% range. The 10% and 20% PGE had intermediate values (ab), without significant differences from 30% PGE (p&#x2009;=&#x2009;1.002). Water (c) had the lowest proportion of dead bacteria (p&#x2009;<&#x2009;.00001) in a range of 5 to 6.7% and lower effectiveness in killing bacteria (p&#x2009;<&#x2009;.05). The PGE alone or mixed with 2% CHX had greater anti-biofilm effectiveness than CHX (p&#x2009;<&#x2009;.05). The old plaque biofilms were more resistant than the 7-day-old plaque (p&#x2009;<&#x2009;.05).<br><br>CONCLUSIONS: The 30% PGE (alone or combined with CHX) exhibited a greater antibiofilm effect on oral multispecies biofilms grown on hydroxyapatite discs than 2% CHX.}, }
@article {pmid39125921, year = {2024}, author = {Rajewska, M and Maciąg, T and Narajczyk, M and Jafra, S}, title = {Carbon Source and Substrate Surface Affect Biofilm Formation by the Plant-Associated Bacterium Pseudomonas donghuensis P482.}, journal = {International journal of molecular sciences}, volume = {25}, number = {15}, pages = {}, doi = {10.3390/ijms25158351}, pmid = {39125921}, issn = {1422-0067}, support = {2015/19/D/NZ9/03588//National Science Center/ ; }, mesh = {*Biofilms/growth &amp; development ; *Pseudomonas/physiology/metabolism/genetics ; *Carbon/metabolism ; Plant Roots/microbiology ; Rhizosphere ; Solanum lycopersicum/microbiology ; Zea mays/microbiology ; Glass ; Bacterial Adhesion ; Glycerol/metabolism ; Polystyrenes ; }, abstract = {The ability of bacteria to colonize diverse environmental niches is often linked to their competence in biofilm formation. It depends on the individual characteristics of a strain, the nature of the colonized surface (abiotic or biotic), or the availability of certain nutrients. Pseudomonas donghuensis P482 efficiently colonizes the rhizosphere of various plant hosts, but a connection between plant tissue colonization and the biofilm formation ability of this strain has not yet been established. We demonstrate here that the potential of P482 to form biofilms on abiotic surfaces and the structural characteristics of the biofilm are influenced by the carbon source available to the bacterium, with glycerol promoting the process. Also, the type of substratum, polystyrene or glass, impacts the ability of P482 to attach to the surface. Moreover, P482 mutants in genes associated with motility or chemotaxis, the synthesis of polysaccharides, and encoding proteases or regulatory factors, which affect biofilm formation on glass, were fully capable of colonizing the root tissue of both tomato and maize hosts. Investigating the role of cellular factors in biofilm formation using these plant-associated bacteria shows that the ability of bacteria to form biofilm on abiotic surfaces does not necessarily mirror its ability to colonize plant tissues. Our research provides a broader perspective on the adaptation of these bacteria to various environments.}, }
@article {pmid39125609, year = {2024}, author = {Alfeqy, MM and El-Hawary, SS and El-Halawany, AM and Rabeh, MA and Alshehri, SA and Abdelmohsen, UR and Safwat, NA and Serry, AM and Fahmy, HA and Ezzat, MI}, title = {Biosynthesis and Characterization of Aeonium arboreum-Derived Silver Nanoparticles: Antimicrobial Activity, Biofilm Inhibition, Antihemolytic Activity, and In Silico Studies.}, journal = {International journal of molecular sciences}, volume = {25}, number = {15}, pages = {}, doi = {10.3390/ijms25158039}, pmid = {39125609}, issn = {1422-0067}, support = {RGP1/192/45//Deanship of Scientific Research at King Khalid University/ ; }, mesh = {*Metal Nanoparticles/chemistry ; *Silver/chemistry/pharmacology ; *Biofilms/drug effects ; *Microbial Sensitivity Tests ; *Molecular Docking Simulation ; Plant Extracts/chemistry/pharmacology ; Anti-Infective Agents/pharmacology/chemistry ; Anti-Bacterial Agents/pharmacology/chemistry ; Candida albicans/drug effects ; Pseudomonas aeruginosa/drug effects ; Computer Simulation ; }, abstract = {Environmentally friendly biosynthesis of silver nanoparticles (AgNPs) from Aeonium arboreum (L.) Webb &amp; Berthel is reported for the first time. The synthesized AgNPs were characterized using UV-Vis, FTIR, TEM, Zeta potential, and XRD analysis, revealing high stability (-29.1 mV), spherical shape, and an average size of 100 nm. The antimicrobial activity levels of both A. arboreum extract and biosynthesized AgNPs were evaluated against five uropathogens (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans). Both the extract and the AgNPs exhibited significant efficacy, particularly against E. coli, with inhibition zones of 27 mm and 30 mm, respectively. LC-MS analysis tentatively identified 11 secondary metabolites in the extract, including quercetin-3-O-glucoside, quercetin-3-O-rhamnoside, myricetin 3-glucoside, and daphneresinol. In silico docking studies revealed promising binding affinities of these metabolites in relation to key enzymes involved in bacterial folate synthesis (dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS)) and DNA replication (DNA gyrase). These findings demonstrate the potential of A. arboreum-based AgNPs and their associated metabolites as a novel therapeutic approach for combating urinary tract infections. Their antimicrobial, antihemolytic, and antibiofilm properties warrant further investigation.}, }
@article {pmid39125195, year = {2024}, author = {Guckeisen, T and Orghici, R and Rathgeber, S}, title = {Correlative Effects on Nanoplastic Aggregation in Model Extracellular Biofilm Substances Investigated with Fluorescence Correlation Spectroscopy.}, journal = {Polymers}, volume = {16}, number = {15}, pages = {}, doi = {10.3390/polym16152170}, pmid = {39125195}, issn = {2073-4360}, abstract = {Recent studies show that biofilm substances in contact with nanoplastics play an important role in the aggregation and sedimentation of nanoplastics. Consequences of these processes are changes in biofilm formation and stability and changes in the transport and fate of pollutants in the environment. Having a deeper understanding of the nanoplastics-biofilm interaction would help to evaluate the risks posed by uncontrolled nanoplastic pollution. These interactions are impacted by environmental changes due to climate change, such as, e.g., the acidification of surface waters. We apply fluorescence correlation spectroscopy (FCS) to investigate the pH-dependent aggregation tendency of non-functionalized polystyrene (PS) nanoparticles (NPs) due to intermolecular forces with model extracellular biofilm substances. Our biofilm model consists of bovine serum albumin (BSA), which serves as a representative for globular proteins, and the polysaccharide alginate, which is a main component in many biofilms, in solutions containing Na[+] with an ionic strength being realistic for fresh-water conditions. Biomolecule concentrations ranging from 0.5 g/L up to at maximum 21 g/L are considered. We use non-functionalized PS NPs as representative for mostly negatively charged nanoplastics. BSA promotes NP aggregation through adsorption onto the NPs and BSA-mediated bridging. In BSA-alginate mixtures, the alginate hampers this interaction, most likely due to alginate-BSA complex formation. In most BSA-alginate mixtures as in alginate alone, NP aggregation is predominantly driven by weaker, pH-independent depletion forces. The stabilizing effect of alginate is only weakened at high BSA contents, when the electrostatic BSA-BSA attraction is not sufficiently screened by the alginate. This study clearly shows that it is crucial to consider correlative effects between multiple biofilm components to better understand the NP aggregation in the presence of complex biofilm substances. Single-component biofilm model systems based on comparing the total organic carbon (TOC) content of the extracellular biofilm substances, as usually considered, would have led to a misjudgment of the stability towards aggregation.}, }
@article {pmid39123725, year = {2024}, author = {Hai, H and Yang, M and Cheng, Z and Ma, K and Shang, F}, title = {Potential Role of SdiA in Biofilm Formation and Drug Resistance in Avian Pathogenic Escherichia coli.}, journal = {Animals : an open access journal from MDPI}, volume = {14}, number = {15}, pages = {}, doi = {10.3390/ani14152199}, pmid = {39123725}, issn = {2076-2615}, abstract = {Avian pathogenic Escherichia coli (APEC) constitutes a significant cause of colibacillosis, a localized or systemic inflammatory disorder in avian species, resulting in considerable economic losses within the global poultry industry. SdiA (suppressor of division inhibitor) is a transcription factor recognized as a LuxR homolog in Escherichia coli, regulating various behaviors, including biofilm formation, multidrug resistance, and the secretion of virulence factors. However, the function of SdiA in APEC strains and its correlation with virulence and multidrug resistance remains unknown. This study probed into the function of SdiA by analyzing the effect of sdiA deletion on the transcription profile of an APEC strain. The microarray data revealed that SdiA upregulates 160 genes and downregulates 59 genes, exerting a particularly remarkable influence on the transcription of multiple virulence genes. A series of antibiotic sensitivity tests, biofilm formation assays, motility assays, and transcriptome analyses were performed, while a Normality test and t-test were conducted on the datasets. This research confirmed that SdiA inhibits biofilm formation by 1.9-fold (p-value < 0.01) and motility by 1.5-fold (p-value < 0.01). RT-qPCR revealed that SdiA positively regulates multidrug resistance by upregulating the expression of yafP, cbrA, and eamB. Collectively, the results of this study indicate the role of SdiA in the pathogenesis of APEC by controlling biofilm formation, motility, and multidrug resistance.}, }
@article {pmid39122151, year = {2024}, author = {Demontier, E and Ster, C and Chamberland, S and Ramanathan, S and Dufour, S and Malouin, F}, title = {Biofilm Dairy Foods Review: Effect of biofilm production on antimicrobial susceptibility of Staphylococcus aureus bovine mastitis strains from the most prevalent Canadian spa types.}, journal = {Journal of dairy science}, volume = {}, number = {}, pages = {}, doi = {10.3168/jds.2024-25238}, pmid = {39122151}, issn = {1525-3198}, abstract = {Staphylococcus aureus intramammary infections often leads to clinical and subclinical mastitis in dairy cattle. Prediction of disease evolution and treatment efficacy based on the characteristics of disease-causing strains of S. aureus would significantly improve management of dairy herds. To study the impact of biofilm production and the influence of genetic lineage, we selected S. aureus isolates from the most prevalent Canadian spa types associated with bovine mastitis. Antimicrobial susceptibility in planktonic growth and for bacteria embedded in biofilm was compared. PCR was used to detect the bap gene responsible for atypical biofilm formation. All Canadian spa types from dairy cattle were susceptible to the 8 antimicrobial agents tested. Only strain sa3493 from spa type t267 showed a resistance to pirlimycin. However, bacteria producing larger amounts of biofilms better survived the bactericidal action of antimicrobial agents even when exposed to concentrations 64 folds higher than the minimal inhibitory concentration determined for planktonic cultures. Pirlimycin was more effective on bacteria producing low to moderate levels of biofilm compared with vancomycin or ceftiofur. Antimicrobial agents did not affect the viability of spa types t13401 and t605 that were high biofilm producers. While both these spa types produced high amounts of biofilm, only t605 possessed the bap gene. We also found a close relationship between DIM at sampling and the presence of spa type t605 isolates. These results suggest that detection of S. aureus spa type may help predict the effectiveness of antimicrobial therapy and that some spa types are more likely to be retrieved toward the end of the lactation.}, }
@article {pmid39122126, year = {2024}, author = {Wang, XT and Zhao, L and Zhang, Q and Wang, B and Xing, D and Nan, J and Ren, NQ and Lee, DJ and Chen, C}, title = {Linking performance to dynamic migration of biofilm ecosystem reveals the role of voltage in the start-up of hybrid microbial electrolysis cell-anaerobic digestion.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131242}, doi = {10.1016/j.biortech.2024.131242}, pmid = {39122126}, issn = {1873-2976}, abstract = {Applied voltage is a crucial parameter in hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) systems for enhancing methane production from waste activated sludge (WAS). This study explored the impact of applied voltage on the initial biofilm formation on electrodes during the MEC-AD startup using raw WAS (Rr) and heat-pretreated WAS (Rh). The findings indicated that the maximum methane productivity for Rr and Rh were 3.4 ± 0.5 and 3.4 ± 0.2 mL/gVSS/d, respectively, increasing 1.5 times and 2.6 times over the productivity at 0 V. The biomass on electrode biofilms for Rr and Rh at 0.8 V increased by 70 % and 100 % compared to 0 V. The core functional microorganisms in the cathode biofilm were Methanobacterium and Syntrophomonas, and Geobacter in the anode biofilm, enhancing methane production through syntrophism and direct interspecies electron transfer, respectively. These results offer academic insights into optimizing AD functional electrode biofilms by applying voltage.}, }
@article {pmid39121346, year = {2024}, author = {Barta, A and Salusso, A and Kúsz, N and Berkecz, R and Schlauer, J and Purger, D and Hohmann, J and Carpinella, MC and Vasas, A}, title = {Phenanthrenes from Juncus articulatus with Antibacterial and Biofilm Formation Inhibitory Activity.}, journal = {Journal of natural products}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.jnatprod.4c00577}, pmid = {39121346}, issn = {1520-6025}, abstract = {Continuing our search for bioactive compounds in species from the Juncaceae family, Juncus articulatus was investigated. Ten previously undescribed phenanthrenes─articulins A-J (1-10)─and ten known compounds─juncuenin B, dehydrojuncuenin B, juncatrin B, ensifolins E, F, H, I, K, juncuenin D, and luzulin A (11-20)─along with other compounds, have been isolated and identified. The isolated compounds were evaluated for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, methicillin-susceptible Staphylococcus aureus (MSSA), and methicillin-resistant Staphylococcus aureus (MRSA). Compounds 12 and 14 exhibited the most potent activity against planktonic and sessile MSSA and MRSA with minimum inhibitory concentration (MIC) values of 15.1 μM (12 for both bacterial strains) and 15.3 μM (14 for both bacterial strains). Compounds 15, 17, and 18 also exhibited activity against both strains, although to a lower extent, with MIC values ranging from 30.0 to 56.8 μM. The inhibition of biofilm formation of these compounds was observed at 15.1-114.3 μM. This study elucidates the phenanthrene composition of J. articulatus and the antibacterial effect of these compounds.}, }
@article {pmid39119620, year = {2024}, author = {Astrada, A and Nakagami, G and Sanada, H}, title = {Challenges in Biofilm Identification in Diabetic Foot Infections: Review of Literature.}, journal = {The international journal of lower extremity wounds}, volume = {}, number = {}, pages = {15347346241273112}, doi = {10.1177/15347346241273112}, pmid = {39119620}, issn = {1552-6941}, abstract = {Foot ulcerations are one of the most common complications of diabetes and one of the major initial causes of amputations. The formation of biofilms on wounds significantly contributes to infections and delayed healing. While existing methods for identifying these biofilms have limitations, there is a need for a convenient tool for its clinical application. This literature review aimed to address the problem with current clinical biofilm identification in wound care and a proposal for biofilm-detection-based wound care in diabetic foot ulcer patients. Identifying biofilms is particularly vital due to the absence of typical signs of infection in DFUs. However, current approaches, although effective, often prove invasive and technically intricate. The wound blotting technique, involving attaching a nitrocellulose membrane and subsequent staining, presents an alternative that is swift and non-invasive. Research highlights the applicability of wound blotting with alcian blue staining in clinical scenarios, consistently producing sensitive outcomes. By addressing the critical need for early biofilm detection, wound blotting holds promise for enhancing DFU management and contributing to strategies aimed at preventing amputations.}, }
@article {pmid39116779, year = {2024}, author = {Guo, M and Tan, S and Wu, Y and Zheng, C and Du, P and Zhu, J and Sun, A and Liu, X}, title = {BrfA functions as a bacterial enhancer-binding protein to regulate functional amyloid Fap-dependent biofilm formation in Pseudomonas fluorescens by sensing cyclic diguanosine monophosphate.}, journal = {Microbiological research}, volume = {287}, number = {}, pages = {127864}, doi = {10.1016/j.micres.2024.127864}, pmid = {39116779}, issn = {1618-0623}, abstract = {The functional amyloid of Pseudomonas (Fap) is essential for the formation of macrocolony biofilms, pellicles, and solid surface-associated (SSA) biofilms of Pseudomonas fluorescens PF07, an isolate from refrigerated marine fish. However, limited information on the expression regulation of fap genes is available. Herein, we found that a novel bacterial enhancer-binding protein (bEBP), BrfA, regulated Fap-dependent biofilm formation by directly sensing cyclic diguanosine monophosphate (c-di-GMP). Our in vivo data showed that the REC domain deletion of BrfA promoted fap gene expression and biofilm formation, and c-di-GMP positively regulated the transcription of fapA in a BrfA-dependent manner. In in vitro experiments, we found that the ATPase activity of BrfA was inhibited by the REC domain and was activated by c-di-GMP. BrfA and the sigma factor RpoN bound to the upstream region of fapA, and the binding ability of BrfA was not affected by either deletion of the REC domain or c-di-GMP. BrfA specifically bound to the three enhancer sites upstream of the fapA promoter, which contain the consensus sequence CA-(N4)-TGA(A/T)ACACC. In vivo experiments using a lacZ fusion reporter indicated that all three BrfA enhancer sites were essential for the activation of fapA transcription. Overall, these findings reveal that BrfA is a new type of c-di-GMP-responsive transcription factor that directly controls the transcription of Fap biosynthesis genes in P. fluorescens. Fap functional amyloids and BrfA-type transcription factors are widespread in Pseudomonas species. The novel insights into the c-di-GMP- and BrfA-dependent expression regulation of fap provided by this work will contribute to the development of antibiofilm strategies.}, }
@article {pmid39116134, year = {2024}, author = {Hansen, KH and Byeon, CH and Liu, Q and Drace, T and Boesen, T and Conway, JF and Andreasen, M and Akbey, &#xdc;}, title = {Structure of biofilm-forming functional amyloid PSMα1 from Staphylococcus aureus.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {121}, number = {33}, pages = {e2406775121}, doi = {10.1073/pnas.2406775121}, pmid = {39116134}, issn = {1091-6490}, mesh = {*Staphylococcus aureus/metabolism/physiology ; *Biofilms/growth &amp; development ; *Amyloid/metabolism/chemistry ; Bacterial Toxins/metabolism/chemistry ; Protein Conformation ; Bacterial Proteins/metabolism/chemistry ; Models, Molecular ; }, abstract = {Biofilm-protected pathogenic Staphylococcus aureus causes chronic infections that are difficult to treat. An essential building block of these biofilms are functional amyloid fibrils that assemble from phenol-soluble modulins (PSMs). PSMα1 cross-seeds other PSMs into cross-β amyloid folds and is therefore a key element in initiating biofilm formation. However, the paucity of high-resolution structures hinders efforts to prevent amyloid assembly and biofilm formation. Here, we present a 3.5 Å resolution density map of the major PSMα1 fibril form revealing a left-handed cross-β fibril composed of two C2-symmetric U-shaped protofilaments whose subunits are unusually tilted out-of-plane. Monomeric α-helical PSMα1 is extremely cytotoxic to cells, despite the moderate toxicity of the cross-β fibril. We suggest mechanistic insights into the PSM functional amyloid formation and conformation transformation on the path from monomer-to-fibril formation. Details of PSMα1 assembly and fibril polymorphism suggest how S. aureus utilizes functional amyloids to form biofilms and establish a framework for developing therapeutics against infection and antimicrobial resistance.}, }
@article {pmid39115732, year = {2024}, author = {Abdul Raheem, N and Selvaraj, GK and Karuppanan, K and Ganesan, G and Soorangkattan, S and Subramanian, B and Ramamurthy Baluraj, S and Rajaiah, DK and Hasan, I}, title = {Bioremediation of heavy metals by an unexplored bacterium, Pseudoxanthomonas mexicana strain GTZY isolated from aerobic-biofilm wastewater system.}, journal = {Environmental science and pollution research international}, volume = {}, number = {}, pages = {}, pmid = {39115732}, issn = {1614-7499}, abstract = {We prompted to characterize a wastewater bacterium, Pseudoxanthomonas mexicana GTZY, that efficiently transforms toxic mercury and arsenic, explores its bioremediation capability, and reveals their relevant gene resistance operons. The isolated strain was characterized by its phylogenetic, biochemical, and phenotypic properties. The strain GTZY potentially removed 84.3% of mercury and their mercury volatilization (Hg(II) to Hg(0)) was confirmed using the X-ray film method, and its respective merA gene was PCR amplified. In addition, strain GTZY efficiently removed arsenate (68.5%) and arsenite (63.2%), and showed resistance up to > 175 and > 55 mM, respectively. Their genomic annotations disclosed the linkage of Tn2-transposon and int1 in both ends of mer operon (merAPTR). The co-existence of arsP and arsH proteins in its intrinsic ars operon (arsCPRH) was extremely diverse from its ancestral species. We believe that the mercury resistance-conferring mer operon of P. mexicana GTZY presumably derived horizontally from other species in the reactor, while the arsenic resistance-conferring intrinsic ars operon was highly diversified and evolved from its ancestral species. By considering the potential of the strain GTZY to transform heavy metals, this can be used to recover contaminated sites.}, }
@article {pmid39113613, year = {2024}, author = {Chen, M and Trotter, VV and Walian, PJ and Chen, Y and Lopez, R and Lui, LM and Nielsen, TN and Malana, RG and Thorgersen, MP and Hendrickson, AJ and Carion, H and Deutschbauer, AM and Petzold, CJ and Smith, HJ and Arkin, AP and Adams, MWW and Fields, MW and Chakraborty, R}, title = {Molecular mechanisms and environmental adaptations of flagellar loss and biofilm growth of Rhodanobacter under environmental stress.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, doi = {10.1093/ismejo/wrae151}, pmid = {39113613}, issn = {1751-7370}, abstract = {Biofilms aid bacterial adhesion to surfaces via direct and indirect mechanisms, and formation of biofilms is considered as an important strategy for adaptation and survival in sub-optimal environmental conditions. However, the molecular underpinnings of biofilm formation in subsurface sediment/groundwater ecosystems where microorganisms often experience fluctuations in nutrient input, pH, nitrate or metal concentrations is underexplored. We examined biofilm formation under different nutrient, pH, metal, and nitrate regimes of 16 Rhodanobacter strains isolated from subsurface groundwater wells spanning diverse pH (3.5 to 5) and nitrate levels (13.7 to 146 mM). Eight Rhodanobacter strains demonstrated significant biofilm growth under low pH, suggesting adaptation to survive and grow at low pH. Biofilms intensified under aluminum stress, particularly in strains possessing fewer genetic traits associated with biofilm formation warranting further investigation. Through RB-TnSeq, proteomics, use of specific mutants and transmission electron microscopy analysis, we discovered flagellar loss under aluminum stress, indicating a potential relationship between motility, metal tolerance, and biofilm growth. Comparative genomic analyses revealed absence of flagella and chemotaxis genes, and presence of putative Type VI secretion system in the high biofilm-forming strain FW021-MT20. This study identifies genetic determinants associated with biofilm growth in a predominant environmental genus, Rhodanobacter, under metal stress and identifies traits aiding survival and adaptation to contaminated subsurface environments.}, }
@article {pmid39112554, year = {2024}, author = {Rumbaugh, KP and Whiteley, M}, title = {Towards improved biofilm models.}, journal = {Nature reviews. Microbiology}, volume = {}, number = {}, pages = {}, pmid = {39112554}, issn = {1740-1534}, abstract = {Biofilms are complex microbial communities that have a critical function in many natural ecosystems, industrial settings as well as in recurrent and chronic infections. Biofilms are highly heterogeneous and dynamic assemblages that display complex responses to varying environmental factors, and those properties present substantial challenges for their study and control. In recent years, there has been a growing interest in developing improved biofilm models to offer more precise and comprehensive representations of these intricate systems. However, an objective assessment for ascertaining the ability of biofilms in model systems to recapitulate those in natural environments has been lacking. In this Perspective, we focus on medical biofilms to delve into the current state-of-the-art in biofilm modelling, emphasizing the advantages and limitations of different approaches and addressing the key challenges and opportunities for future research. We outline a framework for quantitatively assessing model accuracy. Ultimately, this Perspective aims to provide a comprehensive and critical overview of medically focused biofilm models, with the intent of inspiring future research aimed at enhancing the biological relevance of biofilm models.}, }
@article {pmid39111496, year = {2024}, author = {Lin, N and Wang, M and Gong, H and Li, N and Liu, F and Wu, Y and Sun, X and Yang, Q and Tan, X}, title = {Immobilizing DNase in ternary AuAgCu hydrogels to accelerate biofilm disruption for synergistically enhanced therapy of MRSA infections.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {134518}, doi = {10.1016/j.ijbiomac.2024.134518}, pmid = {39111496}, issn = {1879-0003}, abstract = {Bacterial biofilm-related infections have become a significant global concern in public health and economy. Extracellular DNA (eDNA) is regarded as one of the key elements of extracellular polymeric substances (EPS) in bacterial biofilm, providing robust support to maintain the stability of bacterial biofilms for fighting against environmental stresses (such as antibiotics, reactive oxygen species (ROS), and hyperthermia). In this study, ternary AuAgCu hydrogels nanozyme with porous network structures were utilized for the immobilization of DNase (AuAgCu@DNase hydrogels) to realize enhanced biofilm decomposition and antibacterial therapy of MRSA. The prepared AuAgCu@DNase hydrogels can efficiently hydrolyze eDNA in biofilms so that the generated ROS and hyperthermia by laser irradiation can permeate into the interior of the biofilm to achieve deep sterilization. The typical interface interactions between AuAgCu hydrogels and DNase and the excellent photothermal-boost peroxidase-like performances of AuAgCu hydrogels take responsibility for the enhanced antibacterial activity. In the MRSA-infected wounds model, the in vivo antibacterial results revealed that the AuAgCu@DNase hydrogels possess excellent drug-resistant bacteria-killing performance with superb biocompatibility. Meanwhile, the pathological analysis of collagen deposition and fibroblast proliferation of wounds demonstrate highly satisfactory wound healing. This work offers an innovative path for developing nanozyme-enzyme antibacterial composites against drug-resistant bacteria and their biofilms.}, }
@article {pmid39111435, year = {2024}, author = {Liao, R and Song, Z and Zhang, X and Xiong, X and Zhang, Z and Zhao, Z and Sun, F}, title = {Versatile enhancement for anaerobic moving bed biofilm (AnMBBR) treating pretreated landfill leachate by hydrochar: Energy recovery, greenhouse gas emission reduction and underlying microbial mechanisms.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {175161}, doi = {10.1016/j.scitotenv.2024.175161}, pmid = {39111435}, issn = {1879-1026}, abstract = {Hydrochars were prepared from fruit peels (HC-1) and vegetable waste (HC-2), and combined with fiber spheres, respectively, to form homogeneous biocompatible carriers, which were used for anaerobic moving bed biofilm reactor (AnMBBR) to enhance anaerobic digestion (AD) performance and energy recovery of landfill leachate treatment. Compared with the control AnMBBR with conventional fiber spheres as carriers, the chemical oxygen demand (COD) removal efficiency of the AnMBBR with HC-2 increased from 75 % to 88 %, methane yield increased from 77.7 mL/g-COD to 155.3 mL/g-COD, and achieved greenhouse gases (GHG) emission reductions of 1.74 t CO2 eq/a during long-term operation. HC-2-fiber sphere biocarriers provided more sites for attached-growth biomass (AGBS) and significantly enhanced the abundance of functional microbial community, with the relative abundance of methanogenic bacteria Methanothrix increased from 0.03 % to over 24.4 %. Moreover, the gene abundance of most the key enzymes encoding the hydrolysis, acidogenesis and methanogenesis pathways were up-regulated with the assistance of HC-2. Consequently, hydrochar-assisted AnMBBR were effective to enhance methanogenesis performance, energy recovery and carbon reduction for high-strength landfill leachate treatment.}, }
@article {pmid39111368, year = {2024}, author = {Ahmed, F and Mirani, ZA and Urooj, S and Noor Ul Hudda, H and Janees Imdad, M and Zhao, Y and Malakar, PK}, title = {A rare biofilm dispersion strategy demonstrated by Staphylococcus aureus under oxacillin stress.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106838}, doi = {10.1016/j.micpath.2024.106838}, pmid = {39111368}, issn = {1096-1208}, abstract = {Staphylococcus aureus (S. aureus), a versatile Gram-positive bacterium, is implicated in a spectrum of infections, and its resilience is often attributed to biofilm formation. This study investigates the effect of sub-inhibitory doses of oxacillin on biofilm formation by methicillin-resistant S. aureus (MRSA). Specifically, it examines how these doses influence biofilms' development, maturation, and dispersal. The biofilm's zenith reached 48 hours (h) of incubation, followed by a noteworthy decline at 96 h and a distinctive clearance zone around biofilm-positive cells exposed to oxacillin. Scanning electron micrographs unveiled an intriguing active biofilm dispersal mechanism, a rarity in this species. Among 180 isolates, only three carrying the elusive icaD gene exhibited this phenomenon. icaD gene was absent in their counterparts. Notably, the icaD gene emerges as a distinctive marker, crucial in regulating biofilm dispersion and setting these isolates apart. The captivating interplay of oxacillin, biofilm dynamics, and genetic signatures disintegrate novel dimensions in understanding MRSA's adaptive strategies and underscores the importance of the icaD gene in engineering biofilm resilience.}, }
@article {pmid39110759, year = {2024}, author = {Vieira, B and Alcantara, JB and Destro, G and Guerra, MES and Oliveira, S and Lima, CA and Longato, GB and Hakansson, AP and Leite, LC and Darrieux, M and R Converso, T}, title = {Role of the polyamine transporter PotABCD during biofilm formation by Streptococcus pneumoniae.}, journal = {PloS one}, volume = {19}, number = {8}, pages = {e0307573}, doi = {10.1371/journal.pone.0307573}, pmid = {39110759}, issn = {1932-6203}, mesh = {*Biofilms/growth &amp; development ; *Streptococcus pneumoniae/physiology/metabolism ; Animals ; Mice ; Polyamines/metabolism ; Bacterial Proteins/metabolism/genetics ; Pneumococcal Infections/microbiology ; Membrane Transport Proteins/metabolism/genetics ; Operon ; }, abstract = {Streptococcus pneumoniae is a bacterium of great global importance, responsible for more than one million deaths per year. This bacterium is commonly acquired in the first years of life and colonizes the upper respiratory tract asymptomatically by forming biofilms that persist for extended times in the nasopharynx. However, under conditions that alter the bacterial environment, such as viral infections, pneumococci can escape from the biofilm and invade other niches, causing local and systemic disease of varying severity. The polyamine transporter PotABCD is required for optimal survival of the organism in the host. Immunization of mice with recombinant PotD can reduce subsequent bacterial colonization. PotD has also been suggested to be involved in pneumococcal biofilm development. Therefore, in this study we aimed to elucidate the role of PotABCD and polyamines in pneumococcal biofilm formation. First, the formation of biofilms was evaluated in the presence of exogenous polyamines-the substrate transported by PotABCD-added to culture medium. Next, a potABCD-negative strain was used to determine biofilm formation in different model systems using diverse levels of complexity from abiotic surface to cell substrate to in vivo animal models and was compared with its wild-type strain. The results showed that adding more polyamines to the medium stimulated biofilm formation, suggesting a direct correlation between polyamines and biofilm formation. Also, deletion of potABCD operon impaired biofilm formation in all models tested. Interestingly, more differences between wild-type and mutant strains were observed in the more complex model, which emphasizes the significance of employing more physiological models in studying biofilm formation.}, }
@article {pmid39108901, year = {2024}, author = {Haque, MM and Rupok, MRB and Molla, MAH and Rahman, MM and Shozib, HB and Mosharaf, MK}, title = {Rhizoengineering with biofilm producing rhizobacteria ameliorates oxidative stress and enhances bioactive compounds in tomato under nitrogen-deficient field conditions.}, journal = {Heliyon}, volume = {10}, number = {14}, pages = {e34276}, pmid = {39108901}, issn = {2405-8440}, abstract = {Nitrogen (N) deficiency limits crop productivity. In this study, rhizoengineering with biofilm producing rhizobacteria (BPR) contributing to productivity, physiology, and bioactive contents in tomato was examined under N-deficient field conditions. Here, different BPR including Leclercia adecarboxylata ESK12, Enterobacter ludwigii ESK17, Glutamicibacter arilaitensis ESM4, E. cloacae ESM12, Bacillus subtilis ESM14, Pseudomonas putida ESM17 and Exiguobacterium acetylicum ESM24 were used for the rhizoengineering of tomato plants. Rhizoengineered plants showed significant increase in growth attributes (15.73%-150.13 %) compared to the control plants. However, production of hydrogen peroxide (21.49-59.38 %), electrolyte leakage (19.5-38.07 %) and malondialdehyde accumulation (36.27-46.31 %) were increased remarkably more in the control plants than the rhizoengineered plants, thus N deficiency induced the oxidative stress. Compared to the control, photosynthetic rate, leaf temperature, stomatal conductance, intrinsic and instantaneous water use efficiency, relative water content, proline and catalase activity were incredibly enhanced in the rhizoengineered plants, suggesting both non-enzymatic and enzymatic antioxidant systems might protect tomato plants from oxidative stress under N-deficient field conditions. Yield (10.24-66.21 %), lycopene (4.8-7.94 times), flavonoids (52.32-110.46 %), phenolics (9.79-23.5 %), antioxidant activity (34.09-86.36 %) and certain minerals were significantly increased in the tomatoes from rhizoengineered plants. The principal component analysis (PCA) revealed that tomato plants treated with BPR induced distinct profiles compared to the control. Among all the applied BPR strains, ESM4 and ESM14 performed better in terms of biomass production, while ESK12 and ESK17 showed better results for reducing oxidative stress and increasing bioactive compounds in tomato, respectively. Thus, rhizoengineering with BPR can be utilized to mitigate the oxidative damage and increase the productivity and bioactive compounds in tomato under N-deficient field conditions.}, }
@article {pmid39108883, year = {2024}, author = {Swedan, SF and Aldakhily, DB}, title = {Antimicrobial resistance, biofilm formation, and molecular detection of efflux pump and biofilm genes among Klebsiella pneumoniae clinical isolates from Northern Jordan.}, journal = {Heliyon}, volume = {10}, number = {14}, pages = {e34370}, pmid = {39108883}, issn = {2405-8440}, abstract = {The current study aimed to investigate the antimicrobial susceptibility profiles, biofilm production capabilities, and the prevalence of efflux pump and biofilm-associated genes among Klebsiella pneumoniae clinical isolates. One hundred sixty-seven K. pneumoniae isolates were collected from microbiology laboratories in Northern Jordan hospitals. Antimicrobial susceptibility was tested using the Kirby-Bauer method. The double-disk synergy test was used to detect the extended-spectrum beta-lactamase (ESBL) phenotype. PCR was used to detect the frequency of acrAB, tolC, and mdtk efflux pump genes and fimH-1, mrkA, and mrkD biofilm-associated genes among the isolates. The highest nonsusceptibility was observed against azithromycin (87.4 %) and nitrofurantoin (85.0 %). Among the isolates, 75.4 % and 92.2 % were multidrug resistant and produced biofilms, respectively. Efflux pump genes acrAB, tolC, and mdtK were found in 96.4 %, 95.2 %, and 90.4 % of the isolates, respectively. Biofilm-associated genes mrkD, mrkA, and fimH-1 were found in 92.2 %, 89.2 %, and 88.6 % of the isolates, respectively. The presence of the mrkA was significantly associated with biofilm formation. Overall, high percentages of multi-drug resistance, efflux pump, and biofilm-associated genes were observed among the isolates. Subsequent studies are recommended to monitor changes in the prevalence of resistance phenotypes and genotypes of isolates.}, }
@article {pmid39106694, year = {2024}, author = {Su, S and Li, Z and Sun, Y and Gao, S and Gao, Q}, title = {The multifaceted role of TolA protein in promoting survival, biofilm formation and virulence of avian pathogenic Escherichia coli.}, journal = {Poultry science}, volume = {103}, number = {10}, pages = {104142}, doi = {10.1016/j.psj.2024.104142}, pmid = {39106694}, issn = {1525-3171}, abstract = {Avian pathogenic Escherichia coli (APEC) can spread beyond the intestines and cause systemic infections, leading to various clinical manifestations, including airsacculitis, pericarditis, perihepatitis and colisepticemia. The mechanisms facilitating this extraintestinal infections are not fully understood. In this study, we investigate how the tolA gene affects APEC virulence by encoding a protein involved in maintaining outer membrane integrity. We constructed a tolA deletion mutant of APEC strain E058 and evaluated its growth and survival in various environments, including in vitro cultures and in vivo infection models in chickens. We found that the motility-defective ΔtolA mutant exhibits reduced biofilm formation ability and weakened resistance to the environmental stresses, suggesting an important role for TolA in APEC's survival. The lack of tolA gene affects the bacterial ability to resist the host's immune system, such as complement-mediated serum killing or phagocytosis, as shown by the serum killing and macrophage phagocytosis assays. Additionally, in vivo infection studies using chickens demonstrated that the ΔtolA mutant displayed attenuated virulence, evidenced by reduced mortality and lower tissue bacterial burden. Reverse transcription quantitative real-time PCR (RT-qPCR) analysis revealed that inactivation of tolA led to downregulation of virulence genes associated with serum resistance (traT) and flagellar biosynthesis (fliR). Taken together, our findings demonstrate the multifaceted role of TolA protein in promoting the survival, immune evasion, biofilm formation, and virulence of APEC E058. This suggests that targeting TolA could potentially offer new strategies for combating APEC infections.}, }
@article {pmid39107803, year = {2024}, author = {Dame-Teixeira, N and El-Gendy, R and de Oliveira, AS and Holanda, CA and Romeiro, LAS and Do, T}, title = {Engineering a dysbiotic biofilm model for testing root caries interventions through microbial modulation.}, journal = {Microbiome}, volume = {12}, number = {1}, pages = {145}, pmid = {39107803}, issn = {2049-2618}, support = {NIF\ R5\242/AMS_/Academy of Medical Sciences/United Kingdom ; NIF\ R5\242/AMS_/Academy of Medical Sciences/United Kingdom ; NIF\ R5\242/AMS_/Academy of Medical Sciences/United Kingdom ; }, abstract = {BACKGROUND: This study aimed to engineer and optimise a dysbiotic biofilm model to develop in vitro root caries for investigating microbial modulation strategies. The model involved growing complex biofilms from a saliva inoculum collected from four volunteers using two strategies. In the first strategy ("pre-treatment strategy"), bovine root slabs were used, and two natural compounds were incorporated at time 0 of the 10-day biofilm experiment, which included sucrose cycles mimicking the cariogenic environment. In the second strategy ("post-treatment strategy"), mature biofilms were grown in a modified Calgary biofilm device coated with collagen and hydroxyapatite for 7 days and then were exposed to the same natural compounds. The metatranscriptome of each biofilm was then determined and analysed. Collagenase activity was examined, and the biofilms and dentine were imaged using confocal and scanning electron microscopy (SEM). Mineral loss and lesion formation were confirmed through micro-computed tomography (μ-CT).<br><br>RESULTS: The pH confirmed the cariogenic condition. In the metatranscriptome, we achieved a biofilm compositional complexity, showing a great diversity of the metabolically active microbiome in both pre- and post-treatment strategies, including reads mapped to microorganisms other than bacteria, such as archaea and viruses. Carbohydrate esterases had increased expression in the post-treated biofilms and in samples without sugar cycles, while glucosyltransferases were highly expressed in the presence of sucrose cycles. Enrichment for functions related to nitrogen compound metabolism and organic cyclic component metabolism in groups without sucrose compared to the sucrose-treated group. Pre-treatment of the roots with cranberry reduced microbial viability and gelatinase (but not collagenase) activity (p&#x2009;<&#x2009;0.05). SEM images showed the complexity of biofilms was maintained, with a thick extracellular polysaccharides layer.<br><br>CONCLUSIONS: This root caries model was optimized to produce complex cariogenic biofilms and root caries-like lesions, and could be used to test microbial modulation in vitro. Pre-treatments before biofilm development and cariogenic challenges were more effective than post-treatments. The clinical significance lies in the potential to apply the findings to develop varnish products for post-professional tooth prophylaxis, aiming at implementing a strategy for dysbiosis reversal in translational research. Video Abstract.}, }
@article {pmid39106464, year = {2024}, author = {Hapip, CA and Fischer, E and Feldman, TP and Brown, BL}, title = {Formation of Single-Species and Multispecies Biofilm by Isolates from Septic Transfusion Reactions in Platelet Bag Model.}, journal = {Emerging infectious diseases}, volume = {30}, number = {9}, pages = {}, doi = {10.3201/eid3009.240372}, pmid = {39106464}, issn = {1080-6059}, abstract = {During 2018-2021, eight septic transfusion reactions occurred from transfusion of platelet units contaminated with Acinetobacter spp., Staphylococcus saprophyticus, Leclercia adecarboxylata, or a combination of those environmental organisms. Whether biofilm formation contributed to evasion of bacterial risk mitigations, including bacterial culture, point-of-care testing, or pathogen-reduction technology, is unclear. We designed a 12-well plate-based method to evaluate environmental determinants of single-species and multispecies biofilm formation in platelets. We evaluated bacteria isolated from septic transfusion reactions for biofilm formation by using crystal violet staining and enumeration of adherent bacteria. Most combinations of bacteria had enhanced biofilm production compared with single bacteria. Combinations involving L. adecarboxylata had increased crystal violet biofilm production and adherent bacteria. This study demonstrates that transfusion-relevant bacteria can produce biofilms well together. More work is needed to clarify the effect of biofilms on platelet bacterial risk control strategies, but US Food and Drug Administration-recommended strategies remain acceptable.}, }
@article {pmid39105888, year = {2024}, author = {Norouzalinia, F and Asadpour, L and Mokhtary, M}, title = {Anti-microbial, anti-biofilm, and efflux pump inhibitory effects of ellagic acid-bonded magnetic nanoparticles against Escherichia coli isolates.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {39105888}, issn = {1618-1905}, abstract = {The spread of microbial resistance is a threat to public health. In this study, the anti-microbial, anti-biofilm, and efflux pump inhibitory effects of ellagic acid-loaded magnetic nanoparticles (Fe3O4NPs@EA) against beta-lactamase producing Escherichia coli isolates have been investigated. The effects of Fe3O4 NPs@EA on the growth inhibition of E. coli isolates were determined by disc diffusion method and determining the minimum inhibitory concentration was done using broth micro-dilution method. The anti-biofilm effect of nanoparticles was investigated using the microplate method. The efflux pump inhibitory effect of nanoparticles was investigated using cart-wheel method and by investigating the effect of nanoparticles on acrB and tolC genes expression levels. Fe3O4 NPs@EA showed anti-bacterial effects against test bacteria, and the MIC of these nanoparticles varied from 0.19 to 1.56 mg/mL. These nanoparticles caused a 43-62% reduction in biofilm formation of test bacteria compared to control. Furthermore, efflux pump inhibitory effect of these nanoparticles was confirmed at a concentration of 1/8 MIC, and the expression of acrB and tolC genes decreased in bacteria treated with 1/4 MIC Fe3O4 NPs@EA. According to the results, the use of nanoparticles containing ellagic acid can provide a basis for the development of new treatments against drug-resistant E. coli. This substance may improve the concentration of antibiotics in the bacterial cell and increase their effectiveness by inhibiting the efflux in E. coli isolates.}, }
@article {pmid39105738, year = {2024}, author = {Adams, CE and Spicer, SK and Gaddy, JA and Townsend, SD}, title = {Synthesis of a Phosphoethanolamine Cellulose Mimetic and Evaluation of Its Unanticipated Biofilm Modulating Properties.}, journal = {ACS infectious diseases}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsinfecdis.4c00267}, pmid = {39105738}, issn = {2373-8227}, abstract = {When coordinating and adhering to a surface, microorganisms produce a biofilm matrix consisting of extracellular DNA, lipids, proteins, and polysaccharides that are intrinsic to the survival of bacterial communities. Indeed, bacteria produce a variety of structurally diverse polysaccharides that play integral roles in the emergence and maintenance of biofilms by providing structural rigidity, adhesion, and protection from environmental stressors. While the roles that polysaccharides play in biofilm dynamics have been described for several bacterial species, the difficulty in isolating homogeneous material has resulted in few structures being elucidated. Recently, Cegelski and co-workers discovered that uropathogenic Escherichia coli (UPEC) secrete a chemically modified cellulose called phosphoethanolamine cellulose (pEtN cellulose) that plays a vital role in biofilm assembly. However, limited chemical tools exist to further examine the functional role of this polysaccharide across bacterial species. To address this critical need, we hypothesized that we could design and synthesize an unnatural glycopolymer to mimic the structure of pEtN cellulose. Herein, we describe the synthesis and evaluation of a pEtN cellulose glycomimetic which was generated using ring-opening metathesis polymerization. Surprisingly, the synthetic polymers behave counter to native pEtN cellulose in that the synthetic polymers repress biofilm formation in E. coli laboratory strain 11775T and UPEC strain 700415 with longer glycopolymers displaying greater repression. To evaluate the mechanism of action, changes in biofilm and cell morphology were visualized using high resolution field-emission gun scanning electron microscopy which further revealed changes in cell surface appendages. Our results suggest synthetic pEtN cellulose glycopolymers act as an antiadhesive and inhibit biofilm formation across E. coli strains, highlighting a potential new inroad to the development of bioinspired, biofilm-modulating materials.}, }
@article {pmid39104625, year = {2024}, author = {Stoddard, H and Kulas, D and Zolghadr, A and Aloba, S and Schaerer, LG and Putman, L and Valencia, I and Lacey, JA and Shonnard, DR and Techtmann, SM and Ong, RG}, title = {Biofilm mitigation in hybrid chemical-biological upcycling of waste polymers.}, journal = {Frontiers in bioengineering and biotechnology}, volume = {12}, number = {}, pages = {1435695}, pmid = {39104625}, issn = {2296-4185}, abstract = {Introduction: Accumulation of plastic waste in the environment is a serious global issue. To deal with this, there is a need for improved and more efficient methods for plastic waste recycling. One approach is to depolymerize plastic using pyrolysis or chemical deconstruction followed by microbial-upcycling of the monomers into more valuable products. Microbial consortia may be able to increase stability in response to process perturbations and adapt to diverse carbon sources, but may be more likely to form biofilms that foul process equipment, increasing the challenge of harvesting the cell biomass. Methods: To better understand the relationship between bioprocess conditions, biofilm formation, and ecology within the bioreactor, in this study a previously-enriched microbial consortium (LS1_Calumet) was grown on (1) ammonium hydroxide-depolymerized polyethylene terephthalate (PET) monomers and (2) the pyrolysis products of polyethylene (PE) and polypropylene (PP). Bioreactor temperature, pH, agitation speed, and aeration were varied to determine the conditions that led to the highest production of planktonic biomass and minimal formation of biofilm. The community makeup and diversity in the planktonic and biofilm states were evaluated using 16S rRNA gene amplicon sequencing. Results: Results showed that there was very little microbial growth on the liquid product from pyrolysis under all fermentation conditions. When grown on the chemically-deconstructed PET the highest cell density (0.69 g/L) with minimal biofilm formation was produced at 30°C, pH 7, 100 rpm agitation, and 10 sL/hr airflow. Results from 16S rRNAsequencing showed that the planktonic phase had higher observed diversity than the biofilm, and that Rhodococcus, Paracoccus, and Chelatococcus were the most abundant genera for all process conditions. Biofilm formation by Rhodococcus sp. And Paracoccus sp. Isolates was typically lower than the full microbial community and varied based on the carbon source. Discussion: Ultimately, the results indicate that biofilm formation within the bioreactor can be significantly reduced by optimizing process conditions and using pure cultures or a less diverse community, while maintaining high biomass productivity. The results of this study provide insight into methods for upcycling plastic waste and how process conditions can be used to control the formation of biofilm in bioreactors.}, }
@article {pmid39104345, year = {2024}, author = {Wei, ZC and Zhou, C and Ji, L and Hou, DQ and Dong, Y}, title = {[Comparison of the repair effects of Haiao oral biofilm alone or in combination with allogeneic bone graft in bone defects after jaw bone cyst surgery].}, journal = {Shanghai kou qiang yi xue = Shanghai journal of stomatology}, volume = {33}, number = {3}, pages = {285-289}, pmid = {39104345}, issn = {1006-7248}, mesh = {Humans ; *Bone Transplantation/methods ; *Biofilms/drug effects ; Prospective Studies ; Transplantation, Homologous/methods ; }, abstract = {PURPOSE: To compare the repair effects of Haiao oral biofilm alone or in combination with allogeneic bone graft on bone defects after jaw bone cyst surgery.<br><br>METHODS: A prospective study was conducted on 105 patients with bone defects after jaw bone cyst surgery who were admitted to Affiliated Hospital of Jiangnan University from November 2020 to July 2022. According to the random number table methods, the patients were divided into three groups: Haiao membrane group, allogeneic bone graft group and combination group. Among them, Haiao membrane group(35 patients) were repaired using Haiao oral biofilm; allogeneic bone group(35 patients) using allogeneic bone, while combined group (35 patients) using a combination of Haiao oral biofilm and allogeneic bone graft. The clinical basic data of three groups of patients were compared, including the healing effect at the incision, bone density at the bone defect, bone resorption and attachment loss. Statistical analysis was performed with SPSS 22.0 software package.<br><br>RESULTS: There was no significant difference in general clinical data among the three groups (P&#xff1e;0.05). The postoperative restoration effect of gingival soft tissue morphology in combined group was significantly better than that in Haiao membrane group and allogeneic bone graft group (P&#xff1c;0.05). There was no significant difference in bone density at the bone defect site among the three groups before treatment(P&#xff1e;0.05); 6 and 12 months after treatment, the bone density of the three groups was significantly improved (P&#xff1c;0.05), and combined group was significantly higher than the other groups(P&#xff1c;0.05). There was no significant difference in the vertical and lingual bone resorption levels among the three groups before treatment(P&#xff1e;0.05); 6 and 12 months after treatment, the vertical and lingual bone resorption levels of the three groups were significantly reduced (P&#xff1c;0.05), and combined group were significantly lower than the other groups (P&#xff1c;0.05). There was no significant difference in attachment loss among the three groups before treatment(P&#xff1e;0.05); 6 and 12 months after treatment, the attachment loss of the three groups decreased(P&#xff1c;0.05), and combined group was significantly lower than the other groups(P&#xff1c;0.05).<br><br>CONCLUSIONS: The combination of Haiao oral biofilm and allogeneic bone graft has good repair effect in the treatment of bone defects after jaw bone cyst surgery, which is beneficial for the recovery of gingival soft tissue, improvement of bone density, reduction of bone resorption and attachment loss.}, }
@article {pmid39104344, year = {2024}, author = {Zhang, MZ and Kuang, HF and Yang, LY and Luo, W}, title = {[Application of small intestinal submucosa absorbable biofilm in the repair of alveolar bone defects].}, journal = {Shanghai kou qiang yi xue = Shanghai journal of stomatology}, volume = {33}, number = {3}, pages = {279-284}, pmid = {39104344}, issn = {1006-7248}, mesh = {Humans ; *Biofilms ; *Intestinal Mucosa ; Alveolar Bone Loss ; Bone Regeneration ; Intestine, Small ; Absorbable Implants ; }, abstract = {PURPOSE: To study the clinical efficacy of small intestinal submucosa (SIS) absorbable biological membrane in alveolar bone defect repair.<br><br>METHODS: A total of 102 patients with alveolar bone defect who received guided bone regeneration (GBR) in our hospital from January 2020 to January 2022 were selected and divided into Bio-Gide group (51 cases using Bio-Gide absorbable biofilm) and SIS group (51 cases using SIS absorbable biofilm) by computer random number generator. The perioperative related indicators, blood calcium, blood phosphorus, biocompatibility, periodontal attachment loss (PAL) length, pulp sensitivity, tooth mobility, alveolar bone volume and adverse events of the two groups were compared. Statistical analysis was performed with SPSS 24.0 software package.<br><br>RESULTS: There was no significant difference in operation time, intraoperative blood loss, visual analogue scale (VAS) score of pain on the first day after operation, VAS score on the fifth day after operation, wound healing time, blood calcium and phosphorus levels before operation, 1 d and 12 d after operation, PAL length before operation, 3 months, 6 months and 12 months after operation, pulp sensitivity and tooth looseness grade 1 and 2 percentage at 3, 6 and 12 months after operation, bone width increase, bone height increase at 12 months after operation and adverse event rate between the two groups (P&#xff1e;0.05). Compared with Bio-Gide group, the wound healing time and biofilm absorption time were shortened in SIS group(P&#xff1c;0.05), and the incidence of rejection was decreased 12 d after operation (P&#xff1c;0.05).<br><br>CONCLUSIONS: SIS absorbable biofilm and Bio-Gide absorbable biofilm have similar efficacy and safety in repairing GBR for alveolar bone defects, but the former is more biocompatible and the latter can provide longer barrier function.}, }
@article {pmid39102953, year = {2024}, author = {Zhao, Y and Yuan, X and Du, Z and Niu, J and Song, J and Zhai, S and Liu, Y and Nuramkhaan, M}, title = {New insights into N2O emission and electron competition under different chemical oxygen demand to nitrogen ratios in a biofilm system.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {175265}, doi = {10.1016/j.scitotenv.2024.175265}, pmid = {39102953}, issn = {1879-1026}, abstract = {Nitrous oxide (N2O) is a greenhouse gas that could accumulate during the heterotrophic denitrification process. In this study, the effects of different chemical oxygen demand to nitrogen ratio (COD/N) on N2O production and electron competition was investigated. The electron competition was intensified with the decrease of electron supply, and Nos had the best electron competition ability. The model simulation results indicated that the degradation of NOxNs was a combination of diffusion and biological degradation. As reaction proceeding, N2O could accumulate inside biofilm. A thinner biofilm and a longer hydraulic retention time (HRT) might be an effective way to control N2O emission. The application of mathematical model is an opportunity to gain deep understanding of substrate degradation and electron competition inside biofilm.}, }
@article {pmid39102390, year = {2024}, author = {Rimi, SS and Ashraf, MN and Sigma, SH and Ahammed, MT and Siddique, MP and Zinnah, MA and Rahman, MT and Islam, MS}, title = {Biofilm formation, agr typing and antibiotic resistance pattern in methicillin-resistant Staphylococcus aureus isolated from hospital environments.}, journal = {PloS one}, volume = {19}, number = {8}, pages = {e0308282}, doi = {10.1371/journal.pone.0308282}, pmid = {39102390}, issn = {1932-6203}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Methicillin-Resistant Staphylococcus aureus/genetics/drug effects/isolation &amp; purification/physiology ; *Bacterial Proteins/genetics ; Humans ; Anti-Bacterial Agents/pharmacology ; Hospitals ; Microbial Sensitivity Tests ; Trans-Activators/genetics ; Staphylococcal Infections/microbiology ; }, abstract = {Biofilm development significantly enhances the virulence of methicillin-resistant Staphylococcus aureus (MRSA), leading to severe infections and decreased susceptibility to antibiotics, especially in strains associated with hospital environments. This study examined the occurrence of MRSA, their ability to form biofilms, agr typing, and the antibiotic resistance profiles of biofilm-forming MRSA strains isolated from environmental surfaces at Mymensingh Medical College Hospital (MMCH). From 120 swab samples, 86 (71.67%) tested positive for S. aureus. MRSA was identified in 86 isolates using the disk diffusion technique, and by polymerase chain reaction (PCR), 56 (65.1%) isolates were confirmed to carry the mecA gene. The Crystal Violet Microtiter Plate (CVMP) test revealed that 80.35% (45 isolates) were biofilm-forming and 19.6% (11 isolates) were non-biofilm-forming. Out of 45 biofilm producer isolates 37.5% and 42.9% isolates exhibited strong and intermediate biofilm-forming characteristics, respectively. Molecular analysis revealed that 17.78% of MRSA isolates carried at least one gene related to biofilm formation, specifically icaA, icaB, and icaD genes were discovered in 13.33%, 8.89%, 6.67% of the MRSA isolates, respectively. In agr typing, the most prevalent group was agr I (71.11%), followed by group III (17.78%) and group II (11.11%). Group IV was not detected. The distribution of agr gene groups showed a significant difference among biofilm-forming isolates (p < 0.05). In agr group I, 18.75% of isolates carried the icaA gene, 12.5% carried the icaB gene, and 9.37% carried the icaD gene. Biofilm-forming genes were not detected in any of the isolates from agr groups II or III. There are no statistically significant differences between agr groups and the presence of these genes (p > 0.05). Antibiotic resistance varied significantly among agr groups, with agr group I displaying the highest resistance, agr group II, and agr group III exhibiting the least resistance (p < 0.05). Seventy-three (73.3%) of the isolates were multi-drug resistant, with agr group I displaying nineteen MDR patterns. The occurrence of MRSA in hospital environments and their capacity to form biofilm raises concerns for public health. These findings support the importance of further research focused on agr quorum sensing systems as a basis for developing novel antibacterial agents.}, }
@article {pmid39101559, year = {2024}, author = {Brar, NK and Dhariwal, A and Shekhar, S and Junges, R and Hakansson, AP and Petersen, FC}, title = {HAMLET, a human milk protein-lipid complex, modulates amoxicillin induced changes in an ex vivo biofilm model of the oral microbiome.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1406190}, pmid = {39101559}, issn = {1664-302X}, abstract = {Challenges from infections caused by biofilms and antimicrobial resistance highlight the need for novel antimicrobials that work in conjunction with antibiotics and minimize resistance risk. In this study we investigated the composite effect of HAMLET (human alpha-lactalbumin made lethal to tumor cells), a human milk protein-lipid complex and amoxicillin on microbial ecology using an ex vivo oral biofilm model with pooled saliva samples. HAMLET was chosen due to its multi-targeted antimicrobial mechanism, together with its synergistic effect with antibiotics on single species pathogens, and low risk of resistance development. The combination of HAMLET and low concentrations of amoxicillin significantly reduced biofilm viability, while each of them alone had little or no impact. Using a whole metagenomics approach, we found that the combination promoted a remarkable shift in overall microbial composition compared to the untreated samples. A large proportion of the bacterial species in the combined treatment were Lactobacillus crispatus, a species with probiotic effects, whereas it was only detected in a minor fraction in untreated samples. Although resistome analysis indicated no major shifts in alpha-diversity, the results showed the presence of TEM beta-lactamase genes in low proportions in all treated samples but absence in untreated samples. Our study illustrates HAMLET's capability to alter the effects of amoxicillin on the oral microbiome and potentially favor the growth of selected probiotic bacteria when in combination. The findings extend previous knowledge on the combined effects of HAMLET and antibiotics against target pathogens to include potential modulatory effects on polymicrobial biofilms of human origin.}, }
@article {pmid39101130, year = {2024}, author = {Vasconcelos, PGS and Lee, KM and Abuna, GF and Costa, EMMB and Murata, RM}, title = {Monoterpene antifungal activities: evaluating geraniol, citronellal, and linalool on Candida biofilm, host inflammatory responses, and structure-activity relationships.}, journal = {Frontiers in pharmacology}, volume = {15}, number = {}, pages = {1394053}, pmid = {39101130}, issn = {1663-9812}, abstract = {Introduction: Despite the rising concern with fungal resistance, a myriad of molecules has yet to be explored. Geraniol, linalool, and citronellal are monoterpenes with the same molecular formula (C10H18O), however, neither the effect of these compounds on inflammatory axis induced by Candida spp. nor the antibiofilm Structure-Activity Relationship (SAR) have been well-investigated. Herein we analyzed geraniol, linalool and citronellal antifungal activity, cytotoxicity, and distinctive antibiofilm SAR, also the influence of geraniol on Candida spp induced dysregulated inflammatory axis, and in vivo toxicity. Methods: Minimal inhibitory (MIC) and fungicidal (MFC) concentrations against Candida spp were defined, followed by antibiofilm activity (CFU-colony forming unit/mL/g of dry weight). Cytotoxic activity was assessed using human monocytes (THP-1) and oral squamous cell (TR146). Geraniol was selected for further analysis based on antifungal, antibiofilm and cytotoxic results. Geraniol was tested using a dual-chamber co-culture model with TR146 cells infected with C. albicans, and THP-1 cells, used to mimic oral epithelium upon fungal infection. Expression of Candida enzymes (phospholipase-PLB and aspartyl proteases-SAP) and host inflammatory cytokines (interleukins: IL-1β, IL-6, IL-17, IL-18, IL-10, and Tumor necrosis factor-TNF) were analyzed. Lastly, geraniol in vivo toxicity was assessed using Galleria mellonella. Results: MIC values obtained were 1.25-5 mM/mL for geraniol, 25-100 mM/mL for linalool, and 100-200 mM/mL for citronellal. Geraniol 5 and 50 mM/mL reduced yeast viability during biofilm analysis, only 500 mM/mL of linalool was effective against a 72 h biofilm and no biofilm activity was seen for citronellal. LD50 for TR146 and THP-1 were, respectively: geraniol 5.883 and 8.027 mM/mL; linalool 1.432 and 1.709 mM/mL; and citronellal 0.3006 and 0.1825 mM/mL. Geraniol was able to downregulate expression of fungal enzymes and host pro-inflammatory cytokines IL-1β, IL-6, and IL-18. Finally, safety in vivo parameters were observed up to 20 mM/Kg. Discussion: Despite chemical similarities, geraniol presented better antifungal, antibiofilm activity, and lower cytotoxicity when compared to the other monoterpenes. It also showed low in vivo toxicity and capacity to downregulate the expression of fungal enzymes and host pro-inflammatory cytokines. Thus, it can be highlighted as a viable option for oral candidiasis treatment.}, }
@article {pmid39099204, year = {2024}, author = {Algadi, H and Alhoot, MA and Al-Maleki, AR and Purwitasari, N}, title = {Effects of Metal and Metal Oxide Nanoparticles against Biofilm-Forming Bacteria: A systematic Review.}, journal = {Journal of microbiology and biotechnology}, volume = {34}, number = {9}, pages = {1-9}, doi = {10.4014/jmb.2403.03029}, pmid = {39099204}, issn = {1738-8872}, abstract = {Biofilm formation by bacteria poses a significant challenge across diverse industries, displaying resilience against conventional antimicrobial agents. Nanoparticles emerge as a promising alternative for addressing biofilm-related issues. This review aims to assess the efficacy of metal and metal oxide nanoparticles in inhibiting or disrupting biofilm formation by various bacterial species. It delineates trends, identifies gaps, and outlines avenues for future research, emphasizing best practices and optimal nanoparticles for biofilm prevention and eradication. Additionally, it underscores the potential of nanoparticles as substitutes for traditional antibiotics in healthcare and combating antibiotic resistance. A systematic literature search, encompassing Web of Science, PubMed, and Google Scholar from 2015 to 2023, yielded 48 publications meeting the review criteria. These studies employed diverse methods to explore the antibacterial activity of nanoparticles against biofilmforming bacteria strains. The implications of this study are profound, offering prospects for novel antimicrobial agents targeting biofilm-forming bacteria, often resistant to conventional antibiotics. In conclusion, nanoparticles present a promising frontier in countering biofilm-forming bacteria. This review delivers a structured analysis of current research, providing insights into the potential and challenges of nanoparticle utilization against biofilm-related challenges. While nanoparticles exhibit inherent antimicrobial properties with applications spanning healthcare, agriculture, and industries, the review acknowledges limitations such as the narrow scope of tested nanoparticles and the imperative need for extensive research on long-term toxicity and environmental impacts.}, }
@article {pmid39098403, year = {2024}, author = {Stindlova, M and Peroutka, V and Jencova, V and Havlickova, K and Lencova, S}, title = {Application of MTT assay for probing metabolic activity in bacterial biofilm-forming cells on nanofibrous materials.}, journal = {Journal of microbiological methods}, volume = {}, number = {}, pages = {107010}, doi = {10.1016/j.mimet.2024.107010}, pmid = {39098403}, issn = {1872-8359}, abstract = {The quantification of cellular metabolic activity via MTT assay has become a widespread practice in eukaryotic cell studies and is progressively extending to bacterial cell investigations. This study pioneers the application of MTT assay to evaluate the metabolic activity of biofilm-forming cells within bacterial biofilms on nanofibrous materials. The biofilm formation of Staphylococcus aureus and Escherichia coli on nanomaterials electrospun from polycaprolactone (PCL), polylactic acid (PLA), and polyamide (PA) was examined. Various parameters of the MTT assay were systematically investigated, including (i) the dissolution time of the formed formazan, (ii) the addition of glucose, and (iii) the optimal wavelength for spectrophotometric determination. Based on interim findings, a refined protocol suitable for application to nanofibrous materials was devised. We recommend 2 h of the dissolution, the application of glucose, and spectrophotometric measurement at 595 nm to obtain reliable data. Comparative analysis with the reference CFU counting protocol revealed similar trends for both tested bacteria and all tested nanomaterials. The proposed MTT protocol emerges as a suitable method for assessing the metabolic activity of bacterial biofilms on PCL, PLA, and PA nanofibrous materials.}, }
@article {pmid39098160, year = {2024}, author = {Kim, U and Oh, SW}, title = {Antimicrobial resistance induction potential of grapefruit seed extract on multi-species biofilm of E. coli in food industry.}, journal = {International journal of food microbiology}, volume = {424}, number = {}, pages = {110849}, doi = {10.1016/j.ijfoodmicro.2024.110849}, pmid = {39098160}, issn = {1879-3460}, abstract = {Biofilm formation in natural environments involving complex multi-structural arrangements hinders challenges in antimicrobial resistance. This study investigated the antimicrobial resistance potential of grapefruit seed extract (GSE) by examining the formation of mono-, dual-, and multi-species biofilms. We also explored the counterintuitive effect in response to GSE at various concentrations, including minimum inhibitory concentration (MIC) and sub-MIC (1/2 and 1/4 MIC). The results of the swimming and swarming motility tests revealed increased motility at the sub-MIC of GSE. The crystal violet assay demonstrated increased biofilm formation in multi-species biofilms, highlighting the synergistic effect of Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes. At the MIC concentration of GSE, field emission scanning electron microscopy (FE-SEM) revealed cell morphology damage, while sub-MIC increased biofilm formation and architectural complexity. Multi-species biofilms demonstrated greater biofilm-forming ability and antimicrobial resistance than mono-species biofilms, indicating synergistic interactions and enhanced resilience. These findings highlight the importance of understanding biofilm dynamics and antimicrobial resistance to ensure environmental safety.}, }
@article {pmid39098095, year = {2024}, author = {Xu, S and Liu, Z and Ren, P and Liu, Y and Xiao, F and Li, W}, title = {BmfR, a novel GntR family regulator, regulates biofilm formation in marine-derived, Bacillus methylotrophicus B-9987.}, journal = {Microbiological research}, volume = {287}, number = {}, pages = {127859}, doi = {10.1016/j.micres.2024.127859}, pmid = {39098095}, issn = {1618-0623}, abstract = {Biofilms are common living states for microorganisms, allowing them to adapt to environmental changes. Numerous Bacillus strains can form complex biofilms that play crucial roles in biocontrol processes. However, our current understanding of the molecular mechanisms of biofilm formation in Bacillus is mainly based on studies of Bacillus subtilis. Knowledge regarding the biofilm formation of other Bacillus species remains limited. In this study, we identified a novel transcriptional regulator, BmfR, belonging to the GntR family, that regulates biofilm formation in marine-derived Bacillus methylotrophicus B-9987. We demonstrated that BmfR induces biofilm formation by activating the extracellular polysaccharide structural genes epsA-O and negatively regulating the matrix gene repressor, SinR; of note it positively affects the expression of the master regulator of sporulation, Spo0A. Furthermore, database mining for BmfR homologs has revealed their widespread distribution among many bacterial species, mainly Firmicutes and Proteobacteria. This study advances our understanding of the biofilm regulatory network of Bacillus strains, and provides a new target for exploiting and manipulating biofilm formation.}, }
@article {pmid39098075, year = {2024}, author = {Liu, H and Li, L and Ye, W and Zhao, B and Peng, Y and Liu, G and Gao, X and Peng, X}, title = {Simultaneous nitrification and denitrification in a hybrid activated sludge-membrane aerated biofilm reactor (H-MABR) for nitrogen removal from low COD/N interflow: A pilot-scale study.}, journal = {Journal of environmental management}, volume = {367}, number = {}, pages = {122038}, doi = {10.1016/j.jenvman.2024.122038}, pmid = {39098075}, issn = {1095-8630}, abstract = {There are a large number of simple landfills in hilly areas, and the results of previous studies have shown that pollutants in landfills can spread via interflow and cause surface source pollution. The hybrid activated sludge-membrane aerated bioreactor (H-MABR) developed in a previous study can be used for the treatment of interflow with a low chemical oxygen demand (COD)/total nitrogen (TN) ratio, and it has been shown to be effective in laboratory simulations. To investigate the effectiveness of the H-MABR in treating interflow around landfills in real-world applications, an in-situ pilot-scale evaluation of the effectiveness of H-MABR operation was conducted at a landfill. The results indicated that the removal efficiencies of COD, TN, and ammonia nitrogen in interflow by H-MABR were 87.1 ± 6.0%, 80.9 ± 7.9%, and 97.9 ± 1.4%, respectively. The removal rate of TN reached 148.6-205.6 g-N/m[3]·d. The concentration of each pollutant in the effluent was in accordance with China's "Standard for pollution control on the landfill site of municipal solid waste (GB16889-2008)," wherein the COD, TN, and ammonia nitrogen of effluent should be less than 100 mg/L, 40 mg/L, and 25 mg/L, respectively. The results of community composition analysis and PICRUSt analysis based on 16S rRNA gene sequencing showed that there were different dominant functional bacteria between the inner and outer rings, but functional genes involved in the nitrification-denitrification, assimilated nitrate reduction, and dissimilated nitrate reduction pathway were all detected. Furthermore, except for the nitrite oxidation gene narG, the abundance of which did not significantly differ between the inner and outer rings, the abundance of the other functional genes was higher in the outer ring than in the inner ring. An economic evaluation revealed that the operation cost of interflow treatment by the H-MABR was as low as ¥2.78/m[3]; thus, the H-MABR is a shock-load-resistant and cost-effective technology for interflow treatment.}, }
@article {pmid39097900, year = {2024}, author = {Taha Majid, B and Ali Hussein, S and Kamal Rachid, S}, title = {Unraveling the molecular regulation of biofilm underlying effect of chronic disease medications.}, journal = {Cellular and molecular biology (Noisy-le-Grand, France)}, volume = {70}, number = {7}, pages = {15-21}, doi = {10.14715/cmb/2024.70.7.3}, pmid = {39097900}, issn = {1165-158X}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Staphylococcus aureus/drug effects/genetics/physiology ; Humans ; *Enterococcus faecalis/drug effects/genetics/physiology ; *Ursodeoxycholic Acid/pharmacology ; Anti-Bacterial Agents/pharmacology ; Chronic Disease ; Microbial Sensitivity Tests ; Gene Expression Regulation, Bacterial/drug effects ; Benzimidazoles/pharmacology ; Tetrazoles/pharmacology ; Biphenyl Compounds/pharmacology ; }, abstract = {A biofilm is a complex microbial structure that promotes the progression of persistent infections, particularly in nosocomial settings via indwelling medical devices. Conventional antibiotics are often ineffective treatments for biofilms; hence, it is crucial to investigate or design non-antibiotic antibiofilm compounds that can successfully reduce and eradicate biofilm-related infections. This study was an attempt to repurpose chronic disease medications of the antihypertensive and antilipidemic drug classes, including candesartan cilexetil (CC) and ursodeoxycholic acid (UDCA), respectively, to be used as antibiofilm agents against the two infectious pathogens Staphylococcus aureus and Enterococcus faecalis. Crystal violet (CV) staining assay was used to evaluate the antibiofilm activity of the drugs. Real-time polymerase chain reaction (RT-PCR) was performed to determine the transcription levels of the biofilm-related genes (icaA and icaR in S. aureus and fsrC and gelE in E. faecalis) following treatment with different concentrations of CC and UDCA. we found that a concentration of greater than 1.5 µg/ml of CC significantly (p < 0.005) inhibited the biofilm formation of both bacterial isolates, and a concentration of greater than 50 µg/ml of UDCA significantly (p < 0.005) inhibited the biofilm formation of both bacterial isolates. Interestingly, the mRNA expression levels of biofilm-related genes were decreased in the two bacterial isolates at concentrations that were lower than the human pharmaceutical daily doses.}, }
@article {pmid39097145, year = {2024}, author = {Bhandari, S and Upreti, MK and Angbuhang, KB and Shrestha, B and Shrestha, UT}, title = {Increased biofilm-associated Carbapenem-resistant Acinetobacter-calcoaceticus-baumannii complex infections among the hospitalized patients in Kathmandu Model Hospital, Nepal.}, journal = {Journal of global antimicrobial resistance}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jgar.2024.07.012}, pmid = {39097145}, issn = {2213-7173}, }
@article {pmid39097132, year = {2024}, author = {Valdivia Pérez, JA and Nocelli, NE and Bustos, J and Antonio, ML and Smania, A and Vico, RV and Fanani, ML}, title = {Membrane-targeted mechanism for amphiphilic Vitamin C compounds as methicillin-resistant Staphylococcus aureus biofilm eradicating agents.}, journal = {Chemistry and physics of lipids}, volume = {}, number = {}, pages = {105423}, doi = {10.1016/j.chemphyslip.2024.105423}, pmid = {39097132}, issn = {1873-2941}, abstract = {Staphylococcus aureus infections and its biofilm removal is an important concern in health care management. Methicillin-resistant S. aureus is responsible for severe morbidity and mortality worldwide. The extensive use of disinfectants against biofilms has led to negative environmental impacts. Developing new and more potent biofilm eradication agents with minimal detrimental effects on human and environmental health is currently on the agenda. The alkyl esters of L-ascorbic acid (ASCn) are antioxidant amphiphiles, which show antimicrobial capacity against methicillin-sensitive and resistant S. aureus strains. ASC12 and ASC14 formulations are able to kill the persister cells of the deepest layers of the biofilm. We tested the hypothesis that the antimicrobial and antibiofilm capacity found for the ASCn emerges from a combined effect of its amphiphilic and their redox capacity. This mechanism appears related to: I) a larger diffusion capacity of the ASC12 micelles than ASC14 and ASC16 microstructures; II) the neutralization of the ASCn acid hydroxyl when the amphiphile reaches the surface of an anionic surface, followed by a rapid insertion; III) the disruption of cell membrane by alteration of membrane tension and structure and IV) ASCn accumulation in the cell membrane or biofilm extracellular matrix surfaces, reducing functional chemical groups and affecting its biological function.}, }
@article {pmid39097126, year = {2024}, author = {Li, J and Sun, M and Tang, X and Liu, Y and Ou, C and Luo, Y and Wang, L and Hai, L and Deng, L and He, D}, title = {Acidic biofilm microenvironment-responsive ROS generation via a protein nanoassembly with hypoxia-relieving and GSH-depleting capabilities for efficient elimination of biofilm bacteria.}, journal = {Acta biomaterialia}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.actbio.2024.07.044}, pmid = {39097126}, issn = {1878-7568}, abstract = {Reactive oxygen species (ROS) are widely considered to the effective therapeutics for fighting bacterial infections especially those associated with biofilm. However, biofilm microenvironments including hypoxia, limited H2O2, and high glutathione (GSH) level seriously limit the therapeutic efficacy of ROS-based strategies. Herein, we have developed an acidic biofilm microenvironment-responsive antibacterial nanoplatform consisting of copper-dopped bovine serum albumin (CBSA) loaded with copper peroxide (CuO2) synthesized in situ and indocyanine green (ICG). The three-in-one nanotherapeutics (CuO2/ICG@CBSA) are capable of releasing Cu[2+] and H2O2 in a slightly acidic environment, where Cu[2+] catalyzes the conversion of H2O2 into hydroxyl radical (•OH) and consumes the highly expressed GSH to disrupt the redox homeostasis. With the assistance of an 808 nm laser, the loaded ICG not only triggers the production of singlet oxygen ([1]O2) by a photodynamic process, but also provides photonic hyperpyrexia that further promotes the Fenton-like reaction for enhancing •OH production and induces thermal decomposition of CuO2 for the O2-self-supplying [1]O2 generation. The CuO2/ICG@CBSA with laser irradiation demonstrates photothermal-augmented multi-mode synergistic bactericidal effect and is capable of inhibiting biofilm formation and eradicating the biofilm bacteria. Further in vivo experiments suggest that the CuO2/ICG@CBSA can effectively eliminate wound infections and accelerate wound healing. The proposed three-in-one nanotherapeutics with O2/H2O2-self-supplied ROS generating capability show great potential in treating biofilm-associated bacterial infections. STATEMENT OF SIGNIFICANCE: Here, we have developed an acidic biofilm microenvironment-responsive nanoplatform consisting of copper-dopped bovine serum albumin (CBSA) loaded with copper peroxide (CuO2) synthesized in situ and indocyanine green (ICG). The nanotherapeutics (CuO2/ICG@CBSA) are capable of releasing Cu[2+] and H2O2 in an acidic environment, where Cu[2+] catalyzes the conversion of H2O2 into •OH and consumes the overexpressed GSH to improve oxidative stress. With the aid of an 808 nm laser, ICG provides photonic hyperpyrexia for enhancing •OH production, and triggers O2-self-supplying [1]O2 generation. CuO2/ICG@CBSA with laser irradiation displays photothermal-augmented multi-mode antibacterial and antibiofilm effect. Further in vivo experiments prove that CuO2/ICG@CBSA effectively eliminates wound infection and accelerates wound healing. The proposed three-in-one nanotherapeutics show great potential in treating biofilm-associated bacterial infections.}, }
@article {pmid39096840, year = {2024}, author = {Huo, S and Lyu, Z and Wang, X and Liu, S and Chen, X and Yang, M and Liu, Z and Yin, X}, title = {Engineering mesoporous polydopamine-based potentiate STING pathway activation for advanced anti-biofilm therapy.}, journal = {Biomaterials}, volume = {312}, number = {}, pages = {122739}, doi = {10.1016/j.biomaterials.2024.122739}, pmid = {39096840}, issn = {1878-5905}, abstract = {The biofilm-induced "relatively immune-compromised zone" creates an immunosuppressive microenvironment that is a significant contributor to refractory infections in orthopedic endophytes. Consequently, the manipulation of immune cells to co-inhibit or co-activate signaling represents a crucial strategy for the management of biofilm. This study reports the incorporation of Mn[2+] into mesoporous dopamine nanoparticles (Mnp) containing the stimulator of interferon genes (STING) pathway activator cGAMP (Mncp), and outer wrapping by M1-like macrophage cell membrane (m-Mncp). The cell membrane enhances the material's targeting ability for biofilm, allowing it to accumulate locally at the infectious focus. Furthermore, m-Mncp mechanically disrupts the biofilm through photothermal therapy and induces antigen exposure through photodynamic therapy-generated reactive oxygen species (ROS). Importantly, the modulation of immunosuppression and immune activation results in the augmentation of antigen-presenting cells (APCs) and the commencement of antigen presentation, thereby inducing biofilm-specific humoral immunity and memory responses. Additionally, this approach effectively suppresses the activation of myeloid-derived suppressor cells (MDSCs) while simultaneously boosting the activity of T cells. Our study showcases the efficacy of utilizing m-Mncp immunotherapy in conjunction with photothermal and photodynamic therapy to effectively mitigate residual and recurrent infections following the extraction of infected implants. As such, this research presents a viable alternative to traditional antibiotic treatments for biofilm that are challenging to manage.}, }
@article {pmid39095741, year = {2024}, author = {Al-Momani, H and Aolymat, I and Ibrahim, L and Albalawi, H and Al Balawi, D and Albiss, BA and Almasri, M and Alghweiri, S}, title = {Low-dose zinc oxide nanoparticles trigger the growth and biofilm formation of Pseudomonas aeruginosa: a hormetic response.}, journal = {BMC microbiology}, volume = {24}, number = {1}, pages = {290}, pmid = {39095741}, issn = {1471-2180}, mesh = {*Pseudomonas aeruginosa/drug effects/genetics/physiology/growth &amp; development ; *Zinc Oxide/pharmacology ; *Biofilms/drug effects/growth &amp; development ; *Anti-Bacterial Agents/pharmacology ; *Hormesis/drug effects ; Humans ; Metal Nanoparticles/chemistry ; Nanoparticles/chemistry ; Cystic Fibrosis/microbiology ; Gene Expression Regulation, Bacterial/drug effects ; X-Ray Diffraction ; Pseudomonas Infections/microbiology ; Microbial Sensitivity Tests ; Microscopy, Electron, Scanning ; Dose-Response Relationship, Drug ; }, abstract = {INTRODUCTION: Hormesis describes an inverse dose-response relationship, whereby a high dose of a toxic compound is inhibitory, and a low dose is stimulatory. This study explores the hormetic response of low concentrations of zinc oxide nanoparticles (ZnO NPs) toward Pseudomonas aeruginosa.<br><br>METHOD: Samples of P. aeruginosa, i.e. the reference strain, ATCC 27,853, together with six strains recovered from patients with cystic fibrosis, were exposed to ten decreasing ZnO NPs doses (0.78-400&#xa0;&#xb5;g/mL). The ZnO NPs were manufactured from Peganum harmala using a chemical green synthesis approach, and their properties were verified utilizing X-ray diffraction and scanning electron microscopy. A microtiter plate technique was employed to investigate the impact of ZnO NPs on the growth, biofilm formation and metabolic activity of P. aeruginosa. Real-time polymerase chain reactions were performed to determine the effect of ZnO NPs on the expression of seven biofilm-encoding genes.<br><br>RESULT: The ZnO NPs demonstrated concentration-dependent bactericidal and antibiofilm efficiency at concentrations of 100-400&#xa0;&#xb5;g/mL. However, growth was significantly stimulated at ZnO NPs concentration of 25&#xa0;&#xb5;g/mL (ATCC 27853, Pa 3 and Pa 4) and at 12.5&#xa0;&#xb5;g/mL and 6.25&#xa0;&#xb5;g/mL (ATCC 27853, Pa 2, Pa 4 and Pa 5). No significant positive growth was detected at dilutions&#x2009;<&#x2009;6.25&#xa0;&#xb5;g/mL. similarly, biofilm formation was stimulated at concentration of 12.5&#xa0;&#xb5;g/mL (ATCC 27853 and Pa 1) and at 6.25&#xa0;&#xb5;g/mL (Pa 4). At concentration of 12.5&#xa0;&#xb5;g/mL, ZnO NPs upregulated the expression of LasB (ATCC 27853, Pa 1 and Pa 4) and LasR and LasI (ATCC 27853 and Pa 1) as well as RhII expression (ATCC 27853, Pa 2 and Pa 4).<br><br>CONCLUSION: When exposed to low ZnO NPs concentrations, P. aeruginosa behaves in a hormetic manner, undergoing positive growth and biofilm formation. These results highlight the importance of understanding the response of P. aeruginosa following exposure to low ZnO NPs concentrations.}, }
@article {pmid39094962, year = {2024}, author = {Huang, X and Wu, M and Chen, Y and Feng, L and Ji, F and Li, L and Huang, L and Wang, Y and Shen, F and Deng, S and Fang, D}, title = {Ultrahigh carbon utilization in symbiotic Biofilm-Sludge denitrification systems using polymers as sole electron donors.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {131194}, doi = {10.1016/j.biortech.2024.131194}, pmid = {39094962}, issn = {1873-2976}, abstract = {The polymer-based denitrification system is an effective nitrate removal process for treating low carbon/nitrogen wastewater. However, in polymer denitrification systems, carbon used for the denitrification reaction is weakly targeted. Improving the efficiency of carbon utilization in denitrification is important to reduce carbon wastage. In this study, a symbiotic biofilm-sludge denitrification system was constructed using polycaprolactone as electron donors. Results show that the carbon release amount in 120 days was 85.32 ± 0.46 g, and the unit mass of polycaprolactone could remove 1.55 ± 0.01 g NO3[-]-N. Meaningfully, the targeted carbon utilization efficiency for denitrification could achieve 79 %-85 %. The quantitative results showed that the release of electron donors can be well matched to the demand for electron acceptors in the biofilm-sludge denitrification system. Overall, the symbiotic system can improve the nitrate removal efficiency and reduce the waste of carbon source.}, }
@article {pmid39094920, year = {2024}, author = {Yan, C and Nakajima, M and Ikeda-Imafuku, M and Yanagawa, M and Hayatsu, M and Fukuta, T and Shibata, S and Mitragotri, S and Tabeta, K}, title = {Choline and geranate ionic liquid for subgingival biofilm control.}, journal = {International journal of pharmaceutics}, volume = {}, number = {}, pages = {124544}, doi = {10.1016/j.ijpharm.2024.124544}, pmid = {39094920}, issn = {1873-3476}, abstract = {Periodontitis is a chronic inflammatory disease that causes destruction of the periodontium and eventual tooth loss. The priority in the periodontal treatment is to remove the subgingival biofilm. Chemical removal of biofilms using antimicrobial agents has been applied in clinical practice. However, their clinical effect is still limited because the agents must overcome biofilm's significant drug tolerance, which is primarily caused by the extracellular matrix, a physical barrier that attenuates drug diffusion. This study aimed to study the use of ionic liquids (ILs), a new class of biocompatible materials, for controlling subgingival biofilms because of their excellent permeability. Choline and geranate (CAGE) IL was tested for its highly potent antiseptic behavior and permeability. Antibacterial tests revealed that the significant efficacy of CAGE against periodontopathic microorganisms was derived from their ability to destroy cell membrane, as demonstrated by membrane permeability assay and transmission electron microscopy imaging. Antibiofilm tests using two pathogenic biofilm models revealed that CAGE exerted efficacy against the biofilm-embedded bacteria, conspicuously neutralized the biofilms, and eventually destroyed the biofilm structure. Furthermore, the penetration of CAGE into the biofilm was visually confirmed using confocal laser scanning microscopy. This study highlighted the potential of CAGE as a powerful antibiofilm therapeutic.}, }
@article {pmid39094711, year = {2024}, author = {Ramírez, N and Cassola, F and Gambero, A and Sartoratto, A and Gómez Castellanos, LM and Ribeiro, G and Ferreira Rodrigues, RA and Duarte, MCT}, title = {Control of pathogenic bacterial biofilm associated with acne and the anti-inflammatory potential of an essential oil blend.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106834}, doi = {10.1016/j.micpath.2024.106834}, pmid = {39094711}, issn = {1096-1208}, abstract = {Acne is one of the most common skin conditions worldwide, with multifactorial origins it affects areas of the skin with hair follicles and sebaceous glands that become clogged. Bacterial incidence aggravates treatment due to resistance to antimicrobial agents and production of virulence factors such as biofilm formation. Considering the above, this study aims to conduct in vitro evaluations of the antibacterial activity of essential oils (EOs), alone and in combination, against Propionibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis in planktonic and biofilm forms. This study also assessed the anti-inflammatory potential (TNF-α) and the effects of EOs on the viability of human keratinocytes (HaCaT), murine fibroblasts (3T3-L1), and bone marrow-derived macrophages (BMDMs). Of all EOs tested, 13 had active action against P. acnes, 9 against S. aureus, and 9 against S. epidermidis at concentrations of 0.125 to 2.0 mg/mL. Among the most active plant species, a blend of essential oil (BEOs) was selected, with Cymbopogon martini (Roxb.) Will. Watson, Eugenia uniflora L., and Varronia curassavica Jacq., the latter due to its anti-inflammatory action. This BEOs showed higher inhibition rates when compared to chloramphenicol against S. aureus and S. epidermidis, and higher eradication rates when compared to chloramphenicol for the three target species. The BEOs did not affect the cell viability of cell lines evaluated, and the levels of TNF-α decreased. According to these results, the BEOs evaluated showed potential for the development of an alternative natural formulation for the treatment of acne.}, }
@article {pmid39093050, year = {2024}, author = {Basotra, SD and Kumari, Y and Vij, M and Tyagi, A and Sharma, D and Bhattacharyya, MS}, title = {ASLdC3: A Derivative of Acidic Sophorolipid Disrupts Mitochondrial Function, Induces ROS Generation, and Inhibits Biofilm Formation in Candida albicans.}, journal = {ACS infectious diseases}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsinfecdis.4c00155}, pmid = {39093050}, issn = {2373-8227}, abstract = {Fungal infections account for more than 140 million cases of severe and life-threatening conditions each year, causing approximately 1.7 million deaths annually. Candida albicans and related species are the most common human fungal pathogens, causing both superficial (mucosal and cutaneous) and life-threatening invasive infections (candidemia) with a 40-75% mortality rate. Among many virulence factors of Candida albicans, morphological transition from yeast to hyphae, secretion of hydrolytic enzymes, and formation of biofilms are considered to be crucial for pathogenicity. However, the arsenals for the treatment against these pathogens are restricted to only a few classes of approved drugs, the efficacy of which is being compromised by host toxicity, fungistatic activity, and the emergence of drug resistance. In this study, we have described the development of a molecule, exhibiting excellent antifungal activity (MIC 8 μg/mL), by tailoring acidic sophorolipids with aryl alcohols via enzyme catalysis. This novel derivative, ASLdC3, is a surface-active compound that lowers the surface tension of the air-water interface up to 2-fold before reaching the critical micelle concentration of 25 μg/mL. ASLdC3 exhibits excellent antibiofilm properties against Candida albicans and other nonalbicans Candida species. The molecule primarily exhibits its antifungal activity by perturbing mitochondrial function through the alteration of the mitochondrial membrane potential (MMP) and generation of reactive oxygen species (ROS). The ROS damages fungal cell membrane function and cell wall integrity, eventually leading to cell death. ASLdC3 was found to be nontoxic in in vitro assay and nonhemolytic. Besides, it does not cause toxicity in the C. elegans model. Our study provides a valuable foundation for the potential of acidic sophorolipid as a nontoxic, biodegradable precursor for the design and synthesis of novel molecules for use as antimicrobial drugs as well as for other clinical applications.}, }
@article {pmid39091304, year = {2024}, author = {El-Didamony, SE and Kalaba, MH and Sharaf, MH and El-Fakharany, EM and Osman, A and Sitohy, M and Sitohy, B}, title = {Melittin alcalase-hydrolysate: a novel chemically characterized multifunctional bioagent; antibacterial, anti-biofilm and anticancer.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1419917}, doi = {10.3389/fmicb.2024.1419917}, pmid = {39091304}, issn = {1664-302X}, abstract = {The prevalent life-threatening microbial and cancer diseases and lack of effective pharmaceutical therapies created the need for new molecules with antimicrobial and anticancer potential. Bee venom (BV) was collected from honeybee workers, and melittin (NM) was extracted from BV and analyzed by urea-polyacrylamide gel electrophoresis (urea-PAGE). The isolated melittin was hydrolyzed with alcalase into new bioactive peptides and evaluated for their antimicrobial and anticancer activity. Gel filtration chromatography fractionated melittin hydrolysate (HM) into three significant fractions (F1, F2, and F3), that were characterized by electrospray ionization mass spectrometry (ESI-MS) and evaluated for their antimicrobial, anti-biofilm, antitumor, and anti-migration activities. All the tested peptides showed antimicrobial and anti-biofilm activities against Gram-positive and Gram-negative bacteria. Melittin and its fractions significantly inhibited the proliferation of two types of cancer cells (Huh-7 and HCT 116). Yet, melittin and its fractions did not affect the viability of normal human lung Wi-38 cells. The IC50 and selectivity index data evidenced the superiority of melittin peptide fractions over intact melittin. Melittin enzymatic hydrolysate is a promising novel product with high potential as an antibacterial and anticancer agent.}, }
@article {pmid39090348, year = {2024}, author = {Mohan, S and Lavu, V and Ajitkumar, S and Balaji, SK}, title = {Anti-biofilm activity of 445 nm and 970 nm diode laser on mixed species colonies of- aggregatibacter actinomycetemcomitans and porphyromonas gingivalis cultured on titanium discs -an in vitro study.}, journal = {Lasers in medical science}, volume = {39}, number = {1}, pages = {206}, pmid = {39090348}, issn = {1435-604X}, mesh = {*Biofilms/radiation effects/drug effects ; *Porphyromonas gingivalis/physiology ; *Aggregatibacter actinomycetemcomitans ; *Lasers, Semiconductor/therapeutic use ; *Titanium/chemistry ; Humans ; In Vitro Techniques ; }, abstract = {To assess and compare the anti-microbial efficacy of 445 nm and 970 nm diode laser on mixed species biofilm of Aggregatibacter actinomycetemcomitans [A.a] and Porphyromonas gingivalis [P.g] cultured on machined pure titanium discs. A total of 65 machined pure titanium discs with no surface modifications with a 10-mm diameter and a 2-mm height were sterilized by autoclaving at 121 °C for 15 min and incubated with the commercially available bacterial strains ATCC(American Type Culture Collection- P.g 33277 and A.a 29522)mixture of Aggregatibacter actinomycetemcomitans(A.a) and Porphyromonas gingivalis(P.g).After a 2-week incubation period with the mixture of bacteria to develop a mixed species biofilm, the discs were divided into three groups: (1) no treatment (control), (2) 445 nm laser (test), (3) 970 nm laser (test). For each laser wavelength (445 and 970 nm), the discs were exposed to 1.0 W and 2.0 W in continuous wave mode for the times points of 15, 30, and 60 s. The antimicrobial efficacy was assessed by qPCR. A significant reduction in the levels of both species of bacteria was observed between control and the laser intervention groups. A higher efficacy for the 445 nm diode laser against Porphyromonas gingivalis and a similar efficacy against Aggregatibacter actinomycetemcomitans was observed as compared to the 970 nm group. 445 nm wavelength represents a potential and effective laser wavelength which can be used for the management of peri-implant infection. The present study findings also need to be further validated through clinical interventional trials.}, }
@article {pmid39089085, year = {2024}, author = {Oliulla, H and Mizan, MFR and Ashrafudoulla, M and Meghla, NS and Ha, AJ and Park, SH and Ha, SD}, title = {The challenges and prospects of using cold plasma to prevent bacterial contamination and biofilm formation in the meat industry.}, journal = {Meat science}, volume = {217}, number = {}, pages = {109596}, doi = {10.1016/j.meatsci.2024.109596}, pmid = {39089085}, issn = {1873-4138}, abstract = {The risk of foodborne disease outbreaks increases when the pathogenic bacteria are able to form biofilms, and this presents a major threat to public health. An emerging non-thermal cold plasma (CP) technology has proven a highly effective method for decontaminating meats and their products and extended their shelf life. CP treatments have ability to reduce microbial load and, biofilm formation with minimal change of color, pH value, and lipid oxidation of various meat and meat products. The CP technique offers many advantages over conventional processing techniques due to its layout flexibility, nonthermal behavior, affordability, and ecological sustainability. The technology is still in its infancy, and continuous research efforts are needed to realize its full potential in the meat industry. This review addresses the basic principles and the impact of CP technology on biofilm formation, meat quality (including microbiological, color, pH value, texture, and lipid oxidation), and microbial inactivation pathways and also the prospects of this technology.}, }
@article {pmid39088791, year = {2024}, author = {Rahn, HP and Liu, X and Chosy, MB and Sun, J and Cegelski, L and Wender, PA}, title = {Biguanide-Vancomycin Conjugates are Effective Broad-Spectrum Antibiotics against Actively Growing and Biofilm-Associated Gram-Positive and Gram-Negative ESKAPE Pathogens and Mycobacteria.}, journal = {Journal of the American Chemical Society}, volume = {}, number = {}, pages = {}, doi = {10.1021/jacs.4c06520}, pmid = {39088791}, issn = {1520-5126}, abstract = {Strategies to increase the efficacy and/or expand the spectrum of activity of existing antibiotics provide a potentially fast path to clinically address the growing crisis of antibiotic-resistant infections. Here, we report the synthesis, antibacterial efficacy, and mechanistic activity of an unprecedented class of biguanide-antibiotic conjugates. Our lead biguanide-vancomycin conjugate, V-C6-Bg-PhCl (5e), induces highly effective cell killing with up to a 2 orders-of-magnitude improvement over its parent compound, vancomycin (V), against vancomycin-resistant enterococcus. V-C6-Bg-PhCl (5e) also exhibits improved activity against mycobacteria and each of the ESKAPE pathogens, including the Gram-negative organisms. Furthermore, we uncover broad-spectrum killing activity against biofilm-associated Gram-positive and Gram-negative bacteria as well as mycobacteria not observed for clinically used antibiotics such as oritavancin. Mode-of-action studies reveal that vancomycin-like cell wall synthesis inhibition with improved efficacy attributed to enhanced engagement at vancomycin binding sites through biguanide association with relevant cell-surface anions for Gram-positive and Gram-negative bacteria. Due to its potency, remarkably broad activity, and lack of acute mammalian cell toxicity, V-C6-Bg-PhCl (5e) is a promising candidate for treating antibiotic-resistant infections and notoriously difficult-to-treat slowly growing and antibiotic-tolerant bacteria associated with chronic and often incurable infections. More generally, this study offers a new strategy (biguanidinylation) to enhance antibiotic activity and facilitate clinical entry.}, }
@article {pmid39088248, year = {2024}, author = {Walsh, D and Parmenter, C and Bakker, SE and Lithgow, T and Traven, A and Harrison, F}, title = {A new model of endotracheal tube biofilm identifies combinations of matrix-degrading enzymes and antimicrobials able to eradicate biofilms of pathogens that cause ventilator-associated pneumonia.}, journal = {Microbiology (Reading, England)}, volume = {170}, number = {8}, pages = {}, doi = {10.1099/mic.0.001480}, pmid = {39088248}, issn = {1465-2080}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Pneumonia, Ventilator-Associated/microbiology/drug therapy ; *Pseudomonas aeruginosa/drug effects/physiology ; Humans ; *Candida albicans/drug effects/physiology ; *Klebsiella pneumoniae/drug effects/physiology/growth &amp; development ; Intubation, Intratracheal ; Anti-Infective Agents/pharmacology ; Anti-Bacterial Agents/pharmacology ; }, abstract = {Ventilator-associated pneumonia is defined as pneumonia that develops in a patient who has been on mechanical ventilation for more than 48 hours through an endotracheal tube. It is caused by biofilm formation on the indwelling tube, which introduces pathogenic microbes such as Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans into the patient's lower airways. Currently, there is a lack of accurate in vitro models of ventilator-associated pneumonia development. This greatly limits our understanding of how the in-host environment alters pathogen physiology and the efficacy of ventilator-associated pneumonia prevention or treatment strategies. Here, we showcase a reproducible model that simulates the biofilm formation of these pathogens in a host-mimicking environment and demonstrate that the biofilm matrix produced differs from that observed in standard laboratory growth medium. In our model, pathogens are grown on endotracheal tube segments in the presence of a novel synthetic ventilated airway mucus medium that simulates the in-host environment. Matrix-degrading enzymes and cryo-scanning electron microscopy were employed to characterize the system in terms of biofilm matrix composition and structure, as compared to standard laboratory growth medium. As seen in patients, the biofilms of ventilator-associated pneumonia pathogens in our model either required very high concentrations of antimicrobials for eradication or could not be eradicated. However, combining matrix-degrading enzymes with antimicrobials greatly improved the biofilm eradication of all pathogens. Our in vitro endotracheal tube model informs on fundamental microbiology in the ventilator-associated pneumonia context and has broad applicability as a screening platform for antibiofilm measures including the use of matrix-degrading enzymes as antimicrobial adjuvants.}, }
@article {pmid39087223, year = {2024}, author = {Nam, OH and Park, TY and Jeong, SR and Shin, J and Jih, MK}, title = {Antimicrobial effect of two fluoride-releasing adhesive tapes on Streptococcus mutans biofilm.}, journal = {The Journal of clinical pediatric dentistry}, volume = {48}, number = {4}, pages = {132-138}, doi = {10.22514/jocpd.2024.086}, pmid = {39087223}, issn = {1557-5268}, mesh = {*Streptococcus mutans/drug effects ; *Biofilms/drug effects ; *Fluorides/pharmacology/chemistry ; Polyvinyl Alcohol/chemistry/pharmacology ; Microscopy, Confocal ; Microscopy, Electron, Scanning ; Humans ; Cariostatic Agents/pharmacology/chemistry ; Anti-Infective Agents/pharmacology ; }, abstract = {Fluoride-releasing adhesive tapes have been developed as a new fluoride delivery agent. However, application as caries prevention agents remains underexplored. This study aimed at evaluating the antimicrobial activity of two fluoride-releasing adhesive tapes against S. mutans biofilm. Two polyvinyl alcohol (PVA) tapes were investigated: (i) a fluoride-PVA (F-PVA) tape, (ii) a pullulan incorporated F-PVA (PF-PVA) tape. S. mutan strains were cultured and treated with the tapes. Antimicrobial effects were evaluated using the agar diffusion test, field-emission scanning electron microscopy (FE-SEM), and confocal laser scanning microscopy (CLSM). F-PVA tapes showed higher inhibition-zone diameters than PF-PVA at 48 h and 72 h. However, there were no significant differences (p > 0.05) between the effects of F-PVA and PF-PVA. The bio-volume of S. mutans and extracellular polymeric substances significantly decreased in the F-PVA tapes than in the PF-PVA tapes (p < 0.05). FE-SEM micrographs revealed less S. mutans colonization in F-PVA. F-PVA exhibited better antimicrobial activity against S. mutans than PF-PVA.}, }
@article {pmid39086984, year = {2024}, author = {Ullah, N and Hasnain, SZU and Baloch, R and Amin, A and Nasibova, A and Selakovic, D and Rosic, GL and Islamov, S and Naraliyeva, N and Jaradat, N and Mammadova, AO}, title = {Exploring essential oil-based bio-composites: molecular docking and in vitro analysis for oral bacterial biofilm inhibition.}, journal = {Frontiers in chemistry}, volume = {12}, number = {}, pages = {1383620}, doi = {10.3389/fchem.2024.1383620}, pmid = {39086984}, issn = {2296-2646}, abstract = {Oral bacterial biofilms are the main reason for the progression of resistance to antimicrobial agents that may lead to severe conditions, including periodontitis and gingivitis. Essential oil-based nanocomposites can be a promising treatment option. We investigated cardamom, cinnamon, and clove essential oils for their potential in the treatment of oral bacterial infections using in vitro and computational tools. A detailed analysis of the drug-likeness and physicochemical properties of all constituents was performed. Molecular docking studies revealed that the binding free energy of a Carbopol 940 and eugenol complex was -2.0 kcal/mol, of a Carbopol 940-anisaldehyde complex was -1.9 kcal/mol, and a Carbapol 940-eugenol-anisaldehyde complex was -3.4 kcal/mol. Molecular docking was performed against transcriptional regulator genes 2XCT, 1JIJ, 2Q0P, 4M81, and 3QPI. Eugenol cinnamaldehyde and cineol presented strong interaction with targets. The essential oils were analyzed against Staphylococcus aureus and Staphylococcus epidermidis isolated from the oral cavity of diabetic patients. The cinnamon and clove essential oil combination presented significant minimum inhibitory concentrations (MICs) (0.0625/0.0312 mg/mL) against S. epidermidis and S. aureus (0.0156/0.0078 mg/mL). In the anti-quorum sensing activity, the cinnamon and clove oil combination presented moderate inhibition (8 mm) against Chromobacterium voilaceum with substantial violacein inhibition (58% ± 1.2%). Likewise, a significant biofilm inhibition was recorded in the case of S. aureus (82.1% ± 0.21%) and S. epidermidis (84.2% ± 1.3%) in combination. It was concluded that a clove and cinnamon essential oil-based formulation could be employed to prepare a stable nanocomposite, and Carbapol 940 could be used as a compatible biopolymer.}, }
@article {pmid39086652, year = {2024}, author = {Das, S and Kaledhonkar, S}, title = {Physiochemical characterization of a potential Klebsiella phage MKP-1 and analysis of its application in reducing biofilm formation.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1397447}, doi = {10.3389/fmicb.2024.1397447}, pmid = {39086652}, issn = {1664-302X}, abstract = {The common intestinal pathogen Klebsiella pneumoniae (K. pneumoniae) is one of the leading causes of fatal superbug infections that can resist the effects of commonly prescribed medicines. The uncontrolled use or misuse of antibiotics has increased the prevalence of drug-resistant K. pneumoniae strains in the environment. In the quest to search for alternative therapeutics for treating these drug-resistant infections, bacteriophages (bacterial viruses) emerged as potential candidates for in phage therapy against Klebsiella. The effective formulation of phage therapy against drug-resistant Klebsiella infections demands thorough characterization and screening of many bacteriophages. To contribute effectively to the formulation of successful phage therapy against superbug infections by K. pneumoniae, this study includes the isolation and characterization of a novel lytic bacteriophage MKP-1 to consider its potential to be used as therapeutics in treating drug-resistant Klebsiella infections. Morphologically, having a capsid attached to a long non-contractile tail, it was found to be a siphovirus that belongs to the class Caudoviricetes and showed infectivity against different strains of the target host bacterium. Comparatively, this double-stranded DNA phage has a large burst size and is quite stable in various physiological conditions. More interestingly, it has the potential to degrade the tough biofilms formed by K. pneumoniae (Klebsiella pneumoniae subsp. pneumoniae (Schroeter) Trevisan [ATCC 15380]) significantly. Thus, the following study would contribute effectively to considering phage MKP-1 as a potential candidate for phage therapy against Klebsiella infection.}, }
@article {pmid39085984, year = {2024}, author = {Aktekin, MB and Oksuz, Z and Turkmenoglu, B and Istifli, ES and Kuzucu, M and Algul, O}, title = {Synthesis and evaluation of di-heterocyclic benzazole compounds as potential antibacterial and anti-biofilm agents against Staphylococcus aureus.}, journal = {Chemical biology &amp; drug design}, volume = {104}, number = {2}, pages = {e14601}, doi = {10.1111/cbdd.14601}, pmid = {39085984}, issn = {1747-0285}, support = {2021-1-TP3-4120//Mersin University/ ; }, mesh = {*Biofilms/drug effects ; *Staphylococcus aureus/drug effects ; *Anti-Bacterial Agents/pharmacology/chemical synthesis/chemistry ; *Microbial Sensitivity Tests ; *Molecular Docking Simulation ; *DNA Gyrase/metabolism ; Humans ; Heterocyclic Compounds/chemistry/pharmacology/chemical synthesis ; Structure-Activity Relationship ; Cell Line ; Catalytic Domain ; }, abstract = {Cumulative escalation in antibiotic-resistant pathogens necessitates the quest for novel antimicrobial agents, as current options continue to diminish bacterial resistance. Herein, we report the synthesis of di-heterocyclic benzazole structures (12-19) and their in vitro evaluation for some biological activities. Compounds 16 and 17 demonstrated potent antibacterial activity (MIC = 7.81 μg/mL) against Staphylococcus aureus, along with significant anti-biofilm activity. Noteworthy is the capability of Compound 17 to inhibit biofilm formation by at least 50% at sub-MIC (3.90 μg/mL) concentration. Furthermore, both compounds exhibited the potential to inhibit preformed biofilm by at least 50% at the MIC concentration (7.81 μg/mL). Additionally, Compounds 16 and 17 were examined for cytotoxic effects in HFF-1 cells, using the MTT method, and screened for binding interactions within the active site of S. aureus DNA gyrase using in silico molecular docking technique, employing AutoDock 4.2.6 and Schrödinger Glidse programs. Overall, our findings highlight Compounds 16 and 17 as promising scaffolds warranting further optimization for the development of effective antibacterial and anti-biofilm agents.}, }
@article {pmid39084967, year = {2024}, author = {Zang, K and Sun, Y and Jiang, Y and Liu, M and Sun, J and Li, H and Zheng, F and Sun, B}, title = {Preparation and characterization of Baijiu Jiuzao cellulose nanofibers-kafirin composite bio-film with excellent physical properties.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {133993}, doi = {10.1016/j.ijbiomac.2024.133993}, pmid = {39084967}, issn = {1879-0003}, abstract = {Jiuzao is the main solid by-products of Baijiu industry, which contain a high amount of underutilized cellulose and proteins. In recent years, cellulose nanofibers mixed with proteins to prepare biodegradable bio-based film materials have received widespread attention. In this study, we propose a novel method to simultaneously extract kafirin and cellulose from strong-flavor type of Jiuzao, and modify cellulose to prepare cellulose nanofibers by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxide) oxidation-pressure homogenization technique, and finally mix kafirin with cellulose nanofibers to prepare a new biodegradable bio-based composite film. Based on the analysis of one-way and response surface experiments, the highest purity of cellulose was 82.04 %. During cellulose oxidation, when NaClO was added at 25 mmol/g, cellulose nanofibers have a particle size of 80-120 nm, a crystallinity of 65.8°. Finally, kafirin and cellulose nanofibers were mixed to prepare films. The results showed that when cellulose nanofibers were added at 1 %, the film surface was smooth, the light transmittance was 60.8 %, and the tensile strength was 9.17 MPa at maximum, which was 104 % higher than pure protein film. The contact angle was 34.3°. This paper provides new ideas and theoretical basis for preparing biodegradable bio-based composite film materials, and improves the added value of Jiuzao.}, }
@article {pmid39084546, year = {2024}, author = {Teulé-Trull, M and Demiquels-Punzano, E and Pérez, RA and Aparicio, C and Durán-Sindreu, F and Sánchez-López, E and González-Sánchez, JA and Delgado, LM}, title = {REVISION OF EX VIVO ENDODONTIC BIOFILM MODEL USING COMPUTER AIDED DESIGN.}, journal = {Journal of dentistry}, volume = {}, number = {}, pages = {105270}, doi = {10.1016/j.jdent.2024.105270}, pmid = {39084546}, issn = {1879-176X}, abstract = {OBJECTIVE: Most endodontic diseases are bacterium-mediated inflammatory or necrotic process induced by contaminated dental pulp. Although great advances are being performed to obtain more efficient antibacterial strategies for persistent infections, most studies lack of representative models to test their antibacterial effects and their outcomes cannot be promptly translated to clinical practice. Therefore, this study aimed to refine an ex vivo endodontic biofilm model combining human tooth, computer guided design and 3D printing to obtain a more reproducible and predictable model.<br><br>METHODS: Monoradicular teeth were cut using three different methods: hand-held (HCC), mechanical precision (MPC) and computer aid guided cutting (CGC). Then, blocks were reassembled. The different model preparations were assessed in terms of dimensional tolerance, surface analysis, liquid tightness and Enterococcus faecalis biofilm development for 21 days, which was studied by metabolic assays and confocal microscopy. Then, the proposed model was validated using different commercial disinfecting treatments.<br><br>RESULTS: CGC exhibited significantly lower deviation and surface without defects compared to HHC and MPC, leading to superior liquid tightness. Similarly, mature biofilms with high metabolic activity and vitality were observed in all conditions, CGC showing the lowest variation. Regarding the model validation, all antibacterial treatments resulted in the complete eradication of bacteria in the standard 2D model, whereas commercial treatments exhibited varying levels of efficacy in the proposed ex vivo model, from moderately reduction of metabolic activity to complete elimination of biofilm.<br><br>CONCLUSIONS: The novel guided approach represents a more reliable, standardized, and reproducible model for the evaluation of endodontic disinfecting therapies.<br><br>CLINICAL SIGNIFICANCE: During antibacterial treatment development, challenging 3D models using teeth substrates to test antibacterial treatments novel guided approach represents a more reliable, standardized, and reproducible model for the evaluation of endodontic disinfecting therapies.}, }
@article {pmid39084089, year = {2024}, author = {Tang, B and Hung, W and Salam, M and Zhang, L and Yang, Y and Niu, J and Li, H and Zhang, L}, title = {Suspended particulate matter-biofilm aggregates benefit microcystin removal in turbulent water but trigger toxicity toward Daphnia magna.}, journal = {Water research}, volume = {263}, number = {}, pages = {122150}, doi = {10.1016/j.watres.2024.122150}, pmid = {39084089}, issn = {1879-2448}, abstract = {Suspended particulate matter (SPM) and biofilm are critical in removing contaminants in aquatic environments, but the environmental behavior and ecological toxicity of SPM-biofilm aggregates modulated by turbulence intensities are largely unknown. This study determined the removal pathways of microcystin-LR (MC-LR) by SPM and its biofilm under different turbulence intensities (2.25 × 10[-3], 1.01 × 10[-2], and 1.80 × 10[-2] m[2]/s[3]). Then, we evaluated the toxicity of SPM-biofilm aggregates to Daphnia magna. The results revealed that SPM contributed to the adsorption of MC-LR, and the removal of MC-LR can be accelerated with biofilm formation on SPM, with 95.66 % to 97.45 % reduction in MC-LR concentration under the studied turbulence intensities. Higher turbulence intensity triggered more frequent contact of SPM and MC-LR, formed compact but smaller clusters of SPM-biofilm aggregates, and enhanced the abundance of mlrA and mlrB; thus benefiting the adsorption, biosorption, and biodegradation of MC-LR. Furthermore, the SPM-biofilm aggregates formed in turbulent water triggered oxidative stress to Daphnia magna, while a weak lethal toxic effect was identified under moderate turbulence intensity. The results indicate that the toxicity of SPM-biofilm aggregates fail to display a linear relationship with turbulence intensity. These findings offer new perspectives on understanding the environmental behavior and ecological outcomes of SPM and its biofilms in turbulent aquatic environments.}, }
@article {pmid39079336, year = {2024}, author = {Zhang, Y and Li, X and Ren, A and Yao, M and Chen, C and Zhang, H and van der Meer, W and Liu, G}, title = {Impacts of water treatments on bacterial communities of biofilm and loose deposits in drinking water distribution systems.}, journal = {Environment international}, volume = {190}, number = {}, pages = {108893}, doi = {10.1016/j.envint.2024.108893}, pmid = {39079336}, issn = {1873-6750}, abstract = {Treated drinking water is delivered to customers through drinking water distribution systems (DWDSs). Although studies have focused on exploring the microbial ecology of DWDSs, knowledge about the effects of different water treatments on the bacterial community of biofilm and loose deposits in DWDS is limited. This study assessed the effects of additional treatments on the bacterial communities developed in 10 months' old pilot DWDSs. The results showed a similar bacterial community in the pipe-wall biofilm, which was dominated by Novosphingobium spp. (20-82 %) and Sphingomonas spp. (11-53 %), regardless of the treatment applied. The bacterial communities that were retained in the distribution systems (including pipe-wall biofilm and loose deposits) were similar to the particle-associated bacteria (PAB) in the corresponding supply water. The additional treatments showed clear effects of the removal and/or introduction of particles. The genera Aeromonas spp., Clostridium spp., Legionella spp., and Pseudomonas spp., which contain opportunistic pathogenic species, were only detected among the PAB in ion exchange system. Our study demonstrated that the biofilm community is consistent across treatments, and the contribution from bacteria in loose deposits is important but can be controlled by removing particles. These findings offer more insight into the origin and development of microbial ecology in DWDSs and suggest paths for further research on the possibility of managing the microbial ecology in distribution systems.}, }
@article {pmid39079293, year = {2024}, author = {Li, T and Li, CY and Wang, YF and Zhang, JN and Li, H and Wu, HF and Yang, XL and Song, HL}, title = {Insights to the cooperation of double-working potential electroactive biofilm for performance of sulfamethoxazole removal: ARG fate and microorganism communities.}, journal = {Journal of hazardous materials}, volume = {477}, number = {}, pages = {135357}, doi = {10.1016/j.jhazmat.2024.135357}, pmid = {39079293}, issn = {1873-3336}, abstract = {Bioelectrochemical systems (BESs) have shown great potential in enhancing sulfamethoxazole (SMX) removal. However, electroactive biofilms (EBs) constructed with single potentials struggle due to limited biocatalytic activity, hindering deep SMX degradation. Here, we constructed a double-working potential BES (BES-D) to investigate its ability to eliminate SMX and reduce the levels of corresponding antibiotic resistance genes (ARGs). The preferable electrochemical activity of EB in BES-D was confirmed by electrochemical characterization, EPS analysis, physical structure, viability of the biofilm, and cytochrome content. BES-D exhibited a notably greater SMX removal efficiency (94.2 %) than did the single-working potential BES (BES-S) and the open-circuit group (OC). Degradation pathway analysis revealed that the cooperative EB could accelerate the in-depth removal of SMX. Moreover, EB interaction in BES-D decreased the relative abundance of ARGs in biofilms compared to that in BES-S, although the absolute number of ARG copies increased in BES-D effluents. Compared to those in BES-S and OC, more complex cross-niche microbial associations in the EB of BES-D were observed by network analysis of the bacterial community and ARG hosts, enhancing the degradation efficiency of SMX. In conclusion, BES-D has significant potential for SMX removal and the enhancement of EB activity. Nonetheless, the risk of ARG dissemination in effluent remains a concern.}, }
@article {pmid39079190, year = {2024}, author = {Müderris, T and Dursun Manyaslı, G and Kaya, S and Gül Yurtsever, S}, title = {In vitro interactions of combinations of colistin with meropenem, rifampicin and tigecycline in colistin-resistant, biofilm-forming Klebsiella pneumoniae.}, journal = {Diagnostic microbiology and infectious disease}, volume = {110}, number = {2}, pages = {116408}, doi = {10.1016/j.diagmicrobio.2024.116408}, pmid = {39079190}, issn = {1879-0070}, abstract = {In this study, it was aimed to reveal the in vitro interactions of combinations of colistin with meropenem, rifampicin and tigecycline in colistin-resistant, biofilm-forming Klebsiella pneumonia. A total of 30 isolates, 15 of which formed biofilms and 15 did not form biofilms, were randomly selected from K. pneumoniae isolates growing in blood samples. The synergy rates of colistin-meropenem, colistin-tigecycline, colistin-rifampicin combinations in planktonic/sessile bacteria are; It was determined as 83,3%/73,3%, 66,6%/33,3%, 100%/60% respectively. Biofilm inhibitory concentration (BIC) of colistin, meropenem, tigecycline, and rifampicin significantly increased after biofilm formation. The synergistic activity seen in the sessile form was independent of the planktonic form. Although a high synergistic effect was observed in the meropenem-colistin combination on sessile bacteria, colistin had very high BIC in all combinations. Large-scale studies are needed in which the number of isolates studied is large, bacterial resistance profiles are evaluated genomically, and various antimicrobial groups are included.}, }
@article {pmid39077794, year = {2024}, author = {Guedes, GMM and Ocadaque, CJ and Amando, BR and Freitas, AS and Pereira, VC and Cordeiro, RA and Bandeira, SP and Souza, PFN and Rocha, MFG and Sidrim, JJC and Souza Collares Maia Castelo-Branco, D}, title = {Influence of carbonyl cyanide m-chlorophenyl hydrazone on biofilm dynamics, protease, and siderophore production by Burkholderia pseudomallei.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-13}, doi = {10.1080/08927014.2024.2385038}, pmid = {39077794}, issn = {1029-2454}, abstract = {Efflux pump inhibitors are a potential therapeutic strategy for managing antimicrobial resistance and biofilm formation. This article evaluated the effect of carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on the biofilm growth dynamics and the production of virulence factors by Burkholderia pseudomallei. The effects of CCCP on planktonic, growing, and mature biofilm, interaction with antibacterial drugs, and protease and siderophore production were assessed. CCCP MICs ranged between 128 and 256 µM. The CCCP (128 µM) had a synergic effect with all the antibiotics tested against biofilms. Additionally, CCCP reduced (p < .05) the biomass of biofilm growth and mature biofilms at 128 and 512 µM, respectively. CCCP also decreased (p < .05) protease production by growing (128 µM) and induced (p < .05) siderophore release by planktonic cells (128 µM) growing biofilms (12.8 and 128 µM) and mature biofilms (512 µM). CCCP demonstrates potential as a therapeutic adjuvant for disassembling B. pseudomallei biofilms and enhancing drug penetration.}, }
@article {pmid39075606, year = {2024}, author = {Zhang, T and Ji, S and Zhang, M and Wu, F and Li, X and Luo, X and Huang, Q and Li, M and Zhang, Y and Lu, R}, title = {Effect of capsular polysaccharide phase variation on biofilm formation, motility and gene expression in Vibrio vulnificus.}, journal = {Gut pathogens}, volume = {16}, number = {1}, pages = {40}, pmid = {39075606}, issn = {1757-4749}, support = {QN2022044//Research Projects of Nantong Health Commission/ ; MS12021045//Research Projects of Nantong Health Commission/ ; MA2020018//Subject of Nantong Science and Technology Bureau/ ; }, abstract = {Vibrio vulnificus, a significant marine pathogen, undergoes opaque (Op)-translucent (Tr) colony switching based on whether capsular polysaccharide (CPS) is produced. CPS phase variation is sometime accompanied by genetic variation or down-regulation of particular genes, such as wzb. In addition, CPS prevents biofilm formation and is important to the virulence of V. vulnificus. However, the extent to which there is a difference in gene expression between Tr and Op colonies and the impact of CPS phase variation on other behaviors of V. vulnificus remain unknown. In this work, the data have shown that CPS phase variation of V. vulnificus is affected by incubation time. Tr and Op strains exhibited similar growth rates. However, Tr strains had enhanced biofilm formation capacities but reduced swimming motility compared to Op strains. The RNA-seq assay revealed 488 differentially expressed genes, with 214 downregulated and 274 upregulated genes, between Tr and Op colonies. Genes associated with Tad pili and CPS were downregulated, whereas those involved in flagellum were upregulated, in Tr colonies compared with Op colonies. In addition, 9 putative c-di-GMP metabolism-associated genes and 28 genes encoding putative regulators were significantly differentially expressed, suggesting that CPS phase variation is probably strictly regulated in V. vulnificus. Moreover, 8 genes encoding putative porins were also differentially expressed between the two phenotypic colonies, indicating that bacterial outer membrane was remodeled during CPS phase variation. In brief, this work highlighted the gene expression profiles associated with CPS phase variation, but more studies should be performed to disclose the intrinsic mechanisms in the future.}, }
@article {pmid39074665, year = {2024}, author = {Yuan, Q and Lou, Y and Chen, S and Chen, Y and Li, X and Zhang, X and Qian, L and Zhang, Y and Yingxue, S}, title = {Effect of long-term dosage of hydrazine on mainstream anammox process: biofilm characteristics and microbial community.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {142968}, doi = {10.1016/j.chemosphere.2024.142968}, pmid = {39074665}, issn = {1879-1298}, abstract = {The impact of the long-term trace hydrazine (N2H4) exogenous supplementation on activity of the anaerobic ammonium oxidation (anammox) biofilm was investigated in a moving bed biofilm reactor (MBBR) for mainstream wastewater treatment. The results of this study demonstrated that the addition of 2 to 5 mg/L N2H4 enhanced anammox biofilm activity, as evidenced by the augmented nitrogen removal rate (NRR), which increased from 113.4 g/(m[3]·d) to 126.7 g/(m[3]·d) with the introduction of 2 mg/L N2H4. However, a higher concentration of N2H4 (10 mg/L) suppressed anammox activity, leading to a reduced NRR of 91.5 g/(m[3]·d). Bioindicators revealed that the long-term addition of 2 mg/L N2H4 fostered the accumulation of anammox bacteria (AnAOB) biomass, elevating the volatile suspended solids (VSS) content by 12%. Moreover, the structural composition of extracellular polymeric substances (EPS) within the biofilm was altered, resulting in enhanced biofilm strength within the reactor. The protective mechanism of the biofilm was activated, and EPS secretion was stimulated by the continuous N2H4 supplementation. The introduction of an excess dosage of N2H4 led to alterations in the microbial communities, ultimately resulting in a decline in the performance of the reactor. These findings collectively illustrate that N2H4, as an intermediate product, can effectively enhance anammox activity within the MBBR for mainstream wastewater treatment. This study contributes to the understanding of the optimization strategies for anammox processes in wastewater treatment systems.}, }
@article {pmid39074613, year = {2024}, author = {Mahdavi, P and Aliakbarlu, J}, title = {Anti-biofilm effect of sequential application of ozonated water, acetic acid and lactic acid on Salmonella Typhimurium and Staphylococcus aureus biofilms in vitro.}, journal = {Journal of food protection}, volume = {}, number = {}, pages = {100336}, doi = {10.1016/j.jfp.2024.100336}, pmid = {39074613}, issn = {1944-9097}, abstract = {Biofilms are highly resistant to disinfectants and antimicrobials, and are known as the primary source of food contamination. Salmonella Typhimurium and Staphylococcus aureus (S. aureus) have an excellent ability to form biofilm. This study aimed to evaluate the anti-biofilm activity of ozonated water (O), acetic acid (AA), and lactic acid (LA), individually and sequentially, against biofilms of S. Typhimurium and S. aureus formed on the polystyrene surfaces. The anti-biofilm effects of the treatments were evaluated using crystal violet staining and the viable count determination methods. In the staining method, the highest percentage of biofilm mass reduction was induced by successive use of ozonated water and acetic acid (O-AA), which reduced S. aureus biofilm mass by 44.36%. The sequential use of ozonated water and lactic acid (O-LA) could decrease S. Typhimurium biofilm mass by 57.26%. According to the viable count method, the most effective treatment was the sequential use of ozonated water and lactic acid (O-LA), which reduced S. aureus and S. Typhimurium biofilms by 1.76 and 4.06 log, respectively. It was concluded that the sequential use of ozonated water and organic acids can be considered a practical and environmentally friendly approach to control biofilms.}, }
@article {pmid39073000, year = {2024}, author = {Chen, S and Huang, B and Tian, J and Zhang, W}, title = {Advancements of Porphyrin-Derived Nanomaterials for Antibacterial Photodynamic Therapy and Biofilm Eradication.}, journal = {Advanced healthcare materials}, volume = {}, number = {}, pages = {e2401211}, doi = {10.1002/adhm.202401211}, pmid = {39073000}, issn = {2192-2659}, support = {52333014//National Natural Science Foundation of China/ ; 22075079//National Natural Science Foundation of China/ ; 52203009//National Natural Science Foundation of China/ ; }, abstract = {The threat posed by antibiotic-resistant bacteria and the challenge of biofilm formation has highlighted the inadequacies of conventional antibacterial therapies, leading to increased interest in antibacterial photodynamic therapy (aPDT) in recent years. This approach offers advantages such as minimal invasiveness, low systemic toxicity, and notable effectiveness against drug-resistant bacterial strains. Porphyrins and their derivatives, known for their high molar extinction coefficients and singlet oxygen quantum yields, have emerged as crucial photosensitizers in aPDT. However, their practical application is hindered by challenges such as poor water solubility and aggregation-induced quenching. To address these limitations, extensive research has focused on the development of porphyrin-based nanomaterials for aPDT, enhancing the efficacy of photodynamic sterilization and broadening the range of antimicrobial activity. This review provides an overview of various porphyrin-based nanomaterials utilized in aPDT and biofilm eradication in recent years, including porphyrin-loaded inorganic nanoparticles, porphyrin-based polymer assemblies, supramolecular assemblies, metal-organic frameworks (MOFs), and covalent organic frameworks (COFs). Additionally, insights into the prospects of aPDT is offered, highlighting its potential for practical implementation.}, }
@article {pmid39072629, year = {2024}, author = {Poddar, K and Anand, A}, title = {Growing Mycobacterial Biofilm as a Model to Study Antimicrobial Resistance.}, journal = {Journal of visualized experiments : JoVE}, volume = {}, number = {209}, pages = {}, doi = {10.3791/66607}, pmid = {39072629}, issn = {1940-087X}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Mycobacterium smegmatis/drug effects/physiology ; *Drug Resistance, Bacterial ; Bacteriological Techniques/methods ; }, abstract = {Many bacteria thrive in intricate natural communities, exhibiting key attributes of multicellularity such as communication, cooperation, and competition. The most prevalent manifestation of bacterial multicellular behavior is the formation of biofilms, often linked to pathogenicity. Biofilms offer a haven against antimicrobial agents, fostering the emergence of antimicrobial resistance. The conventional practice of cultivating bacteria in shake flask liquid cultures fails to represent their proper physiological growth in nature, consequently limiting our comprehension of their intricate dynamics. Notably, the metabolic and transcriptional profiles of bacteria residing in biofilms closely resemble those of naturally growing cells. This parallelism underscores the significance of biofilms as an ideal model for foundational and translational research. This article focuses on utilizing Mycobacterium smegmatis as a model organism to illustrate a technique for cultivating pellicle biofilms. The approach is adaptable to various culture volumes, facilitating its implementation for diverse experimental objectives such as antimicrobial studies. Moreover, the method's design enables the qualitative or quantitative evaluation of the biofilm-forming capabilities of different mycobacterial species with minor adjustments.}, }
@article {pmid39071848, year = {2024}, author = {Zhu, Q and Zheng, Y and Zhou, X and Wang, D and Yuan, M and Qian, D and Liang, S and Yu, W and Yang, J and Hou, H and Hu, J}, title = {c-di-GMP and AHL signals-triggered chemical communication under electrical signaling disruption restores Geobacter sulfurreducens biofilm formation.}, journal = {ISME communications}, volume = {4}, number = {1}, pages = {ycae096}, pmid = {39071848}, issn = {2730-6151}, abstract = {Electrogenic biofilms, which have attracted considerable attention in simultaneous wastewater treatment and energy recovery in bioelectrochemical systems, are regulated by chemical communication and potassium channel-mediated electrical signaling. However, how these two communication pathways interact with each other has not been thoroughly investigated. This study first explored the roles of chemical communication, including intracellular bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) and extracellular N-acyl-homoserine lactone (AHL)-mediated quorum sensing, in electrogenic biofilm formation through an integrated analysis of transcriptomics and metabolomics. Electrical signaling disruption inhibited the formation and electroactivity of Geobacter sulfurreducens biofilm, which was mainly ascribed to the reduction in biofilm viability and extracellular protein/polysaccharide ratio. The upregulation of expression levels of genes encoding c-di-GMP and AHL synthesis by transcriptomic analysis, and the increased secretion of N-butanoyl-L-homoserine lactone by metabolomic analysis confirmed the enhancement of chemical communication under electrical signaling disruption, thus indicating a compensatory mechanism among different signaling pathways. Furthermore, protein-protein interaction network showed the convergence of different signaling pathways, with c-di-GMP-related genes acting as central bridges. This study highlights the interaction of different signaling pathways, especially the resilience of c-di-GMP signaling to adverse external stresses, thereby laying the foundation for facilitating electrogenic biofilm formation under adverse conditions in practical applications.}, }
@article {pmid39071379, year = {2024}, author = {Prentice, JA and Kasivisweswaran, S and van de Weerd, R and Bridges, AA}, title = {Biofilm dispersal patterns revealed using far-red fluorogenic probes.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2024.07.15.603607}, pmid = {39071379}, issn = {2692-8205}, abstract = {Bacteria frequently colonize niches by forming multicellular communities called biofilms. To explore new territories, cells exit biofilms through an active process called dispersal. Biofilm dispersal is essential for bacteria to spread between infection sites, yet how the process is executed at the single-cell level remains mysterious. Here, we characterize dispersal at unprecedented resolution for the global pathogen Vibrio cholerae. To do so, we first developed a far-red cell-labeling strategy that overcomes pitfalls of fluorescent protein-based approaches. We reveal that dispersal initiates at the biofilm periphery and ~25% of cells never disperse. We define novel micro-scale patterns that occur during dispersal, including biofilm compression and the formation of dynamic channels. These patterns are attenuated in mutants that reduce overall dispersal or that increase dispersal at the cost of homogenizing local mechanical properties. Collectively, our findings provide fundamental insights into the mechanisms of biofilm dispersal, advancing our understanding of how pathogens disseminate.}, }
@article {pmid39071348, year = {2024}, author = {Bottura, B and McConnell, G and Florek, LC and Smiley, MK and Martin, R and Eana, A and Dayton, HT and Eckartt, KN and Price-Whelan, AM and Hoskisson, PA and Dietrich, LEP and Rooney, LM}, title = {Oxygen Microenvironments in E. coli Biofilm Nutrient Transport Channels: Insights from Complementary Sensing Approaches.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, pmid = {39071348}, issn = {2692-8205}, support = {R01 AI103369/AI/NIAID NIH HHS/United States ; }, abstract = {Chemical gradients and the emergence of distinct microenvironments in biofilms are vital to the stratification, maturation and overall function of microbial communities. These gradients have been well characterised throughout the biofilm mass but the microenvironment of recently discovered nutrient transporting channels in Escherichia coli biofilms remains unexplored. This study employs three different oxygen sensing approaches to provide a robust quantitative overview of the oxygen gradients and microenvironments throughout the biofilm transport channel networks formed by E. coli macrocolony biofilms. Oxygen nanosensing combined with confocal laser scanning microscopy established that the oxygen concentration changes along the length of biofilm transport channels. Electrochemical sensing provided precise quantification of the oxygen profile in the transport channels, showing similar anoxic profiles compared with the adjacent cells. Anoxic biosensing corroborated these approaches, providing an overview of the oxygen utilisation throughout the biomass. The discovery that transport channels maintain oxygen gradients contradicts the previous literature that channels are completely open to the environment along the apical surface of the biofilm. We provide a potential mechanism for the sustenance of channel microenvironments via orthogonal visualisations of biofilm thin sections showing thin layers of actively growing cells. This complete overview of the oxygen environment in biofilm transport channels primes future studies aiming to exploit these emergent structures for new bioremediation approaches.}, }
@article {pmid39071244, year = {2024}, author = {Ballah, FM and Hoque, MN and Islam, MS and Faisal, GM and Rahman, AMT and Khatun, MM and Rahman, M and Hassan, J and Rahman, MT}, title = {Genomic Insights of a Methicillin-Resistant Biofilm-Producing Staphylococcus aureus Strain Isolated From Food Handlers.}, journal = {BioMed research international}, volume = {2024}, number = {}, pages = {5516117}, pmid = {39071244}, issn = {2314-6141}, mesh = {*Biofilms/growth &amp; development/drug effects ; Humans ; *Methicillin-Resistant Staphylococcus aureus/genetics/drug effects/isolation &amp; purification ; *Staphylococcal Infections/microbiology ; Whole Genome Sequencing ; Genomics ; Genome, Bacterial/genetics ; Food Handling ; Anti-Bacterial Agents/pharmacology ; Microbial Sensitivity Tests ; Virulence/genetics ; Virulence Factors/genetics ; Phylogeny ; Drug Resistance, Multiple, Bacterial/genetics ; }, abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) is an important zoonotic pathogen associated with a wide range of infections in humans and animals. Thus, the emergence of MRSA clones poses an important threat to human and animal health. This study is aimed at elucidating the genomics insights of a strong biofilm-producing and multidrug-resistant (MDR) S. aureus MTR_BAU_H1 strain through whole-genome sequencing (WGS). The S. aureus MTR_BAU_H1 strain was isolated from food handlers' hand swabs in Bangladesh and phenotypically assessed for antimicrobial susceptibility and biofilm production assays. The isolate was further undergone to high throughput WGS and analysed using different bioinformatics tools to elucidate the genetic diversity, molecular epidemiology, sequence type (ST), antimicrobial resistance, and virulence gene distribution. Phenotypic analyses revealed that the S. aureus MTR_BAU_H1 strain is a strong biofilm-former and carries both antimicrobial resistance (e.g., methicillin resistance; mecA, beta-lactam resistance; blaZ and tetracycline resistance; tetC) and virulence (e.g., sea, tsst, and PVL) genes. The genome of the S. aureus MTR_BAU_H1 belonged to ST1930 that possessed three plasmid replicons (e.g., rep16, rep7c, and rep19), seven prophages, and two clustered regularly interspaced short palindromic repeat (CRISPR) arrays of varying sizes. Phylogenetic analysis showed a close evolutionary relationship between the MTR_BAU_H1 genome and other MRSA clones of diverse hosts and demographics. The MTR_BAU_H1 genome harbours 42 antimicrobial resistance genes (ARGs), 128 virulence genes, and 273 SEED subsystems coding for the metabolism of amino acids, carbohydrates, proteins, cofactors, vitamins, minerals, and lipids. This is the first-ever WGS-based study of a strong biofilm-producing and MDR S. aureus strain isolated from human hand swabs in Bangladesh that unveils new information on the resistomes (ARGs and correlated mechanisms) and virulence potentials that might be linked to staphylococcal pathogenesis in both humans and animals.}, }
@article {pmid39071174, year = {2024}, author = {Kranjec, C and Mathew, JP and Ovchinnikov, K and Fadayomi, I and Yang, Y and Kjos, M and Li, WW}, title = {A bacteriocin-based coating strategy to prevent vancomycin-resistant Enterococcus faecium biofilm formation on materials of interest for indwelling medical devices.}, journal = {Biofilm}, volume = {8}, number = {}, pages = {100211}, pmid = {39071174}, issn = {2590-2075}, abstract = {The ever-increasing use of exogenous materials as indwelling medical devices in modern medicine offers to pathogens new ways to gain access to human body and begin, in some cases, life threatening infections. Biofouling of such materials with bacteria or fungi is a major concern during surgeries, since this is often associated with biofilm formation and difficult to treat, recalcitrant infections. Intense research efforts have therefore developed several strategies to shield the medical devices' surface from colonization by pathogenic microorganisms. Here, we used dopamine as a coupling agent to coat four different materials of medical interest (plastic polyetheretherketone (PEEK), stainless steel, titanium and silicone catheter) with the bacteriocins, enterocin EJ97-short and the thiopeptide micrococcin P1. Water contact angle measurements and x-ray photoelectron spectroscopy were used to verify the effective coating of the materials. The effect of bacteriocins coated on these materials on the biofilm formation by a vancomycin resistant Enterococcus faecium (VRE) strain was studied by biofilm-oriented antimicrobial test (BOAT) and electron scanning microscopy. The in vitro biocompatibility of bacteriocin-modified biomaterials was tested on cultured human cells. The results demonstrated that the binding of the bacteriocins to the implant surfaces is achieved, and the two bacteriocins in combination could inhibit biofilm formation by E. faecium on all four materials. The modified implant showed no cytotoxicity to the human cells tested. Therefore, surface modification with the two bacteriocins may offer a novel and effective way to prevent biofilm formation on a wide range of implant materials.}, }
@article {pmid39070877, year = {2024}, author = {Rodriguez-Merchan, EC}, title = {Biofilm Related Total Knee Arthroplasty Infection: Prevention, Diagnosis and Treatment.}, journal = {The archives of bone and joint surgery}, volume = {12}, number = {7}, pages = {531-534}, pmid = {39070877}, issn = {2345-4644}, abstract = {Biofilm related implant infection is undoubtedly a relevant challenge in total knee arthroplasty (TKA) with our comprehension steadily progressing and novel management approaches being developed. The aim of this article was to review the most important advances in approaches to combat infections due to biofilm-forming bacteria in TKA. The main conclusions were the following: 1) Fundamental management techniques for infected TKA include open DAIR (debridement, antibiotics, and implant retention), and one and two-stage revision TKA; 2) Continuous local antibiotic perfusion (CLAP) appears to diminish the risk of periprosthetic joint infection (PJI); 3) Restraint of quorum sensing seems to avert PJI after TKA; 4) A recent in vitro study showed promising results in the prevention and management of PJI after TKA using PMMA [poly(methyl methacrylate)] loaded with up to 100 mg of rifampin.}, }
@article {pmid39070325, year = {2024}, author = {Echhpal, UR and Shah, KK and Ahmed, N}, title = {Effectiveness of Denture Cleansers on Candida albicans Biofilm on Conventionally Fabricated, Computer-Aided Design/Computer-Aided Manufacturing-Milled, and Rapid-Prototyped Denture Base Resins: An In Vitro Study.}, journal = {Cureus}, volume = {16}, number = {6}, pages = {e63290}, pmid = {39070325}, issn = {2168-8184}, abstract = {INTRODUCTION: Conventionally fabricated denture base resins have been used for over 150 years. Newer denture base resins can provide a superior fit and may be customized to the patient's characteristics, but the literature on their cleansibility remains limited. The oral cavity can be a hub for thousands of microflora. The maintenance of complete dentures by edentulous patients depends not only on the maintenance of the patient but also on the material used, biofilm adherence, and polishability.<br><br>MATERIALS AND METHODS: Cuboid specimens of 10 &#xd7; 5 &#xd7; 2 mm were designed using the Meshmixer version 3.5 software (Meshmixer, Australia). The standard tessellation (STL) file was imported&#xa0;and sent for printing (NextDent, Netherlands) (Group 1), milling in polymethyl methacrylate (PMMA) (Ivotion, Ivoclar, Schaan, Liechtenstein) (Group 2), and wax milling (Upcera, China), followed by flasking, counter flasking, and packing using heat-cured acrylic resin (DPI, India) (Group 3). The obtained specimens were polished using pumice and sterilized using a UV sterilization unit. The specimens were then immersed in a suspension of candida broth. After three days of biofilm formation, a colony count was performed and noted as colony-forming units per milliliter (CFU/mL). Specimens were treated using Secure denture cleansing tablets (Ghent, New York), table salt (iodized table salt, Tata, India),&#xa0;Clinsodent (ICPA, Mumbai, India), and Polident denture cleansing powder (Polident, Ontario, Canada). A colony count was done after treatment, and the data were tabulated. Statistical analysis was done using SPSS software to compare the efficiency of denture cleansers in all three groups, and statistical significance was set at 0.05. The Kolmogorov-Smirnov test was done to confirm the normality of the data, followed by a one-way analysis of variance (ANOVA) test to compare the efficiency of denture cleansers on the removal of candida colonies.<br><br>RESULTS: Milled denture base resins showed a significantly lower colony count when compared to printed and conventionally fabricated denture base resins. The denture cleansers showed high efficacy in all groups, with the most significant being Secure, which showed a mean difference ranging from 8.114 to 9.887 CFU/mL, followed by Clinsodent,&#xa0;showing a mean of 6.699-9.863 CFU/mL, followed closely by Polident, showing 4.964-7.114 CFU/mL, followed by table salt, being 5.254-8.920 CFU/mL. The 95% confidence interval confirmed statistical significance.<br><br>CONCLUSION: The highest candida colony count was demonstrated by the conventional, followed by rapid prototyping, and was least with milled denture base resins. Following treatment with denture cleansers, Secure demonstrated almost complete eradication of colonies, making it the most effective option. Salt exhibited the lowest efficiency, followed closely by Polident and Clinsodent, and the most effective was Secure denture cleanser.}, }
@article {pmid39069959, year = {2024}, author = {Kathju, A and Nistico, L and Stoodley, P}, title = {Bacterial Biofilm on Tissue Expander and Acellular Dermal Graft After Breast Reconstruction.}, journal = {Surgical infections}, volume = {}, number = {}, pages = {}, doi = {10.1089/sur.2024.156}, pmid = {39069959}, issn = {1557-8674}, abstract = {A 27-year-old female underwent bilateral mastectomy with left axillary dissection and had immediate breast reconstruction with textured silicone implants and acellular dermal graft (ADG) reinforcement of the inferior quadrants. The patient was maintained on oral antibiotics postoperatively and initially did well. However, she subsequently presented with fever, erythema, and tenderness in the left chest and was admitted for intravenous antibiotic therapy. Despite improvement of her symptoms, she ultimately cultured positive for Staphylococcus aureus and had the tissue expander and the ADG material explanted. These explanted specimens were immediately examined with confocal microscopy using Live/Dead staining under hydrated conditions for the presence of bacterial biofilms. Biofilm bacteria were clearly visualized adherent to both the tissue expander shell and also to the ADG surface. This is the first direct demonstration of viable bacteria in biofilm configuration on the surface of a tissue expander and acellular dermal graft after breast reconstruction.}, }
@article {pmid39068786, year = {2024}, author = {Ge, Z and Ai, D and Ma, Z and Li, Y and Zhang, J}, title = {Evolution and distribution of antibiotic resistance genes in submerged macrophytes and biofilm systems: From seasonal monitoring to mesocosm experiments.}, journal = {Journal of environmental management}, volume = {367}, number = {}, pages = {121947}, doi = {10.1016/j.jenvman.2024.121947}, pmid = {39068786}, issn = {1095-8630}, abstract = {The aquatic ecosystem has been extensively investigated as a hotspot for the spread of antibiotic resistance genes (ARGs); yet, the evolution and distribution of ARGs profiles in submerged macrophytes biofilms and surrounding water remained unclear. In this study, the dynamic distribution and seasonal variations of microbial communities and ARGs profiles were investigated, alongside their assembly processes and mutual interactions. Bacitracin and multidrug resistance genes were predominant, constituting more than 60% of the total ARGs abundance. The deterministic processes (<65%), influenced by the physicochemical properties of the river environment, governed the assembly and composition of ARGs profiles, exhibiting significant seasonal variation. The peak diversity (21 types) and abundance (0.316 copy ratios) of ARGs were detected during the summer. Proteobacteria and Actinobacteria were the dominant bacterial phyla, accounting for 38.41-85.50% and 4.03-27.09% of the microbial community, respectively. Furthermore, Proteobacteria, especially genera such as Acinetobacter, Burkholderia, and Pseudomonas, with various resistance sequences, were the primary carriers of multiple ARGs. Notably, the genetic exchanges between biofilms and surrounding water facilitated the further propagation of high-risk ARGs, posing greater ecological risks. Redundancy analysis indicated that the total nitrogen and temperature in water determined the fate of pathogenic-resistant species. These findings provided theoretical support for the mitigation of ARGs contamination in aquatic environments.}, }
@article {pmid39068090, year = {2024}, author = {Wu, C and Mangal, U and Seo, JY and Kim, H and Bai, N and Cha, JY and Lee, KJ and Kwon, JS and Choi, SH}, title = {Enhancing biofilm resistance and preserving optical translucency of 3D printed clear aligners through carboxybetaine-copolymer surface treatment.}, journal = {Dental materials : official publication of the Academy of Dental Materials}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.dental.2024.07.009}, pmid = {39068090}, issn = {1879-0097}, abstract = {OBJECTIVES: This study aimed to use a carboxybetaine methacrylate (CBMA) copolymer solution to surface treat 3D printed clear aligners at different fabrication stages, to impart antifouling properties, and assess the surface treatment at various fabrication stages' impact on physico-mechanical characteristics.<br><br>METHODS: Surface treatments using a blend of 2-hydroxyethyl methacrylate (HEMA) and CBMA, termed CCS, were performed at various stages of 3D printed clear aligner fabrication. Experimental groups, CB1, CB2, and CB3, were determined by the stage of surface treatment during post-processing. CB1, CB2, and CB3 received treatment before post-curing, after post-curing, and after post-processing, respectively. Untreated samples served as controls. Physical and mechanical properties were assessed through tensile testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and UV-Vis spectroscopy. The surface was further characterized through scanning electron microscopy and contact angle measurements. The cytotoxicity was assessed with 7-day elution and agar diffusion assays. Lastly, bacterial biofilm resistance was evaluated using confocal laser scanning microscopy. Crystal violet assay was performed using Streptococcus mutans.<br><br>RESULTS: Surface treatment during CB1 stage exerted the most significantly unfavorable influence on properties of the 3D printed aligner resin. CB2 samples showed the maximum preservation of translucency even after 7-day aging. CB2 and CB3 phases showed enhanced hydrophilicity of sample surfaces with reduced adhesion of multispecies biofilm and S. mutans.<br><br>SIGNIFICANCE: Application of CCS surface treatment immediately after post-curing (CB2) can enhance the biofilm resistance of 3D printed clear aligners while maintaining high fidelity to optical translucency and constituent mechanical properties.}, }
@article {pmid39067645, year = {2024}, author = {Wan, C and Ju, X and Xu, D and Ou, J and Zhu, M and Lu, G and Li, K and Jiang, W and Li, C and Hu, X and Tian, Y and Niu, Z}, title = {Escherichia coli exopolysaccharides disrupt Pseudomonas aeruginosa biofilm and increase its antibiotic susceptibility.}, journal = {Acta biomaterialia}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.actbio.2024.07.028}, pmid = {39067645}, issn = {1878-7568}, abstract = {Pseudomonas aeruginosa (P. aeruginosa) is a major pathogen that causes infectious diseases. It has high tendency to form biofilms, resulting in the failure of traditional antibiotic therapies. Inspired by the phenomenon that co-culture of Escherichia coli (E. coli) and P. aeruginosa leads to a biofilm reduction, we reveal that E. coli exopolysaccharides (EPS) can disrupt P. aeruginosa biofilm and increase its antibiotic susceptibility. The results show that E. coli EPS effectively inhibit biofilm formation and disrupt mature biofilms in P. aeruginosa, Staphylococcus aureus, and E. coli itself. The maximal inhibition and disruption rates against P. aeruginosa biofilm are 40% and 47%, respectively. Based on the biofilm-disrupting ability of E. coli EPS, we develop an E. coli EPS/antibiotic combining strategy for the treatment of P. aeruginosa biofilms. The combination with E. coli EPS increases the antibacterial efficiency of tobramycin against P. aeruginosa biofilms in vitro and in vivo. This study provides a promising strategy for treating biofilm infections. STATEMENT OF SIGNIFICANCE: Biofilm formation is a leading cause of chronic infections. It blocks antibiotics, increases antibiotic-tolerance, and aids in immune evasion, thus representing a great challenge in clinic. This study proposes a promising approach to combat pathogenic Pseudomonas aeruginosa (P. aeruginosa) biofilms by combining Escherichia coli exopolysaccharides with antibiotics. This strategy shows high efficiency in different P. aeruginosa stains, including two laboratory strains, PAO1 and ATCC 10145, as well as a clinically acquired carbapenem-resistant strain. In addition, in vivo experiments have shown that this approach is effective against implanted P. aeruginosa biofilms and can prevent systemic inflammation in mice. This strategy offers new possibilities to address the clinical failure of conventional antibiotic therapies for microbial biofilms.}, }
@article {pmid39067337, year = {2024}, author = {Song, W and Ma, R and Liang, Z and Li, J and Dong, J and Du, X and Wang, Z and Li, X}, title = {Biofilm growth characteristic and footprint identification in gravity-driven ceramic membrane bioreactor with electro-coagulation under extreme conditions for roofing rainwater purification.}, journal = {Journal of environmental management}, volume = {367}, number = {}, pages = {121944}, doi = {10.1016/j.jenvman.2024.121944}, pmid = {39067337}, issn = {1095-8630}, abstract = {The identification of biofilm growth footprints influencing on the biofilm detachment and breakup can advance research into how biofilms form. Thus, a gravity-driven ceramic membrane bioreactor (GDCMBR) was used to investigate the growth, detachment and breakup of biofilm using rainwater pretreated by electrocoagulation under 70-days continuous operation. The in-situ ultrasonic time-domain reflectometry (UTDR) technique was applied to non-invasively determine the biofilm thickness. Initially, the biofilm was slowly thickening, but it would collapse and became thinner after accumulating to a certain level, and then it thickened again in a later period, following a cyclic pattern of 'thickening - collapsing - thickening'. This is because the biofilm growth is related with the accumulation of flocs, however, excessive floc formation results in the biofilm being overweight till reaching the thickness limit and thus collapsing. Subsequently, the biofilm gradually thickens again due to the floc production and continuous deposition. Although the biofilm was dynamically changing, the water quality of treatment of the biofilm always remained stable. Ammonia nitrogen and total phosphorus have been almost completely removed, while CODMn removal efficiency was around 25%. And total bacteria amount in the membrane concentrate was obviously higher than that in the influent with the greater microbial activity, demonstrating the remarkable enrichment effect on bacteria. The understanding of biofilm growth characteristic and footprint identification enables us to develop rational approaches to control biofilm structure for efficient GDCMBR performance and operation lifespan.}, }
@article {pmid39066983, year = {2024}, author = {Khan, MAR and Wang, BW and Lin, HC and Yang, YL and Liaw, CC}, title = {Structure-Functional Activity of Pyrone Derivatives for Inhibition of Barnacle Settlement and Biofilm Formation.}, journal = {Marine biotechnology (New York, N.Y.)}, volume = {}, number = {}, pages = {}, pmid = {39066983}, issn = {1436-2236}, support = {MOST108-2320-B-110-006-MY3//Ministry of Science and Technology grant/ ; NSYSU-KMU 111-I06//National Sun Yat-sen University-Kaohsiung Medical University Joint Research Project/ ; }, abstract = {Naturally occurring 6-pentyl-2H-pyran-2-one and its synthetic analogues greatly inhibit the settlement of Amphibalanus amphitrite cyprids and the growth and biofilm formation of marine bacteria. To optimize the antifouling activities of pyrone derivatives, this study designed pyrone analogues by modifying functional groups, such as the benzyl group, cyclopentane, and halides, substituted on both sides of a pyrone. The antifouling effects of the synthesized pyrone derivatives were subsequently evaluated against five marine biofilm-forming bacteria, Loktanella hongkongensis, Staphylococcus cohnii, S. saprophyticus, Photobacterium angustum, and Alteromonas macleodii, along with barnacle cyprids of Amphibalanus amphitrite. Substituting nonpolar parts-such as the aliphatic, cyclopentyl, or phenyl moieties on C-5 or the furan moieties on C-3-not only increased antibacterial activity and inhibited biofilm formation but also inhibited barnacle cyprid settlement when compared to 6-pentyl-2H-pyran-2-one.}, }
@article {pmid39066496, year = {2024}, author = {Power, AD and Mok, WWK}, title = {Agar and agarose used for Staphylococcus aureus biofilm cultivation impacts fluoroquinolone tolerance.}, journal = {Journal of applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jambio/lxae191}, pmid = {39066496}, issn = {1365-2672}, abstract = {AIMS: Staphylococcus aureus is an opportunistic pathogen whose treatment is further complicated by its ability to form biofilms. In this study, we examine the impact of growing S. aureus biofilms on different polymerizing surfaces, specifically agar and agarose, on the pathogen's tolerance to fluoroquinolones.<br><br>METHODS AND RESULTS: Biofilms of two methicillin-resistant strains of S. aureus were grown on agar or agarose in the presence of the same added nutrients, and their antibiotic susceptibility to two fluoroquinolones, moxifloxacin (MXF) and delafloxacin (DLX), were measured. We also compared the metabolism and extracellular polymeric substances (EPS) production of biofilms that were grown on agar and agarose.<br><br>CONCLUSIONS: Biofilms that were grown on agarose were consistently more susceptible to antibiotics than those grown on agar. We found that in biofilms that were grown on agar, extracellular protein composition was higher, and adding EPS to agarose-grown biofilms increased their tolerance to DLX to levels that were comparable to agar-grown biofilms.}, }
@article {pmid39065765, year = {2024}, author = {Mohammed, EJ and Abdelaziz, AEM and Mekky, AE and Mahmoud, NN and Sharaf, M and Al-Habibi, MM and Khairy, NM and Al-Askar, AA and Youssef, FS and Gaber, MA and Saied, E and AbdElgayed, G and Metwally, SA and Shoun, AA}, title = {Biomedical Promise of Aspergillus Flavus-Biosynthesized Selenium Nanoparticles: A Green Synthesis Approach to Antiviral, Anticancer, Anti-Biofilm, and Antibacterial Applications.}, journal = {Pharmaceuticals (Basel, Switzerland)}, volume = {17}, number = {7}, pages = {}, pmid = {39065765}, issn = {1424-8247}, support = {RSP2024R505//King Saud University/ ; }, abstract = {This study utilized Aspergillus flavus to produce selenium nanoparticles (Se-NPs) in an environmentally friendly and ecologically sustainable manner, targeting several medicinal applications. These biosynthesized Se-NPs were meticulously characterized using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), and UV-visible spectroscopy (UV), revealing their spherical shape and size ranging between 28 and 78 nm. We conducted further testing of Se-NPs to evaluate their potential for biological applications, including antiviral, anticancer, antibacterial, antioxidant, and antibiofilm activities. The results indicate that biosynthesized Se-NPs could be effective against various pathogens, including Salmonella typhimurium (ATCC 14028), Bacillus pumilus (ATCC 14884), Staphylococcus aureus (ATCC 6538), Clostridium sporogenes (ATCC 19404), Escherichia coli (ATCC 8739), and Bacillus subtilis (ATCC 6633). Additionally, the biosynthesized Se-NPs exhibited anticancer activity against three cell lines: pancreatic carcinoma (PANC1), cervical cancer (Hela), and colorectal adenocarcinoma (Caco-2), with IC50 values of 177, 208, and 216 μg/mL, respectively. The nanoparticles demonstrated antiviral activity against HSV-1 and HAV, achieving inhibition rates of 66.4% and 15.1%, respectively, at the maximum non-toxic concentration, while also displaying antibiofilm and antioxidant properties. In conclusion, the biosynthesized Se-NPs by A. flavus present a promising avenue for various biomedical applications with safe usage.}, }
@article {pmid39065310, year = {2024}, author = {Van Rooyen, B and De Wit, M and Osthoff, G and Van Niekerk, J}, title = {Cactus Pear Mucilage (Opuntia spp.) as a Novel Functional Biopolymer: Mucilage Extraction, Rheology and Biofilm Development.}, journal = {Polymers}, volume = {16}, number = {14}, pages = {}, pmid = {39065310}, issn = {2073-4360}, abstract = {The investigation of novel, natural polymers has gained considerably more exposure for their desirable, often specific, functional properties. Multiple researchers have explored these biopolymers to determine their potential to address many food processing, packaging and environmental concerns. Mucilage from the cactus pear (Opuntia ficus-indica) is one such biopolymer that has been identified as possessing a functional potential that can be used in an attempt to enhance food properties and reduce the usage of non-biodegradable, petroleum-based packaging in the food industry. However, variations in the structural composition of mucilage and the different extraction methods that have been reported by researchers have considerably impacted mucilage's functional potential. Although not comparable, these factors have been investigated, with a specific focus on mucilage applications. The natural ability of mucilage to bind water, alter the rheology of a food system and develop biofilms are considered the major applications of mucilage's functional properties. Due to the variations that have been reported in mucilage's chemical composition, specifically concerning the proportions of uronic acids, mucilage's rheological and biofilm properties are influenced differently by changes in pH and a cross-linker. Exploring the factors influencing mucilage's chemical composition, while co-currently discussing mucilage functional applications, will prove valuable when evaluating mucilage's potential to be considered for future commercial applications. This review article, therefore, discusses and highlights the key factors responsible for mucilage's specific functional potential, while exploring important potential food processing and packaging applications.}, }
@article {pmid39065268, year = {2024}, author = {Cate, JD and Sullivan, YZ and King, MD}, title = {Inhibition of Microbial Growth and Biofilm Formation in Pure and Mixed Bacterial Samples.}, journal = {Microorganisms}, volume = {12}, number = {7}, pages = {}, pmid = {39065268}, issn = {2076-2607}, support = {5R21AI169046-02A1/NH/NIH HHS/United States ; CBET 2034048//NSF/ ; TEX09746//USDA NIFA Hatch Project/ ; }, abstract = {Hydraulic fracturing, or fracking, requires large amounts of water to extract fossil fuel from rock formations. As a result of hydraulic fracturing, the briny wastewater, often termed back-produced fracturing or fracking water (FW), is pumped into holding ponds. One of the biggest challenges with produced water management is controlling microbial activity that could reduce the pond water's reusable layer and pose a significant environmental hazard. This study focuses on the characterization of back-produced water that has been hydraulically fractured using chemical and biological analysis and the development of a high-throughput screening method to evaluate and predict the antimicrobial effect of four naturally and commercially available acidic inhibitors (edetic acid, boric acid, tannic acid, and lactic acid) on the growth of the FW microbiome. Liquid cultures and biofilms of two laboratory model strains, the vegetative Escherichia coli MG1655, and the spore-forming Bacillus atrophaeus (also known as Bacillus globigii, BG) bacteria, were used as reference microorganisms. Planktonic bacteria in FW were more sensitive to antimicrobials than sessile bacteria in biofilms. Spore-forming BG bacteria exhibited more sensitivity to acidic inhibitors than the vegetative E. coli cells. Organic acids were the most effective bacterial growth inhibitors in liquid culture and biofilm.}, }
@article {pmid39065121, year = {2024}, author = {Shi, W and Zhang, Q and Li, H and Du, D and Ma, X and Wang, J and Jiang, J and Liu, C and Kou, L and Ren, J}, title = {Biofilm Formation, Motility, and Virulence of Listeria monocytogenes Are Reduced by Deletion of the Gene lmo0159, a Novel Listerial LPXTG Surface Protein.}, journal = {Microorganisms}, volume = {12}, number = {7}, pages = {}, pmid = {39065121}, issn = {2076-2607}, support = {32160834//National Natural Science Foundation of China/ ; 32160833//National Natural Science Foundation of China/ ; 32260895//National Natural Science Foundation of China/ ; RCZK202042//Shihezi University high level talent research launch project/ ; }, abstract = {Listeria monocytogenes (L. monocytogenes) is a foodborne pathogen that causes listeriosis in humans and other animals. Surface proteins with the LPXTG motif have important roles in the virulence of L. monocytogenes. Lmo0159 is one such protein, but little is known about its role in L. monocytogenes virulence, motility, and biofilm formation. Here, we constructed and characterized a deletion mutant of lmo0159 (∆lmo0159). We analyzed not only the capacity of biofilm formation, motility, attachment, and intracellular growth in different cell types but also LD50; bacterial load in mice's liver, spleen, and brain; expression of virulence genes; and survival time of mice after challenge. The results showed that the cross-linking density of the biofilm of ∆lmo0159 strain was lower than that of WT by microscopic examination. The expression of biofilm-formation and virulence genes also decreased in the biofilm state. Subsequently, the growth and motility of ∆lmo0159 in the culture medium were enhanced. Conversely, the growth and motility of L. monocytogenes were attenuated by ∆lmo0159 at both the cellular and mouse levels. At the cellular level, ∆lmo0159 reduced plaque size; accelerated scratch healing; and attenuated the efficiency of adhesion, invasion, and intracellular proliferation in swine intestinal epithelial cells (SIEC), RAW264.7, mouse-brain microvascular endothelial cells (mBMEC), and human-brain microvascular endothelial cells (hCMEC/D3). The expression of virulence genes was also inhibited. At the mouse level, the LD50 of the ∆lmo0159 strain was 10[0.97] times higher than that of the WT strain. The bacterial load of the ∆lmo0159 strain in the liver and spleen was lower than that of the WT strain. In a mouse model of intraperitoneal infection, the deletion of the lmo0159 gene significantly prolonged the survival time of the mice, suggesting that the lmo0159 deletion mutant also exhibited reduced virulence. Thus, our study identified lmo0159 as a novel virulence factor among L. monocytogenes LPXTG proteins.}, }
@article {pmid39065070, year = {2024}, author = {Burdová, A and Véghová, A and Minarovičová, J and Drahovská, H and Kaclíková, E}, title = {The Relationship between Biofilm Phenotypes and Biofilm-Associated Genes in Food-Related Listeria monocytogenes Strains.}, journal = {Microorganisms}, volume = {12}, number = {7}, pages = {}, pmid = {39065070}, issn = {2076-2607}, support = {313011V336//European Regional Development Fund/ ; 720/2023/MPRVSR-930//Ministry of Agriculture and Rural Development of the Slovak Republic/ ; }, abstract = {Listeria monocytogenes is an important pathogen responsible for listeriosis, a serious foodborne illness associated with high mortality rates. Therefore, L. monocytogenes is considered a challenge for the food industry due to the ability of some strains to persist in food-associated environments. Biofilm production is presumed to contribute to increased L. monocytogenes resistance and persistence. The aims of this study were to (1) assess the biofilm formation of L. monocytogenes isolates from a meat processing facility and sheep farm previously characterized and subjected to whole-genome sequencing and (2) perform a comparative genomic analysis to compare the biofilm formation and the presence of a known set of biofilm-associated genes and related resistance or persistence markers. Among the 37 L. monocytogenes isolates of 15 sequence types and four serogroups involved in this study, 14%, 62%, and 24% resulted in the formation of weak, moderate, and strong biofilm, respectively. Increased biofilm-forming ability was associated with the presence of the stress survival islet 1 (SSI-1), inlL, and the truncated inlA genes. Combining the phenotypic and genotypic data may contribute to understanding the relationships between biofilm-associated genes and L. monocytogenes biofilm-forming ability, enabling improvement in the control of this foodborne pathogen.}, }
@article {pmid39065026, year = {2024}, author = {Li, Z and Zhang, M and Lei, G and Lu, X and Yang, X and Kan, B}, title = {A Single Base Change in the csgD Promoter Resulted in Enhanced Biofilm in Swine-Derived Salmonella Typhimurium.}, journal = {Microorganisms}, volume = {12}, number = {7}, pages = {}, pmid = {39065026}, issn = {2076-2607}, support = {2022YFC2303900//the National Key Research and Development Program of China/ ; }, abstract = {Pathogenic Salmonella strains causing gastroenteritis typically can colonize and proliferate in the intestines of multiple host species. They retain the ability to form red dry and rough (rdar) biofilms, as seen in Salmonella enterica serovar Typhimurium. Conversely, Salmonella serovar like Typhi, which can cause systemic infections and exhibit host restriction, are rdar-negative. In this study, duck-derived strains and swine-derived strains of S. Typhimurium locate on independent phylogenetic clades and display relative genomic specificity. The duck isolates appear more closely related to human blood isolates and invasive non-typhoidal Salmonella (iNTS), whereas the swine isolates were more distinct. Phenotypically, compared to duck isolates, swine isolates exhibited enhanced biofilm formation that was unaffected by the temperature. The transcriptomic analysis revealed the upregulation of csgDEFG transcription as the direct cause. This upregulation may be mainly attributed to the enhanced promoter activity caused by the G-to-T substitution at position -44 of the csgD promoter. Swine isolates have created biofilm polymorphisms by altering a conserved base present in Salmonella Typhi, iNTS, and most Salmonella Typhimurium (such as duck isolates). This provides a genomic characteristics perspective for understanding Salmonella transmission cycles and evolution.}, }
@article {pmid39063012, year = {2024}, author = {Liu, X and Hu, J and Wang, W and Yang, H and Tao, E and Ma, Y and Sha, S}, title = {Mycobacterial Biofilm: Mechanisms, Clinical Problems, and Treatments.}, journal = {International journal of molecular sciences}, volume = {25}, number = {14}, pages = {}, pmid = {39063012}, issn = {1422-0067}, support = {LJKZ0846//Scientific Research Program of Liaoning Province, China/ ; }, mesh = {*Biofilms/drug effects/growth &amp; development ; Humans ; Animals ; *Antitubercular Agents/pharmacology/therapeutic use ; Mycobacterium tuberculosis/drug effects/physiology ; Tuberculosis/drug therapy/microbiology ; Bacterial Proteins/metabolism/genetics ; Virulence ; }, abstract = {Tuberculosis (TB) remains a threat to human health worldwide. Mycobacterium tuberculosis (Mtb) and other nontuberculous mycobacteria (NTM) can form biofilms, and in vitro and animal experiments have shown that biofilms cause serious drug resistance and mycobacterial persistence. Deeper investigations into the mechanisms of mycobacterial biofilm formation and, consequently, the exploration of appropriate antibiofilm treatments to improve the efficiency of current anti-TB drugs will be useful for curing TB. In this review, the genes and molecules that have been recently reported to be involved in mycobacterial biofilm development, such as ABC transporter, Pks1, PpiB, GroEL1, MprB, (p)ppGpp, poly(P), and c-di-GMP, are summarized. Biofilm-induced clinical problems, including biofilm-related infections and enhanced virulence, as well as their possible mechanisms, are also discussed in detail. Moreover, we also illustrate newly synthesized anti-TB agents that target mycobacterial biofilm, as well as some assistant methods with high efficiency in reducing biofilms in hosts, such as the use of nanoparticles.}, }
@article {pmid39062838, year = {2024}, author = {Zhang, Y and Zhao, X and Wang, J and Liao, L and Qin, H and Zhang, R and Li, C and He, Y and Huang, S}, title = {VmsR, a LuxR-Type Regulator, Contributes to Virulence, Cell Motility, Extracellular Polysaccharide Production and Biofilm Formation in Xanthomonas oryzae pv. oryzicola.}, journal = {International journal of molecular sciences}, volume = {25}, number = {14}, pages = {}, pmid = {39062838}, issn = {1422-0067}, support = {2020GXNSFDA297026//Guangxi Natural Science Foundation/ ; 32360045//National Natural Science Foundation of China/ ; 32060600//National Natural Science Foundation of China/ ; }, mesh = {*Xanthomonas/pathogenicity/genetics/metabolism ; *Biofilms/growth &amp; development ; *Polysaccharides, Bacterial/metabolism/biosynthesis ; Virulence/genetics ; *Gene Expression Regulation, Bacterial ; *Bacterial Proteins/genetics/metabolism ; Trans-Activators/genetics/metabolism ; Oryza/microbiology ; Plant Diseases/microbiology ; Promoter Regions, Genetic ; Repressor Proteins/genetics/metabolism ; }, abstract = {LuxR-type regulators play pivotal roles in regulating numerous bacterial processes, including bacterial motility and virulence, thereby exerting a significant influence on bacterial behavior and pathogenicity. Xanthomonas oryzae pv. oryzicola, a rice pathogen, causes bacterial leaf streak. Our research has identified VmsR, which is a response regulator of the two-component system (TCS) that belongs to the LuxR family. These findings of the experiment reveal that VmsR plays a crucial role in regulating pathogenicity, motility, biofilm formation, and the production of extracellular polysaccharides (EPSs) in Xoc GX01. Notably, our study shows that the vmsR mutant exhibits a reduced swimming motility but an enhanced swarming motility. Furthermore, this mutant displays decreased virulence while significantly increasing EPS production and biofilm formation. We have uncovered that VmsR directly interacts with the promoter regions of fliC and fliS, promoting their expression. In contrast, VmsR specifically binds to the promoter of gumB, resulting in its downregulation. These findings indicate that the knockout of vmsR has profound effects on virulence, motility, biofilm formation, and EPS production in Xoc GX01, providing insights into the intricate regulatory network of Xoc.}, }
@article {pmid39062493, year = {2024}, author = {Vadillo-Rodríguez, V and Fernández-Babiano, I and Pérez-Giraldo, C and Fernández-Calderón, MC}, title = {Anti-Biofilm Perspectives of Propolis against Staphylococcus epidermidis Infections.}, journal = {Biomolecules}, volume = {14}, number = {7}, pages = {}, pmid = {39062493}, issn = {2218-273X}, support = {PID2022-140422OB-I00//Agencia Estatal de Investigaci&#xf3;n/ ; Una manera de hacer Europa.//FEDER Una manera de hacer Europa./ ; }, mesh = {*Biofilms/drug effects/growth &amp; development ; *Staphylococcus epidermidis/drug effects/physiology ; *Propolis/pharmacology/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Microbial Sensitivity Tests ; Humans ; Bacterial Adhesion/drug effects ; Staphylococcal Infections/drug therapy/microbiology ; }, abstract = {Staphylococcus epidermis has emerged as the main causative agent of medical device-related infections. Their major pathogenicity factor lies in its ability to adhere to surfaces and proliferate into biofilms, which increase their resistance to antibiotics. The main objective of this study was to evaluate the use and the mechanism of action of an ethanolic extract of Spanish propolis (EESP) as a potential alternative for preventing biofilm-related infections caused by S. epidermidis. The chemical composition of propolis is reported and its antibacterial activity against several strains of S. epidermidis with different biofilm-forming capacities evaluated. The influence of sub-inhibitory concentrations (sub-MICs) of EESP on their growth, physicochemical surface properties, adherence, and biofilm formation were studied. EESP interferes with planktonic cells, homogenizing their physicochemical surface properties and introducing a significant delay in their growth. The adherence and biofilms at the EESP concentrations investigated were decreased up to 90.5% among the strains. Microscopic analysis indicated that the planktonic cells that survived the treatment were the ones that adhere and proliferate on the surfaces. The results obtained suggest that the EESP has a high potential to be used as an inhibitor of both the adhesion and biofilm formation of S. epidermidis.}, }
@article {pmid39061313, year = {2024}, author = {Pirușcă, IA and Balaure, PC and Grumezescu, V and Irimiciuc, SA and Oprea, OC and Bîrcă, AC and Vasile, B and Holban, AM and Voinea, IC and Stan, MS and Trușcă, R and Grumezescu, AM and Croitoru, GA}, title = {New Fe3O4-Based Coatings with Enhanced Anti-Biofilm Activity for Medical Devices.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {7}, pages = {}, pmid = {39061313}, issn = {2079-6382}, abstract = {With the increasing use of invasive, interventional, indwelling, and implanted medical devices, healthcare-associated infections caused by pathogenic biofilms have become a major cause of morbidity and mortality. Herein, we present the fabrication, characterization, and in vitro evaluation of biocompatibility and anti-biofilm properties of new coatings based on Fe3O4 nanoparticles (NPs) loaded with usnic acid (UA) and ceftriaxone (CEF). Sodium lauryl sulfate (SLS) was employed as a stabilizer and modulator of the polarity, dispersibility, shape, and anti-biofilm properties of the magnetite nanoparticles. The resulting Fe3O4 functionalized NPs, namely Fe3O4@SLS, Fe3O4@SLS/UA, and Fe3O4@SLS/CEF, respectively, were prepared by co-precipitation method and fully characterized by XRD, TEM, SAED, SEM, FTIR, and TGA. They were further used to produce nanostructured coatings by matrix-assisted pulsed laser evaporation (MAPLE) technique. The biocompatibility of the coatings was assessed by measuring the cell viability, lactate dehydrogenase release, and nitric oxide level in the culture medium and by evaluating the actin cytoskeleton morphology of murine pre-osteoblasts. All prepared nanostructured coatings exhibited good biocompatibility. Biofilm growth inhibition ability was tested at 24 h and 48 h against Staphylococcus aureus and Pseudomonas aeruginosa as representative models for Gram-positive and Gram-negative bacteria. The coatings demonstrated good biocompatibility, promoting osteoblast adhesion, migration, and growth without significant impact on cell viability or morphology, highlighting their potential for developing safe and effective antibacterial surfaces.}, }
@article {pmid39061305, year = {2024}, author = {Mishra, A and Aggarwal, A and Khan, F}, title = {Medical Device-Associated Infections Caused by Biofilm-Forming Microbial Pathogens and Controlling Strategies.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {7}, pages = {}, pmid = {39061305}, issn = {2079-6382}, support = {RS-2023-00241461//National Research Foundation/ ; }, abstract = {Hospital-acquired infections, also known as nosocomial infections, include bloodstream infections, surgical site infections, skin and soft tissue infections, respiratory tract infections, and urinary tract infections. According to reports, Gram-positive and Gram-negative pathogenic bacteria account for up to 70% of nosocomial infections in intensive care unit (ICU) patients. Biofilm production is a main virulence mechanism and a distinguishing feature of bacterial pathogens. Most bacterial pathogens develop biofilms at the solid-liquid and air-liquid interfaces. An essential requirement for biofilm production is the presence of a conditioning film. A conditioning film provides the first surface on which bacteria can adhere and fosters the growth of biofilms by creating a favorable environment. The conditioning film improves microbial adherence by delivering chemical signals or generating microenvironments. Microorganisms use this coating as a nutrient source. The film gathers both inorganic and organic substances from its surroundings, or these substances are generated by microbes in the film. These nutrients boost the initial growth of the adhering bacteria and facilitate biofilm formation by acting as a food source. Coatings with combined antibacterial efficacy and antifouling properties provide further benefits by preventing dead cells and debris from adhering to the surfaces. In the present review, we address numerous pathogenic microbes that form biofilms on the surfaces of biomedical devices. In addition, we explore several efficient smart antiadhesive coatings on the surfaces of biomedical device-relevant materials that manage nosocomial infections caused by biofilm-forming microbial pathogens.}, }
@article {pmid39061301, year = {2024}, author = {D'Aquila, P and De Rose, E and Sena, G and Scorza, A and Cretella, B and Passarino, G and Bellizzi, D}, title = {Quorum Quenching Approaches against Bacterial-Biofilm-Induced Antibiotic Resistance.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {7}, pages = {}, pmid = {39061301}, issn = {2079-6382}, abstract = {With the widespread phenomenon of antibiotic resistance and the diffusion of multiple drug-resistant bacterial strains, enormous efforts are being conducted to identify suitable alternative agents against pathogenic microorganisms. Since an association between biofilm formation and antibiotic resistance phenotype has been observed, a promising strategy pursued in recent years focuses on controlling and preventing this formation by targeting and inhibiting the Quorum Sensing (QS) system, whose central role in biofilm has been extensively demonstrated. Therefore, the research and development of Quorum Quenching (QQ) compounds, which inhibit QS, has gradually attracted the attention of researchers and has become a new strategy for controlling harmful microorganisms. Among these, a number of both natural and synthetic compounds have been progressively identified as able to interrupt the intercellular communication within a microbial community and the adhesion to a surface, thus disintegrating mature/preformed biofilms. This review describes the role played by QS in the formation of bacterial biofilms and then focuses on the mechanisms of different natural and synthetic QS inhibitors (QSIs) exhibiting promising antibiofilm ability against Gram-positive and Gram-negative bacterial pathogens and on their applications as biocontrol strategies in various fields.}, }
@article {pmid39061295, year = {2024}, author = {Santajit, S and Tunyong, W and Horpet, D and Binmut, A and Kong-Ngoen, T and Wisessaowapak, C and Thavorasak, T and Pumirat, P and Indrawattana, N}, title = {Unveiling the Antimicrobial, Anti-Biofilm, and Anti-Quorum-Sensing Potential of Paederia foetida Linn. Leaf Extract against Staphylococcus aureus: An Integrated In Vitro-In Silico Investigation.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {7}, pages = {}, pmid = {39061295}, issn = {2079-6382}, support = {RGNS 64-205//Office of the Permanent Secretary, Ministry of Higher Education, Science, Research and Innova-tion (OPS MHESI), Thailand Science Research and Innovation (TSRI)/ ; FF-113/2567//Mahidol University (Fundamental Fund: fiscal year 2024 by National Science Research and In-novation Fund (NSRF))./ ; }, abstract = {Antimicrobial resistance poses a global health threat, with Staphylococcus aureus emerging as a notorious pathogen capable of forming stubborn biofilms and regulating virulence through quorum sensing (QS). In the quest for novel therapeutic strategies, this groundbreaking study unveils the therapeutic potential of Paederia foetida Linn., an Asian medicinal plant containing various bioactive compounds, contributing to its antimicrobial activities, in the battle against S. aureus. Through a comprehensive approach, we investigated the effect of ethanolic P. foetida leaf extract on S. aureus biofilms, QS, and antimicrobial activity. The extract exhibited promising inhibitory effects against S. aureus including the biofilm-forming strain and MRSA. Real-time PCR analysis revealed significant downregulation of key virulence and biofilm genes, suggesting interference with QS. Biofilm assays quantified the extract's ability to disrupt and prevent biofilm formation. LC-MS/MS analysis identified quercetin and kaempferol glycosides as potential bioactive constituents, while molecular docking studies explored their binding to the QS transcriptional regulator SarA. Computational ADMET predictions highlighted favorable intestinal absorption but potential P-glycoprotein interactions limiting oral bioavailability. While promising anti-virulence effects were demonstrated, the high molecular weights and excessive hydrogen bond donors/acceptors of the flavonoid glycosides raise concerns regarding drug-likeness and permeability. This integrated study offers valuable insights for developing novel anti-virulence strategies to combat antimicrobial resistance.}, }
@article {pmid39061287, year = {2024}, author = {Sena, G and De Rose, E and Crudo, M and Filippelli, G and Passarino, G and Bellizzi, D and D'Aquila, P}, title = {Essential Oils from Southern Italian Aromatic Plants Synergize with Antibiotics against Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis Cell Growth and Biofilm Formation.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {7}, pages = {}, pmid = {39061287}, issn = {2079-6382}, abstract = {The spread of antibiotic-resistant pathogens has prompted the development of novel approaches to identify molecules that synergize with antibiotics to enhance their efficacy. This study aimed to investigate the effects of ten Essential Oils (EOs) on the activity of nine antibiotics in influencing growth and biofilm formation in Escherichia coli, Pseudomonas aeruginosa, and Enterococcus faecalis. The effects of the EOs alone and in combination with antibiotics on both bacterial growth and biofilm formation were analyzed by measuring the MIC values through the broth microdilution method and the crystal violet assay, respectively. All EOs inhibited the growth of E. coli (1.25 ≤ MIC ≤ 5 mg/mL) while the growth of P. aeruginosa and E. faecalis was only affected by EOs from Origanum vulgare, (MIC = 5 mg/mL) and O. vulgare (MIC = 1.25 mg/mL) and Salvia rosmarinus (MIC = 5 mg/mL), respectively. In E. coli, most EOs induced a four- to sixteen-fold reduction in the MIC values of ampicillin, ciprofloxacin, ceftriaxone, gentamicin, and streptomycin, while in E. faecalis such a reduction is observed in combinations of ciprofloxacin with C. nepeta, C. bergamia, C. limon, C. reticulata, and F. vulgare, of gentamicin with O. vulgare, and of tetracycline with C. limon and O. vulgare. A smaller effect was observed in P. aeruginosa, in which only C. bergamia reduced the concentration of tetracycline four-fold. EO-antibiotic combinations also inhibit the biofilm formation. More precisely, all EOs with ciprofloxacin in E. coli, tetracycline in P. aeruginosa, and gentamicin in E. faecalis showed the highest percentage of inhibition. Combinations induce up- and down-methylation of cytosines and adenines compared to EO or antibiotics alone. The study provides evidence about the role of EOs in enhancing the action of antibiotics by influencing key processes involved in resistance mechanisms such as biofilm formation and epigenetic changes. Synergistic interactions should be effectively considered in dealing with pathogenic microorganisms.}, }
@article {pmid39061277, year = {2024}, author = {Musa, L and Toppi, V and Stefanetti, V and Spata, N and Rapi, MC and Grilli, G and Addis, MF and Di Giacinto, G and Franciosini, MP and Casagrande Proietti, P}, title = {High Biofilm-Forming Multidrug-Resistant Salmonella Infantis Strains from the Poultry Production Chain.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {7}, pages = {}, pmid = {39061277}, issn = {2079-6382}, abstract = {The ability of Salmonella species to adhere to surfaces and form biofilms, leading to persistent environmental reservoirs, might represent a direct link between environmental contamination and food processing contamination. The purpose of this study was to investigate the biofilm-forming ability of 80 multidrug-resistant (MDR) and extended-spectrum beta-lactamase (ESBL) producing Salmonella enterica serovar Infantis strains isolated from the broiler food chain production through whole genome sequencing (WGS), PCR, and morphotype association assays. Biofilm formation was quantified by testing the strains at two different temperatures, using 96-well polystyrene plates. The rough and dry colony (rdar) morphotype was assessed visually on Congo red agar (CRA) plates. Based on our results, all tested S. Infantis strains produced biofilm at 22 °C with an rdar morphotype, while at 37 °C, all the isolates tested negative, except one positive. Most isolates (58.75%) exhibited strong biofilm production, while 36.25% showed moderate production. Only 5 out of 80 (6.25%) were weak biofilm producers. WGS analysis showed the presence of the fim cluster (fimADF) and the csg cluster (csgBAC and csgDEFG), also described in S. Typhimurium, which are responsible for fimbriae production. PCR demonstrated the presence of csgD, csgB, and fimA in all 80 S. Infantis strains. To our knowledge, this is the first study comparing the effects of two different temperatures on the biofilm formation capacity of ESBL producing S. Infantis from the broiler production chain. This study highlights that the initial biofilm components, such as curli and cellulose, are specifically expressed at lower temperatures. It is important to emphasize that within the broiler farm, the environmental temperature ranges between 18-22 °C, which is the optimum temperature for in vitro biofilm formation by Salmonella spp. This temperature range facilitates the expression of biofilm-associated genes, contributing to the persistence of S. Infantis in the environment. This complicates biosecurity measures and makes disinfection protocols on the farm and in the production chain more difficult, posing serious public health concerns.}, }
@article {pmid39060129, year = {2024}, author = {Bian, C and Lyu, M and Zhu, M and Liu, M and Xie, X and Weir, MD and Hack, GD and Masri, R and Zhang, K and Bai, Y and Xu, HHK and Zhang, N}, title = {Novel antibacterial orthodontic elastomeric ligature with oral biofilm-regulatory ability to prevent enamel demineralization.}, journal = {Dental materials : official publication of the Academy of Dental Materials}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.dental.2024.07.015}, pmid = {39060129}, issn = {1879-0097}, abstract = {OBJECTIVES: To synthesize a novel antibacterial orthodontic elastomeric ligature incorporating dimethylaminohexadecyl methacrylate (DMAHDM) for the first time to prevent enamel demineralization during orthodontic therapy.<br><br>METHODS: Various mass fractions of DMAHDM (ranging from 0&#xa0;% to 20&#xa0;%) were grafted onto commercial elastomeric ligatures using an ultraviolet photochemical grafting method and were characterized. The optimal DMAHDM concentration was determined based on biocompatibility and mechanical properties, and the antibacterial efficacy was evaluated in a whole-plaque biofilm model. TaqMan real-time polymerase chain reaction and fluorescence in situ hybridization were used to assess the microbial regulatory ability of the multispecies biofilms. Furthermore, an in vitro tooth demineralization model was established to explore its preventive effects on enamel demineralization. Statistical analysis involved a one-way analysis of variance and LSD post hoc tests at a significance level of 0.05.<br><br>RESULTS: The elastomeric ligature containing 2&#xa0;% mass fraction of DMAHDM exhibited excellent mechanical properties, favorable biocompatibility, and the most effective antibacterial ability against microorganisms, which decreased by almost two logarithms (P&#xa0;<&#xa0;0.05). It significantly reduced the proportion of Streptococcus mutans in the multispecies plaque biofilm by 25&#xa0;% at 72&#xa0;h, leading to an enhanced biofilm microenvironment. Moreover, the novel elastomeric ligature demonstrated an obvious preventive effect on enamel demineralization, with an elastic modulus 30&#xa0;% higher and hardness 62&#xa0;% higher than those of the control group within 3 months (P&#xa0;<&#xa0;0.05).<br><br>SIGNIFICANCE: The integration of DMAHDM with an elastomeric ligature holds significant promise for regulating biofilms and preventing enamel demineralization in orthodontic applications.}, }
@article {pmid39059950, year = {2024}, author = {Byun, KH and Kang, M and Seon Koo, M and Lim, MC and Sik Ok, G and Jung Kim, H}, title = {Potential risk of biofilm-forming Bacillus cereus group in fresh-cut lettuce production chain.}, journal = {Food research international (Ottawa, Ont.)}, volume = {191}, number = {}, pages = {114692}, doi = {10.1016/j.foodres.2024.114692}, pmid = {39059950}, issn = {1873-7145}, mesh = {*Lactuca/microbiology ; *Biofilms/growth &amp; development ; *Bacillus cereus/genetics/metabolism/isolation &amp; purification/physiology ; *Enterotoxins/genetics/metabolism ; *Food Microbiology ; Bacillus thuringiensis/genetics/physiology ; Spores, Bacterial/genetics ; Anti-Bacterial Agents/pharmacology ; Food Contamination/analysis ; Microbial Sensitivity Tests ; Foodborne Diseases/microbiology ; Genotype ; }, abstract = {Bacillus cereus and Bacillus thuringiensis, which belong to the B. cereus group, are widely distributed in nature and can cause food poisoning symptoms. In this study, we collected 131 isolates belonging to the B. cereus group, comprising 124B. cereus and seven B. thuringiensis isolates, from fresh-cut lettuce production chain and investigated their potential risk by analyzing genotypic (enterotoxin and emetic toxin gene profiles) and phenotypic (antibiotic susceptibility, sporulation, and biofilm formation) characteristics. Enterotoxin genes were present only in B. cereus, whereas the emetic toxin gene was not detected in any of the B. cereus isolates. All isolates were susceptible to vancomycin, which is a last resort for treating B. cereus group infection symptoms, but generally resistant to β-lactam antimicrobials, and had the ability to form spores (at an average sporulation rate of 24.6 %) and biofilms at 30 °C. Isolates that formed strong biofilms at 30 °C had a superior possibility of forming a dense biofilm by proliferating at 10 °C compared to other isolates. Additionally, confocal laser scanning microscopy (CLSM) images revealed a notable presence of spores within the submerged biofilm formed at 10 °C, and the strengthened attachment of biofilm inner cells to the substrate was further revealed through biofilm structure parameters analysis. Collectively, our study revealed the prevalence and contamination levels of B. cereus and B. thuringiensis at fresh-cut lettuce production chain and investigated their genotypic and phenotypic characteristics, aiming to provide valuable insights for the development of potential risk management strategies to ensure food safety, especially along the cold chain.}, }
@article {pmid39059895, year = {2024}, author = {Bombelli, A and Araya-Cloutier, C and Abee, T and den Besten, HMW}, title = {Disinfectant efficacy of glabridin against dried and biofilm cells of Listeria monocytogenes and the impact of residual organic matter.}, journal = {Food research international (Ottawa, Ont.)}, volume = {191}, number = {}, pages = {114613}, doi = {10.1016/j.foodres.2024.114613}, pmid = {39059895}, issn = {1873-7145}, mesh = {*Listeria monocytogenes/drug effects/growth &amp; development ; *Isoflavones/pharmacology ; *Biofilms/drug effects/growth &amp; development ; *Phenols/pharmacology ; *Food Microbiology ; Disinfectants/pharmacology ; Microbial Sensitivity Tests ; Stainless Steel ; Anti-Bacterial Agents/pharmacology ; Animals ; }, abstract = {Glabridin is an antimicrobial compound which can be extracted from plants, such as liquorice (Glycyrrhiza glabra) roots. Although its activity against foodborne pathogens and spoilage microorganisms has already been reported, the investigation of potential applications as a surface disinfectant is still largely unexplored. Hence, this study evaluated the disinfectant efficacy of glabridin against Listeria monocytogenes. The activity of glabridin was first tested in vitro in a nutrient-rich medium against eight strains of L. monocytogenes, including food isolates and the model strain EGDe. The tested strains showed similar susceptibility with minimal inhibitory and bactericidal concentrations of 12.5 µg/mL and 25 µg/mL, respectively. Subsequently, L. monocytogenes L6, FBR17 and EGDe were selected to assess the efficacy of glabridin against dried cells (according to the European standard EN 13697:2015 + A1:2019) and biofilm cells on stainless steel surfaces. Moreover, the impact of food residual organic matter was investigated using skim milk, cantaloupe and smoked salmon solution as soiling components. Our results showed that applying 200 µg/mL of glabridin resulted in a substantial reduction (>3 log10) of dried and biofilm cells of L. monocytogenes in standard conditions (i.e. low level of residual organic matter). Cantaloupe soiling components slightly reduced the activity of glabridin, while the efficacy of glabridin when tested with salmon and skim milk residuals was substantially affected. Comparative analysis using standardized protein contents provided evidence that the type of food matrices and type of proteins may impact the activity of glabridin as a disinfectant. Overall, this study showed low strain variability for the activity of glabridin against L. monocytogenes and shed light on the possible application of this natural antimicrobial compound as a surface disinfectant.}, }
@article {pmid39059770, year = {2024}, author = {Tan, GSE and Chia, GJM and Thevasagayam, NM and Loy, DSQ and Prakki, SRS and Lim, ZQ and Chua, JY and Chia, JWZ and Marimuthu, K and Vasoo, S and Ng, OT and Poh, BF and Ang, BSP}, title = {Whole-genome sequencing establishes persistence of biofilm-associated Pseudomonas aeruginosa detected from microbiological surveillance of gastrointestinal endoscopes.}, journal = {The Journal of hospital infection}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jhin.2024.07.007}, pmid = {39059770}, issn = {1532-2939}, abstract = {BACKGROUND: An increased incidence of P. aeruginosa in microbiological surveillance (MS) cultures from gastrointestinal endoscopes was detected between March 2020 to March 2023 in Tan Tock Seng Hospital Singapore. The aim of this report is to describe the use of whole-genome sequencing (WGS) in this investigation.<br><br>METHODS: WGS was performed for all P. aeruginosa isolates with pairwise comparison of isolates to assess for genomic linkage. Comprehensive review of reprocessing practices and environmental sampling was performed.<br><br>FINDINGS: Twenty-two P. aeruginosa isolates were detected from endoscopic MS cultures. Fifteen (68%) isolates were available for WGS. Eighteen pairwise comparisons of isolates were made, of which 10 were found to be genomically linked. One endoscope had P. aeruginosa repeatedly cultured from subsequent MS that were genomically linked and persistent despite repeat endoscopic reprocessing, establishing the persistence of biofilm that could not be eradicated with routine reprocessing. All P. aeruginosa isolates cultured from other different endoscopes were genetically distinct. Investigation into reprocessing practices revealed the use of air/water valves connected to endoscopes during clinical use. Inspection of these valves revealed the presences of cracks and tears. All other environmental samples were negative.<br><br>CONCLUSIONS: The WGS findings helped to deprioritize common source contamination and supported the hypothesis of biofilm buildup within endoscopes leading to repeatedly positive MS cultures that were genomically linked. This was possibly related to incomplete reprocessing of the damaged air/water valves, resulting in biofilm build up. All faulty valves were changed and subsequently cleaned separately with ultrasonic cleaning followed by sterilization which resolved this incident.}, }
@article {pmid39059308, year = {2024}, author = {Xia, G and Sun, Z and Huang, J and Qi, J and Yao, J}, title = {Biodegradation of carbon disulfide and hydrogen sulfide using a moving bed biofilm reactor coupled with sulfur recycling: Performance, mechanism, and potential application.}, journal = {Journal of environmental management}, volume = {367}, number = {}, pages = {121943}, doi = {10.1016/j.jenvman.2024.121943}, pmid = {39059308}, issn = {1095-8630}, abstract = {In this work, a moving bed biofilm reactor (MBBR) was equipped for simultaneous biodegradation of CS2 and H2S. MBBR was started up and operated with different inlet concentrations and retention time; results indicated that approximately 81.9% CS2 and 93.9% H2S could be degraded, and the maximum elimination capacities of 209.3 g/(m[3]·h) and 138.5 g/(m[3]·h) were achieved for CS2 and H2S, respectively. The biodegradation mechanisms, including mass transfer, kinetics, and electron transfer, were then investigated. The mass transfer fraction and the maximum degradation rate per unit filter volume were calculated for evaluating the characteristics of mass transfer in MBBR. The variations of extracellular polymeric substances secretion, electron transport system activity and ATP enzyme activity showed that MBBR had an excellent performance for waste gas purification. Subsequently, the recovery of sulfur was explored via morphology, crystal structure, and generation kinetics, indicating that a modified Gompertz model could precisely describe the kinetics of sulfur recovery, and the product selectivity of 51.7% was achieved for sulfur. The microbial community analysis suggested that the dominant genera for biodegradation and sulfur recovery were Acidithiobacillus and Mycobacterium. Finally, MBBR system was validated for treatment of actual waste gas; results indicated that maximum elimination capacities of 134.1 g/(m[3]·h) and 117.1 g/(m[3]·h) were obtained for CS2 and H2S, respectively, suggesting that MBBR had the potential for application.}, }
@article {pmid39057985, year = {2024}, author = {Liu, C and Qian, R and Shi, W and Kou, L and Wang, J and Ma, X and Ren, H and Gao, S and Ren, J}, title = {EⅡB Mutation Reduces the Pathogenicity of Listeria monocytogenes by Negatively Regulating Biofilm Formation Ability, Infective Capacity, and Virulence Gene Expression.}, journal = {Veterinary sciences}, volume = {11}, number = {7}, pages = {}, pmid = {39057985}, issn = {2306-7381}, support = {RCZK202042//Shihezi University high level talent research launch project/ ; 32160833//National Natural Science Foundation of China/ ; 32160834//Natural Science Foundation of China/ ; }, abstract = {To explore the role of the membrane permease ⅡB (EⅡB) gene of Listeria pathogenicity island 4 (LIPI-4) in the virulence of Listeria monocytogenes, both an EⅡB deletion strain (∆EⅡB) and a complemented strain were constructed. In vitro experiments demonstrated that EⅡB deletion affected the biofilm formation ability of the wild-type strain (Lm928). Moreover, this deletion decreased the intracellular proliferation abilities of L. monocytogenes. Mice infected with ∆EⅡB survived longer and experienced less weight loss on days 1, 2, and 3 post-infection. The bacterial load in the liver tissue of ∆EⅡB-infected mice was significantly reduced, and a considerable decrease in the blood levels of inflammatory cytokines IL-β, IL-6, IL-10, and TNF-α were observed. Following EⅡB deletion, 65% (13/20) of genes were downregulated, 25% (5/20) were upregulated, and 10% (2/20) showed no change. These findings suggest that EⅡB deletion may reduce both the in vivo and in vitro virulence levels as well as the biofilm formation ability of Lm928 by downregulating the transcription levels of genes associated with virulence and biofilm formation. These findings provide a foundation for further examining the pathogenic mechanisms of LIPI-4 and EⅡB in L. monocytogenes.}, }
@article {pmid39057504, year = {2024}, author = {Alifah, N and Palungan, J and Ardayanti, K and Ullah, M and Nurkhasanah, AN and Mustopa, AZ and Lallo, S and Agustina, R and Yoo, JW and Hasan, N}, title = {Development of Clindamycin-Releasing Polyvinyl Alcohol Hydrogel with Self-Healing Property for the Effective Treatment of Biofilm-Infected Wounds.}, journal = {Gels (Basel, Switzerland)}, volume = {10}, number = {7}, pages = {}, pmid = {39057504}, issn = {2310-2861}, support = {96/IV/KS/11/2022 and 4538/UN4.22/PT.01.03/2022//This study was supported by the Indonesia Endowment Funds for Education (LPDP) and the National Research and Innovation Agency/Badan Riset dan Inovasi Nasional (BRIN) under the scheme of Program Riset dan Inovasi untuk Indonesia Maju (RIIM) with the contr/ ; }, abstract = {Self-healing hydrogels have good mechanical strength, can endure greater external force, and have the ability to heal independently, resulting in a strong bond between the wound and the material. Bacterial biofilm infections are life-threatening. Clindamycin (Cly) can be produced in the form of a self-healing hydrogel preparation. It is noteworthy that the antibacterial self-healing hydrogels show great promise as a wound dressing for bacterial biofilm infection. In this study, we developed a polyvinyl alcohol/borax (PVA/B) self-healing hydrogel wound dressing that releases Cly. Four ratios of PVA, B, and Cly were used to make self-healing hydrogels: F1 (4%:0.8%:1%), F2 (4%:1.2%:1%), F3 (1.6%:1%), and F4 (4%:1.6%:0). The results showed that F4 had the best physicochemical properties, including a self-healing duration of 11.81 ± 0.34 min, swelling ratio of 85.99 ± 0.12%, pH value of 7.63 ± 0.32, and drug loading of 98.34 ± 11.47%. The B-O-C cross-linking between PVA and borax caused self-healing, according to FTIR spectra. The F4 formula had a more equal pore structure in the SEM image. The PVA/B-Cly self-healing hydrogel remained stable at 6 ± 2 °C for 28 days throughout the stability test. The Korsmeyer-Peppas model released Cly by Fickian diffusion. In biofilm-infected mouse wounds, PVA/B-Cly enhanced wound healing and re-epithelialization. Our results indicate that the PVA/B-Cly produced in this work has reliable physicochemical properties for biofilm-infected wound therapy.}, }
@article {pmid39057422, year = {2024}, author = {Caudal, F and Roullier, C and Rodrigues, S and Dufour, A and Artigaud, S and Le Blay, G and Bazire, A and Petek, S}, title = {Anti-Biofilm Extracts and Molecules from the Marine Environment.}, journal = {Marine drugs}, volume = {22}, number = {7}, pages = {}, pmid = {39057422}, issn = {1660-3397}, support = {PhD SPOQS project//University of Southern Brittany/ ; PhD SPOQS project//Institut de Recherche pour le D&#xe9;veloppement/ ; ANR-17-EURE-0015 (MARESISTOME flagship project)//ISblue/ ; SPOQS project//Laboratoire des Sciences de l'Environnement Marin/ ; SPOQS project//Laboratoire de Biotechnologie et Chimie Marines/ ; }, mesh = {*Biofilms/drug effects ; *Aquatic Organisms ; *Anti-Bacterial Agents/pharmacology/chemistry/isolation &amp; purification ; Animals ; Bacteria/drug effects ; Humans ; Biological Products/pharmacology/isolation &amp; purification/chemistry ; }, abstract = {Pathogenic bacteria and their biofilms are involved in many diseases and represent a major public health problem, including the development of antibiotic resistance. These biofilms are known to cause chronic infections for which conventional antibiotic treatments are often ineffective. The search for new molecules and innovative solutions to combat these pathogens and their biofilms has therefore become an urgent need. The use of molecules with anti-biofilm activity would be a potential solution to these problems. The marine world is rich in micro- and macro-organisms capable of producing secondary metabolites with original skeletons. An interest in the chemical strategies used by some of these organisms to regulate and/or protect themselves against pathogenic bacteria and their biofilms could lead to the development of bioinspired, eco-responsible solutions. Through this original review, we listed and sorted the various molecules and extracts from marine organisms that have been described in the literature as having strictly anti-biofilm activity, without bactericidal activity.}, }
@article {pmid39057048, year = {2024}, author = {Eltabey, SM and Ibrahim, AH and Zaky, MM and Ibrahim, AE and Alrashdi, YBA and El Deeb, S and Saleh, MM}, title = {The Promising Effect of Ascorbic Acid and Paracetamol as Anti-Biofilm and Anti-Virulence Agents against Resistant Escherichia coli.}, journal = {Current issues in molecular biology}, volume = {46}, number = {7}, pages = {6805-6819}, pmid = {39057048}, issn = {1467-3045}, abstract = {Escherichia coli is a major cause of serious infections, with antibiotic resistance rendering many treatments ineffective. Hence, novel strategies to combat this pathogen are needed. Anti-virulence therapy is a promising new approach for the subsequent era. Recent research has examined the impact of sub-inhibitory doses of ascorbic acid and paracetamol on Escherichia coli virulence factors. This study evaluated biofilm formation, protease production, motility behavior, serum resistance, expression of virulence-regulating genes (using RT-PCR), and survival rates in a mouse model. Ascorbic acid significantly reduced biofilm formation, protease production, motility, and serum resistance from 100% in untreated isolates to 22-89%, 10-89%, 2-57%, and 31-35% in treated isolates, respectively. Paracetamol also reduced these factors from 100% in untreated isolates to 16-76%, 1-43%, 16-38%, and 31-35%, respectively. Both drugs significantly down-regulated virulence-regulating genes papC, fimH, ompT_m, stcE, fliC, and kpsMTII. Mice treated with these drugs had a 100% survival rate compared with 60% in the positive control group control inoculated with untreated bacteria. This study highlights the potential of ascorbic acid and paracetamol as anti-virulence agents, suggesting their use as adjunct therapies alongside conventional antimicrobials or as alternative treatments for resistant Escherichia coli infections.}, }
@article {pmid39055850, year = {2024}, author = {Outomuro Ruiz, JM and Gerner, E and Rahimi, S and Alarcón, LA and Mijakovic, I}, title = {Biofilm formation and dispersal of Staphylococcus aureus wound isolates in microtiter plate-based 2-D wound model.}, journal = {Heliyon}, volume = {10}, number = {13}, pages = {e33872}, pmid = {39055850}, issn = {2405-8440}, abstract = {Biofilm-associated wound infections in diabetic and immunocompromised patients are an increasing threat due to rising antibiotic resistance. Various wound models have been used to screen for efficient antiinfection treatments. However, results from in vitro models do not always match in vivo results, and this represents a bottleneck for development of new infection treatments. In this study, a static 2-D microtiter plate-based biofilm model was tested for growing clinically relevant Staphylococcus aureus wound isolates in various operating conditions, seeking to identify an optimal setup that would yield physiologically relevant results. Specifically, the tested variables included wound-mimicking growth media, precoating of surface with different proteins, multiwell plates with various surface properties, and the effect of bacterial pre-attachment step. Our results indicated that protein precoating is a key factor for supporting biofilm growth. The same wound isolate responded with significant differences in biofilm formation to different wound-mimicking media. Biofilm dispersal, as a proxy for effectiveness of antibiofilm treatments, was also investigated in response to proteinase K. The dispersal effect of proteinase K showed that the biofilm dispersal is contingent upon the specific wound isolate, with isolates CCUG 35571 and ATCC 6538 showing considerable dispersal responses. In conclusion, this study observed a higher biofilm formation in isolates when a protein precoating of collagen type I was applied but being dependent on the growth media selected. That is why we recommend to use simulated wound fluid or a wound-mimicking growth media to perform similar studies. Furthermore, proteinase K is suggested as an important factor that could affect biofilm dispersal within such models, since biofilm dispersal was induced in isolates CCUG 35571 and ATCC 6538 in simulated wound fluid on precoated collagen type I plates.}, }
@article {pmid39054781, year = {2024}, author = {Li, Y and Liang, X and Chen, N and Yuan, X and Wang, J and Wu, Q and Ding, Y}, title = {The promotion of biofilm dispersion: a new strategy for eliminating foodborne pathogens in the food industry.}, journal = {Critical reviews in food science and nutrition}, volume = {}, number = {}, pages = {1-25}, doi = {10.1080/10408398.2024.2354524}, pmid = {39054781}, issn = {1549-7852}, abstract = {Food safety is a critical global concern due to its direct impact on human health and overall well-being. In the food processing environment, biofilm formation by foodborne pathogens poses a significant problem as it leads to persistent and high levels of food contamination, thereby compromising the quality and safety of food. Therefore, it is imperative to effectively remove biofilms from the food processing environment to ensure food safety. Unfortunately, conventional cleaning methods fall short of adequately removing biofilms, and they may even contribute to further contamination of both equipment and food. It is necessary to develop alternative approaches that can address this challenge in food industry. One promising strategy in tackling biofilm-related issues is biofilm dispersion, which represents the final step in biofilm development. Here, we discuss the biofilm dispersion mechanism of foodborne pathogens and elucidate how biofilm dispersion can be employed to control and mitigate biofilm-related problems. By shedding light on these aspects, we aim to provide valuable insights and solutions for effectively addressing biofilm contamination issues in food industry, thus enhancing food safety and ensuring the well-being of consumers.}, }
@article {pmid39054303, year = {2024}, author = {Moghadam, MJ and Maktabi, S and Zarei, M and Koohi, PM}, title = {Controlling Staphylococcus aureus Biofilm on Food Contact Surfaces: The Efficacy of Oliveria decumbens Essential Oil and its Implications on Biofilm-Related Genes.}, journal = {Journal of applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jambio/lxae187}, pmid = {39054303}, issn = {1365-2672}, abstract = {AIMS: This study aimed to investigate the effect of Oliveria decumbens essential oil (Od-EO) on the phenotypic properties and gene expression of Staphylococcus aureus biofilm on commonly used food contact surfaces.<br><br>METHODS: The minimum inhibitory concentration and minimum bactericidal concentration of Od-EO on Staphylococcus aureus ATCC25923 were determined to be 0.5 and 1&#xa0;&#xb5;l/mL, respectively. Crystal violet staining, scanning electron microscopy (SEM), biofilm metabolic activity evaluation and Real-time PCR analysis were used to assess the anti-biofilm properties of Od-EO.<br><br>RESULTS: The results demonstrated that Od-EO exhibited significant anti-biofilm properties against S. aureus and effectively reduced the metabolic activity of biofilm cells. Furthermore, the inhibitory effects of Od-EO on biofilm formation were more pronounced on Stainless Steel (SS) compared to High Density Polyethylene (HDPE) surfaces. Real-time PCR analysis revealed that Od-EO downregulated the expression of biofilm-related genes (icaA, icaD, clfA, clfB, FnbA, FnbB, hld) in S. aureus grown on SS, while the expression levels of all studied genes except hld in the biofilm formed on HDPE remained unchanged or increased.<br><br>CONCLUSIONS: One of the main anti-biofilm mechanisms of the Od-EO on the HDPE is related to the disturbance in the QS of the cells. These findings highlight the potential of Od-EO as an effective agent for controlling and inhibiting S. aureus biofilm in the food industry and its potential use in disinfectant compounds.}, }
@article {pmid39053599, year = {2024}, author = {Li, P and Luo, Y and Tian, J and Cheng, Y and Wang, S and An, X and Zheng, J and Yan, H and Duan, H and Zhang, J and Pan, Z and Chen, Y and Wang, R and Zhou, H and Wang, Z and Tan, Z and Li, X}, title = {Outdoor tubular photobioreactor microalgae-microorganisms biofilm treatment of municipal wastewater: Enhanced heterotrophic assimilation and synergistic aerobic denitrogenation.}, journal = {Bioresource technology}, volume = {408}, number = {}, pages = {131151}, doi = {10.1016/j.biortech.2024.131151}, pmid = {39053599}, issn = {1873-2976}, abstract = {This research evaluated a microalgae consortium (MC) in a pilot-scale tubular photobioreactor for municipal wastewater (MWW) treatment, compared with an aeration column photobioreactor. Transitioning from suspended MC to a microalgae-microbial biofilm (MMBF) maintained treatment performance despite increasing influent from 50 L to 150 L in a 260 L system. Carbon and nitrogen removal were effective, but phosphorus removal varied due to biofilm shading and the absence of phosphorus-accumulating organisms. High influent flow caused MMBF detachment due to shear stress. Stabilizing and re-establishing the MMBF showed that a stable phycosphere influenced microbial diversity and interactions, potentially destabilizing the MMBF. Heterotrophic nitrification-aerobic denitrification bacteria were crucial for MC equilibrium. Elevated gene expression related to nitrogen fixation, organic nitrogen metabolism, and nitrate reduction confirmed strong microalgal symbiosis, highlighting MMBF's treatment potential. This study supports the practical application of microalgae in wastewater treatment.}, }
@article {pmid39052827, year = {2024}, author = {Liu, S and Li, Y and Xu, H and Kearns, DB and Wu, Y}, title = {Active interface bulging in Bacillus subtilis swarms promotes self-assembly and biofilm formation.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {121}, number = {31}, pages = {e2322025121}, doi = {10.1073/pnas.2322025121}, pmid = {39052827}, issn = {1091-6490}, mesh = {*Bacillus subtilis/physiology ; *Biofilms/growth &amp; development ; }, abstract = {Microbial communities such as biofilms are commonly found at interfaces. However, it is unclear how the physical environment of interfaces may contribute to the development and behavior of surface-associated microbial communities. Combining multimode imaging, single-cell tracking, and numerical simulations, here, we found that activity-induced interface bulging promotes colony biofilm formation in Bacillus subtilis swarms presumably via segregation and enrichment of sessile cells in the bulging area. Specifically, the diffusivity of passive particles is ~50% lower inside the bulging area than elsewhere, which enables a diffusion-trapping mechanism for self-assembly and may account for the enrichment of sessile cells. We also uncovered a quasilinear relation between cell speed and surface-packing density that underlies the process of active interface bulging. Guided by the speed-density relation, we demonstrated reversible formation of liquid bulges by manipulating the speed and local density of cells with light. Over the course of development, the active bulges turned into striped biofilm structures, which eventually give rise to a large-scale ridge pattern. Our findings reveal a unique physical mechanism of biofilm formation at air-solid interface, which is pertinent to engineering living materials and directed self-assembly in active fluids.}, }
@article {pmid39052320, year = {2024}, author = {Tang, M and Yang, R and Zhuang, Z and Han, S and Sun, Y and Li, P and Fan, K and Cai, Z and Yang, Q and Yu, Z and Yang, L and Li, S}, title = {Divergent molecular strategies drive evolutionary adaptation to competitive fitness in biofilm formation.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, doi = {10.1093/ismejo/wrae135}, pmid = {39052320}, issn = {1751-7370}, abstract = {Biofilm is a group of heterogeneously structured and densely packed bacteria with limited access to nutrients and oxygen. These intrinsic features can allow a mono-species biofilm to diversify into polymorphic subpopulations, determining the overall community's adaptive capability to changing ecological niches. However, the specific biological functions underlying biofilm diversification and fitness adaptation are poorly demonstrated. Here, we launched and monitored the experimental evolution of Pseudomonas aeruginosa biofilms, finding that two divergent molecular trajectories were adopted for adaptation to higher competitive fitness in biofilm formation: one involved hijacking bacteriophage superinfection to aggressively inhibit kin competitors, whereas the other induced a subtle change in c-di-GMP signaling to gain a positional advantage via enhanced early biofilm adhesion. Bioinformatics analyses implicated that similar evolutionary strategies were prevalent among clinical P. aeruginosa strains, indicative of parallelism between natural and experimental evolution. Divergence in the molecular bases illustrated the adaptive values of genomic plasticity for gaining competitive fitness in biofilm formation. Finally, we demonstrated that these fitness-adaptive mutations reduced bacterial virulence. Our findings revealed how the mutations intrinsically generated from the biofilm environment influence the evolution of P. aeruginosa.}, }
@article {pmid39049919, year = {2024}, author = {Prajapati, RA and Jadeja, GC}, title = {Red dragon fruit-soy protein isolate biofilm: UV-blocking, antioxidant &amp; improved mechanical properties for sustainable food packaging.}, journal = {Journal of food science and technology}, volume = {61}, number = {9}, pages = {1686-1700}, pmid = {39049919}, issn = {0022-1155}, abstract = {UNLABELLED: In this study, an active biofilm was developed by incorporating red dragon fruit peel (RDF) extract into soy protein isolate (SPI) film matrix for sustainable food packaging. The addition of betalain-rich-RDF extract (1-7 wt%) significantly improved UV-blocking and antioxidant properties of the film compared to the control film. As wt% of RDF-extract increased, water vapor permeability, water solubility, and elongation at break decreased by 1.06 × 10[-10] g m m[-2] s[-1] Pa[-1], 34.25%, and 133.25%, respectively. On the other hand, Tensile strength increased significantly (P < 0.05) by 78.76%. FTIR results confirmed the intermolecular interaction between RDF extract and SPI through hydrogen bonding, while XRD result showed a decrease in the crystallinity degree of the film with RDF extract addition. However, no significant change in the TGA curve between extract-incorporated SPI films was observed. SEM analysis revealed that SPI B and SPI D films had a more compact and denser structure than the control film, while AFM analysis showed an increase in Ra and Rq values representing higher surface roughness of SPI D film. SPI D film also significantly (P < 0.05) decreased the weight loss and increased total soluble solids of freshly cut apples over 7-day storage period.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-024-05940-2.}, }
@article {pmid39049800, year = {2024}, author = {Aydin, A and Sudagidan, M and Abdramanov, A and Yurt, MNZ and Mamatova, Z and Ozalp, VC}, title = {Horse Meat Microbiota: Determination of Biofilm Formation and Antibiotic Resistance of Isolated Staphylococcus Spp.}, journal = {Foodborne pathogens and disease}, volume = {}, number = {}, pages = {}, doi = {10.1089/fpd.2023.0171}, pmid = {39049800}, issn = {1556-7125}, abstract = {Domestic horses could be bred for leisure activities and meat production, as is already the case in many countries. Horse meat is consumed in various countries, including Kazakhstan and Kyrgyzstan, and with the increase in this consumption, horses are registered as livestock by the Food and Agricultural Organization. In this study, horse meat microbiota of horse samples (n = 56; 32 samples from Kazakhstan and 24 samples from Kyrgyzstan) from two countries, Kazakhstan (n = 3) and Kyrgyzstan (n = 1), were investigated for the first time by next-generation sequencing and metabarcoding analysis. The results demonstrated that Firmicutes, Proteobacteria, and Actinobacteria were the dominant bacterial phyla in all samples. In addition, three (5.4%) Staphylococcus strains were isolated from the Uzynagash region, Kazakhstan. Staphylococcus strains were identified as Staphylococcus warneri, S. epidermidis, and S. pasteuri by partial 16S rRNA DNA gene Sanger sequencing. All three Staphylococcus isolates were nonbiofilm formers; only the S. pasteuri was detected as multidrug-resistant (resistant to penicillin, cefoxitin, and oxacillin). In addition, S. pasteuri was found to carry mecA, mecC, and tetK genes. This is the first study to detect potentially pathogenic Staphylococcus spp. in horse meat samples originating from Kazakhstan. In conclusion, it should be carefully considered that undercooked horse meat may pose a risk to consumers in terms of pathogens such as antibiotic-resistant Staphylococcus isolates.}, }
@article {pmid39048998, year = {2024}, author = {Pourhajibagher, M and Ghafari, HA and Bahador, A}, title = {Postbiotic mediators derived from Lactobacillus species enhance riboflavin-mediated antimicrobial photodynamic therapy for eradication of Streptococcus mutans planktonic and biofilm growth.}, journal = {BMC oral health}, volume = {24}, number = {1}, pages = {836}, pmid = {39048998}, issn = {1472-6831}, mesh = {*Biofilms/drug effects ; *Streptococcus mutans/drug effects ; *Riboflavin/pharmacology ; *Photochemotherapy/methods ; *Microbial Sensitivity Tests ; Lactobacillus/drug effects ; Photosensitizing Agents/pharmacology ; Plankton/drug effects ; Lacticaseibacillus casei/drug effects ; Anti-Bacterial Agents/pharmacology ; }, abstract = {BACKGROUND: Streptococcus mutans has been implicated as a primary causative agent of dental caries and one of its important virulence properties is an ability to form biofilm on tooth surfaces. Thus, strategies to prevent and control S. mutans biofilms are requested. The present study aimed to examine the eradication of S. mutans planktonic and biofilm cells using riboflavin (Rib)-mediated antimicrobial photodynamic therapy (aPDT) enhanced by postbiotic mediators derived from Lactobacillus species.<br><br>MATERIALS AND METHODS: Minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of Rib and postbiotic mediators were determined. The antimicrobial and anti-biofilm effects of Rib-mediated aPDT (Rib plus blue light), Rib-mediated aPDT in combination with postbiotic mediators derived from Lactobacillus casei (LC) (aPDT[+&#x2009;LC]), and Rib-mediated aPDT in combination with postbiotic mediators derived from Lactobacillus plantarum (LP) (aPDT[+&#x2009;LP]) were evaluated. The anti-virulence potential of Rib-mediated aPDT, aPDT[+&#x2009;LC], and aPDT[+&#x2009;LP] were assessed by measuring the expression of the gtfB gene using quantitative real-time polymerase chain reaction (qRT-PCR) at the highest concentrations of Rib, LC, and LP, at which the S. mutans had proliferation as the same as in the control (non-treated) group.<br><br>RESULTS: According to the results, the MIC doses of LC, LP, and Rib were 64&#xa0;&#xb5;g/mL, 128&#xa0;&#xb5;g/mL, and 128&#xa0;&#xb5;g/mL, respectively, while the MBC values of LC, LP, and Rib were 128&#xa0;&#xb5;g/mL, 256&#xa0;&#xb5;g/mL, and 256&#xa0;&#xb5;g/mL, respectively. Rib-mediated aPDT, aPDT[+&#x2009;LP], and aPDT[+&#x2009;LC] showed a significant reduction in Log10 CFU/mL of S. mutans compared to the control group (4.2, 4.9, and 5.2 Log10 CFU/mL, respectively; all P&#x2009;<&#x2009;0.05). The most destruction of S. mutans biofilms was observed after treatment with aPDT[+&#x2009;LC] followed by aPDT[+&#x2009;LP] and Rib-mediated aPDT (77.5%, 73.3%, and 67.6%, respectively; all P&#x2009;<&#x2009;0.05). The concentrations of 31.2&#xa0;&#xb5;g/mL, 62.5&#xa0;&#xb5;g/mL, and 62.5&#xa0;&#xb5;g/mL were considered as the highest concentrations of LC, LP, and Rib, respectively, at which S. mutans replicates as same as the control group and were used for gtfB gene expression assay using qRT-PCR during Rib-mediated aPDT, aPDT[+&#x2009;LP], and aPDT[+&#x2009;LC] treatments. Gene expression results revealed that aPDT[+&#x2009;LP] and aPDT[+&#x2009;LC] could decrease the gene expression level of gtfB by 6.3- and 5.7-fold, respectively (P&#x2009;<&#x2009;0.05), while only 5.1-fold reduction was observed after Rib-mediated aPDT (P&#x2009;<&#x2009;0.05).<br><br>CONCLUSION: Our findings indicate that aPDT[+&#x2009;LP] and aPDT[+&#x2009;LC] hold promise for use as a treatment to combat S. mutans planktonic and biofilms growth as well as anti-virulence as a preventive strategy to inhibit biofilms development via reduction of gtfB gene expression.}, }
@article {pmid39047804, year = {2024}, author = {Haque, A and Chowdhury, A and Islam Bhuiyan, MN and Bhowmik, B and Afrin, S and Sarkar, R and Haque, MM}, title = {Molecular characterization, antibiotic resistant pattern and biofilm forming potentiality of bacterial community associated with Ompok pabda fish farming in southwestern Bangladesh.}, journal = {Microbial pathogenesis}, volume = {194}, number = {}, pages = {106818}, doi = {10.1016/j.micpath.2024.106818}, pmid = {39047804}, issn = {1096-1208}, abstract = {Ompok pabda is gaining popularity in the aquaculture industry due to its increasing demand; however research on microbial diversity and antibiotic susceptibility remains limited. The present study was designed to identify the bacterial pathogens commonly found in the pabda farming system with their biofilm forming potential and antibiotic susceptibility. Different bacterial strains were isolated from water, sediments and gut, gill of pabda fish and the isolates were identified based on their morphological traits, biochemical and molecular analysis. Antibiotic susceptibilities, antibiotic resistance gene determination and biofilm formation capabilities were evaluated by disc diffusion method, PCR amplification and Microtiter plate (MTP) assay, respectively. The respective isolates of gill and gut of pabda aquaculture and their environments were: Exiguobacterium spp. (25 %), Enterococcus spp. (20 %), Bacillus spp. (10 %), Acinetobacter spp. (10 %), Enterobacter spp. (10 %), Aeromonas spp. (10 %), Lactococcus spp. (5 %), Klebsiella spp. (5 %) and Kurthia spp. (5 %). Antibiotic resistance frequencies were found to be relatively high, especially for trimethoprim (95 %), sulfafurazole (75 %), ampicillin (60 %), amoxicillin-clavulanic acid (55 %), and cephradine (50 %). 30 % isolates were categorized as DR bacteria followed by 30 % isolates were MDR bacteria and 40 % were classified as XDR bacteria. Moreover, 4 antibiotic resistant genes were detected with sul1 (30 %), dfrA1 (10 %), tetC (40 %), and qnrA (5 %) of isolates. Based on the microtiter plate method, 20 %, 25 %, and 30 % of isolates were found to produce strong, moderate, and weak biofilms, respectively. The findings suggest that biofilm forming bacterial strains found in O. pabda fish farm may be a potential source of numerous antibiotic-resistant bacteria. The study sheds new light on antibiotic resistance genes, which are typically inherited by bacteria and play an important role in developing effective treatments or control strategies.}, }
@article {pmid39046262, year = {2024}, author = {Sheikhy, M and Karbasizade, V and Ghanadian, M and Fazeli, H}, title = {Evaluation of chlorogenic acid and carnosol for anti-efflux pump and anti-biofilm activities against extensively drug-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0393423}, doi = {10.1128/spectrum.03934-23}, pmid = {39046262}, issn = {2165-0497}, abstract = {UNLABELLED: Efflux pumps and biofilm play significant roles in bacterial antibiotic resistance. This study investigates the potential of chlorogenic acid (CGA) and carnosol (CL), as phenolic and diterpene compounds, respectively, for their inhibitory effects on efflux pumps. Among the 12 multidrug-resistant (MDR) strains of Staphylococcus aureus and Pseudomonas aeruginosa isolated from nosocomial skin infections, eight strains were identified as extensively drug resistant (XDR) using the disc diffusion method. The presence of efflux pumps in MDR strains of S. aureus and P. aeruginosa was screened using carbonyl cyanide-m-chlorophenylhydrazone. Between the 12 MDR strains of S. aureus and P. aeruginosa, 80% (4 out of 5) of the S. aureus strains and 85.7% (6 out of 7) of the P. aeruginosa strains exhibited active efflux pumps associated with gentamicin resistance. The checkerboard assay results, in combination with gentamicin, demonstrated that CGA exhibited a reduction in the minimum inhibitory concentration (MIC) for XDR S. aureus strain. Similarly, CL showed a synergistic effect and reduced the MIC for both XDR strains of S. aureus and P. aeruginosa. Flow cytometry was used to examine efflux pump activity at sub-MIC concentrations of 1/8, 1/4, and 1/2 MIC in comparison to the control. In XDR S. aureus, CGA demonstrated 39%, 70%, and 19% inhibition, while CL exhibited 74%, 73.5%, and 62% suppression. In XDR P. aeruginosa, CL exhibited inhibition rates of 25%, 10%, and 15%. The inhibition of biofilm formation was assessed using the microtiter plate method, resulting in successful inhibition of biofilm formation. Finally, the MTT assay was conducted, and it confirmed minimal cytotoxicity. Given the significant reduction in efflux pump activity and biofilm formation observed with CGA and CL in this study, these compounds can be considered as potential inhibitors of efflux pumps and biofilm formation, offering potential strategies to overcome antimicrobial resistance.<br><br>IMPORTANCE: In summary, CGA and CL demonstrated promising potentiating antimicrobial effects against XDR strains of Staphylococcus aureus and Pseudomonas aeruginosa, suggesting their probably potential as candidates for addressing nosocomial pathogens. They exhibited significant suppression of efflux pump activity, indicating a possible successful inhibition of this mechanism. Moreover, all substances effectively inhibited biofilm formation, while showing minimal cytotoxicity. However, further advancement to clinical trials is needed to evaluate the feasibility of utilizing CGA and CL for reversing bacterial XDR efflux and determining their efficacy against biofilms. These trials will provide valuable insights into the practical applications of these compounds in combating drug-resistant infections.}, }
@article {pmid39046242, year = {2024}, author = {Xue, J and Li, S and Wang, L and Zhao, Y and Zhang, L and Zheng, Y and Zhang, W and Chen, Z and Jiang, T and Sun, Y}, title = {Enhanced fatty acid biosynthesis by Sigma28 in stringent responses contributes to multidrug resistance and biofilm formation in Helicobacter pylori.}, journal = {Antimicrobial agents and chemotherapy}, volume = {}, number = {}, pages = {e0085024}, doi = {10.1128/aac.00850-24}, pmid = {39046242}, issn = {1098-6596}, abstract = {The metabolic state of bacteria significantly contributes to their resistance to antibiotics; however, the specific metabolic mechanisms conferring antimicrobial resistance in Helicobacter pylori remain largely understudied. Employing transcriptomic and non-targeted metabolomics, we characterized the metabolic reprogramming of H. pylori when challenged with antibiotic agents. We observed a notable increase in both genetic and key proteomic components involved in fatty acid biosynthesis. Inhibition of this pathway significantly enhanced the antibiotic susceptibility of the sensitive and multidrug-resistant H. pylori strains while also disrupting their biofilm-forming capacities. Further analysis revealed that antibiotic treatment induced a stringent response, triggering the expression of the hp0560-hp0557 operon regulated by Sigma28 (σ[28]). This activation in turn stimulated the fatty acid biosynthetic pathway, thereby enhancing the antibiotic tolerance of H. pylori. Our findings reveal a novel adaptive strategy employed by H. pylori to withstand antibiotic stress.}, }
@article {pmid39046207, year = {2024}, author = {Keskin, BH and Şahin, &#x130; and Kahraman, G and Duran, PK and Dülger, G and Durmuş, MA and Ceylan, AN and Çalışkan, E and Öksüz, &#x15e;}, title = {[Investigation of Biofilm Formation, Anti-Quorum Sensing Activity and Antimicrobial Resistance in Corynebacterium Species Isolated from Clinical Samples].}, journal = {Mikrobiyoloji bulteni}, volume = {58}, number = {3}, pages = {239-258}, doi = {10.5578/mb.20249704}, pmid = {39046207}, issn = {0374-9096}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Corynebacterium/drug effects/isolation &amp; purification/growth &amp; development ; Humans ; *Anti-Bacterial Agents/pharmacology ; *Corynebacterium Infections/microbiology ; *Microbial Sensitivity Tests ; *Quorum Sensing/drug effects ; Drug Resistance, Bacterial ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Indoles/pharmacology ; }, abstract = {An increasing number of different clinical infections caused by Corynebacteria have been reported in the last decade. The aim of this study was to evaluate the antibiotic resistance rates, biofilm formation capacities and to investigate the ''anti-quorum-sensing (anti-QS)'' activities of corynebacteria, which were divided into three groups according to the type of growth in culture (pure, with another pathogenic bacterium and polymicrobial growth). In total 240 Corynebacterium spp. isolates from different clinical specimens sent to the medical microbiology laboratories of Düzce University Faculty of Medicine Hospital and Başakşehir Çam and Sakura City Hospital between June 2021 and June 2022 were classified into three groups: pure, isolated with another pathogen and polymicrobial, according to their growth patterns in culture. Bacteria were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) Biotyper (Bruker, Germany) at an external centre. Antibiotic susceptibilities were determined by disc diffusion method and for vancomycin broth microdilution method was used. Results were interpreted according to EUCAST recommendations. The biofilm-forming properties of the isolates were determined quantitatively. Bioactive components of 17 isolates with strong biofilm formation were extracted and anti-QS activity was determined by agar diffusion method using Chromobacterium violaceum ATCC 12472 strain and then violacein pigment production was measured quantitatively. Of the 240 Corynebacterium spp. isolates, 138 (58%) were pure, 52 (22%) were isolated with another pathogen and 50 (20%) were part of a polymicrobial infection. Of the isolates, 140 were identified as C.striatum, 34 as C.amycolatum and 24 as Corynebacterium afermentans. When the antibiotic resistance rates of the Corynebacterium isolates were analysed according to the groups, the resistance rates to rifampicin and tetracycline antibiotics were found to be statistically significantly lower in the polymicrobial group than in the other groups. The resistance rates to penicillin, clindamycin, ciprofloxacin, moxifloxacin, rifampicin, tetracycline and linezolid were 96.7%, 88.3%, 86.3%, 73.8%, 62.5%, 59.2% and 0.8%, respectively. While all isolates were susceptible to vancomycin, linezolid resistance was detected in two C.afermentans isolates. When the biofilm formation ability was analysed, it was observed that 87 (36.3%) isolates formed biofilm. The biofilm formation rate of the isolates in the polymicrobial growth group was lower than the other two groups. The anti-QS activity of 17 isolates with strong biofilm formation was investigated and none of the Corynebacterium extracts tested were found to have anti-QS activity (inhibition of violacein pigment production without inhibiting bacterial growth) in the QS study with C.violaceum, whereas five isolate extracts had antibacterial activity (inhibition of bacterial growth). Four of the bacterial extracts with antimicrobial activity belonged to C.amycolatum and one to C.afermentans. In conclusion, when both antibiotic resistance rates and biofilm formation rates were analysed, the corynebacteria growing in culture with another pathogen showed similar characteristics to the corynebacteria growing as a pure culture. Therefore, it was thought that corynebacteria growing with another pathogen should not be ignored. In addition, the antimicrobial effects of some corynebacterial extracts suggested that more QS studies should be carried out with microbiota bacteria.}, }
@article {pmid39046206, year = {2024}, author = {Öztaş Gülmüş, E and Akçelik, N and Özdemir, C and Akçelik, M}, title = {[Effect of Quorum Sensing Systems on Biofilm Formation and Virulence in Salmonella].}, journal = {Mikrobiyoloji bulteni}, volume = {58}, number = {3}, pages = {225-238}, doi = {10.5578/mb.20240038}, pmid = {39046206}, issn = {0374-9096}, mesh = {*Quorum Sensing ; *Biofilms/growth &amp; development ; *Carbon-Sulfur Lyases/genetics ; Virulence ; *Bacterial Proteins/genetics/metabolism ; *Homoserine/analogs &amp; derivatives ; *Gene Expression Regulation, Bacterial ; Mutation ; Virulence Factors/genetics ; 4-Butyrolactone/analogs &amp; derivatives/metabolism ; Animals ; Salmonella/pathogenicity/genetics ; }, abstract = {In recent years, as the paradigm of communication between cells has been clarified, the ability of bacteria to change their gene expression patterns in response to various extracellular signals has attracted great interest. In particular, intracellular and intercellular communication between bacterial populations, called quorum sensing (QS), is essential for coordinating physiological and genetic activities. QS studies are critical, particularly in elucidating the regulatory mechanisms of infectious processes in food-borne pathogens. Elucidating the QS mechanisms in Salmonella is effective in silencing the virulence factors in the fight against this bacterium. The aims of this study were; to create luxS gene mutants that play a vital role in the QS activity of Salmonella and to determine the effect of this mutation on the expression of virulence genes in the bacteria and to determine the impact of synthetic N-hexanoyl-homoserine lactone (C6HSL) on biofilm formation and AI-2 signaling pathway of Salmonella wild strain and luxS gene mutants. luxS gene mutants were constructed by recombining the gene region with the chloramphenicol gene cassette based on homologous region recombination. In the luxS mutants obtained in this way, the expression of eight different virulence genes (hilA, invA, inv, glgC, fimF, fliF, lpfA, gyrA), which have essential roles in Salmonella pathogenicity, was determined by quantitative real-time reverse transcriptase polymerase chain reaction (rRT-qPCR) method and compared with natural strains. As a result of these studies, it was determined that the expression of each gene examined was significantly reduced in luxS mutant strains. The relative AI-2 activities of Salmonella strains were analyzed depending on time. It was determined that the highest activity occurred at the fourth hour and the AI-2 activities of luxS mutants were reduced compared to the wild strain. Finally, it was determined that C6HSL increased the biofilm activity of Salmonella Typhimurium DMC4, SL1344 wild strains, and mutants, mainly at the 72nd hour. In conclusion, our results proved that C6HSL stimulated QS communication in all strains and increased biofilm of Salmonella formation and autoinducer activity. This situation determines that Salmonella responds to external signals by using QS systems. In addition, this research contributed to provide additional information on interspecies communication mechanisms to develop strategies to prevent biofilm formation of this pathogen.}, }
@article {pmid39045150, year = {2024}, author = {Breivik, A and Mulic, A and Sehic, A and Valen, HR and Kopperud, S and Stein, L and Khan, Q}, title = {Accumulation and removal of Streptococcus mutans biofilm on enamel and root surfaces in vitro.}, journal = {Biomaterial investigations in dentistry}, volume = {11}, number = {}, pages = {41059}, pmid = {39045150}, issn = {2641-5275}, abstract = {OBJECTIVE: This study aimed to quantitatively investigate the accumulation of Streptococcus mutans biofilm on enamel and root surfaces and assess the amount of biofilm removal using (1) experimental toothpaste and (2) water, in a closed system of flow chamber.<br><br>METHODS: Eight sound premolars were embedded in epoxy resin and polished with silicon carbide grinding papers to display enamel and root surfaces. To mimic biofilm, cultures of Streptococcus mutans were prepared and grown on the tooth surfaces over night before they were exposed to either 2 liters of Milli Q water or 2 liters of 40% experimental toothpaste in the flow chamber. The amount of biofilm was measured and quantified in Fluorescence microscopy. Mean fluorescence values were recorded and analysed using Microsoft&#xae; Excel&#xae; (MS Excel 2016).<br><br>RESULTS: The ability to grow biofilm was equally present at both the enamel and root surfaces. The use of water and 40% experimental toothpaste showed a significant reduction of areas covered with biofilm on both enamel and root dentin in comparison to untreated surfaces (p < 0.01). Significantly more biofilm was removed from enamel compared to root surfaces when treated with either water and toothpaste (p < 0.01). Slightly less biofilm was removed by the use of water compared to toothpaste on both enamel and root dentin surfaces, although the differences were not statistically significant.<br><br>CONCLUSION: The results indicate that less biofilm is removed from the root surfaces than enamel by the use of water and 40% experimental toothpaste in flow chamber. Assessing oral biofilm accumulation and monitoring biofilm formation on enamel and root dentin surfaces give oral health professionals important directions that could strenghten the significance of dental caries prevention. Improving older individuals' oral hygiene practices should therefore be considered an important measure to prevent root caries.}, }
@article {pmid39044574, year = {2024}, author = {Wang, Z and Chen, J and You, Z and Liu, X and Zhang, J}, title = {[Advances in mechanisms of biofilm formation and drug resistance of Staphylococcus aureus].}, journal = {Sheng wu gong cheng xue bao = Chinese journal of biotechnology}, volume = {40}, number = {7}, pages = {2038-2051}, doi = {10.13345/j.cjb.230803}, pmid = {39044574}, issn = {1872-2075}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Staphylococcus aureus/drug effects/physiology ; *Anti-Bacterial Agents/pharmacology ; Humans ; Staphylococcal Infections/microbiology ; Drug Resistance, Multiple, Bacterial ; Drug Resistance, Bacterial ; }, abstract = {Staphylococcus aureus is a common pathogenic bacterium. However, due to the abuse of antibiotics, multiple drug-resistant S. aureus (DR S. aureus) has emerged in a large number, which seriously threatens human health. DR S. aureus usually forms biofilms by attaching on contact surfaces and secreting macromolecules including polysaccharides, proteins, and lipids, thus encasing themselves in a self-generated polymeric matrix. A biofilm provides an efficacious barrier that protects bacteria from detrimental environmental factors. Simultaneously, it protects DR S. aureus from the host immune system and attenuates the penetration and killing effects of drugs, serving as a key structure for the development of drug resistance. Therefore, gaining an in-depth understanding of the DR S. aureus biofilm is crucial for treating related infectious diseases. In this paper, we summarize recent research progress in the biofilm formation mechanism, drug resistance mechanism, and measures for inhibition and clearance of DR S. aureus and provide an outlook on the future research directions.}, }
@article {pmid39042175, year = {2024}, author = {Kirchhoff, L and Arweiler-Harbeck, D and Meyer, M and Buer, J and Lang, S and Steinmann, J and Bertram, R and Deuss, E and Höing, B}, title = {Bacterial biofilm formation on headpieces of Cochlear implants.}, journal = {European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery}, volume = {}, number = {}, pages = {}, pmid = {39042175}, issn = {1434-4726}, abstract = {INTRODUCTION: Bacterial biofilm formation on medical devices, such as Cochlear implants (CI), can lead to chronic infections. Not only the inner parts of the implant but also the externally located headpiece might be associated with prolonged superficial skin eczema resulting in the inability of wearing the headpiece. In this study, the surface of three CI headpieces from different manufacturers were examined for bacterial biofilm formation.<br><br>MATERIALS AND METHODS: Two bacterial species associated with implant-related infections were tested: Pseudomonas aeruginosa (ATCC9027) and Staphylococcus aureus (ATCC6538). Biofilms were formed over 24&#xa0;h in tryptic soy broth at 36&#xa0;&#xb0;C. Biofilm formation was detected in form of biomass measurement by crystal violet staining. CI headpiece dummies of three manufacturers were used.<br><br>RESULTS: Both tested bacterial species formed biofilms on the examined CI headpiece-surfaces in a species-dependent manner with higher biofilm formation of P. aeruginosa. For both, S. aureus and P. aeruginosa, biofilm formation on the CI components was comparable to a polystyrene control surface. Between the three manufacturers, no significant difference in biofilm formation was found.<br><br>DISCUSSION: The tested bacteria displayed biofilm formation on the CI headpieces in a species-specific manner with higher amount of biofilm formed by P. aeruginosa. The biofilm formation was comparable between the manufacturers. In this study, an enhanced biofilm formation on CI headpieces could not be demonstrated. These in vitro tests suggest a minor role of bacterial biofilm on the CI headpiece in skin infections under the CI headpiece.}, }
@article {pmid39040541, year = {2024}, author = {Pan, Z and Dai, C and Li, W}, title = {Material-based treatment strategies against intraosseous implant biofilm infection.}, journal = {Biochemistry and biophysics reports}, volume = {39}, number = {}, pages = {101764}, pmid = {39040541}, issn = {2405-5808}, abstract = {Implant-associated infections present a significant clinical obstacle for orthopedic practitioners, with bacterial biofilm formation serving as a pivotal factor in the initiation, progression, and management of such infections. Conventional approaches have proven inadequate in fully eradicating biofilm-related infections. Consequently, novel material-based therapeutic strategies have been developed, encompassing the utilization of antimicrobial agents, delivery vehicles, and synergistic antibacterial systems. In this review, we provide a succinct overview of recent advancements in anti-biofilm strategies, with the aim of offering insights that may aid in the treatment of intraosseous implant infections.}, }
@article {pmid39040382, year = {2024}, author = {Chandraraj, SS and Suyambulingam, I and Edayadulla, N and Divakaran, D and Singh, MK and Sanjay, MR and Siengchin, S}, title = {Characterization of Calotropis gigantiea plant leaves biomass-based bioplasticizers for biofilm applications.}, journal = {Heliyon}, volume = {10}, number = {13}, pages = {e33641}, pmid = {39040382}, issn = {2405-8440}, abstract = {The present surge in environmental consciousness has pushed for the use of biodegradable plasticizers, which are sustainable and abundant in plant resources. As a result of their biocompatibility and biodegradability, Calotropis gigantiea leaf plasticizers (CLP) serve as viable alternatives to chemical plasticizers. First time, the natural plasticizers from the Calotropis leaves were extracted for this study using a suitable chemical approach that was also environmentally friendly. The XRD results showed a reduced crystallinity index of 20.2 % and a crystalline size of 5.3 nm, respectively. TGA study revealed that the CLP has good thermal stability (244 °C). Through FT-IR study, the existence of organic compounds in CLP can be investigated by key functional groups such as alcohol, amine, amide, hydrocarbon, alkene, aromatic, etc. Further the presence of alcoholic, amino, and carboxyl constituents was confirmed by UV investigation. SEM, EDAX analysis, and AFM are used to examine the surface morphology of the isolated plasticizer. SEM pictures reveal rough surfaces on the CLP surface pores, which makes them suitable for plasticizing new bioplastics with improved mechanical properties. Poly (butylene adipate-co-terephthalate) (PBAT), a biodegradable polymer matrix, was used to investigate the plasticization impact after the macromolecules were characterised. The biofilm PBAT/CLP had a thickness of 0.8 mm. In addition, the reinforcement interface was examined using scanning electron microscopy. When CLP is loaded differently in PBAT, the tensile strength and young modulus change from 15.30 to 24.60 MPa and from 137 to 168 MPa, respectively. CLP-reinforced films demonstrated better surface compatibility and enhanced flexibility at a loading of 2 % when compared to pure PBAT films. Considering several documented characteristics, CLP may prove to be an excellent plasticizer for resolving environmental issues in the future.}, }
@article {pmid39039267, year = {2024}, author = {Silva, AR and Melo, LF and Keevil, CW and Pereira, A}, title = {Legionella colonization and 3D spatial location within a Pseudomonas biofilm.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {16781}, pmid = {39039267}, issn = {2045-2322}, support = {LEPABE//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e a Tecnologia/ ; }, mesh = {*Biofilms/growth &amp; development ; *Legionella pneumophila/physiology ; *Pseudomonas fluorescens/physiology ; Legionella/physiology ; Microscopy, Confocal ; Tomography, Optical Coherence ; }, abstract = {Biofilms are known to be critical for Legionella settlement in engineered water systems and are often associated with Legionnaire's Disease events. One of the key features of biofilms is their heterogeneous three-dimensional structure which supports the establishment of microbial interactions and confers protection to microorganisms. This work addresses the impact of Legionella pneumophila colonization of a Pseudomonas fluorescens biofilm, as information about the interactions between Legionella and biofilm structures is scarce. It combines a set of meso- and microscale biofilm analyses (Optical Coherence Tomography, Episcopic Differential Interference Contrast coupled with Epifluorescence Microscopy and Confocal Laser Scanning Microscopy) with PNA-FISH labelled L. pneumophila to tackle the following questions: (a) does the biofilm structure change upon L. pneumophila biofilm colonization?; (b) what happens to L. pneumophila within the biofilm over time and (c) where is L. pneumophila preferentially located within the biofilm? Results showed that P. fluorescens structure did not significantly change upon L. pneumophila colonization, indicating the competitive advantage of the first colonizer. Imaging of PNA-labelled L. pneumophila showed that compared to standard culture recovery it colonized to a greater extent the 3-day-old P. fluorescens biofilms, presumably entering in VBNC state by the end of the experiment. L. pneumophila was mostly located in the bottom regions of the biofilm, which is consistent with the physiological requirements of both bacteria and confers enhanced Legionella protection against external aggressions. The present study provides an expedited methodological approach to address specific systematic laboratory studies concerning the interactions between L. pneumophila and biofilm structure that can provide, in the future, insights for public health Legionella management of water systems.}, }
@article {pmid39038400, year = {2024}, author = {Gao, SC and Fan, XX and Zhang, Z and Li, RT and Zhang, Y and Gao, TP and Liu, Y}, title = {A dual-function mixed-culture biofilm for sulfadiazine removal and electricity production using bio-electrochemical system.}, journal = {Biosensors &amp; bioelectronics}, volume = {263}, number = {}, pages = {116552}, doi = {10.1016/j.bios.2024.116552}, pmid = {39038400}, issn = {1873-4235}, abstract = {Sulfadiazine (SDZ) is frequently detected in environmental samples, arousing much concern due to its toxicity and hard degradation. This study investigated the electricity generation capabilities, SDZ removal and microbial communities of a highly efficient mixed-culture system using repeated transfer enrichments in a bio-electrochemical system. The mixed-culture biofilm (S160-T2) produced a remarkable current density of 954.12 ± 15.08 μA cm[-2] with 160 mg/L SDZ, which was 32.9 and 1.8 times higher than that of Geobacter sulfurreducens PCA with 40 mg/L SDZ and without additional SDZ, respectively. Especially, the impressive SDZ removal rate of 98.76 ± 0.79% was achieved within 96 h using the further acclimatized mixed-culture. The removal efficiency of this mixed-culture for SDZ through the bio-electrochemical system was 1.1 times higher than that using simple anaerobic biodegradation. Furthermore, the current density and removal efficiency in this system gradually decreased with increasing SDZ concentrations from 0 to 800 mg/L. In addition, community diversity data demonstrated that the dominant genera, Geobacter and Escherichia-Shigella, were enriched in mixed-culture biofilm, which might be responsible for the current production and SDZ removal. This work confirmed the important roles of acclimatized microbial consortia and co-substrates in the simultaneous removal of SDZ and electricity generation in an electrochemical system.}, }
@article {pmid39037897, year = {2024}, author = {Zermeño-Pérez, D and Chouirfa, H and Rodriguez, BJ and Dürig, T and Duffy, P and Cróinín, T&#xd3;}, title = {Bioresorbable Polyester Coatings with Antifouling and Antimicrobial Properties for Prevention of Biofilm Formation in Early Stage Infections on Ti6Al4V Hard-Tissue Implants.}, journal = {ACS applied bio materials}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsabm.4c00832}, pmid = {39037897}, issn = {2576-6422}, abstract = {Implants made from titanium are used as prostheses because of their biocompatibility and their mechanical properties close to those of human bone. However, the risk of bacterial infection is always a major concern during surgery, and the development of biofilm can make these infections difficult to treat. A promising strategy to mitigate against bacterial infections is the use of antifouling and antimicrobial coatings, where bioresorbable polymers can play an important role due to their controlled degradability and sustained drug release, as well as excellent biocompatibility. In the present study, poly(d,l-lactide) (PDLLA) and poly[d,l-lactide-co-methyl ether poly(ethylene glycol)] (PDLLA-PEG) were studied, varying the PEG content (20-40% w/w) to analyze the effectiveness of PEG as an antifouling molecule. In addition, silver sulfadiazine (AgSD) was used as an additional antimicrobial agent with a concentration ≤5% w/w and incorporated into the PEGylated polymers to create a polymer with both antifouling and antimicrobial properties. Polymers synthesized were applied using spin coating to obtain homogeneous coatings to protect samples made from titanium/aluminum/vanadium (Ti6Al4V). The polymer coatings had a smoothing effect in comparison to that of the uncoated material, decreasing the contact area available for bacterial colonization. It was also noted that PEG addition into the polymeric chain developed amphiphilic materials with a decrease in contact angle from the most hydrophobic (Ti6Al4V) to the most hydrophilic PDLLA-PEG (60/40), highlighting the increase in water uptake contributing to the hydration layer formation, which confers the antifouling effect on the coating. This study demonstrated that the addition of PEG above 20% w/w and AgSD above 1% w/v into the formulation was able to decrease bacterial adherence against clinically relevant biofilm former strains Staphylococcus aureus and Pseudomonas aeruginosa.}, }
@article {pmid39037809, year = {2024}, author = {Aydın, E and Kocaaga, M and Temel, A}, title = {Association of antibiotic resistance and biofilm formation in Escherichia coli ST131/O25b.}, journal = {Acta microbiologica et immunologica Hungarica}, volume = {}, number = {}, pages = {}, doi = {10.1556/030.2024.02275}, pmid = {39037809}, issn = {1588-2640}, abstract = {Urinary tract infections are becoming difficult to treat every year due to antibiotic resistance. Uropathogenic Escherichia coli (UPEC) isolates pose a threat with a combined expression of multidrug-resistance and biofilm formation. ST131 clone is a high-risk pandemic clone due to its strong association with antimicrobial resistance, which has been reported frequently in recent years. This study aims to define risk factors, clinical outcomes, and bacterial genetics associated with ST131/O25b UPEC. In this study, antibiotic susceptibility and species-level identification of 61 clinical E. coli strains were determined by automated systems. Detection of extended-spectrum beta-lactamases was assessed by double-disk synergy test. Biofilm formation was quantified by spectrophotometric method. Virulence genes (iutA, sfa cnf-1, iroN, afa, papA, fimA), antibiotic resistance genes (blaCTX-M, blaTEM, blaSHV, blaOXA, qnrA, qnrB, qnrS, ant(2')-Ia, ant(3)-Ia, aac(3)-IIa, mcr-1, mcr-2, mcr-3, mcr-4) were investigated by PCR. The following beta-lactamase genes were identified, blaTEM (n = 53, 86.8%), blaCTX-M (n = 59, 96.7%), blaSHV (n = 47, 77.0%), and blaOXA-1 (n = 27, 44.2%). Our data revealed that 93.4% of (57/61) E. coli isolates were biofilm-producers. O25pabBspe and trpA2 were investigated for the presence of ST131/O25b clone. Among multidrug resistant isolates, co-existence of O25pabBspe and trpA2 was detected in 29 isolates (47.5%). The fimH30 and H30Rx subclones were detected in four isolates that are strong biofilm-producers. These results suggest that clinical E. coli strains may become reservoirs of virulence and antibiotic resistance genes. This study demonstrates a significant difference in biofilm formation between E. coli ST131 and non-ST131 isolates. Moreover, 86.21% (n = 25) of ST131 isolates produced strong to moderate biofilms, while only 43.75% (n = 14) of non-ST131 isolates showed the ability to form strong biofilms. Presence of iutA and fimA genes in the majority of ST131 strains showed an important role in biofilm formation. These findings suggest application of iutA and fimA gene suppressors in treatment of infections caused by biofilm-producing drug-resistant ST131 strains.}, }
@article {pmid39037271, year = {2024}, author = {Mookherjee, A and Mitra, M and Sason, G and Jose, PA and Martinenko, M and Pietrokovski, S and Jurkevitch, E}, title = {Flagellar stator genes control a trophic shift from obligate to facultative predation and biofilm formation in a bacterial predator.}, journal = {mBio}, volume = {}, number = {}, pages = {e0071524}, doi = {10.1128/mbio.00715-24}, pmid = {39037271}, issn = {2150-7511}, abstract = {UNLABELLED: The bacterial predator Bdellovibrio bacteriovorus is considered to be obligatorily prey (host)-dependent (H-D), and thus unable to form biofilms. However, spontaneous host-independent (H-I) variants grow axenically and can form robust biofilms. A screen of 350 H-I mutants revealed that single mutations in stator genes fliL or motA were sufficient to generate flagellar motility-defective H-I strains able to adhere to surfaces but unable to develop biofilms. The variants showed large transcriptional shifts in genes related to flagella, prey-invasion, and cyclic-di-GMP (CdG), as well as large changes in CdG cellular concentration relative to the H-D parent. The introduction of the parental fliL allele resulted in a full reversion to the H-D phenotype, but we propose that specific interactions between stator proteins prevented functional complementation by fliL paralogs. In contrast, specific mutations in a pilus-associated protein (Bd0108) mutant background were necessary for biofilm formation, including secretion of extracellular DNA (eDNA), proteins, and polysaccharides matrix components. Remarkably, fliL disruption strongly reduced biofilm development. All H-I variants grew similarly without prey, showed a strain-specific reduction in predatory ability in prey suspensions, but maintained similar high efficiency in prey biofilms. Population-wide allele sequencing suggested additional routes to host independence. Thus, stator and invasion pole-dependent signaling control the H-D and the H-I biofilm-forming phenotypes, with single mutations overriding prey requirements, and enabling shifts from obligate to facultative predation, with potential consequences on community dynamics. Our findings on the facility and variety of changes leading to facultative predation also challenge the concept of Bdellovibrio and like organisms being obligate predators.<br><br>IMPORTANCE: The ability of bacteria to form biofilms is a central research theme in biology, medicine, and the environment. We show that cultures of the obligate (host-dependent) "solitary" predatory bacterium Bdellovibrio bacteriovorus, which cannot replicate without prey, can use various genetic routes to spontaneously yield host-independent (H-I) variants that grow axenically (as a single species, in the absence of prey) and exhibit various surface attachment phenotypes, including biofilm formation. These routes include single mutations in flagellar stator genes that affect biofilm formation, provoke motor instability and large motility defects, and disrupt cyclic-di-GMP intracellular signaling. H-I strains also exhibit reduced predatory efficiency in suspension but high efficiency in prey biofilms. These changes override the requirements for prey, enabling a shift from obligate to facultative predation, with potential consequences on community dynamics.}, }
@article {pmid39035353, year = {2024}, author = {Zuberi, A and Ahmad, N and Ahmad, H and Saeed, M and Ahmad, I}, title = {Beyond antibiotics: CRISPR/Cas9 triumph over biofilm-associated antibiotic resistance infections.}, journal = {Frontiers in cellular and infection microbiology}, volume = {14}, number = {}, pages = {1408569}, pmid = {39035353}, issn = {2235-2988}, mesh = {*Biofilms/drug effects/growth &amp; development ; *CRISPR-Cas Systems ; *Anti-Bacterial Agents/pharmacology ; Humans ; Bacteria/drug effects/genetics ; Drug Resistance, Bacterial/genetics ; Bacterial Infections/microbiology/drug therapy ; Gene Editing ; }, abstract = {A complex structure known as a biofilm is formed when a variety of bacterial colonies or a single type of cell in a group sticks to a surface. The extracellular polymeric compounds that encase these cells, often consisting of proteins, eDNA, and polysaccharides, exhibit strong antibiotic resistance. Concerns about biofilm in the pharmaceutical industry, public health, and medical fields have sparked a lot of interest, as antibiotic resistance is a unique capacity exhibited by these biofilm-producing bacteria, which increases morbidity and death. Biofilm formation is a complicated process that is controlled by several variables. Insights into the processes to target for the therapy have been gained from multiple attempts to dissect the biofilm formation process. Targeting pathogens within a biofilm is profitable because the bacterial pathogens become considerably more resistant to drugs in the biofilm state. Although biofilm-mediated infections can be lessened using the currently available medications, there has been a lot of focus on the development of new approaches, such as bioinformatics tools, for both treating and preventing the production of biofilms. Technologies such as transcriptomics, metabolomics, nanotherapeutics and proteomics are also used to develop novel anti-biofilm agents. These techniques help to identify small compounds that can be used to inhibit important biofilm regulators. The field of appropriate control strategies to avoid biofilm formation is expanding quickly because of this spurred study. As a result, the current article addresses our current knowledge of how biofilms form, the mechanisms by which bacteria in biofilms resist antibiotics, and cutting-edge treatment approaches for infections caused by biofilms. Furthermore, we have showcased current ongoing research utilizing the CRISPR/Cas9 gene editing system to combat bacterial biofilm infections, particularly those brought on by lethal drug-resistant pathogens, concluded the article with a novel hypothesis and aspirations, and acknowledged certain limitations.}, }
@article {pmid39035281, year = {2024}, author = {Wongsuwanlert, M and Teanpaisan, R and Ruangsri, P and Kaewdech, A and Sunpaweravong, S and Pahumunto, N}, title = {Effect of mouthwash containing poly l-Lysine and glycerol monolaurate on oral Helicobacter pylori relating to biofilm eradication, anti-adhesion, and pro-inflammatory cytokine suppression.}, journal = {Journal of dental sciences}, volume = {19}, number = {3}, pages = {1748-1757}, pmid = {39035281}, issn = {2213-8862}, abstract = {BACKGROUND/PURPOSE: Helicobacter pylori has been found to be related to periodontitis, and the oral cavity has been considered a reservoir for H. pylori gastritis infection. Thus, this study evaluated the effect of mouthwash containing poly l-Lysine and glycerol monolaurate on inhibiting H. pylori growth, biofilm formation, cell cytotoxicity, adhesion ability, cagA mRNA expression, and pro-inflammatory cytokines stimulated by H. pylori.<br><br>MATERIALS AND METHODS: Nineteen H. pylori strains were isolated from the oral cavity. The effectiveness of mouthwash containing poly l-Lysine and glycerol monolaurate was examined for its ability to inhibit H. pylori growth and biofilm formation and was tested for cell viability in oral epithelial cells (H357), gastric adenocarcinoma cells (AGS), and periodontal ligament cells (PDL). Additionally, the mouthwash was tested for reducing cagA mRNA expression, adhesion ability to H357 and AGS cells, and pro-inflammatory cytokines stimulated with H. pylori in AGS and PDL cells.<br><br>RESULTS: The mouthwash containing poly l-Lysine and glycerol monolaurate could eradicate the biofilm by 14.9-19.9% after incubation at 5&#xa0;min, and cell viability revealed 77.2, 79.8, and 100.0% for AGS, H357, and PDL cells, respectively. Moreover, the mouthwash containing poly l-Lysine and glycerol monolaurate could down-regulate cagA mRNA expression, reduce adhesion of H. pylori by approximately 9.5-47.8% for H357&#xa0;cells and 24.5-62.9% for AGS cells, and decrease pro-inflammatory cytokines, especially interleukin-8, stimulated with H. pylori.<br><br>CONCLUSION: Mouthwash containing poly l-Lysine and glycerol monolaurate could inhibit H. pylori growth and reduce their virulence expression. The mouthwash also revealed low cytotoxicity to oral and gastric cells.}, }
@article {pmid39034023, year = {2024}, author = {Liu, Y and Dai, A and Xia, L and Zhou, Y and Ren, T and Huang, Y and Zhou, Y}, title = {Deciphering the roles of nitrogen source in sharping synchronous metabolic pathways of linear alkylbenzene sulfonate and nitrogen in a membrane biofilm for treating greywater.}, journal = {Environmental research}, volume = {260}, number = {}, pages = {119650}, doi = {10.1016/j.envres.2024.119650}, pmid = {39034023}, issn = {1096-0953}, abstract = {Nitrogen (N) source is an important factor affecting biological wastewater treatment. Although the oxygen-based membrane biofilm showed excellent greywater treatment performance, how N source impacts the synchronous removal of organics and N is still unclear. In this work, how N species (urea, nitrate and ammonia) affect synchronous metabolic pathways of organics and N were evaluated during greywater treatment in the membrane biofilm. Urea and ammonia achieved efficient chemical oxygen demand (>97.5%) and linear alkylbenzene sulfonate (LAS, >98.5%) removal, but nitrate enabled the maximum total N removal (80.8 ± 2.6%). The nitrate-added system had poor LAS removal ratio and high residual LAS, promoting the accumulation of effluent protein-like organics and fulvic acid matter. N source significantly induced bacterial community succession, and the increasing of corresponded functional flora can promote the transformation and utilization of microbial-mediated N. The nitrate system was more conducive to the accumulation of denitrification related microorganisms and enzymes, enabling the efficient N removal. Combining with high amount of ammonia monooxygenase that contributing to LAS and N co-metabolism, LAS mineralization related microbes and functional enzymes were generously accumulated in the urea and ammonia systems, which achieved the high efficiency of organics and LAS removal.}, }
@article {pmid39033146, year = {2024}, author = {Varin-Simon, J and Colin, M and Velard, F and Tang-Fichaux, M and Ohl, X and Mongaret, C and Gangloff, SC and Reffuveille, F}, title = {Cutibacterium acnes biofilm formation is influenced by bone microenvironment, implant surfaces and bacterial internalization.}, journal = {BMC microbiology}, volume = {24}, number = {1}, pages = {270}, pmid = {39033146}, issn = {1471-2180}, mesh = {*Biofilms/growth &amp; development ; *Titanium ; *Prosthesis-Related Infections/microbiology ; Humans ; Bacterial Adhesion ; Propionibacteriaceae/physiology/genetics/drug effects ; Prostheses and Implants/microbiology ; Bone and Bones/microbiology ; Plastics ; Alloys ; Surface Properties ; }, abstract = {BACKGROUND: The bacterial persistence, responsible for therapeutic failures, can arise from the biofilm formation, which possesses a high tolerance to antibiotics. This threat often occurs when a bone and joint infection is diagnosed after a prosthesis implantation. Understanding the biofilm mechanism is pivotal to enhance prosthesis joint infection (PJI) treatment and prevention. However, little is known on the characteristics of Cutibacterium acnes biofilm formation, whereas this species is frequently involved in prosthesis infections.<br><br>METHODS: In this study, we compared the biofilm formation of C. acnes PJI-related strains and non-PJI-related strains on plastic support and textured titanium alloy by (i) counting adherent and viable bacteria, (ii) confocal scanning electronic microscopy observations after biofilm matrix labeling and (iii) RT-qPCR experiments.<br><br>RESULTS: We highlighted material- and strain-dependent modifications of C. acnes biofilm. Non-PJI-related strains formed aggregates on both types of support but with different matrix compositions. While the proportion of polysaccharides signal was higher on plastic, the proportions of polysaccharides and proteins signals were more similar on titanium. The changes in biofilm composition for PJI-related strains was less noticeable. For all tested strains, biofilm formation-related genes were more expressed in biofilm formed on plastic that one formed on titanium. Moreover, the impact of C. acnes internalization in osteoblasts prior to biofilm development was also investigated. After internalization, one of the non-PJI-related strains biofilm characteristics were affected: (i) a lower quantity of adhered bacteria (80.3-fold decrease), (ii) an increase of polysaccharides signal in biofilm and (iii) an activation of biofilm gene expressions on textured titanium disk.<br><br>CONCLUSION: Taken together, these results evidenced the versatility of C. acnes biofilm, depending on the support used, the bone environment and the strain.}, }
@article {pmid39033094, year = {2024}, author = {Xu, KZ and You, C and Wang, YJ and Dar, OI and Yin, LJ and Xiang, SL and Jia, AQ}, title = {Repurposing promethazine hydrochloride to inhibit biofilm formation against Burkholderia thailandensis.}, journal = {Medical microbiology and immunology}, volume = {213}, number = {1}, pages = {16}, pmid = {39033094}, issn = {1432-1831}, support = {Qhyb2022-46//Innovative Research Projects for Postgraduates in Hainan Province/ ; Qhyb2021-38//Innovative Research Projects for Postgraduates in Hainan Province/ ; 82160664//National Natural Science Foundation of China/ ; 221CXTD434//Natural Science Foundation of Hainan Province/ ; }, mesh = {*Biofilms/drug effects/growth &amp; development ; *Burkholderia/drug effects/physiology/genetics ; *Promethazine/pharmacology ; *Drug Repositioning ; Molecular Docking Simulation ; Anti-Bacterial Agents/pharmacology ; Lipase/metabolism/genetics ; Gene Expression Regulation, Bacterial/drug effects ; Bacterial Proteins/genetics/metabolism ; Humans ; Quorum Sensing/drug effects ; }, abstract = {Melioidosis is a severe infectious disease caused by Burkholderia pseudomallei, an intracellular pathogen with a high mortality rate and significant antibiotic resistance. The high mortality rate and resistance to antibiotics have drawn considerable attention from researchers studying melioidosis. This study evaluated the effects of various concentrations (75, 50, and 25 µg/mL) of promethazine hydrochloride (PTZ), a potent antihistamine, on biofilm formation and lipase activity after 24 h of exposure to B. thailandensis E264. A concentration-dependent decrease in both biofilm biomass and lipase activity was observed. RT-PCR analysis revealed that PTZ treatment not only made the biofilm structure loose but also reduced the expression of btaR1, btaR2, btaR3, and scmR. Single gene knockouts of quorum sensing (QS) receptor proteins (∆btaR1, ∆btaR2, and ∆btaR3) were successfully constructed. Deletion of btaR1 affected biofilm formation in B. thailandensis, while deletion of btaR2 and btaR3 led to reduced lipase activity. Molecular docking and biological performance results demonstrated that PTZ inhibits biofilm formation and lipase activity by suppressing the expression of QS-regulated genes. This study found that repositioning PTZ reduced biofilm formation in B. thailandensis E264, suggesting a potential new approach for combating melioidosis.}, }
@article {pmid39033083, year = {2024}, author = {Junior, HLA and Assis, TM and Faria, EC and Costa, LRK and Ibaldo, BM}, title = {Piedraia hortae: biofilm formation and its importance in the pathogenesis of Piedra nigra (black piedra).}, journal = {Anais brasileiros de dermatologia}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.abd.2023.12.005}, pmid = {39033083}, issn = {1806-4841}, abstract = {BACKGROUND: Little is known about the ultrastructure of Piedraia hortae.<br><br>OBJECTIVE: To examine a P. hortae colony with scanning electron microscopy and investigate possible contributions to its pathogenesis.<br><br>RESULTS: On low magnifications, two distinct aspects of the colony are identified, a compact area and a filamentous area. Analysis of the filamentous area demonstrates hyphae adhered by a thin reticular substance. A recurring finding is the adhesion between the fungal filaments in parallel. On high magnifications, the micro fibrillar substance adhering the hyphae to each other becomes very evident. Examination of the compact area shows the hyphae embedded in the reticular matrix forming a biofilm and the colony well adhered. On high magnification, it can be observed that the hyphae are within this fibrillar matrix, which has the same appearance as the filamentous substance that adheres the hyphae to each other.<br><br>STUDY LIMITATIONS: Only one strain was examined.<br><br>CONCLUSIONS: The formation of biofilm with fungal structures and reticulated extracellular substance is important in the pathogenesis of Piedra nigra.}, }
@article {pmid39031267, year = {2024}, author = {Allami, M and Mohammed, EJ and Alnaji, Z and A Jassim, S}, title = {Antibiotic resistance and its correlation with biofilm formation and virulence genes in Klebsiella pneumoniae isolated from wounds.}, journal = {Journal of applied genetics}, volume = {}, number = {}, pages = {}, pmid = {39031267}, issn = {2190-3883}, abstract = {Klebsiella pneumoniae is the most important species of the Klebsiella genus and often causes hospital infections. These bacteria have a high resistance to most of the available drugs, which has caused concern all over the world. In this study, we investigated the antibiotic resistance profile and the ability to produce extended-spectrum beta-lactamase (ESBL) among K. pneumoniae isolates, and then we investigated the relationship between these two factors with biofilm formation and the prevalence of different virulence genes. In this study, 130 isolates of K. pneumoniae isolated from wounds were investigated. The antibiotic resistance of the isolates was evaluated by the disk diffusion method. The microtiter plate method was used to measure biofilm formation. The prevalence of virulence genes was detected by multiplex PCR. Among the examined isolates, 85.3% showed multidrug resistance. 87.6% of the isolates were ESBL-positive. Imipenem, meropenem, and fosfomycin were the most effective drugs. The ability of the isolates to produce biofilm was strong (80%), moderate (12.3%), and weak (7.6%), respectively. fimH, mrKD, entB, and tolC virulence genes were observed in all isolates. High prevalence of antibiotic resistance (especially multidrug resistance), high prevalence of ESBL-producing isolates, the ability of all isolates to biofilm formation, and the presence of fimH, mrKD, entB, and tolC virulence genes in all isolates show the importance of these factors in the pathogenesis of K. pneumoniae isolates in Iraq.}, }
@article {pmid39030869, year = {2024}, author = {Hou, Z and Ren, X and Sun, Z and An, R and Huang, M and Gao, C and Yin, M and Liu, G and He, D and Du, H and Tang, R}, title = {Trash into Treasure: Nano-coating of Catheter Utilizes Urine to Deprive H2S Against Persister and Rip Biofilm Matrix.}, journal = {Advanced healthcare materials}, volume = {}, number = {}, pages = {e2401067}, doi = {10.1002/adhm.202401067}, pmid = {39030869}, issn = {2192-2659}, support = {82101011,82260477//National Natural Science Foundation of China/ ; lzujbky-2022-ey19//Fundamental Research Funds for the Central Universities/ ; 20YF8WA084,20YF8FA073//Natural Science Foundation of Gansu Province of China/ ; 20JR10FA670//Scientific and Technological Foundation of Gansu Province/ ; GXH20220530-16//Gansu Association for Science and Technology/ ; 20JR10RA653-ZDKF20210301//open fund of Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, Gansu Province/ ; lzuyxcx-2022-182//Medical Innovation and Development Project of Lanzhou University/ ; lzukqky-2021-q01,lzukqky-2021-q07,lzukqky-2022-q03//Hospital of Stomatology Lanzhou University Scientific Research Project/ ; 2024B-003//Education Technology Innovation Project of Gansu Province in 2024/ ; PKUSS20200103//Youth Research Fund of Peking University School and Hospital of Stomatology/ ; }, abstract = {Bacteria-derived hydrogen sulfide (H2S) often contributes to the emergence of antibiotic-recalcitrant bacteria, especially persister (a sub-population of dormant bacteria), thus causing the treatment failure of Catheter-associated urinary tract infection (CAUTI). Here, an H2S harvester nanosystem to prevent the generation of persister bacteria and disrupt the dense biofilm matrix by the self-adaptive ability of shape-morphing is prepared. The nanosystem possesses a core-shell structure that is composed of liquid metal nanoparticle (LM NP), AgNPs, and immobilized urease. The nanosystem decomposes urea contained in urine to generate ammonia for eliminating bacteria-derived H2S. Depending on the oxidative layer of liquid metal, the nanosystem also constitutes a long-lasting reservoir for temporarily storing bacteria-derived H2S, when urease transiently overloads or in the absence of urine in a catheter. Depriving H2S can prevent the emergence of persistent bacteria, enhancing the bacteria-killing efficiency of Ga[3+] and Ag[+] ions. Even when the biofilm has formed, the urine flow provides heat to trigger shape morphing of the LM NP, tearing the biofilm matrix. Collectively, this strategy can turn trash (urea) into treasure (H2S scavengers and biofilm rippers), and provides a new direction for the antibacterial materials application in the medical field.}, }
@article {pmid39029506, year = {2024}, author = {Montoya-Hinojosa, EI and Villarreal-Treviño, L and Bocanegra-Ibarias, P and Camacho-Ortiz, A and Flores-Treviño, S}, title = {Drug Resistance in Biofilm and Planktonic Cells of Achromobacter spp., Burkholderia spp., and Stenotrophomonas maltophilia Clinical Isolates.}, journal = {Microbial drug resistance (Larchmont, N.Y.)}, volume = {}, number = {}, pages = {}, doi = {10.1089/mdr.2023.0301}, pmid = {39029506}, issn = {1931-8448}, abstract = {Background: Biofilm production in nonfermenting Gram-negative bacteria influences drug resistance. The aim of this work was to evaluate the effect of different antibiotics on biofilm eradication of clinical isolates of Achromobacter, Burkholderia, and Stenotrophomonas maltophilia. Methods: Clinical isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry in a third-level hospital in Monterrey, Mexico. Crystal violet staining was used to determine biofilm production. Drug susceptibility testing was determined by broth microdilution in planktonic cells and biofilm cells. Results: Resistance in planktonic cells was moderate to trimethoprim-sulfamethoxazole, and low to chloramphenicol, minocycline, levofloxacin (S. maltophilia and Burkholderia), ceftazidime, and meropenem (Burkholderia and Achromobacter). Biofilm eradication required higher drug concentrations of ceftazidime, chloramphenicol, levofloxacin, and trimethoprim-sulfamethoxazole than planktonic cells (p < 0.05). Levofloxacin showed biofilm eradication activity in S. maltophilia, minocycline and meropenem in Burkholderia, and meropenem in Achromobacter. Conclusions: Drug resistance increased due to biofilm production for some antibiotics, particularly ceftazidime and trimethoprim-sulfamethoxazole for all three pathogens, chloramphenicol for S. maltophilia and Burkholderia, and levofloxacin for Burkholderia. Some antibiotics could be used for the treatment of biofilm-associated infections in our population, such as levofloxacin for S. maltophilia, minocycline and meropenem for Burkholderia, and meropenem for Achromobacter.}, }
@article {pmid39028551, year = {2024}, author = {Malik, A and Oludiran, A and Poudel, A and Alvarez, OB and Woodward, C and Purcell, EB}, title = {RelQ-mediated alarmone signalling regulates growth, stress-induced biofilm formation and spore accumulation in Clostridioides difficile.}, journal = {Microbiology (Reading, England)}, volume = {170}, number = {7}, pages = {}, doi = {10.1099/mic.0.001479}, pmid = {39028551}, issn = {1465-2080}, mesh = {*Biofilms/growth &amp; development ; *Clostridioides difficile/genetics/metabolism/physiology/growth &amp; development ; *Spores, Bacterial/growth &amp; development/metabolism/genetics ; *Bacterial Proteins/genetics/metabolism ; *Gene Expression Regulation, Bacterial ; *Signal Transduction ; *Stress, Physiological ; Anti-Bacterial Agents/pharmacology ; Ligases/genetics/metabolism ; Gene Deletion ; Oxidative Stress ; }, abstract = {The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm formation in the presence of sublethal stress, the ΔrelQ strain cannot upregulate biofilm production in response to stress. Deletion of relQ slows spore accumulation in planktonic cultures but accelerates it in biofilms. This work establishes biofilm formation and spore accumulation as alarmone-mediated processes in C. difficile and reveals the importance of RelQ in stress-induced biofilm regulation.}, }
@article {pmid39027105, year = {2024}, author = {Wang, L and Liu, P and Wu, Y and Pei, H and Cao, X}, title = {Inhibitory effect of Lonicera japonica flos on Streptococcus mutans biofilm and mechanism exploration through metabolomic and transcriptomic analyses.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1435503}, pmid = {39027105}, issn = {1664-302X}, abstract = {INTRODUCTION: Streptococcus mutans was the primary pathogenic organism responsible for dental caries. Lonicera japonica flos (LJF) is a traditional herb in Asia and Europe and consumed as a tea beverage for thousands of years.<br><br>METHODS: The inhibitory effect and mechanism of LJF on biofilm formation by S. mutans was investigated. The active extracts of LJF were validated for their inhibitory activity by examining changes in surface properties such as adherence, hydrophobicity, auto-aggregation abilities, and exopolysaccharides (EPS) production, including water-soluble glucan and water-insoluble glucan.<br><br>RESULTS AND DISCUSSION: LJF primarily inhibited biofilm formation through the reduction of EPS production, resulting in alterations in cell surface characteristics and growth retardation in biofilm formation cycles. Integrated transcriptomic and untargeted metabolomics analyses revealed that EPS production was modulated through two-component systems (TCS), quorum sensing (QS), and phosphotransferase system (PTS) pathways under LJF stress conditions. The sensing histidine kinase VicK was identified as an important target protein, as LJF caused its dysregulated expression and blocked the sensing of autoinducer II (AI-2). This led to the inhibition of response regulator transcriptional factors, down-regulated glycosyltransferase (Gtf) activity, and decreased production of water-insoluble glucans (WIG) and water-soluble glucans (WSG). This is the first exploration of the inhibitory effect and mechanism of LJF on S. mutans, providing a theoretical basis for the application of LJF in functional food, oral health care, and related areas.}, }
@article {pmid39026137, year = {2024}, author = {Jagaba, AH and Abdulazeez, I and Lawal, DU and Affam, AC and Mu'azu, ND and Soja, UB and Usman, AK and Noor, A and Lim, JW and Aljundi, IH}, title = {A review on the application of biochar as an innovative and sustainable biocarrier material in moving bed biofilm reactors for dye removal from environmental matrices.}, journal = {Environmental geochemistry and health}, volume = {46}, number = {9}, pages = {333}, pmid = {39026137}, issn = {1573-2983}, mesh = {*Charcoal/chemistry ; *Biofilms ; *Coloring Agents/chemistry ; *Bioreactors ; Water Pollutants, Chemical ; Biodegradation, Environmental ; Waste Disposal, Fluid/methods ; }, abstract = {Dye decolorization through biological treatment techniques has been gaining momentum as it is based on suspended and attached growth biomass in both batch and continuous modes. Hence, this review focused on the contribution of moving bed biofilm reactors (MBBR) in dye removal. MBBR have been demonstrated to be an excellent technology for pollution extraction, load shock resistance, and equipment size and energy consumption reduction. The review went further to highlight different biocarrier materials for biofilm development this review identified biochar as an innovative and environmentally friendly material produced through the application of different kinds of reusable or recyclable wastes and biowastes. Biochar as a carbonized waste biomass could be a better competitor and environmentally friendly substitute to activated carbon given its lower mass costs. Biochar can be easily produced particularly in rural locations where there is an abundance of biomass-based trash. Given that circular bioeconomy lowers dependency on natural resources by turning organic wastes into an array of useful products, biochar empowers the creation of competitive goods. Thus, biochar was identified as a novel, cost-effective, and long-term management strategy since it brings about several essential benefits, including food security, climate change mitigation, biodiversity preservation, and sustainability improvement. This review concludes that integrating two treatment methods could greatly lead to better color, organic matter, and nutrients removal than a single biological MBBR treatment process.}, }
@article {pmid39024943, year = {2024}, author = {Wang, X and Chen, C and Hu, J and Liu, C and Ning, Y and Lu, F}, title = {Current strategies for monitoring and controlling bacterial biofilm formation on medical surfaces.}, journal = {Ecotoxicology and environmental safety}, volume = {282}, number = {}, pages = {116709}, doi = {10.1016/j.ecoenv.2024.116709}, pmid = {39024943}, issn = {1090-2414}, abstract = {Biofilms, intricate microbial communities that attach to surfaces, especially medical devices, form an exopolysaccharide matrix, which enables bacteria to resist environmental pressures and conventional antimicrobial agents, leading to the emergence of multi-drug resistance. Biofilm-related infections associated with medical devices are a significant public health threat, compromising device performance. Therefore, developing effective methods for supervising and managing biofilm growth is imperative. This in-depth review presents a systematic overview of strategies for monitoring and controlling bacterial biofilms. We first outline the biofilm creation process and its regulatory mechanisms. The discussion then progresses to advancements in biosensors for biofilm detection and diverse treatment strategies. Lastly, this review examines the obstacles and new perspectives associated with this domain to facilitate the advancement of innovative monitoring and control solutions. These advancements are vital in combating the spread of multi drug-resistant bacteria and mitigating public health risks associated with infections from biofilm formation on medical instruments.}, }
@article {pmid39023225, year = {2024}, author = {Zhao, L and Li, W and Liu, Y and Qi, Y and An, N and Yan, M and Wang, Z and Zhou, M and Yang, S}, title = {Designing Fast-Moving Antibacterial Microtorpedoes to Treat Lethal Bacterial Biofilm Infections.}, journal = {ACS nano}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsnano.4c04995}, pmid = {39023225}, issn = {1936-086X}, abstract = {Engineering fast-moving microrobot swarms that can physically disassemble bacterial biofilms and kill the bacteria released from the biofilms is a promising way to combat bacterial biofilm infections. Here, we report electrochemical design of Ag7O8NO3 microtorpedoes with outstanding antibacterial performance and meanwhile capable of moving at speeds of hundreds of body lengths per second in clinically used H2O2 aqueous solutions. These fast-moving antibacterial Ag7O8NO3 microtorpedoes could penetrate into and disintegrate the bacterial biofilms and, in turn, kill the bacteria released from the biofilms. Based on the understanding of the growth behavior of the microtorpedoes, we could fine-tune the morphology of the microtorpedoes to accelerate the moving speed and increase their penetration depth into the biofilms simply via controlling the potential waveforms. We further developed an automatic shaking method to selectively peel off the uniformly structured microtorpedoes from the electrode surface, realizing continuous electrochemical production of the microtorpedoes. Animal experiments proved that the microtorpedo swarms greatly increased the survival rate of the mice infected by lethal biofilms to >90%. We used the electrochemical method to design and massively produce uniformly structured fast-moving antibacterial microtorpedo swarms with application potentials in treatment of lethal bacterial biofilm infections.}, }
@article {pmid39023091, year = {2024}, author = {Li, C and Gao, D and Li, C and Cheng, G and Zhang, L}, title = {Fighting against biofilm: The antifouling and antimicrobial material.}, journal = {Biointerphases}, volume = {19}, number = {4}, pages = {}, doi = {10.1116/6.0003695}, pmid = {39023091}, issn = {1559-4106}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Biofouling/prevention &amp; control ; *Anti-Infective Agents/pharmacology/chemistry ; Biocompatible Materials/chemistry/pharmacology ; Anti-Bacterial Agents/pharmacology/chemistry ; }, abstract = {Biofilms are groups of microorganisms protected by self-secreted extracellular substances. Biofilm formation on the surface of biomaterial or engineering materials becomes a severe challenge. It has caused significant health, environmental, and societal concerns. It is believed that biofilms lead to life-threatening infection, medical implant failure, foodborne disease, and marine biofouling. To address these issues, tremendous effort has been made to inhibit biofilm formation on materials. Biofilms are extremely difficult to treat once formed, so designing material and coating bearing functional groups that are capable of resisting biofilm formation has attracted increasing attention for the last two decades. Many types of antibiofilm strategies have been designed to target different stages of biofilm formation. Development of the antibiofilm material can be classified into antifouling material, antimicrobial material, fouling release material, and integrated antifouling/antimicrobial material. This review summarizes relevant research utilizing these four approaches and comments on their antibiofilm properties. The feature of each method was compared to reveal the research trend. Antibiofilm strategies in fundamental research and industrial applications were summarized.}, }
@article {pmid39021701, year = {2024}, author = {Andersen, JB and Rybtke, M and Tolker-Nielsen, T}, title = {The dynamics of biofilm development and dispersal should be taken into account when quantifying biofilm via the crystal violet microtiter plate assay.}, journal = {Biofilm}, volume = {8}, number = {}, pages = {100207}, pmid = {39021701}, issn = {2590-2075}, abstract = {The crystal violet microtiter plate biofilm assay is often used to compare the amount of biofilm formed by a mutant versus wild-type or a compound-treated biofilm versus the non-treatment control. In many of these studies the amount of biofilm is assessed only at one single time point. However, if the dynamics of biofilm development of the mutant (or compound-treated biofilm) is different than that of the wild-type (or non-treatment control), then biofilm quantification at a single time point may give misleading results. To overcome this shortcoming of the common biofilm quantification technique, we recommend to use a serial dilution-based crystal violet microtiter plate biofilm assay for easy assessment of the dynamics of biofilm development and dispersal. We demonstrate that the dilution-resolved crystal violet assay displays the dynamics of Pseudomonas aeruginosa biofilm development and dispersal as efficient as a time-resolved crystal violet assay. In addition, focusing on mutants of different parts of the c-di-GMP signaling system in P. aeruginosa, we provide an example illustrating the need to assess biofilm dynamics instead of quantifying biofilm biomass at a single time point.}, }
@article {pmid39021314, year = {2024}, author = {Gomes Guimarães, G and Alves, F and Gonçalves, I and Silva E Carvalho, I and Toneth Ponce Ayala, E and Pratavieira, S and Salvador Bagnato, V}, title = {The synergistic effect of photodynamic and sonodynamic inactivation against Candida albicans biofilm.}, journal = {Journal of biophotonics}, volume = {}, number = {}, pages = {e202400190}, doi = {10.1002/jbio.202400190}, pmid = {39021314}, issn = {1864-0648}, support = {001//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento Pessoal de N&#xed;vel Superior (CAPES)/ ; 465&#x2009;360/2014-9//National Council for Scientific and Technological Development-CNPq/ ; 306919/2019-2//National Council for Scientific and Technological Development-CNPq/ ; 305072/2022-6//National Council for Scientific and Technological Development-CNPq/ ; 131017/2022-5//National Council for Scientific and Technological Development-CNPq/ ; 440237/2021-1//National Council for Scientific and Technological Development-CNPq/ ; 2013/07276-1//S&#xe3;o Paulo Research Foundation (FAPESP)/ ; 2014/50857-8//S&#xe3;o Paulo Research Foundation (FAPESP)/ ; 2021/01324-0//S&#xe3;o Paulo Research Foundation (FAPESP)/ ; }, abstract = {Candida albicans biofilm can cause diseases that are resistant to conventional antifungal agents. Photodynamic (PDI), sonodynamic (SDI), and sonophotodynamic (SPDI) inactivation have arisen as promising antimicrobial strategies. This study evaluated these treatments mediated by curcumin against C. albicans biofilms. For this, C. albicans biofilms were submitted to PDI, SDI, or SPDI with different light and ultrasound doses, then, the viability assay was performed to measure the effectiveness. Finally, a mathematical model was suggested to fit acquired experimental data and understand the synergistic effect of light and ultrasound in different conditions. The results showed that SPDI, PDI, and SDI reduced the viability in 6 ± 1; 1 ± 1; and 2 ± 1 log, respectively, using light at 60 J/cm[2], ultrasound at 3 W/cm[2], and 80 μM of curcumin. The viability reduction was proportional to the ultrasound and light doses delivered. These results encourage the use of SPDI for the control of microbial biofilm.}, }
@article {pmid39021233, year = {2024}, author = {Emiliano, JVDS and Fusieger, A and Camargo, AC and Rodrigues, FFDC and Nero, LA and Perrone, &#xcd;T and Carvalho, AF}, title = {Staphylococcus aureus in Dairy Industry: Enterotoxin Production, Biofilm Formation, and Use of Lactic Acid Bacteria for Its Biocontrol.}, journal = {Foodborne pathogens and disease}, volume = {}, number = {}, pages = {}, doi = {10.1089/fpd.2023.0170}, pmid = {39021233}, issn = {1556-7125}, abstract = {Staphylococcus aureus is a well-known pathogen capable of producing enterotoxins during bacterial growth in contaminated food, and the ingestion of such preformed toxins is one of the major causes of food poisoning around the world. Nowadays 33 staphylococcal enterotoxins (SEs) and SE-like toxins have been described, but nearly 95% of confirmed foodborne outbreaks are attributed to classical enterotoxins SEA, SEB, SEC, SED, and SEE. The natural habitat of S. aureus includes the skin and mucous membranes of both humans and animals, allowing the contamination of milk, its derivatives, and the processing facilities. S. aureus is well known for the ability to form biofilms in food processing environments, which contributes to its persistence and cross-contamination in food. The biocontrol of S. aureus in foods by lactic acid bacteria (LAB) and their bacteriocins has been studied for many years. Recently, LAB and their metabolites have also been explored for controlling S. aureus biofilms. LAB are used in fermented foods since in ancient times and nowadays characterized strains (or their purified bacteriocin) can be intentionally added to prolong food shelf-life and to control the growth of potentially pathogenic bacteria. Regarding the use of these microorganism and their metabolites (such as organic acids and bacteriocins) to prevent biofilm development or for biofilm removal, it is possible to conclude that a complex network behind the antagonistic activity remains poorly understood at the molecular level. The use of approaches that allow the characterization of these interactions is necessary to enhance our understanding of the mechanisms that govern the inhibitory activity of LAB against S. aureus biofilms in food processing environments.}, }
@article {pmid39020257, year = {2024}, author = {Zarei, M and Ghahfarokhi, MG and Sabaeian, M and Sepahi, M and Alirezaie, S and Mohebi, M}, title = {Effect of plasma-activated water on planktonic and biofilm cells of Vibrio parahaemolyticus strains isolated from cutting board surfaces in retail seafood markets.}, journal = {Journal of applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jambio/lxae182}, pmid = {39020257}, issn = {1365-2672}, abstract = {AIMS: This research aimed to analyze cutting board surfaces in seafood markets to find Vibrio parahaemolyticus, assess the isolates' ability to form biofilms, generate and evaluate characteristics of plasma-activated water (PAW), and compare the effect of PAW on planktonic and biofilm cells of the isolated V. parahaemolyticus strains.<br><br>METHODS AND RESULTS: A total of 11 V. parahaemolyticus strains were isolated from 8.87% of the examined cutting boards. Biofilm-forming ability was evaluated for these isolates at temperatures of 10, 20, and 30&#xb0;C using crystal violet staining. Four strains with the highest biofilm potential were selected for further analysis. The pH of the PAW used in the study was 3.41&#xb1;0.04, and the initial concentrations of hydrogen peroxide, nitrate, and nitrite were 108&#xb1;9.6 &#xb5;M, 742&#xb1;61 &#xb5;M, and 36.3&#xb1;2.9 &#xb5;M, respectively. However, these concentrations decreased significantly within 3-4 days during storage at room temperature. PAW exhibited significant antimicrobial effects on V. parahaemolyticus planktonic cells, reducing viable bacteria up to 4.54 log CFU/ml within 20 minutes. PAW also reduced the number of biofilm cells on stainless steel (up to 3.55 log CFU/cm2) and high-density polyethylene (up to 3.06 log CFU/cm2) surfaces, although to a lesser extent than planktonic cells.<br><br>CONCLUSIONS: PAW exhibited significant antibacterial activity against V. parahaemolyticus cells, although its antibacterial properties diminished over time. Furthermore, the antibacterial activity of PAW against biofilm cells of V. parahaemolyticus was less pronounced compared to the planktonic cells. Therefore, the actual effectiveness of PAW in seafood processing environments can be affected by biofilms that may form on various surfaces such as cutting boards if they are not cleaned properly.}, }
@article {pmid39020245, year = {2024}, author = {Huang, Z and Li, Y and Yin, W and Raby, RBN and Liang, H and Yu, B}, title = {A magnetic-guided nano-antibacterial platform for alternating magnetic field controlled vancomycin release in staphylococcus aureus biofilm eradication.}, journal = {Drug delivery and translational research}, volume = {}, number = {}, pages = {}, pmid = {39020245}, issn = {2190-3948}, support = {81974323//National Natural Science Foundation of China/ ; 2020A1515010055//Natural Science Foundation of Guangdong Province/ ; zdyf201993//Science and Technology Development Plan Project of Chenzhou/ ; }, abstract = {Bacterial resilience within biofilms, rendering them up to 1000 times more resistant to antibiotic drugs, poses a formidable challenge. This study introduces a targeted biofilm eradication strategy, termed "target-penetration-killing-eradication", implemented through magnetic micro-robotic technology. Specifically, we present the development of a magnetic-guided nano-antibacterial platform designed for alternating magnetic field (AMF) controlled vancomycin release in the eradication of Staphylococcus aureus biofilms. To address the issue of premature vancomycin release in physiological conditions, we employed a temperature-sensitive linking agent, 4,4'-azobis(4-cyano valeric acid), facilitating the conjugation of vancomycin onto Fe3O4/CS nanocomposites, resulting in the novel construct Fe3O4@CS-ACVA-VH. The release mechanism adheres to first-order kinetics and Fickian diffusion, with each 10-min AMF treatment releasing approximately 8.4 ± 1.1% of vancomycin. The potency of vancomycin in the release solution was similar to that of the original drug (MIC: 7.4 ± 3.5 vs. 5.6 μg/mL). Fe3O4@CS-ACVA-VH exhibited sustained antibacterial efficacy, inhibiting bacterial growth for four consecutive days and preventing the formation of bacterial biofilms on its surface. Contact-inhibition bacterial activity of Fe3O4@CS-ACVA-VH against S. aureus was 0.046875 mg/mL. Conceptually validating our approach, we emphasize Fe3O4@CS-ACVA-VH's exceptional ability to penetrate S. aureus biofilms under static magnetic field attraction. Furthermore, the nano-platform offers the unique advantage of on-demand vancomycin release through alternating magnetic field stimulation, effectively clearing a larger biofilm area. This multifunctional nano-platform demonstrates magnetic-guided biofilm penetration followed by controlled vancomycin release, presenting a promising strategy for enhanced biofilm eradication.}, }
@article {pmid39019725, year = {2024}, author = {Bueno, FL and Badaró, MM and Pagnano, VO and Curylofo, PA and Oliveira, VC and Macedo, AP and Watanabe, E and Paranhos, HFO and Silva-Lovato, CH}, title = {Effect of disinfectants on multispecies biofilm, the physical and mechanical properties of polymethyl methacrylate, and the corrosion of cobalt chromium alloy.}, journal = {The Journal of prosthetic dentistry}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.prosdent.2024.06.019}, pmid = {39019725}, issn = {1097-6841}, abstract = {STATEMENT OF PROBLEM: The optimal disinfection protocol that controls adverse effects and promotes effective antimicrobial action on removable prostheses is unclear.<br><br>PURPOSE: This in vitro study investigated the effect of disinfectant solutions on the biological, physical, mechanical, and chemical properties of removable prosthesis materials.<br><br>MATERIAL AND METHODS: Specimens of polymethyl methacrylate (PMMA) and cobalt chromium (Co-Cr) alloy were immersed in distilled water (PMMA) or artificial saliva (Co-Cr) as the control and in 0.25% sodium hypochlorite (NaOCl0.25%), 0.5% chloramine T (CT0.5%), and 0.15% Triclosan (TR0.15%). The antibiofilm activity was evaluated by microbial load and cell metabolisms of the mixed biofilm. Physical (color change, sorption, solubility, and surface roughness), mechanical (hardness, flexural, and impact strength), and chemical (corrosion) properties were analyzed before and after simulating a 5-year immersion. Laser confocal microscopy, scanning electron microscopy (SEM), and dispersive energy spectroscopy (EDS) complemented the analyses. The data were analyzed by using the Mann-Whitney U test, Kruskal-Wallis with Dunn posttests, 1-way ANOVA, and repeated measures ANOVA (&#x3b1;=.05).<br><br>RESULTS: All solutions were effective against bacteria, but only NaOCl0.25% eliminated Candida spp. TR0.15%, and CT0.5% increased cell metabolisms. For interaction (time and solution), there was a reduction in PMMA hardness in the control and TR0.15%. Color, sorption, solubility, and flexural strength did not change. CT0.5% and TR0.15% were similar for impact resistance. CT0.5% caused the lowest roughness. NaOCl0.25% showed the greatest corrosive potential. Dark spots were seen under SEM in Co-Cr stored with NaOCl0.25% and TR0.15%. EDS indicated different proportions of oxygen, cobalt, chromium, and molybdenum.<br><br>CONCLUSIONS: NaOCl0.25% had the best antimicrobial action. CT0.5% and TR0.15% have potential. Hardness and roughness changes were clinically acceptable, and the other properties remained unchanged. All the solutions caused color changes. NaOCl0.25% was unsatisfactory for use with Co-Cr, CT0.5% was intermediate, and TR0.15% was suitable.}, }
@article {pmid39019323, year = {2024}, author = {Siu, SY and Pudipeddi, A and Vishwanath, V and Cheng Lee, AH and Tin Cheung, AW and Pan Cheung, GS and Neelakantan, P}, title = {Effect of Novel and Traditional Intracanal Medicaments on Biofilm Viability and Composition.}, journal = {Journal of endodontics}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.joen.2024.07.003}, pmid = {39019323}, issn = {1878-3554}, abstract = {INTRODUCTION: The aim of this study was to test the hypothesis that a combination of D-amino acids (DAA) and trans-cinnamaldehyde (TC) demonstrates superior antibiofilm activity to calcium hydroxide (CH) and untreated controls.<br><br>METHODS: In this 3-part in vitro study, the concentration of DAAs (D-methionine, D-leucine, D-tyrosine, and D-tryptophan) that would significantly decrease Enterococcus faecalis and Actinomyces naeslundii biofilm biomass was first determined. Then, the effect of TC + selected DAAs on polymicrobial biofilms was characterized by quantifying the biomass and biofilm viability. Finally, the antibiofilm effects of TC+DAA was compared with CH and untreated controls by (i) determining bacterial viability and (ii) quantifying biofilm matrix composition using selective fluorescence-binding analysis. Statistical analysis was performed using one-way ANOVA and appropriate multiple comparisons test, with P<.05 considered as statistically significant.<br><br>RESULTS: TC (0.06%) + D-tyrosine (1 mM) + D-tryptophan (25 mM) significantly reduced the biomass and biofilm viability compared to the control (P<.05). While no significant difference was observed between TC+DAA and CH in the cultivable bacterial counts (P>.05), confocal microscopy demonstrated a significantly greater percentage of dead bacteria in TC+DAA-treated biofilms compared to CH and the control (P<.05). TC+DAA significantly decreased the biovolume and all the examined components of the biofilm matrix quantity compared to the control, while CH significantly reduced only the exopolysaccharide quantity (P<.05).<br><br>CONCLUSION: TC + D-tyrosine + D-tryptophan demonstrated superior antibiofilm activity (biofilm bacterial killing and reduction of matrix quantity) to CH and has potential to be developed as an intracanal medicament.}, }
@article {pmid39017726, year = {2024}, author = {Carvalho, FS and Tarabal, VS and Livio, DF and Cruz, LF and Monteiro, APF and Parreira, AG and Guimarães, PPG and Scheuerman, K and Chagas, RCR and da Silva, JA and Gonçalves, DB and Granjeiro, JM and Sinisterra, RD and Segura, MEC and Granjeiro, PA}, title = {Production and characterization of the lipopeptide with anti-adhesion for oral biofilm on the surface of titanium for dental implants.}, journal = {Archives of microbiology}, volume = {206}, number = {8}, pages = {354}, pmid = {39017726}, issn = {1432-072X}, support = {APQ- 00855-19//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de Minas Gerais/ ; 306076/2017-9//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; 001//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; }, mesh = {*Titanium/pharmacology/chemistry ; *Biofilms/drug effects/growth &amp; development ; *Bacterial Adhesion/drug effects ; *Dental Implants/microbiology ; *Lipopeptides/pharmacology ; *Microbial Sensitivity Tests ; Humans ; Anti-Bacterial Agents/pharmacology ; Staphylococcus aureus/drug effects/physiology ; Bacillus subtilis/drug effects ; Porphyromonas gingivalis/drug effects/physiology/growth &amp; development ; Aggregatibacter actinomycetemcomitans/drug effects ; Surface Properties ; Fibroblasts/drug effects ; Fusobacterium nucleatum/drug effects ; Cell Survival/drug effects ; Osteoblasts/drug effects ; Surface-Active Agents/pharmacology ; }, abstract = {Titanium implants are subject to bacterial adhesion and peri-implantitis induction, and biosurfactants bring a new alternative to the fight against infections. This work aimed to produce and characterize the biosurfactant from Bacillus subtilis ATCC 19,659, its anti-adhesion and antimicrobial activity, and cell viability. Anti-adhesion studies were carried out against Streptococcus sanguinis, Staphylococcus aureus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Proteus mirabilis as the minimum inhibitory concentration and the minimum bactericidal concentration. Cell viability was measured against osteoblast and fibroblast cells. The biosurfactant was classified as lipopeptide, with critical micelle concentration at 40 µg mL[- 1], and made the titanium surface less hydrophobic. The anti-adhesion effect was observed for Staphylococcus aureus and Streptococcus sanguinis with 54% growth inhibition and presented a minimum inhibitory concentration of 15.7 µg mL[- 1] for Streptococcus sanguinis and Aggregatibacter actinomycetemcomitans. The lipopeptide had no cytotoxic effect and demonstrated high potential application against bacterial biofilms.}, }
@article {pmid39015665, year = {2024}, author = {Tian, Z and Xiong, Y and Li, G and Cao, X and Li, X and Du, C and Zhang, L}, title = {Food wastewater treatment using a hybrid biofilm reactor: nutrient removal performance and functional microorganisms on filler biofilm and suspended sludge.}, journal = {RSC advances}, volume = {14}, number = {31}, pages = {22470-22479}, pmid = {39015665}, issn = {2046-2069}, abstract = {In this study, a laboratory-scale hybrid biofilm reactor (HBR) was constructed to treat food wastewater (FWW) before it is discharged into the sewer. The chemical oxygen demand (COD) of 29 860 mg L[-1] in FWW was degraded to 200-350 mg L[-1] using the HBR under the operating parameters of COD load 1.68 kg m[-3] d[-1], hydraulic retention time (HRT) of 426.63 h, dissolved oxygen (DO) of 8-9 mg L[-1], and temperature of 22-23 °C. The biomass of biofilm on the surface of filler was 2.64 g L[-1] for column A and 0.91 g L[-1] for column O. Microbial analysis revealed richer and more diverse microorganisms in filler biofilms compared to those in suspended sludge. The hybrid filler was conducive to the development of functional microbial species, including phyla Firmicutes, Actinobacteriota, and Chloroflexi, and genus level norank_f_JG30-KF-CM45, which will improve FWW treatment efficiency. Moreover, the microorganisms on the filler biofilm had more connections and relationships than those in the suspended sludge. The combination of an up-flow anaerobic sludge bed (UASB) and HBR was demonstrated to be an economical strategy for practical applications as a shorter HRT of 118.34 h could be obtained. Overall, this study provides reliable data and a theoretical basis for the application of HBR and FWW treatments.}, }
@article {pmid39014985, year = {2024}, author = {Duggan DiDominic, KL and Shapleigh, JP and Walter, MT and Wang, YS and Reid, MC and Regan, JM}, title = {Microbial diversity and gene abundance in denitrifying bioreactors: A comparison of the woodchip surface biofilm versus the interior wood matrix.}, journal = {Journal of environmental quality}, volume = {}, number = {}, pages = {}, doi = {10.1002/jeq2.20600}, pmid = {39014985}, issn = {1537-2537}, support = {1922551//National Science Foundation Research Traineeship (NRT) Program/ ; 2019-67019-29461//U.S. Department of Agriculture/ ; }, abstract = {Excessive amounts of nitrogen (N) and phosphorus (P) can lead to eutrophication in water sources. Woodchip bioreactors have shown success in removing N from agricultural runoff, but less is known regarding P removal. Woodchip bioreactors are subsurface basins filled with woodchips installed downgradient of agricultural land to collect and treat drainage runoff. Microorganisms use the woodchips as a carbon (C) source to transform N in the runoff, with unresolved biological impacts on P. This study aims to explore microbial communities present in the bioreactor and determine whether milling woodchips to probe the microbial communities within them reveals hidden microbial diversities or potential activities. Metagenomic sequencing and bioinformatic analyses were performed on six woodchip samples (i.e., three unmilled and three milled) collected from a 10-year-old woodchip bioreactor treating agricultural tile drainage. All samples had similar DNA purity, yield, quality, and microbial diversity regardless of milling. However, when sequences were aligned against various protein libraries, our results indicated greater relative abundance of denitrification and P transformation proteins on the outside of the woodchips (unmilled), while the interior of woodchips (milled) exhibited more functional gene abundance for carbohydrate breakdown. Thus, it may be important to characterize microbial communities both within woodchips, and on woodchip surfaces, to gain a more holistic understanding of coupled biogeochemical cycles on N, P, and C in woodchip bioreactors. Based on these findings, we advise that future microbial research on woodchips (and potentially other permeable organic materials) examine both the surface biofilm and the interior organic material during initial studies. Once researchers determine where specific proteins or enzymes of interest are most prevalent, subsequent studies may then focus on either one or both aspects, as needed.}, }
@article {pmid39012538, year = {2024}, author = {Tang, D and Lin, Y and Yao, H and Liu, Y and Xi, Y and Li, M and Mao, A}, title = {Effect of L-HSL on biofilm and motility of Pseudomonas aeruginosa and its mechanism.}, journal = {Applied microbiology and biotechnology}, volume = {108}, number = {1}, pages = {418}, pmid = {39012538}, issn = {1432-0614}, support = {12065001//12065001/ ; 32160025//32160025/ ; }, mesh = {*Pseudomonas aeruginosa/drug effects/physiology/genetics ; *Biofilms/drug effects/growth &amp; development ; *Quorum Sensing/drug effects ; *Caenorhabditis elegans/drug effects/microbiology ; Animals ; *4-Butyrolactone/analogs &amp; derivatives/pharmacology/metabolism ; Anti-Bacterial Agents/pharmacology ; Gene Expression Profiling ; Homoserine/analogs &amp; derivatives/metabolism/pharmacology ; Gene Expression Regulation, Bacterial/drug effects ; }, abstract = {Pseudomonas aeruginosa (P. aeruginosa) biofilm formation is a crucial cause of enhanced antibiotic resistance. Quorum sensing (QS) is involved in regulating biofilm formation; QS inhibitors block the QS signaling pathway as a new strategy to address bacterial resistance. This study investigated the potential and mechanism of L-HSL (N-(3-cyclic butyrolactone)-4-trifluorophenylacetamide) as a QS inhibitor for P. aeruginosa. The results showed that L-HSL effectively inhibited the biofilm formation and dispersed the pre-formed biofilm of P. aeruginosa. The production of extracellular polysaccharides and the motility ability of P. aeruginosa were suppressed by L-HSL. C. elegans infection experiment showed that L-HSL was non-toxic and provided protection to C. elegans against P. aeruginosa infection. Transcriptomic analysis revealed that L-HSL downregulated genes related to QS pathways and biofilm formation. L-HSL exhibits a promising potential as a therapeutic drug for P. aeruginosa infection. KEY POINTS: • Chemical synthesis of N-(3-cyclic butyrolactone)-4-trifluorophenylacetamide, named L-HSL. • L-HSL does not generate survival pressure on the growth of P. aeruginosa and can inhibit the QS system. • KEGG enrichment analysis found that after L-HSL treatment, QS-related genes were downregulated.}, }
@article {pmid39012148, year = {2024}, author = {Ayala, JC and Balthazar, JT and Shafer, WM}, title = {Transcriptional responses of Neisseria gonorrhoeae to glucose and lactate: implications for resistance to oxidative damage and biofilm formation.}, journal = {mBio}, volume = {}, number = {}, pages = {e0176124}, doi = {10.1128/mbio.01761-24}, pmid = {39012148}, issn = {2150-7511}, support = {IK6 BX005390/BX/BLRD VA/United States ; R01 AI021150/AI/NIAID NIH HHS/United States ; }, abstract = {Understanding how bacteria adapt to different environmental conditions is crucial for advancing knowledge regarding pathogenic mechanisms that operate during infection as well as efforts to develop new therapeutic strategies to cure or prevent infections. Here, we investigated the transcriptional response of Neisseria gonorrhoeae, the causative agent of gonorrhea, to L-lactate and glucose, two important carbon sources found in the host environment. Our study revealed extensive transcriptional changes that gonococci make in response to L-lactate, with 37% of the gonococcal transcriptome being regulated, compared to only 9% by glucose. We found that L-lactate induces a transcriptional program that would negatively impact iron transport, potentially limiting the availability of labile iron, which would be important in the face of the multiple hydrogen peroxide attacks encountered by gonococci during its lifecycle. Furthermore, we found that L-lactate-mediated transcriptional response promoted aerobic respiration and dispersal of biofilms, contrasting with an anaerobic condition previously reported to favor biofilm formation. Our findings suggest an intricate interplay between carbon metabolism, iron homeostasis, biofilm formation, and stress response in N. gonorrhoeae, providing insights into its pathogenesis and identifying potential therapeutic targets.IMPORTANCEGonorrhea is a prevalent sexually transmitted infection caused by the human pathogen Neisseria gonorrhoeae, with ca. 82 million cases reported worldwide annually. The rise of antibiotic resistance in N. gonorrhoeae poses a significant public health threat, highlighting the urgent need for alternative treatment strategies. By elucidating how N. gonorrhoeae responds to host-derived carbon sources such as L-lactate and glucose, this study offers insights into the metabolic adaptations crucial for bacterial survival and virulence during infection. Understanding these adaptations provides a foundation for developing novel therapeutic approaches targeting bacterial metabolism, iron homeostasis, and virulence gene expression. Moreover, the findings reported herein regarding biofilm formation and L-lactate transport and metabolism contribute to our understanding of N. gonorrhoeae pathogenesis, offering potential avenues for preventing and treating gonorrhea infections.}, }
@article {pmid39012136, year = {2024}, author = {Motta, EVS and de Jong, TK and Gage, A and Edwards, JA and Moran, NA}, title = {Glyphosate effects on growth and biofilm formation in bee gut symbionts and diverse associated bacteria.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0051524}, doi = {10.1128/aem.00515-24}, pmid = {39012136}, issn = {1098-5336}, abstract = {UNLABELLED: Biofilm formation is a common adaptation enabling bacteria to thrive in various environments and withstand external pressures. In the context of host-microbe interactions, biofilms play vital roles in establishing microbiomes associated with animals and plants and are used by opportunistic microbes to facilitate survival within hosts. Investigating biofilm dynamics, composition, and responses to environmental stressors is crucial for understanding microbial community assembly and biofilm regulation in health and disease. In this study, we explore in vivo colonization and in vitro biofilm formation abilities of core members of the honey bee (Apis mellifera) gut microbiota. Additionally, we assess the impact of glyphosate, a widely used herbicide with antimicrobial properties, and a glyphosate-based herbicide formulation on growth and biofilm formation in bee gut symbionts as well as in other biofilm-forming bacteria associated with diverse animals and plants. Our results demonstrate that several strains of core bee gut bacterial species can colonize the bee gut, which probably depends on their ability to form biofilms. Furthermore, glyphosate exposure elicits variable effects on bacterial growth and biofilm formation. In some instances, the effects correlate with the bacteria's ability to encode a susceptible or tolerant version of the enzyme inhibited by glyphosate in the shikimate pathway. However, in other instances, no such correlation is observed. Testing the herbicide formulation further complicates comparisons, as results often diverge from glyphosate exposure alone, suggesting that co-formulants influence bacterial growth and biofilm formation. These findings highlight the nuanced impacts of environmental stressors on microbial biofilms, with both ecological and host health-related implications.<br><br>IMPORTANCE: Biofilms are essential for microbial communities to establish and thrive in diverse environments. In the honey bee gut, the core microbiota member Snodgrassella alvi forms biofilms, potentially aiding the establishment of other members and promoting interactions with the host. In this study, we show that specific strains of other core members, including Bifidobacterium, Bombilactobacillus, Gilliamella, and Lactobacillus, also form biofilms in vitro. We then examine the impact of glyphosate, a widely used herbicide that can disrupt the bee microbiota, on bacterial growth and biofilm formation. Our findings demonstrate the diverse effects of glyphosate on biofilm formation, ranging from inhibition to enhancement, reflecting observations in other beneficial or pathogenic bacteria associated with animals and plants. Thus, glyphosate exposure may influence bacterial growth and biofilm formation, potentially shaping microbial establishment on host surfaces and impacting health outcomes.}, }
@article {pmid39012102, year = {2024}, author = {Conway, J and Delanois, RE and Mont, MA and Stavrakis, A and McPherson, E and Stolarski, E and Incavo, S and Oakes, D and Salvagno, R and Adams, JS and Kisch-Hancock, A and Tenorio, E and Leighton, A and Ryser, S and Kauvar, LM and Bernthal, NM}, title = {Phase 1 study of the pharmacokinetics and clinical proof-of-concept activity of a biofilm-disrupting human monoclonal antibody in patients with chronic prosthetic joint infection of the knee or hip.}, journal = {Antimicrobial agents and chemotherapy}, volume = {}, number = {}, pages = {e0065524}, doi = {10.1128/aac.00655-24}, pmid = {39012102}, issn = {1098-6596}, abstract = {UNLABELLED: We report the results of a first-in-human phase 1 clinical study to evaluate TRL1068, a native human monoclonal antibody that disrupts bacterial biofilms with broad-spectrum activity against both Gram-positive and Gram-negative species. The study population consisted of patients with chronic periprosthetic joint infections (PJIs) of the knee or hip, including both monomicrobial and polymicrobial infections, that are highly resistant to antibiotics due to biofilm formation. TRL1068 was administered via a single pre-surgical intravenous infusion in three sequentially ascending dose groups (6, 15, and 30 mg/kg). Concomitant perioperative antibiotics were pathogen-targeted as prescribed by the treating physician. In this double-blinded study, 4 patients were randomized to receive placebo and 11 patients to receive TRL1068 on day 1, as well as targeted antibiotics for 7 days prior to the scheduled removal of the infected implant and placement of an antibiotic-eluting spacer as the first stage of the standard of care two-stage exchange arthroplasty. No adverse events attributable to TRL1068 were reported. TRL1068 serum half-life was 15-18 days. At day 8, the concentration in synovial fluid was approximately 60% of the blood level and thus at least 15-fold above the threshold for biofilm-disrupting activity in vitro. Explanted prostheses were sonicated to release adherent bacteria for culture, with elimination of the implant bacteria observed in 3 of the 11 patients who received TRL1068, which compares favorably to prior PJI treatments. None of the patients who received TRL1068 had a relapse of the original infection by the end of the study (day 169).<br><br>CLINICAL TRIALS: This study is registered with ClinicalTrials.gov as NCT04763759.}, }
@article {pmid39011568, year = {2024}, author = {Martins, PHR and Romo, AIB and Gouveia, FS and Paz, IA and Nascimento, NRF and Andrade, AL and Rodríguez-López, J and de Vasconcelos, MA and Teixeira, EH and Moraes, CAF and Lopes, LGF and Sousa, EHS}, title = {Anti-bacterial, anti-biofilm and synergistic effects of phenazine-based ruthenium(II) complexes.}, journal = {Dalton transactions (Cambridge, England : 2003)}, volume = {53}, number = {30}, pages = {12627-12640}, doi = {10.1039/d4dt01033g}, pmid = {39011568}, issn = {1477-9234}, mesh = {*Phenazines/chemistry/pharmacology ; *Anti-Bacterial Agents/pharmacology/chemistry/chemical synthesis ; *Ruthenium/chemistry/pharmacology ; *Biofilms/drug effects ; *Coordination Complexes/chemistry/pharmacology/chemical synthesis ; *Microbial Sensitivity Tests ; Drug Synergism ; Staphylococcus aureus/drug effects ; }, abstract = {Antimicrobial resistance has become a global threat to human health, which is coupled with the lack of novel drugs. Metallocompounds have emerged as promising diverse scaffolds for the development of new antibiotics. Herein, we prepared some metal compounds mainly focusing on cis-[Ru(bpy)(dppz)(SO3)(NO)](PF6) (PR02, bpy = 2,2'-bipyridine, dppz = dipyrido[3,2-a:2',3'-c]phenazine), in which phenazinic and nitric oxide ligands along with sulfite conferred some key properties. This compound exhibited a redox potential for bound NO[+/0] of -0.252 V (vs. Ag|AgCl) and a high pH for nitrosyl-nitro conversion of 9.16, making the nitrosyl ligand the major species. These compounds were still able to bind to DNA structures. Interestingly, reduced glutathione (GSH) was unable to promote significant NO/HNO release, an uncommon feature of many similar systems. However, this reducing agent was essential to generate superoxide radicals. Antimicrobial studies were carried out using six bacterial strains, where none or very low activity was observed for Gram-negative bacteria. However, PR02 and PR (cis-[Ru(bpy)(dppz)Cl2]) showed high antibacterial activity in some Gram-positive strains (MBC for S. aureus up to 4.9 μmol L[-1]), where the activity of PR02 was similar to or at least 4-fold better than that of PR. Besides, PR02 showed capacity to inhibit bacterial biofilm formation, a major health issue leading to bacterial tolerance to antibiotics. Interestingly, we also showed that PR02 can function in synergism with the known antibiotic ampicillin, improving their action up to 4-fold even against resistant strains. Altogether, these results showed that PR02 is a promising antimicrobial nitrosyl ruthenium compound combining features beyond its killing action, which deserves further biological studies.}, }
@article {pmid39011151, year = {2024}, author = {Macià, MD and Borghi, E and Oliver, A}, title = {Eurobiofilms 2022: A translational perspective of biofilm-related persistent infections.}, journal = {Biofilm}, volume = {7}, number = {}, pages = {100168}, pmid = {39011151}, issn = {2590-2075}, }
@article {pmid39010993, year = {2024}, author = {El-Subeyhi, M and Hamid, LL and Gayadh, EW and Saod, WM and Ramizy, A}, title = {Biogenic Synthesis and Characterisation of Novel Potassium Nanoparticles by Capparis spinosa Flower Extract and Evaluation of Their Potential Antibacterial, Anti-biofilm and Antibiotic Development.}, journal = {Indian journal of microbiology}, volume = {64}, number = {2}, pages = {548-557}, pmid = {39010993}, issn = {0046-8991}, abstract = {Scientific researches on the synthesis, characterisation, and biological activity of potassium nanoparticles (K NPs) are extremely rare. In our study, we successfully synthesised a novel form of K NPs using Capparis spinosa (C. spinosa) flower extract as a reducing and capping agent. The formation of K NPs in new form (K2O NPs) was confirmed by UV-vis and XRD spectra. Furthermore, the FTIR results indicated the presence of specific active biomolecules in the C. spinosa extract which played a crucial role in reducing and stabilising K2O NPs. SEM imaging demonstrated that the K2O NPs exhibited irregular shapes with nanosizes ranging between 25 and 95 nm. Remarkably, the biosynthesised K2O NPs displayed considerable antibacterial activity against a wide range of multidrug-resistant (MDR) pathogenic bacteria. K2O NPs demonstrated considerable anti-biofilm activity against preformed biofilms produced by MDR bacteria. Combining K2O NPs with conventional antibiotics greatly improved their efficacy in compacting the MDR bacterial strains. Industrially, bulk form of potassium oxides was commonly used in the preparation of various antimicrobial compounds such as detergents, bleach, and oxidising solutions. The synthesis of potassium oxide in nanoform has shown remarkable biological efficacy, making it a promising therapeutic approach for pharmaceutical and medical applications.}, }
@article {pmid39009474, year = {2024}, author = {Mahto, KU and Das, S}, title = {Electroactive biofilm communities in microbial fuel cells for the synergistic treatment of wastewater and bioelectricity generation.}, journal = {Critical reviews in biotechnology}, volume = {}, number = {}, pages = {1-20}, doi = {10.1080/07388551.2024.2372070}, pmid = {39009474}, issn = {1549-7801}, abstract = {Increasing industrialization and urbanization have contributed to a significant rise in wastewater discharge and exerted extensive pressure on the existing natural energy resources. Microbial fuel cell (MFC) is a sustainable technology that utilizes wastewater for electricity generation. MFC comprises a bioelectrochemical system employing electroactive biofilms of several aerobic and anaerobic bacteria, such as Geobacter sulfurreducens, Shewanella oneidensis, Pseudomonas aeruginosa, and Ochrobacterum pseudiintermedium. Since the electroactive biofilms constitute a vital part of the MFC, it is crucial to understand the biofilm-mediated pollutant metabolism and electron transfer mechanisms. Engineering electroactive biofilm communities for improved biofilm formation and extracellular polymeric substances (EPS) secretion can positively impact the bioelectrochemical system and improve fuel cell performance. This review article summarizes the role of electroactive bacterial communities in MFC for wastewater treatment and bioelectricity generation. A significant focus has been laid on understanding the composition, structure, and function of electroactive biofilms in MFC. Various electron transport mechanisms, including direct electron transfer (DET), indirect electron transfer (IET), and long-distance electron transfer (LDET), have been discussed. A detailed summary of the optimization of process parameters and genetic engineering strategies for improving the performance of MFC has been provided. Lastly, the applications of MFC for wastewater treatment, bioelectricity generation, and biosensor development have been reviewed.}, }
@article {pmid39009090, year = {2024}, author = {Li, X and Xiao, L and Sui, X and Li, M and Wang, N and Sun, Z and Li, T and Cao, X and Li, B}, title = {Municipal solid waste leachate treatment by three-stage membrane aeration biofilm reactor system.}, journal = {Chemosphere}, volume = {363}, number = {}, pages = {142847}, doi = {10.1016/j.chemosphere.2024.142847}, pmid = {39009090}, issn = {1879-1298}, abstract = {A combined process of coagulation pretreatment and three-stage membrane aeration biofilm reactor (MABR) system was successfully applied for the first time to treat actual municipal solid waste leachate (MSWL), which was characterized by high concentrations of toxic hard-to-degrade organics and salinity. The results showed that 9.8%-21.3% of organics could be removed from actual MSWL by coagulation with polymeric aluminum chloride (PAC). Three-stage MABR contributed 95.6% of the chemical oxygen demand (COD) removal, with the influent COD concentration ranging from 6000 to 7000 mg/L. At the same time, the removal efficiencies of total nitrogen (TN) and ammonia (NH4[+]-N) could reach to 84.3% and 79.9% without the addition of external carbon source, respectively. The nitrifying/denitrifying bacteria were enriched in the biofilm including Thiobacillus, Azoarcus and Methyloversatilis, which supported the MABR with high nitrogen removal efficiency and significantly toxic tolerance. Principal component analysis (PCA) and the Pearson correlation coefficients (r) illustrated that aeration pressure is a crucial operational parameter, exhibiting a strong correlation between the MABR performance and microbial communities. This work demonstrates that MABR is an effective and low-energy option for simultaneous removal of carbon and nitrogen in the treatment of MSWL.}, }
@article {pmid39008846, year = {2024}, author = {Dey, R and Mukherjee, R and Biswas, S and Haldar, J}, title = {Stimuli-Responsive Release-Active Dressing: A Promising Solution for Eradicating Biofilm-Mediated Wound Infections.}, journal = {ACS applied materials &amp; interfaces}, volume = {16}, number = {29}, pages = {37795-37805}, doi = {10.1021/acsami.4c09820}, pmid = {39008846}, issn = {1944-8252}, mesh = {*Biofilms/drug effects ; *Anti-Bacterial Agents/chemistry/pharmacology ; *Bandages ; *Wound Infection/drug therapy/microbiology ; *Methicillin-Resistant Staphylococcus aureus/drug effects/physiology ; Animals ; Mice ; Hydrogen-Ion Concentration ; Staphylococcal Infections/drug therapy ; Microbial Sensitivity Tests ; Humans ; Carboxymethylcellulose Sodium/chemistry/pharmacology ; }, abstract = {Biofilm-mediated wound infections pose a significant challenge due to the limitations of conventional antibiotics, which often exhibit narrow-spectrum activity, fail to eliminate recurrent bacterial contamination, and are unable to penetrate the biofilm matrix. While the search for alternatives has explored the use of metal nanoparticles and synthetic biocides, these solutions often suffer from unintended toxicity to surrounding tissues and lack controlled administration and release. In this study, we engineered a pH-responsive release-active dressing film based on carboxymethyl cellulose, incorporating a synthetic antibacterial molecule (SAM-17). The dressing film exhibited optimal mechanical stability for easy application and demonstrated excellent fluid absorption properties, allowing for prolonged moisturization at the site of injury. The film exhibited pH-dependent release of cargo, with 78% release within 24 h at acidic pH, enabling targeted antibacterial drug delivery within the wound microenvironment. Furthermore, the release-active film effectively eliminated repeated challenges of bacterial contamination. Remarkably, the film demonstrated a minimal toxicity profile in both in vitro and in vivo models. The film eliminated preformed bacterial biofilms, achieving a reduction of 2.5 log against methicillin-resistant Staphylococcus aureus (MRSA) and 4.1 log against vancomycin-resistant S. aureus (VRSA). In a biofilm-mediated MRSA wound infection model, this release-active film eradicated the biofilm-embedded bacteria by over 99%, resulting in accelerated wound healing. These findings highlight the potential of this film as an effective candidate for tackling biofilm-associated wound infections.}, }
@article {pmid39003969, year = {2024}, author = {Jardak, M and Lami, R and Saadaoui, O and Jlidi, H and Stien, D and Aifa, S and Mnif, S}, title = {Control of Staphylococcus epidermidis biofilm by surfactins of an endophytic bacterium Bacillus sp. 15 F.}, journal = {Enzyme and microbial technology}, volume = {180}, number = {}, pages = {110477}, doi = {10.1016/j.enzmictec.2024.110477}, pmid = {39003969}, issn = {1879-0909}, abstract = {The present paper deals with the preparation and annotation of a surfactin(s) derived from a culture of the endophytic bacterium Bacillus 15 F. The LC-MS analysis of the acetonitrile fraction confirmed the presence of surfactins Leu/Ile7 C15, Leu/Ile7 C14 and Leu/Ile7 C13 with [M+H][+] at m/z 1036.6895, 1022.6741 and 1008.6581, respectively. Various concentrations of the surfactin(s) (hereafter referred to as surfactin-15 F) were used to reduce the adhesion of Staphylococcus epidermidis S61, which served as a model for studying antibiofilm activity on polystyrene surfaces. Incubation of Staphylococcus epidermidis S61 with 62.5 µg/ml of surfactin-15 F resulted in almost complete inhibition of biofilm formation (90.3 ± 3.33 %), and a significant reduction of cell viability (resazurin-based fluorescence was more than 200 times lower). The antiadhesive effect of surfactin-15 F was confirmed by scanning electron microscopy. Surfactin-15 F demonstrated an eradication effect against preformed biofilm, causing severe disruption of Staphylococcus epidermidis S61 biofilm structure and reducing viability. The results suggest that surfactins produced by endophytic bacteria could be an alternative to synthetic products. Surfactin-15 F, used in wound dressings, demonstrated an efficient treatment of the preformed Staphylococcus epidermidis S61 biofilm, and thus having a great potential in medical applications.}, }
@article {pmid39002458, year = {2024}, author = {Cao, J and Xu, A and Gao, D and Gong, X and Cheng, L and Zhou, Q and Yang, T and Gong, F and Liu, Z and Liang, H}, title = {Enhance PD/A biofilm formation via a novel biochar/tourmaline modified-biocarriers to treat low-strength contaminated surface water: Initial adhesion and high-substrate microenvironment.}, journal = {Journal of environmental management}, volume = {366}, number = {}, pages = {121803}, doi = {10.1016/j.jenvman.2024.121803}, pmid = {39002458}, issn = {1095-8630}, abstract = {In this work, a novel polyurethane carrier modified with biochar and tourmaline/zeolite powder at ratio of 1:1 and 1:2 was developed to promote the formation of biofilms and the synergy of overall bacterial activity for Partial Denitrification/Anammox to treat low-nitrogen contaminated surface water. Based on the batch experiment, the modified biocarrier, BTP2 (biochar: tourmaline = 2: 1), exhibited the highest total nitrogen removal efficiency (83.63%) under influent total nitrogen of 15 mg/L and COD/NO3[-] of 3. The dense biofilm was formed in inner side of biocarrier owing to the increased surface roughness and various functional groups suggested by scanning electron microscopy and Fourier-transform infrared analysis. The EPS content increased from 200.15 to 220.26 mg/g VSS in BTP2 system. Besides, the rapid NH4[+] capture and organics release of the modified carrier fueled the growth of anammox and denitrification bacteria, with the activity of 2.13 ± 0.52 mg N/gVSS/h and 6.70 ± 0.52 mg N/gVSS/h (BTP2). High-throughput sequencing unraveled the increased abundances of Candidatus_Competibacter (0.82%), Thauera (0.60%) and Candidatus_Brocadia (0.55%) which was responsible for the synergy of incomplete reduction of NO3[-] to NO2[-] and NH4[+] oxidation. Overall, this study provided a valid and simple-control guide for biofilm formation towards rapid enrichment and great collaboration of Anammox and denitrification bacteria.}, }
@article {pmid39002428, year = {2024}, author = {Jyoti, K and Soni, K and Chandra, R}, title = {Pharmaceutical industrial wastewater exhibiting the co-occurrence of biofilm-forming genes in the multidrug-resistant bacterial community poses a novel environmental threat.}, journal = {Aquatic toxicology (Amsterdam, Netherlands)}, volume = {273}, number = {}, pages = {107019}, doi = {10.1016/j.aquatox.2024.107019}, pmid = {39002428}, issn = {1879-1514}, abstract = {The interaction of the environment with the effluent of wastewater treatment plants, having antibiotics, multidrug-resistant (MDR) bacteria, and biofilm-forming genes (BFGs), has vast environmental risks. Antibiotic pollution bottlenecks environmental bacteria and has the potential to significantly lower the biodiversity of environmental bacteria, causing an alteration in ecological equilibrium. It can induce selective pressure for antibiotic resistance (AR) and can transform the non-resistant environmental bacteria into a resistant form through HGT. This study investigated the occurrence of MDR bacteria, showing phenotypic and genotypic characteristics of biofilm. The bacteria were isolated from the pharmaceutical wastewater treatment plants (WWTPs) of Dehradun and Haridwar (India), located in the pharmaceutical areas. The findings of this study demonstrate the coexistence of BFGs and MDR clinical bacteria in the vicinity of pharmaceutical industrial wastewater treatment plants. A total of 47 bacteria were isolated from both WWTPs and tested for antibiotic resistance to 13 different antibiotics; 16 isolates (34.04 %) tested positive for MDR. 5 (31.25 %) of these 16 MDR isolates were producing biofilm and identified as Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Burkholderia cepacia. The targeted BFGs in this study were ompA, bap and pslA. The most common co-occurring gene was ompA (80 %), with pslA (40 %) being the least common. A. baumannii contains all three targeted genes, whereas B. cepacia only has bap. Except for B. cepacia, all the biofilm-forming MDR isolates show AR to all the tested antibiotics and prove that the biofilm enhances the AR potential. The samples of both wastewater treatment plants also showed the occurrence of tetracycline, ampicillin, erythromycin and chloramphenicol, along with high levels of BOD, COD, PO4[-3], NO3[-], heavy metals and organic pollutants. The co-occurrence of MDR and biofilm-forming tendency in the clinical strain of bacteria and its environmental dissemination may have an array of hazardous impacts on human and environmental health.}, }
@article {pmid39000327, year = {2024}, author = {Mechmechani, S and Yammine, J and Alhuthali, S and El Mouzawak, M and Charvourou, G and Ghasrsallaoui, A and Chihib, NE and Doulgeraki, A and Karam, L}, title = {Study of the Resistance of Staphylococcus aureus Biofilm, Biofilm-Detached Cells, and Planktonic Cells to Microencapsulated Carvacrol Used Alone or Combined with Low-pH Treatment.}, journal = {International journal of molecular sciences}, volume = {25}, number = {13}, pages = {}, pmid = {39000327}, issn = {1422-0067}, support = {CA18113//EuromicropH COST action/ ; }, mesh = {*Biofilms/drug effects ; *Staphylococcus aureus/drug effects/physiology ; *Cymenes/pharmacology ; Hydrogen-Ion Concentration ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology ; Plankton/drug effects ; Capsules ; Drug Compounding/methods ; Drug Resistance, Bacterial/drug effects ; }, abstract = {Microbial biofilms pose severe problems in the medical field and food industry, as they are the cause of many serious infections and food-borne diseases. The extreme biofilms' resistance to conventional anti-microbial treatments presents a major challenge to their elimination. In this study, the difference in resistance between Staphylococcus aureus DSMZ 12463 biofilms, biofilm-detached cells, and planktonic cells against microcapsules containing carvacrol was assessed. The antimicrobial/antibiofilm activity of low pH disinfection medium containing the microencapsulated carvacrol was also studied. In addition, the effect of low pH on the in vitro carvacrol release from microcapsules was investigated. The minimum inhibitory concentration of microencapsulated carvacrol was 0.625 mg mL[-1]. The results showed that biofilms exhibited greater resistance to microencapsulated carvacrol than the biofilm-detached cells and planktonic cells. Low pH treatment alone, by hydrochloric acid addition, showed no bactericidal effect on any of the three states of S. aureus strain. However, microencapsulated carvacrol was able to significantly reduce the planktonic cells and biofilm-detached cells below the detection limit (no bacterial counts), and the biofilm by approximatively 3 log CFU mL[-1]. In addition, results showed that microencapsulated carvacrol combined with low pH treatment reduced biofilm by more than 5 log CFU mL[-1]. Thus, the use of microencapsulated carvacrol in acidic environment could be a promising approach to combat biofilms from abiotic surfaces.}, }
@article {pmid38998500, year = {2024}, author = {Wu, D and Hao, L and Liu, X and Li, X and Zhao, G}, title = {The Anti-Biofilm Properties of Phloretin and Its Analogs against Porphyromonas gingivalis and Its Complex Flora.}, journal = {Foods (Basel, Switzerland)}, volume = {13}, number = {13}, pages = {}, pmid = {38998500}, issn = {2304-8158}, support = {21978101//National Natural Science Foundation of China/ ; 22278159//National Natural Science Foundation of China/ ; }, abstract = {Porphyromonas gingivalis is crucial for the pathogenesis of periodontitis. This research investigated the effects of the fruit-derived flavonoid phloretin and its analogs on the growth of pure P. gingivalis and the flora of P. gingivalis mixed with the symbiotic oral pathogens Fusobacterium nucleatum and Streptococcus mitis. The results showed that the tested flavonoids had little effect on the biofilm amount of pure P. gingivalis, but significantly reduced the biofilm amount of mixed flora to 83.6~89.1%. Biofilm viability decreased to 86.7~92.8% in both the pure- and mixed-bacterial groups after naringenin and phloretin treatments. SEM showed that phloretin and phlorizin displayed a similar and remarkable destructive effect on P. gingivalis and the mixed biofilms. Transcriptome analysis confirmed that biofilm formation was inhibited by these flavonoids, and phloretin significantly regulated the transcription of quorum sensing. Phlorizin and phloretin reduced AI-2 activity to 45.9% and 55.4%, respectively, independent of the regulation of related gene transcription. This research marks the first finding that these flavonoids possess anti-biofilm properties against P. gingivalis and its intricate bacterial community, and the observed performance variations, driven by structural differences, underscore the existence of intriguing structure-activity relationships.}, }
@article {pmid38998429, year = {2024}, author = {Fernández-Grajera, M and Pacha-Olivenza, MA and Fernández-Calderón, MC and González-Martín, ML and Gallardo-Moreno, AM}, title = {Dynamic Adhesive Behavior and Biofilm Formation of Staphylococcus aureus on Polylactic Acid Surfaces in Diabetic Environments.}, journal = {Materials (Basel, Switzerland)}, volume = {17}, number = {13}, pages = {}, pmid = {38998429}, issn = {1996-1944}, support = {TED2021-131345B-I00//Ministerio de Ciencia, Innovaci&#xf3;n y Universidades/ ; TED2021-131345B-I00//Fondo Europeo de Desarrollo Regional/ ; PID2022-140422OB-I00//Ministerio de Ciencia, Innovaci&#xf3;n y Universidades/ ; PID2022-140422OB-I00//Fondo Europeo de Desarrollo Regional/ ; IB20092//Consejer&#xed;a de Educaci&#xf3;n y Empleo, Junta de Extremadura/ ; Action VI-03//Universidad de Extremadura/ ; }, abstract = {Interest in biodegradable implants has focused attention on the resorbable polymer polylactic acid. However, the risk of these materials promoting infection, especially in patients with existing pathologies, needs to be monitored. The enrichment of a bacterial adhesion medium with compounds that are associated with human pathologies can help in understanding how these components affect the development of infectious processes. Specifically, this work evaluates the influence of glucose and ketone bodies (in a diabetic context) on the adhesion dynamics of S. aureus to the biomaterial polylactic acid, employing different approaches and discussing the results based on the physical properties of the bacterial surface and its metabolic activity. The combination of ketoacidosis and hyperglycemia (GK2) appears to be the worst scenario: this system promotes a state of continuous bacterial colonization over time, suppressing the stationary phase of adhesion and strengthening the attachment of bacteria to the surface. In addition, these supplements cause a significant increase in the metabolic activity of the bacteria. Compared to non-enriched media, biofilm formation doubles under ketoacidosis conditions, while in the planktonic state, it is glucose that triggers metabolic activity, which is practically suppressed when only ketone components are present. Both information must be complementary to understand what can happen in a real system, where planktonic bacteria are the ones that initially colonize a surface, and, subsequently, these attached bacteria end up forming a biofilm. This information highlights the need for good monitoring of diabetic patients, especially if they use an implanted device made of PLA.}, }
@article {pmid38995023, year = {2024}, author = {Danhorn, T and Hentzer, M and Givskov, M and Parsek, MR and Fuqua, C}, title = {Erratum for Danhorn et al., "Phosphorus Limitation Enhances Biofilm Formation of the Plant Pathogen Agrobacterium tumefaciens through the PhoR-PhoB Regulatory System".}, journal = {Journal of bacteriology}, volume = {}, number = {}, pages = {e0023824}, doi = {10.1128/jb.00238-24}, pmid = {38995023}, issn = {1098-5530}, }
@article {pmid38992841, year = {2024}, author = {Yui, S and Karia, K and Ali, S}, title = {Evaluation of novel disinfection methods for the remediation of heavily contaminated TMVs and water systems with Pseudomonas aeruginosa biofilm: considerations for new and existing healthcare water systems.}, journal = {The Journal of hospital infection}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jhin.2024.05.024}, pmid = {38992841}, issn = {1532-2939}, abstract = {BACKGROUND: Pseudomonas aeruginosa is a leading cause of nosocomial Gram-negative bacteraemia. Water systems are a well-documented source of P. aeruginosa and established biofilms are difficult to remove.<br><br>AIM: To evaluate the efficacy of regular flushing, peracetic acid disinfection, in-tap thermal disinfection and in-line thermal disinfection to eradicate P. aeruginosa biofilm in a colonised tap model.<br><br>METHODS: A simulated tap system was constructed and inoculated with a reference and an environmental strain of P. aeruginosa to form biofilm. Water samples were collected from the taps and P. aeruginosa levels enumerated following disinfection methods. To simulate regular flushing, taps were flushed for 5 minutes, 5 times per day with water tested daily. Peracetic acid (4000 PPM) was manually injected into the system and flushed through the system with a pump. Thermal flushing at 60&#xb0;C was performed in-line and with an in-tap bypass valve. Tests were conducted with cross-linked polyethylene (PEX) piping and repeated with copper piping.<br><br>FINDINGS: Regular flushing and peracetic acid applied with a pump did not reduce P. aeruginosa levels. A limited reduction was observed when manually injecting peracetic acid. In-tap thermal flushing eradicated P. aeruginosa in copper piping but not PEX. In-line thermal flushing was the most effective at reducing P. aeruginosa levels; however, did not eradicate the biofilm.<br><br>CONCLUSION: In-line thermal flushing was the most effective method to remove P. aeruginosa biofilm. Results vary significantly with the strain of bacteria and the composition of the plumbing. Several methods used in combination may be necessary to remove established biofilm.}, }
@article {pmid38992475, year = {2024}, author = {Isolani, R and Pilatti, F and de Paula, MN and Valone, L and da Silva, EL and de Oliveira Caleare, A and Seixas, FAV and Hensel, A and Mello, JCP}, title = {Limonium brasiliense rhizomes extract against virulence factors of Porphyromonas gingivalis: Inhibition of gingipains, bacterial adhesion, and biofilm formation.}, journal = {Fitoterapia}, volume = {177}, number = {}, pages = {106120}, doi = {10.1016/j.fitote.2024.106120}, pmid = {38992475}, issn = {1873-6971}, abstract = {Periodontitis is clinically characterized by destruction of the tooth support system and tooth loss. Porphyromonas gingivalis (Pg) plays a dominant role in periodontitis. Fractions and isolated compounds from an acetone-water extract of the roots of Limonium brasiliense (Lb) were tested in vitro for their anti-adhesive capacity against Pg on human KB buccal cells, influence on gingipains, the main virulence factors of Pg, and biofilm formation. Fractions EAF and FLB7 (50 μg/mL) reduced the bacterial adhesion of Pg to KB cells significantly (63 resp. 70%). The proanthocyanidin samarangenin A inhibited the adhesion (72%, 30 μM), samarangenin B (71%, 20 μM), and the flavan-3-ol epigallocatechin-3-O-gallate (79%, 30 μM). Fraction AQF, representing hydrophilic compounds, reduced the proteolytic activity of Arginin-specific gingipain (IC50 12.78 μg/mL). Fractions EAF and FLB7, characterized by lipohilic constituents, inhibited Arg-gingipain (IC50 3 μg/mL). On Lysine-specific gingipain, AQF has an IC50 15.89, EAF 14.15, and FLB7 6 μg/mL. The reduced bacterial adhesion is due to a strong interaction of proanthocyanidins with gingipains. AQF, EAF, and FLB7 significantly inhibited biofilm formation: IC50 11.34 (AQF), 11.66 (EAF), and 12.09 μg/mL (FLB7). In silico analysis indicated, that the polyphenols act against specific targets of Pg, not affecting mammalian cells. Therefore, Lb might be effective for prevention of periodontal disease by influencing virulence factors of Pg.}, }
@article {pmid38991244, year = {2024}, author = {Heusser, A and Wackernagel, I and Reinmann, M and Udert, KM}, title = {Increasing urine nitrification performance with sequential membrane aerated biofilm reactors.}, journal = {Water research}, volume = {261}, number = {}, pages = {122019}, doi = {10.1016/j.watres.2024.122019}, pmid = {38991244}, issn = {1879-2448}, abstract = {This study aimed to investigate whether separating organics depletion from nitrification increases the overall performance of urine nitrification. Separate organics depletion was facilitated with membrane aerated biofilm reactors (MABRs). The high pH and ammonia concentration in stored urine inhibited nitrification in the first stage and therewith allowed the separation of organics depletion from nitrification. An organics removal of 70 % was achieved at organic loading rates in the influent of 3.7 gCOD d[-1] m[-2]. Organics depletion in a continuous flow stirred tank reactor (CSTR) for organics depletion led to ammonia stripping through diffused aeration of up to 13 %. Using an MABR, diffusion into the lumen amounted for 4 % ammonia loss only. In the MABR, headspace volume and therefore ammonia loss through the headspace was negligible. By aerating the downstream MABR for nitrification with the off-gas of the MABR for organics depletion, 96 % of the ammonia stripped in the first stage could be recovered in the second stage, so that the overall ammonia loss was negligibly low. Nitrification of the organics-depleted urine was studied in MABRs, CSTRs, and sequencing batch reactors in fed batch mode (FBRs), the latter two operated with suspended biomass. The experiments demonstrated that upstream organics depletion can double the nitrification rate. In a laboratory-scale MABR, nitrification rates were recorded of up to 830 mgNL[-1] d[-1] (3.1 gN m[-2] d[-1]) with ambient air and over 1500 mgNL[-1] d[-1] (6.7 gN m[-2] d[-1]) with oxygen-enriched air. Experiments with a laboratory-scale MABR showed that increasing operational parameters such as pH, recirculation flow, scouring frequency, and oxygen content increased the nitrification rate. The nitrification in the MABR was robust even at high pH setpoints of 6.9 and was robust against process failures arising from operational mistakes. The hydraulic retention time (HRT) required for nitrification was only 1 to 2 days. With the preceding organics depletion, the HRT for our system requires 2 to 3 days in total, whereas a combined activated sludge system requires 4 to 8 days. The N2O concentration in the off-gas increases with increasing nitrification rates; however, the N2O emission factor was 2.8 % on average and independent of nitrification rates. These results indicate that the MABR technology has a high potential for efficient and robust production of ammonium nitrate from source-separated urine.}, }
@article {pmid38991000, year = {2024}, author = {Arif, M and Asif, A and Nazeer, K and Sultan, S and Riaz, S}, title = {Coexistence of β-lactamase genes and biofilm forming potential among carbapenem-resistant Acinetobacter baumannii in Lahore, Pakistan.}, journal = {Journal of infection in developing countries}, volume = {18}, number = {6}, pages = {943-949}, doi = {10.3855/jidc.19119}, pmid = {38991000}, issn = {1972-2680}, mesh = {*Biofilms/growth &amp; development ; *beta-Lactamases/genetics ; Humans ; Pakistan ; *Acinetobacter baumannii/genetics/drug effects ; Male ; Cross-Sectional Studies ; Adult ; Middle Aged ; Female ; *Acinetobacter Infections/microbiology ; *Anti-Bacterial Agents/pharmacology ; *Carbapenems/pharmacology ; Microbial Sensitivity Tests ; Young Adult ; Bacterial Proteins/genetics ; Adolescent ; }, abstract = {INTRODUCTION: Our goal was to investigate the antimicrobial resistance due to beta-lactamase genes and virulent determinants (biofilm-forming ability) expressed by Acinetobacter collected from health settings in Pakistan. A cross-sectional study was conducted for the molecular characterization of carbapenemases and biofilm-producing strains of Acinetobacter spp.<br><br>METHODOLOGY: Two twenty-three imipenem-resistant Acinetobacter isolates were analyzed from 2020 to 2023.The combination disk test and modified hodge test were performed. Biofilm forming ability was determined by polystyrene tube assay. Multiplex polymerase chain reaction (PCR) for virulent and biofilm-forming genes, and 16S rRNA sequencing were performed.<br><br>RESULTS: 118 (52.9%) carbapenem-resistant Acinetobacter (CR-AB) were isolated from wounds and pus, 121 (54.2%) from males, and 92 (41.2%) from 26-50-years-olds. More than 80% of strains produced &#x3b2;-lactamases and carbapenemases. Based on the PCR amplification of the ITS gene, 174 (78.0%) CR-AB strains were identified from CR-Acinetobacter non-baumannii (ANB). Most CR-AB were strong and moderate biofilm producers. Genetic analysis revealed the blaOXA-23, blaTEM, blaCTX-M blaNDM-1 and blaVIM were prevalent in CR-AB with frequencies 91 (94.8%), 68 (70.8%), 19 (19.7%), 53 (55.2%), 2 (2.0%) respectively. Among virulence genes, OmpA was dominant in CR-AB isolates from wound (83, 86.4%), csuE 63 (80.7%) from non-wound specimens and significantly correlated with blaNDM and blaOXA genes. Phylogenetic analysis revealed three different clades for strains based on specimens.<br><br>CONCLUSIONS: CR-AB was highly prevalent in Pakistan and associated with wound infections. The genes, blaOXA-23, blaTEM, blaCTX-M, and blaNDM-1 were detected in CR-AB. Most CR-AB were strong biofilm producers with virulent genes OmpA and csuE.}, }
@article {pmid38990088, year = {2024}, author = {Leistikow, KR and May, DS and Suh, WS and Vargas Asensio, G and Schaenzer, AJ and Currie, CR and Hristova, KR}, title = {Bacillus subtilis-derived peptides disrupt quorum sensing and biofilm assembly in multidrug-resistant Staphylococcus aureus.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0071224}, doi = {10.1128/msystems.00712-24}, pmid = {38990088}, issn = {2379-5077}, abstract = {UNLABELLED: Multidrug-resistant Staphylococcus aureus is one of the most clinically important pathogens in the world, with infections leading to high rates of morbidity and mortality in both humans and animals. The ability of S. aureus to form biofilms protects cells from antibiotics and promotes the transfer of antibiotic resistance genes; therefore, new strategies aimed at inhibiting biofilm growth are urgently needed. Probiotic species, including Bacillus subtilis, are gaining interest as potential therapies against S. aureus for their ability to reduce S. aureus colonization and virulence. Here, we search for strains and microbially derived compounds with strong antibiofilm activity against multidrug-resistant S. aureus by isolating and screening Bacillus strains from a variety of agricultural environments. From a total of 1,123 environmental isolates, we identify a single strain B. subtilis 6D1, with a potent ability to inhibit biofilm growth, disassemble mature biofilm, and improve antibiotic sensitivity of S. aureus biofilms through an Agr quorum sensing interference mechanism. Biochemical and molecular networking analysis of an active organic fraction revealed multiple surfactin isoforms, and an uncharacterized peptide was driving this antibiofilm activity. Compared with commercial high-performance liquid chromatography grade surfactin obtained from B. subtilis, we show these B. subtilis 6D1 peptides are significantly better at inhibiting biofilm formation in all four S. aureus Agr backgrounds and preventing S. aureus-induced cytotoxicity when applied to HT29 human intestinal cells. Our study illustrates the potential of exploring microbial strain diversity to discover novel antibiofilm agents that may help combat multidrug-resistant S. aureus infections and enhance antibiotic efficacy in clinical and veterinary settings.<br><br>IMPORTANCE: The formation of biofilms by multidrug-resistant bacterial pathogens, such as Staphylococcus aureus, increases these microorganisms' virulence and decreases the efficacy of common antibiotic regimens. Probiotics possess a variety of strain-specific strategies to reduce biofilm formation in competing organisms; however, the mechanisms and compounds responsible for these phenomena often go uncharacterized. In this study, we identified a mixture of small probiotic-derived peptides capable of Agr quorum sensing interference as one of the mechanisms driving antibiofilm activity against S. aureus. This collection of peptides also improved antibiotic killing and protected human gut epithelial cells from S. aureus-induced toxicity by stimulating an adaptive cytokine response. We conclude that purposeful strain screening and selection efforts can be used to identify unique probiotic strains that possess specially desired mechanisms of action. This information can be used to further improve our understanding of the ways in which probiotic and probiotic-derived compounds can be applied to prevent bacterial infections or improve bacterial sensitivity to antibiotics in clinical and agricultural settings.}, }
@article {pmid38990043, year = {2024}, author = {Momeni, SS and Cao, X and Xie, B and Rainey, K and Childers, NK and Wu, H}, title = {Intraspecies interactions of Streptococcus mutans impact biofilm architecture and virulence determinants in childhood dental caries.}, journal = {mSphere}, volume = {9}, number = {7}, pages = {e0077823}, pmid = {38990043}, issn = {2379-5042}, support = {R01 DE017954/DE/NIDCR NIH HHS/United States ; R01 DE022350/DE/NIDCR NIH HHS/United States ; R01DE022350, T90DE022736//HHS | NIH | National Institute of Dental and Craniofacial Research (NIDCR)/ ; R01DE016684//HHS | NIH | National Institute of Dental and Craniofacial Research (NIDCR)/ ; DE029527//HHS | NIH | National Institute of Dental and Craniofacial Research (NIDCR)/ ; }, mesh = {*Biofilms/growth &amp; development ; *Streptococcus mutans/genetics/physiology/pathogenicity ; *Dental Caries/microbiology ; Humans ; Animals ; Child, Preschool ; Drosophila/microbiology ; Virulence ; Microbial Interactions ; Genotype ; Female ; Male ; Child ; Hydrogen-Ion Concentration ; Virulence Factors/genetics ; Disease Models, Animal ; Microscopy, Confocal ; }, abstract = {Early childhood dental caries (ECC) is the most common chronic disease among children, especially among low socioeconomic populations. Streptococcus mutans is most frequently associated with initiation of ECC. Although many studies report children with multiple S. mutans strains (i.e., genotypes) have greater odds of developing ECC, studies investigating intraspecies interactions in dental caries are lacking. This study investigates the impact of intraspecies interactions on cariogenic and fitness traits of clinical S. mutans isolates using in vitro and in vivo approaches. Association analysis evaluated if presence of multiple S. mutans genotypes within the first year of colonization was associated with caries. Initially, clinical S. mutans isolates from 10 children were evaluated. S. mutans strains (G09 and G18, most prevalent) isolated from one child were used for subsequent analysis. Biofilm analysis was performed for single and mixed cultures to assess cariogenic traits, including biofilm biomass, intra-polysaccharide, pH, and glucan. Confocal laser scanning microscopy (CLSM) and time-lapse imaging were used to evaluate spatial and temporal biofilm dynamics, respectively. A Drosophila model was used to assess colonization in vivo. Results showed the mean biofilm pH was significantly lower in co-cultured biofilms versus monoculture. Doubling of S. mutans biofilms was observed by CLSM and in vivo colonization in Drosophila for co-cultured S. mutans. Individual strains occupied specific domains in co-culture and G09 contributed most to increased co-culture biofilm thickness and colonization in Drosophila. Biofilm formation and acid production displayed distinct signatures in time-lapsed experiments. This study illuminates that intraspecies interactions of S. mutans significantly impacts biofilm acidity, architecture, and colonization.IMPORTANCEThis study sheds light on the complex dynamics of a key contributor to early childhood dental caries (ECC) by exploring intraspecies interactions of different S. mutans strains and their impact on cariogenic traits. Utilizing clinical isolates from children with ECC, the research highlights significant differences in biofilm architecture and acid production in mixed versus single genotype cultures. The findings reveal that co-cultured S. mutans strains exhibit increased cell density and acidity, with individual strains occupying distinct domains. These insights, enhanced by use of time-lapsed confocal laser scanning microscopy and a Drosophila model, offer a deeper understanding of ECC pathogenesis and potential avenues for targeted interventions.}, }
@article {pmid38989494, year = {2024}, author = {Datla, VDD and Uppalapati, LV and Pilli, HPK and Mandava, J and Kantheti, S and Komireddy, SNK and Chandolu, V}, title = {Effect of ultrasonic and Er,Cr:YSGG laser-activated irrigation protocol on dual-species root canal biofilm removal: An in vitro study.}, journal = {Journal of conservative dentistry and endodontics}, volume = {27}, number = {6}, pages = {613-620}, pmid = {38989494}, issn = {2950-4708}, abstract = {AIM: The aim of the study was to investigate the disinfecting efficacy of a standardized irrigating solution activated by ultrasonics or laser irradiation on mature dual-species biofilms at different root levels in vitro.<br><br>MATERIALS AND METHODS: Conventional access cavity preparations were done on 160 single-rooted mandibular premolar teeth with single canals. Freshly extracted oral microbial strains of Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, and Candida albicans after biochemical confirmation were used to generate two discrete dual-species microbial inoculums. The sterilized tooth samples were randomly segregated into two groups (n = 80) and inoculated with a mixed inoculum of S. aureus + E. faecalis strains (Group 1) and S. mutans + C. albicans strains (Group 2), respectively. Following the 21-day incubation period under aerobic conditions, the infected specimens in each group were divided into four subgroups (n = 20) and subjected to experimental treatment protocols. This included a positive control (no treatment of biofilms), syringe irrigation alone with TruNatomy needle, passive ultrasonically activated irrigation with 20# Irrisafe tip, and laser agitation of irrigant with Er,Cr:YSGG laser using RFT 2 laser tip. Root canals of experimental specimens (except the control samples) are instrumented with TruNatomy rotary file system using 1:1 mixture of 3% NaOCl and 18% etidronic acid as irrigants. The quantitative assessment of reduction in viable biofilm microbes after treatment was done using colony-forming unit counts and confocal laser scanning microscopy image analysis. The obtained data were analyzed statistically with a significant level set at 0.05.<br><br>RESULTS: Laser-assisted irrigation has shown a considerably higher mean percentage reduction of microbes compared to ultrasonic agitation and the syringe irrigation showed the least microbial reduction (P = 0.001). No significant difference was noted between the three root regions of ultrasonic and laser groups (P > 0.05), whereas in the syringe groups, apical portions showed higher microbial counts compared to cervical and mid-root regions (P = 0.001).<br><br>CONCLUSION: Erbium laser-assisted irrigation has performed superior to ultrasonic agitation against both the experimental dual-species biofilms, while the syringe irrigation showed the least microbial reduction specifically at apical root portions.}, }
@article {pmid38988529, year = {2024}, author = {Wang, D and Zeng, N and Li, C and Li, Z and Zhang, N and Li, B}, title = {Fungal biofilm formation and its regulatory mechanism.}, journal = {Heliyon}, volume = {10}, number = {12}, pages = {e32766}, pmid = {38988529}, issn = {2405-8440}, abstract = {Fungal biofilm is a microbial community composed of fungal cells and extracellular polymeric substances (EPS). In recent years, fungal biofilms have played an increasingly important role in many fields. However, there are few studies on fungal biofilms and their related applications and development are still far from enough. Therefore, this review summarizes the composition and function of EPS in fungal biofilms, and improves and refines the formation process of fungal biofilms according to the latest viewpoints. Moreover, based on the study of Saccharomyces cerevisiae and Candida albicans, this review summarizes the gene regulation network of fungal biofilm synthesis, which is crucial for systematically understanding the molecular mechanism of fungal biofilm formation. It is of great significance to further develop effective methods at the molecular level to control harmful biofilms or enhance and regulate the formation of beneficial biofilms. Finally, the quorum sensing factors and mixed biofilms formed by fungi in the current research of fungal biofilms are summarized. These results will help to deepen the understanding of the formation process and internal regulation mechanism of fungal biofilm, provide reference for the study of EPS composition and structure, formation, regulation, group behavior and mixed biofilm formation of other fungal biofilms, and provide strategies and theoretical basis for the control, development and utilization of fungal biofilms.}, }
@article {pmid38988475, year = {2024}, author = {Khadraoui, N and Essid, R and Damergi, B and Fares, N and Gharbi, D and Forero, AM and Rodríguez, J and Abid, G and Kerekes, EB and Limam, F and Jiménez, C and Tabbene, O}, title = {Myrtus communis leaf compounds as novel inhibitors of quorum sensing-regulated virulence factors and biofilm formation: In vitro and in silico investigations.}, journal = {Biofilm}, volume = {8}, number = {}, pages = {100205}, pmid = {38988475}, issn = {2590-2075}, abstract = {Antibiotic resistance of the Gram-negative bacterium Pseudomonas aeruginosa and its ability to form biofilm through the Quorum Sensing (QS) mechanism are important challenges in the control of infections caused by this pathogen. The extract of Myrtus communis (myrtle) showed strong anti-QS effect on C hromobacterium . violaceum 6267 by inhibiting 80 % of the production of violacein pigment at a sub-MIC concentration of 1/8 (31.25 μg/mL). In addition, the extract exhibited an inhibitory effect on virulence factors of P. aeruginosa PAO1 at half MIC (125 μg/mL), significantly reducing the formation of biofilms (72.02 %), the swarming activity (75 %), and the production of protease (61.83 %) and pyocyanin (97 %). The active fraction also downregulated the expression of selected regulatory genes involved in the biofilm formation and QS in the P. aeruginosa PAO1 strain. These genes included the autoinducer synthase genes (lasI and rhlI), the genes involved in the expression of their corresponding receptors (lasR and rhlR), and the pqsA genes. The analysis of the active fraction by HPLC/UV/MS and NMR allowed the identification of three phenolic compounds, 3,5-di-O-galloylquinic acid, myricetin 3-O-α-l-rhamnopyranoside (myricitrin), and myricetin 3-O-(2″-O-galloyl)-ß-d-galactopyranoside. In silico studies showed that 3,5-di-O-galloylquinic acid, with an affinity score of -9.20 kcal/mol, had the highest affinity to the active site of the CviR protein (3QP8), a QS receptor from C. violaceum. Additionally, myricetin 3-O-α-l-rhamnopyranoside (myricitrin) and myricetin 3-O-(2″-O-galloyl)-ß-d-galactopyranoside interact to a lesser extent with 3QP8. In conclusion, this study contributed significantly to the discovery of new QS inhibitors from M. communis leaves against resistant Gram-negative pathogens.}, }
@article {pmid38988413, year = {2024}, author = {Dietl, S and Merkl, P and Sotiriou, GA}, title = {Prevention of uropathogenic E. coli biofilm formation by hydrophobic nanoparticle coatings on polymeric substrates.}, journal = {RSC applied interfaces}, volume = {1}, number = {4}, pages = {667-670}, pmid = {38988413}, issn = {2755-3701}, abstract = {Biofilms in infections are a major health-care challenge and strategies to reduce their formation on medical devices are crucial. Fabrication of superhydrophobic coatings based on hydrocarbon adsorption on rare-earth oxides constitutes an attractive strategy, but their capacity to prevent biofilm formation has not been studied. Here, we explore a scalable and reproducible nanofabrication process for the manufacture of such superhydrophobic coatings and study their antibiofilm activity against clinically-relevant uropathogenic E. coli. These coatings reduce bacterial biofilm formation and prevent biofouling with potential applications preventing medical device related infections.}, }
@article {pmid38986879, year = {2024}, author = {Han, NN and Yang, JH and Fan, NS and Jin, RC}, title = {Mechanistic insight into microbial interaction and metabolic pattern of anammox consortia on surface-modified biofilm carrier with extracellular polymeric substances.}, journal = {Bioresource technology}, volume = {407}, number = {}, pages = {131092}, doi = {10.1016/j.biortech.2024.131092}, pmid = {38986879}, issn = {1873-2976}, abstract = {The extremely slow growth rate of anaerobic ammonia oxidation (anammox) bacteria limits full-scale application of anammox process worldwide. In this study, extracellular polymeric substances (EPS)-coated polypropylene (PP) carriers were prepared for biofilm formation. The biomass adhesion rate of EPS-PP carrier was 12 times that of PP carrier, and EPS-PP achieved significant enrichment of E. coli BY63. The 120-day continuous flow experiment showed that the EPS-PP carrier accelerated the formation of anammox biofilm, and the nitrogen removal efficiency increased by 10.5 %. In addition, the abundance of Candidatus Kuenenia in EPS-PP biofilm was 27.1%. Simultaneously, amino acids with high synthesis cost and the metabolites of glycerophospholipids related to biofilm formation on EPS-PP biofilm were significantly up-regulated. Therefore, EPS-PP carriers facilitated the rapid formation of anammox biofilm and promoted the metabolic activity of functional bacteria, which further contributed to the environmental and economic sustainability of anammox process.}, }
@article {pmid38986504, year = {2024}, author = {Martin, JD and Tisler, S and Scheel, M and Svendsen, S and Anwar, MZ and Zervas, A and Ekelund, F and Bester, K and Hansen, LH and Jacobsen, CS and Ellegaard-Jensen, L}, title = {Total RNA analysis of the active microbiome on moving bed biofilm reactor carriers under incrementally increasing micropollutant concentrations.}, journal = {FEMS microbiology ecology}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsec/fiae098}, pmid = {38986504}, issn = {1574-6941}, abstract = {Micropollutants are increasingly prevalent in the aquatic environment. A major part of these originates from wastewater treatment plants since traditional treatment technologies do not remove micropollutants sufficiently. Moving bed biofilm reactors (MBBRs), however, have been shown to aid in micropollutant removal when applied to conventional wastewater treatment as a polishing step. Here, we used Total RNA sequencing to investigate both the active microbial community and functional dynamics of MBBR biofilms when these were exposed to increasing micropollutant concentrations over time. Concurrently, we conducted batch culture experiments using biofilm carriers from the MBBRs to assess micropollutant degradation potential. Our study showed that biofilm eukaryotes, in particular protozoa, were negatively influenced by micropollutant exposure, in contrast to prokaryotes that increased in relative abundance. Further, we found several functional genes that were differentially expressed between the MBBR with added micropollutants and the control. These include genes involved in aromatic and xenobiotic compound degradation. Moreover, the biofilm carrier batch experiment showed vastly different alterations in benzotriazole and diclofenac degradation following the increased micropollutant concentrations in the MBBR. Ultimately, this study provides essential insights into the microbial community and functional dynamics of MBBRs and how an increased load of micropollutants influences these dynamics.}, }
@article {pmid38984682, year = {2024}, author = {Fruleux, T and Sauleau, P and Caudal, F and Champion, M and Chauvin, L and Castro, M and Le Duigou, A}, title = {Marine biofilm formation on flax fibre reinforced biocomposites.}, journal = {Biofouling}, volume = {40}, number = {7}, pages = {415-430}, doi = {10.1080/08927014.2024.2373870}, pmid = {38984682}, issn = {1029-2454}, mesh = {*Biofilms/growth &amp; development ; *Flax/microbiology/chemistry ; *Pseudoalteromonas/physiology ; Bacterial Adhesion ; }, abstract = {Artificial reefs represent useful tools to revitalize coastal and ocean ecosystems. Their formulation determines the biofilm formation which is the prerequisite for the colonization process by marine micro- and macroorganisms. In comparison with concrete, biobased polymers offer improved characteristics, including architecture, formulation, rugosity and recycling. This article aims to explore a new scale of artificial reef made of biocomposites reinforced with a high flax fibre (Linum utilatissimum) content (30%). Cellular adhesion and resulting biofilm formation were assessed using two marine microorganisms: Pseudoalteromonas sp. 3J6 and Cylindrotheca closterium. The influence of flax fibre leachates and plastic monomers on the growth of those marine microorganisms were also evaluated. Results indicated that the introduction of flax fibres inside the polymer matrix modified its physicochemical properties thus modulating adhesion and biofilm formation depending on the microorganism. This study gives insights for further developments of novel functionalized artificial reefs made of biocomposites.}, }
@article {pmid38982956, year = {2024}, author = {Ramaiah, KB and Suresh, I and Srinandan, CS and Sai Subramanian, N and Rayappan, JBB}, title = {A dual-sensing strategy for the early diagnosis of urinary tract infections via detecting biofilm cellulose using aromatic amino acid-capped Au and Ag nanoparticles.}, journal = {Journal of materials chemistry. B}, volume = {}, number = {}, pages = {}, doi = {10.1039/d4tb00902a}, pmid = {38982956}, issn = {2050-7518}, abstract = {Currently, urinary tract infection (UTI) diagnosis focuses on planktonic cell detection rather than biofilm detection, but the facile identification of UPEC bacterial biofilms is crucial in UTI diagnosis as the biofilm formed by bacteria is the causative agent of recurrent and chronic UTIs. Therefore, in this work, we developed a simple, cost-effective, colorimetric, and electrochemical-based strategy for the detection of cellulose in urine. Cellulose, a biofilm matrix component, was detected using tyrosine-capped gold and silver nanoparticles through a visible colorimetric change with a decrease in the absorbance intensity and a decrease in current response in the case of cyclic voltammetry. The sensor displayed a linear detection range of 10-70 mg mL[-1] for colorimetry and 10-300 μg mL[-1] for cyclic voltammetry with a good selectivity of <2.8% and a recovery rate of 95-100% in real-time sample analysis. Moreover, the binding affinity of cellulose with tyrosine was investigated using molecular docking studies to validate the sensing mechanism. We anticipate that our work will aid clinicians in the implementation of rapid, cost-effective, and definitive diagnosis of UTIs.}, }
@article {pmid38980701, year = {2024}, author = {Yazdani-Ahmadabadi, H and Yu, K and Gonzalez, K and Luo, HD and Lange, D and Kizhakkedathu, JN}, title = {Long-Term Prevention of Biofilm Formation by Polycatechol-Based Supramolecular Assemblies with Low Molecular Weight Polymers on Surfaces.}, journal = {ACS applied materials &amp; interfaces}, volume = {16}, number = {29}, pages = {38631-38644}, pmid = {38980701}, issn = {1944-8252}, mesh = {*Biofilms/drug effects ; *Catechols/chemistry/pharmacology ; *Polymers/chemistry/pharmacology ; *Staphylococcus aureus/drug effects/physiology ; Molecular Weight ; Surface Properties ; Anti-Bacterial Agents/pharmacology/chemistry ; Coated Materials, Biocompatible/chemistry/pharmacology ; }, abstract = {Achievement of a stable surface coating with long-term resistance to biofilm formation remains a challenge. Catechol-based polymerization chemistry and surface deposition are used as tools for surface modification of diverse materials. However, the control of surface deposition of the coating, surface coverage, coating properties, and long-term protection against biofilm formation remain to be solved. We report a new approach based on supramolecular assembly to generate long-acting antibiofilm coating. Here, we utilized catechol chemistry in combination with low molecular weight amphiphilic polymers for the generation of such coatings. Screening studies with diverse low molecular weight (LMW) polymers and different catechols are utilized to identify lead compositions, which resulted in a thick coating with high surface coverage, smoothness, and antibiofilm activity. We have identified that small supramolecular assemblies (∼10 nm) formed from a combination of polydopamine and LMW poly(N-vinyl caprolactam) (PVCL) resulted in relatively thick coating (∼300 nm) with excellent surface coverage in comparison to other polymers and catechol combinations. The coating properties, such as thickness (10-300 nm) and surface hydrophilicity (with water contact angle: 20-60°), are readily controlled. The optimal coating composition showed excellent antibiofilm properties with long-term (>28 days) antibiofilm activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) strains. We further utilized the combination of optimal binary coating with silver to generate a coating with sustained release of silver ions, resulting in killing both adhered and planktonic bacteria and preventing long-term surface bacterial colonization. The new coating method utilizing LMW polymers opens a new avenue for the development of a novel class of thick, long-acting antibiofilm coatings.}, }
@article {pmid38979200, year = {2024}, author = {Korshoj, LE and Kielian, T}, title = {Bacterial single-cell RNA sequencing captures biofilm transcriptional heterogeneity and differential responses to immune pressure.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2024.06.28.601229}, pmid = {38979200}, issn = {2692-8205}, abstract = {Biofilm formation is an important mechanism of survival and persistence for many bacterial pathogens. These multicellular communities contain subpopulations of cells that display vast metabolic and transcriptional diversity along with high recalcitrance to antibiotics and host immune defenses. Investigating the complex heterogeneity within biofilm has been hindered by the lack of a sensitive and high-throughput method to assess stochastic transcriptional activity and regulation between bacterial subpopulations, which requires single-cell resolution. We have developed an optimized bacterial single-cell RNA sequencing method, BaSSSh-seq, to study Staphylococcus aureus diversity during biofilm growth and transcriptional adaptations following immune cell exposure. We validated the ability of BaSSSh-seq to capture extensive transcriptional heterogeneity during biofilm compared to planktonic growth. Application of new computational tools revealed transcriptional regulatory networks across the heterogeneous biofilm subpopulations and identification of gene sets that were associated with a trajectory from planktonic to biofilm growth. BaSSSh-seq also detected alterations in biofilm metabolism, stress response, and virulence that were tailored to distinct immune cell populations. This work provides an innovative platform to explore biofilm dynamics at single-cell resolution, unlocking the potential for identifying biofilm adaptations to environmental signals and immune pressure.}, }
@article {pmid38977975, year = {2024}, author = {Alabdullatif, M}, title = {Evaluating the effects of temperature and agitation on biofilm formation of bacterial pathogens isolated from raw cow milk.}, journal = {BMC microbiology}, volume = {24}, number = {1}, pages = {251}, pmid = {38977975}, issn = {1471-2180}, mesh = {Animals ; *Biofilms/growth &amp; development ; *Milk/microbiology ; *Temperature ; Cattle ; *Bacteria/isolation &amp; purification/classification/growth &amp; development ; Saudi Arabia ; Food Microbiology ; Bacterial Physiological Phenomena ; }, abstract = {OBJECTIVES: To study the effect of agitation and temperature on biofilm formation (cell aggregates embedded within a self-produced matrix) by pathogenic bacteria isolated from Raw cow milk (RCM).<br><br>METHODS: A 40 RCM samples were gathered from eight dairy farms in Riyadh, Saudi Arabia. After bacterial culturing and isolation, gram staining was performed, and all pathogenic, identified using standard criteria established by Food Standards Australia New Zealand (FSANZ), and non-pathogenic bacteria were identified using VITEK-2 and biochemical assays. To evaluate the effects of temperature and agitation on biofilm formation, isolated pathogenic bacteria were incubated for 24&#xa0;h under the following conditions: 4&#xa0;&#xb0;C with no agitation (0&#xa0;rpm), 15&#xa0;&#xb0;C with no agitation, 30&#xa0;&#xb0;C with no agitation, 30&#xa0;&#xb0;C with 60&#xa0;rpm agitation, and 30&#xa0;&#xb0;C with 120&#xa0;rpm agitation. Then, biofilms were measured using a crystal violet assay.<br><br>RESULTS: Of the eight farm sites, three exhibited non-pathogenic bacterial contamination in their raw milk samples. Of the total of 40 raw milk samples, 15/40 (37.5%; from five farms) were contaminated with pathogenic bacteria. Overall, 346 bacteria were isolated from the 40 samples, with 329/346 (95.1%) considered as non-pathogenic and 17/346 (4.9%) as pathogenic. Most of the isolated pathogenic bacteria exhibited a significant (p&#x2009;<&#x2009;0.01) increase in biofilm formation when grown at 30&#xa0;&#xb0;C compared to 4&#xa0;&#xb0;C and when grown with 120&#xa0;rpm agitation compared to 0&#xa0;rpm.<br><br>CONCLUSION: Herein, we highlight the practices of consumers in terms of transporting and storing (temperature and agitation) can significantly impact on the growth of pathogens and biofilm formation in RCM.}, }
@article {pmid38977038, year = {2024}, author = {Kumar Jaiswal, V and Dutta Gupta, A and Sonwani, RK and Shekher Giri, B and Sharan Singh, R}, title = {Enhanced biodegradation of 2, 4-dichlorophenol in packed bed biofilm reactor by impregnation of polyurethane foam with Fe3O4 nanoparticles: Bio-kinetics, process optimization, performance evaluation and toxicity assessment.}, journal = {Bioresource technology}, volume = {406}, number = {}, pages = {131085}, doi = {10.1016/j.biortech.2024.131085}, pmid = {38977038}, issn = {1873-2976}, mesh = {*Chlorophenols ; *Polyurethanes/chemistry ; *Biofilms/drug effects ; *Biodegradation, Environmental ; Kinetics ; *Bioreactors ; Water Pollutants, Chemical ; Animals ; }, abstract = {In this work, an effort has been made to enhance the efficacy of biological process for the effective degradation of 2, 4-dichlorophenol (2, 4-DCP) from wastewater. The polyurethane foam was modified with Fe3O4 nanoparticles and combined with polyvinyl alcohol, sodium alginate, and bacterial consortium for biodegradation of 2, 4-DCP in a packed bed biofilm reactor. The maximum removal efficiency of 2, 4-DCP chemical oxygen demand, and total organic carbon were found to be 92.51 ± 0.83 %, 86.85 ± 1.32, and 91.78 ± 1.24 %, respectively, in 4 days and 100 mg L[-1] of 2, 4-DCP concentration at an influent loading rate of 2 mg L[-1]h[-1] and hydraulic retention time of 50 h. Packed bed biofilm reactor was effective for up to four cycles to remove 2, 4-DCP. Growth inhibition kinetics were evaluated using the Edward model, yielding maximum growth rate of 0.45 day[-1], inhibition constant of 110.6 mg L[-1], and saturation constant of 62.3 mg L[-1].}, }
@article {pmid38975180, year = {2024}, author = {Jonblat, S and As-Sadi, F and El Khoury, A and Badr, N and Kallassy, M and Chokr, A}, title = {Determining the dispersion time in Staphylococcus epidermidis biofilm using physical and molecular approaches.}, journal = {Heliyon}, volume = {10}, number = {12}, pages = {e32389}, pmid = {38975180}, issn = {2405-8440}, abstract = {Despite being an innocuous commensal of human skin and mucous membranes, Staphylococcus epidermidis, infects surgical wounds and causes infections through biofilm formation. This study evaluates, in a time-dependent experiment, the self-dispersion of S. epidermidis CIP 444 biofilm when formed on borosilicate glass (hydrophilic) and polystyrene (hydrophobic) surfaces, using physical and molecular approaches. During a seven-day period of incubation, absorbance measurement revealed a drop in biofilm optical density on both studied surfaces on day 4 (0.043-0.035 nm/cm[2], polystyrene), (0.06-0.053 nm/cm[2], borosilicate glass). Absorbance results were correlated with crystal violet staining that showed a clear detachment from day 4. The blue color increases again on day 7, with an increase in biofilm optical density indicating the regeneration of the biofilm. Changes in gene expression in the S. epidermidis biofilm were assessed using a real-time reverse transcription-polymerase chain reaction. High expression of agr genes was detected on days 4 and 5, confirming our supposition of dispersion in this period, autolysin genes like atlE1 and aae were upregulated from day 3 until day 6 and the genes responsible for slime production and biofilm accumulation, were upregulated on days 4, 5, and 6 (ica ADBC) and on days 5, 6 and 7 (aap), indicating a dual process taking place. These findings suggest that S. epidermidis CIP 444 biofilms disperse at day 4 and reform at day 7. Over the course of the seven-day investigation, 2[-ΔΔCt] results showed that some genes in the biofilm were dramatically enhanced while others were significantly decreased as compared to planktonic ones.}, }
@article {pmid38974467, year = {2024}, author = {Myers, C and Atkins, GR and Villarreal, J and Sutton, RB and Cornwall, GA}, title = {The mouse epididymal amyloid matrix is a mammalian counterpart of a bacterial biofilm.}, journal = {iScience}, volume = {27}, number = {6}, pages = {110152}, pmid = {38974467}, issn = {2589-0042}, abstract = {The mouse epididymis is a long tubule connecting the testis to the vas deferens. Its primary functions are to mature spermatozoa into motile and fertile cells and to protect them from pathogens that ascend the male tract. We previously demonstrated that a functional extracellular amyloid matrix surrounds spermatozoa in the epididymal lumen and has host defense functions, properties not unlike that of an extracellular biofilm that encloses and protects a bacterial community. Here we show the epididymal amyloid matrix also structurally resembles a biofilm by containing eDNA, eRNA, and mucin-like polysaccharides. Further these structural components exhibit comparable behaviors and perform functions such as their counterparts in bacterial biofilms. Our studies suggest that nature has used the ancient building blocks of bacterial biofilms to form an analogous structure that nurtures and protects the mammalian male germline.}, }
@article {pmid38974376, year = {2024}, author = {Hu, Z and Yin, X and Fan, G and Liao, X}, title = {Global Trends in Orthopedic Biofilm Research: A Bibliometric Analysis of 1994-2022.}, journal = {Journal of multidisciplinary healthcare}, volume = {17}, number = {}, pages = {3057-3069}, pmid = {38974376}, issn = {1178-2390}, abstract = {OBJECTIVE: Bibliometric analysis is commonly used to visualize the knowledge foundation, trends, and patterns in a specific scientific field by performing a quantitative evaluation of the relevant literature. The purpose of this study was to perform a bibliometric analysis of recent studies in the field of orthopedic biofilm research and identify its current trends and hotspots.<br><br>METHODS: Research studies were retrieved from the Web of Science Core Collection and Scopus databases and analyzed in bibliometrix with R package (4.2.2).<br><br>RESULTS: A total of 2426 literature were included in the study. Journal of orthopaedic research and Clinical orthopaedics and related research ranked first in terms of productivity and impact, with 57 published articles and 32 h-index, respectively. Trampuz A, Ohio State Univ and the United States ranked as the most productive authors, institutions, and countries. Biofilm formation, role of sonication, biomaterial mechanism and antibiotic loading have been investigated as the trend and hotspots in the field of orthopedic biofilm research.<br><br>CONCLUSION: This study provides a thorough overview of the state of the art of current orthopedic biofilm research and offers valuable insights into recent trends and hotspots in this field.}, }
@article {pmid38973924, year = {2024}, author = {Sedighi, O and Bednarke, B and Sherriff, H and Doiron, AL}, title = {Nanoparticle-Based Strategies for Managing Biofilm Infections in Wounds: A Comprehensive Review.}, journal = {ACS omega}, volume = {9}, number = {26}, pages = {27853-27871}, pmid = {38973924}, issn = {2470-1343}, abstract = {Chronic wounds containing opportunistic bacterial pathogens are a growing problem, as they are the primary cause of morbidity and mortality in developing and developed nations. Bacteria can adhere to almost every surface, forming architecturally complex communities called biofilms that are tolerant to an individual's immune response and traditional treatments. Wound dressings are a primary source and potential treatment avenue for biofilm infections, and research has recently focused on using nanoparticles with antimicrobial activity for infection control. This Review categorizes nanoparticle-based approaches into four main types, each leveraging unique mechanisms against biofilms. Metallic nanoparticles, such as silver and copper, show promising data due to their ability to disrupt bacterial cell membranes and induce oxidative stress, although their effectiveness can vary based on particle size and composition. Phototherapy-based nanoparticles, utilizing either photodynamic or photothermal therapy, offer targeted microbial destruction by generating reactive oxygen species or localized heat, respectively. However, their efficacy depends on the presence of light and oxygen, potentially limiting their use in deeper or more shielded biofilms. Nanoparticles designed to disrupt extracellular polymeric substances directly target the biofilm structure, enhancing the penetration and efficacy of antimicrobial agents. Lastly, nanoparticles that induce biofilm dispersion represent a novel strategy, aiming to weaken the biofilm's defense and restore susceptibility to antimicrobials. While each method has its advantages, the selection of an appropriate nanoparticle-based treatment depends on the specific requirements of the wound environment and the type of biofilm involved. The integration of these nanoparticles into wound dressings not only promises enhanced treatment outcomes but also offers a reduction in the overall use of antibiotics, aligning with the urgent need for innovative solutions in the fight against antibiotic-tolerant infections. The overarching objective of employing these diverse nanoparticle strategies is to replace antibiotics or substantially reduce their required dosages, providing promising avenues for biofilm infection management.}, }
@article {pmid38973863, year = {2024}, author = {Wong, MY and Lin, BS and Hu, PS and Huang, TY and Huang, YK}, title = {Nanoparticles of Cs0.33WO3 as Antibiofilm Agents and Photothermal Treatment to Inhibit Biofilm Formation.}, journal = {ACS omega}, volume = {9}, number = {26}, pages = {28144-28154}, pmid = {38973863}, issn = {2470-1343}, abstract = {Metal oxide nanoparticles with photothermal properties have attracted considerable research attention for their use in biomedical applications. Cesium tungsten oxide (Cs0.33WO3) nanoparticles (NPs) exhibit strong absorption in the NIR region due to localized surface plasmon resonance, through which they convert light to heat; hence, they can be applied to photothermal treatment for bacteria and biofilm ablation. Herein, Cs0.33WO3 NPs were synthesized through solid-phase synthesis, and their physical properties were characterized through Zetasizer, energy dispersive X-ray spectroscopy, Fourier transform infrared spectrometer, and scanning and transmission electron microscopy (SEM and TEM, respectively). Burkholderia cenocepacia isolates were cultured in tryptic soy broth supplemented with glucose, and the biofilm inhibition and antibiofilm effects of the NPs were determined using a crystal violet assay and the Cell Counting Kit-8 (CCK-8) assay. The biofilm morphology and viability of NP-treated cultures after NIR irradiation were evaluated through SEM and confocal microscopy, respectively. The cytotoxicity of NPs to human macrophages was also assessed using the CCK-8 assay. The NPs effectively inhibited biofilm formation, with a formation rate of <10% and a viability rate of <50% at the concentration of ≥200 μg/mL. The confocal analysis revealed that NIR irradiation markedly enhanced biofilm cytotoxicity after treatment with the NPs. The assay of cytotoxicity to human macrophages demonstrated the biocompatibility of the NPs and NIR irradiation. In sum, the Cs0.33WO3 NPs displayed effective biofilm inhibition and antibiofilm activity at 200 μg/mL treatment concentration; they exhibited an enhancement effect under the NIR irradiation, suggesting Cs0.33WO3 NPs are a potential candidate agent for NIR-irradiated photothermal treatment in bacterial biofilm inhibition and antibiofilm.}, }
@article {pmid38973737, year = {2024}, author = {Ji, Y and Hao, J and Tao, X and Li, Z and Chen, L and Qu, N}, title = {Preparation and anti-tumor activity of paclitaxel silk protein nanoparticles encapsulated by biofilm.}, journal = {Pharmaceutical development and technology}, volume = {29}, number = {6}, pages = {627-638}, doi = {10.1080/10837450.2024.2376075}, pmid = {38973737}, issn = {1097-9867}, mesh = {*Paclitaxel/administration &amp; dosage/pharmacokinetics/pharmacology ; *Nanoparticles/chemistry ; Animals ; Humans ; *Antineoplastic Agents, Phytogenic/administration &amp; dosage/pharmacokinetics/pharmacology ; *Biofilms/drug effects ; *Silk/chemistry ; Cell Line, Tumor ; Mice ; Drug Carriers/chemistry ; Escherichia coli/drug effects ; Biological Availability ; Male ; Rats ; Mice, Inbred BALB C ; }, abstract = {In order to overcome the poor bioavailability of paclitaxel (PTX), in this study, self-assembled paclitaxel silk fibronectin nanoparticles (PTX-SF-NPs) were encapsulated with outer membrane vesicles of Escherichia coli (E. coil), and biofilm-encapsulated paclitaxel silk fibronectin nanoparticles (OMV-PTX-SF-NPs) were prepared by high-pressure co-extrusion, the size and zeta potential of the OMV-PTX-SF-NPs were measured. The antitumor effects of OMV-PTX-SF-NPs were evaluated by cellular and pharmacodynamic assays, and pharmacokinetic experiments were performed. The results showed that hydrophobic forces and hydrogen bonding played a major role in the interaction between paclitaxel and filipin proteins, and the size of OMV-PTX-SF-NPs was 199.8 ± 2.8 nm, zeta potential was -17.8 ± 1.3 mv. The cellular and in vivo pharmacokinetic assays demonstrated that the OMV-PTX-SF-NPs possessed a promising antitumor effect. Pharmacokinetic experiments showed that the AUC0-∞ of OMV-PTX-SF-NPs was 5.314 ± 0.77, which was much larger than that of free PTX, which was 0.744 ± 0.14. Overall, we have successfully constructed a stable oral formulation of paclitaxel with a sustained-release effect, which is able to effectively increase the bioavailability of paclitaxel, improve the antitumor activity, and reduce the adverse effects.}, }
@article {pmid38972505, year = {2024}, author = {Ohara, K and Tomiyama, K and Okuda, T and Tsutsumi, K and Ishihara, C and Hashimoto, D and Fujii, Y and Chikazawa, T and Kurita, K and Mukai, Y}, title = {Dipotassium glycyrrhizate prevents oral dysbiosis caused by Porphyromonas gingivalis in an in vitro saliva-derived polymicrobial biofilm model.}, journal = {Journal of oral biosciences}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.job.2024.07.001}, pmid = {38972505}, issn = {1880-3865}, abstract = {OBJECTIVES: Oral microbiome dysbiosis prevention is important to avoid the onset and progression of periodontal disease. Dipotassium glycyrrhizate (GK2) is a licorice root extract with anti-inflammatory effects, and its associated mechanisms have been well-reported. However, their effects on the oral microbiome have not been investigated. This study aimed to elucidate the effects of GK2 on the oral microbiome using an in vitro polymicrobial biofilm model.<br><br>METHODS: An in vitro saliva-derived polymicrobial biofilm model was used to evaluate the effects of GK2 on the oral microbiome. One-week anaerobic culture was performed, in which GK2 was added to the medium. Subsequently, microbiome analysis was performed based on the V1-V2 region of the 16S rRNA gene, and pathogenicity indices were assessed. We investigated the effects of GK2 on various bacterial monocultures by evaluating its inhibitory effects on cell growth, based on culture turbidity.<br><br>RESULTS: GK2 treatment altered the microbiome structure and decreased the relative abundance of periodontal pathogenic bacteria, including Porphyromonas. Moreover, GK2 treatment reduced the DPP4 activity -a pathogenicity index of periodontal disease. Specifically, GK2 exhibited selective antibacterial activity against periodontal pathogenic bacteria.<br><br>CONCLUSIONS: These findings suggest that GK2 has a selective antibacterial effect against periodontal pathogenic bacteria; thus, preventing oral microbiome dysbiosis. Therefore, GK2 is expected to contribute to periodontal disease prevention by modulating the oral microbiome toward a state with low inflammatory potential, thereby utilizing its anti-inflammatory properties on the host.}, }
@article {pmid38972366, year = {2024}, author = {Chaves, AC and Boa Ventura, PV and Pereira, MS and da Silva, BF and de Carvalho, FJN and Costa, RA and Lima, BP and Maciel, WC and Carneiro, VA}, title = {Preliminary snapshot reveals a relationship between multidrug-resistance and biofilm production among enterobacteriaceae isolated from fecal samples of farm-raised poultry in ceará, Brazil.}, journal = {Microbial pathogenesis}, volume = {193}, number = {}, pages = {106778}, doi = {10.1016/j.micpath.2024.106778}, pmid = {38972366}, issn = {1096-1208}, mesh = {Animals ; *Biofilms/growth &amp; development/drug effects ; Brazil ; *Drug Resistance, Multiple, Bacterial ; *beta-Lactamases/genetics/metabolism ; *Feces/microbiology ; *Enterobacteriaceae/drug effects/isolation &amp; purification/genetics ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology ; *Chickens/microbiology ; *Farms ; Bacterial Proteins/genetics/metabolism ; Poultry/microbiology ; Enterobacteriaceae Infections/microbiology/veterinary ; }, abstract = {Antimicrobial resistance and biofilm formation by microbial pathogens pose a significant challenge to poultry production systems due to the persistent risk of dissemination and compromise of bird health and productivity. In this context, the study aimed to investigate the occurrence of different multiresistance phenotypes and the biofilm-forming ability of Enterobacteriaceae isolated from broiler chicken excreta in poultry production units in Ceará, Brazil. Samples were collected from three distinct broiler breeding facilities and subjected to isolation, identification, antibiotic susceptibility testing, phenotypic screening for β-lactamases enzymes, and biofilm formation evaluation. Seventy-one strains were identified, being Escherichia coli (37 %) and Proteus mirabilis (32 %), followed by Klebsiella pneumoniae (11 %), Providencia stuartii (9 %), Klebsiella aerogenes (6 %), Alcaligenes faecalis (4 %), and Salmonella sp. (1 %). A significant proportion (87 %) of multiresistant strains were detected. For the phenotypic evaluation of β-lactamases production, strains with resistance to second and third-generation cephalosporins and carbapenems were tested. About 4 of 6 and 10 of 26 were positive for inducible chromosomal AmpC β-lactamase and extended-spectrum β-lactamase (ESBL), respectively. Regarding biofilm formation, it was observed that all MDR strains were capable of forming biofilm. In this sense the potential of these MDR bacteria to develop biofilms becomes a significant concern, representing a real threat to both human and animal health, as biofilms offer stability, antimicrobial protection, and facilitate genetic transfer.}, }
@article {pmid38972365, year = {2024}, author = {Devi B, A and K V, L and Sugumar, S}, title = {Isolation and characterization of bacteriophages against E.coli urinary tract infection and evaluating their anti-biofilm activity and antibiotic synergy.}, journal = {Microbial pathogenesis}, volume = {193}, number = {}, pages = {106789}, doi = {10.1016/j.micpath.2024.106789}, pmid = {38972365}, issn = {1096-1208}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Urinary Tract Infections/microbiology ; *Uropathogenic Escherichia coli/drug effects/virology ; *Anti-Bacterial Agents/pharmacology ; Humans ; *Escherichia coli Infections/microbiology ; *Bacteriophages/isolation &amp; purification/physiology ; Phage Therapy ; Myoviridae/isolation &amp; purification/physiology ; Drug Synergism ; Microbial Sensitivity Tests ; }, abstract = {Urinary tract infections (UTIs) by Uropathogenic Escherichia coli (UPEC) are a significant health concern, especially due to the increasing prevalence of antibiotic resistance. This study focuses on isolating and characterizing bacteriophages specific to UPEC strains isolated from UTI samples. The isolated phages were assessed for their ability to target and lyse UPEC in vitro, focusing on their efficacy in disrupting biofilms, a key virulence factor contributing to UTI recurrence and antibiotic resistance. The morphological structure observed by TEM belongs to Myoviridae, the phage exhibited icosahedral symmetry with a long non-constricting tail, the approximate measurement of the phage head was 39 nm in diameter, and the phage tail was 105.317 nm in length. One-step growth experiments showed that the latent period was approximately 20 min, followed by a rise period of 40 min, and a growth plateau was reached within 20 min and the burst size observed was 26 phages/infected bacterial cells. These phages were capable of killing cells within the biofilms, leading to a reduction in living cell counts after a single treatment. This study highlights the potential of phages to play a significant role in disrupting, inactivating, and destroying Uropathogenic Escherichia coli (UPEC) biofilms. Such findings could be instrumental in developing treatment strategies that complement antibiotics and disinfectants. The phage-antibiotic synergistic activity was compared to have the possibility to facilitate the advancement of focused and enduring alternatives to traditional antibiotic therapies for UTIs.}, }
@article {pmid38971825, year = {2024}, author = {Choi, HY and Kim, WG}, title = {Tyrosol blocks E. coli anaerobic biofilm formation via YbfA and FNR to increase antibiotic susceptibility.}, journal = {Nature communications}, volume = {15}, number = {1}, pages = {5683}, pmid = {38971825}, issn = {2041-1723}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Phenylethyl Alcohol/analogs &amp; derivatives/pharmacology ; *Anti-Bacterial Agents/pharmacology ; *Escherichia coli/drug effects ; *Pseudomonas aeruginosa/drug effects/physiology ; *Nitric Oxide/metabolism ; Escherichia coli Proteins/metabolism/genetics/antagonists &amp; inhibitors ; Anaerobiosis/drug effects ; Microbial Sensitivity Tests ; Gene Expression Regulation, Bacterial/drug effects ; Cyclic GMP/metabolism/analogs &amp; derivatives ; Bacterial Proteins/metabolism/genetics/antagonists &amp; inhibitors ; }, abstract = {Bacteria within mature biofilms are highly resistant to antibiotics than planktonic cells. Oxygen limitation contributes to antibiotic resistance in mature biofilms. Nitric oxide (NO) induces biofilm dispersal; however, low NO levels stimulate biofilm formation, an underexplored process. Here, we introduce a mechanism of anaerobic biofilm formation by investigating the antibiofilm activity of tyrosol, a component in wine. Tyrosol inhibits E. coli and Pseudomonas aeruginosa biofilm formation by enhancing NO production. YbfA is identified as a target of tyrosol and its downstream targets are sequentially determined. YbfA activates YfeR, which then suppresses the anaerobic regulator FNR. This suppression leads to decreased NO production, elevated bis-(3'-5')-cyclic dimeric GMP levels, and finally stimulates anaerobic biofilm formation in the mature stage. Blocking YbfA with tyrosol treatment renders biofilm cells as susceptible to antibiotics as planktonic cells. Thus, this study presents YbfA as a promising antibiofilm target to address antibiotic resistance posed by biofilm-forming bacteria, with tyrosol acting as an inhibitor.}, }
@article {pmid38971078, year = {2024}, author = {Ren, Y and Oleszkiewicz, JA and Uyaguari, M and Devlin, TR}, title = {Response and recovery of nitrifying moving bed biofilm reactor systems exposed to 1°C with varying levels of ammonia starvation.}, journal = {Water research}, volume = {261}, number = {}, pages = {122026}, doi = {10.1016/j.watres.2024.122026}, pmid = {38971078}, issn = {1879-2448}, abstract = {This study investigated the impact of varying total ammonia nitrogen (TAN) feed levels along with water temperature decreases on the performance of nitrifying moving bed biofilm reactor (MBBR) at 1 °C and its recovery at 3 °C. Five MBBR reactors were operated with different TAN concentrations as water temperature decreased from 20 to 3 °C: reactor R1 at 30 mg N/L, reactor R2 at 20 mg N/L, reactor R3 at 15 mg N/L, reactor R4 at 10 mg N/L and reactor R5 at 0 mg N/L. The corresponding biofilm characteristics were also analyzed to understand further nitrifying MBBR under different TAN feeding scenarios. The findings revealed that the higher TAN levels were before reaching 1 °C, the better nitrification performance and the more biomass grew. However, the highest TAN concentration (30 mg N/L) might negatively affect the nitrification performance, the activity of nitrifiers, and the growth of biofilms at 1 °C because of the toxic effects of un-ionized or free ammonia (FA). It was observed that the activities of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were affected by FA concentrations ranging from 0.2 to 0.7 mg N/L at 1 °C, but they could gradually be adapted to such inhibitory environment, with NOB recovering more quickly and robustly than AOB. The study identified 20 mg N/L (67 % of maximum influent TAN at 1 °C in R2 as the optimal TAN feeding concentration, achieving over 90 % TAN removal and a surface area removal rate (SARR) of 0.78 ± 0.02 g N/m[2]·d at 1 °C. Meanwhile, R2 also exhibited the highest biofilm mass, with total solids at 13.3 mg/carrier and volatile solids at 11.3 mg/carrier. As TAN was removed, nitrite accumulation was observed at 1 °C, and higher influent TAN concentrations prior to 1 °C appeared to delay the accumulation. When water temperature increased from 1 °C to 3 °C, nitrification performance improved significantly in all reactors without nitrite accumulation, and the higher TAN feeding in the previous stage led to faster recovery. Compared with 20 °C, biofilm became thinner and denser at 1 °C and 3 °C. Furthermore, this study revealed significant shifts in microbial community composition and nitrifier abundances in response to changes in water temperature and influent TAN levels. The dominant nitrifiers were identified as Nitrosomonadaceae (AOB) and Nitrospiraceae (NOB). At 1 °C, the nitrifier abundances were significantly correlated with SARRs, FA, and biofilm density. R2, which exhibited the best nitrification performance, maintained higher nitrifier abundances at 1 °C.}, }
@article {pmid38971076, year = {2024}, author = {Yu, M and Guo, W and Liang, Y and Xiang, H and Xia, Y and Feng, H}, title = {Towards rapid formation of electroactive biofilm: insights from thermodynamics and electric field manipulation.}, journal = {Water research}, volume = {261}, number = {}, pages = {121992}, doi = {10.1016/j.watres.2024.121992}, pmid = {38971076}, issn = {1879-2448}, abstract = {Electroactive biofilm (EAB) has garnered significant attention due to its effectiveness in pollutant remediation, electricity generation, and chemical synthesis. However, achieving precise control over the rapid formation of EAB presents challenges for the practical implementation of bioelectrochemical technology. In this study, we investigated the regulation of EAB formation by manipulating applied electric potential. We developed a modified XDLVO model for the applied electric field and quantitatively assessed the feasibility of existing rapid formation strategies for EAB. Our results revealed that electrostatic (EL) force significantly influenced EAB formation in the presence of the applied electric field, with the potential difference between the electrode and the microbial solution being the primary determinant of EL force. Compared to -0.2 V and 0 V vs.Ag/AgCl, EAB exhibited the highest electrochemical performance at 0.2 V vs.Ag/AgCl, with a maximum current density of 6.044 ± 0.10 A/m[2], surpassing that at -0.2 V vs.Ag/AgCl and 0 V vs.Ag/AgCl by 1.73 times and 1.31 times, respectively. Furthermore, EAB demonstrated the highest biomass accumulation, measuring a thickness of 25 ± 2 μm at 0.2 V vs. Ag/AgCl, representing increases of 1.67 and 1.25 times compared to -0.2 V vs.Ag/AgCl and 0 V vs.Ag/AgCl, respectively. The strong electrostatic attraction under the anodic potential promoted the formation of a monolayer of biofilm. Additionally, the hydrophilicity and hydrophobicity of the biofilm were altered following inversion culture. The Lewis acid-base (AB) attraction offset the electrostatic repulsion caused by negative charges, it is beneficial for the formation of biofilms. This study, for the first time, elucidated the difference in the formation of cathode and anode biofilm from a thermodynamic perspective in the context of electric field introduction, laying the theoretical foundation for the directional regulation of the rapid formation of typical electroactive biofilms.}, }
@article {pmid38969785, year = {2024}, author = {Rafique, M and Naveed, M and Mumtaz, MZ and Niaz, A and Alamri, S and Siddiqui, MH and Waheed, MQ and Ali, Z and Naman, A and Rehman, SU and Brtnicky, M and Mustafa, A}, title = {Unlocking the potential of biofilm-forming plant growth-promoting rhizobacteria for growth and yield enhancement in wheat (Triticum aestivum L.).}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {15546}, pmid = {38969785}, issn = {2045-2322}, mesh = {*Triticum/microbiology/growth &amp; development ; *Biofilms/growth &amp; development ; *Rhizosphere ; *Plant Roots/microbiology/growth &amp; development ; *Soil Microbiology ; Bacteria/classification/genetics/metabolism/growth &amp; development/isolation &amp; purification ; Plant Development ; Biomass ; }, abstract = {Plant growth-promoting rhizobacteria (PGPR) boost crop yields and reduce environmental pressures through biofilm formation in natural climates. Recently, biofilm-based root colonization by these microorganisms has emerged as a promising strategy for agricultural enhancement. The current work aims to characterize biofilm-forming rhizobacteria for wheat growth and yield enhancement. For this, native rhizobacteria were isolated from the wheat rhizosphere and ten isolates were characterized for plant growth promoting traits and biofilm production under axenic conditions. Among these ten isolates, five were identified as potential biofilm-producing PGPR based on in vitro assays for plant growth-promoting traits. These were further evaluated under controlled and field conditions for their impact on wheat growth and yield attributes. Surface-enhanced Raman spectroscopy analysis further indicated that the biochemical composition of the biofilm produced by the selected bacterial strains includes proteins, carbohydrates, lipids, amino acids, and nucleic acids (DNA/RNA). Inoculated plants in growth chamber resulted in larger roots, shoots, and increase in fresh biomass than controls. Similarly, significant increases in plant height (13.3, 16.7%), grain yield (29.6, 17.5%), number of tillers (18.7, 34.8%), nitrogen content (58.8, 48.1%), and phosphorus content (63.0, 51.0%) in grains were observed in both pot and field trials, respectively. The two most promising biofilm-producing isolates were identified through 16 s rRNA partial gene sequencing as Brucella sp. (BF10), Lysinibacillus macroides (BF15). Moreover, leaf pigmentation and relative water contents were significantly increased in all treated plants. Taken together, our results revealed that biofilm forming PGPR can boost crop productivity by enhancing growth and physiological responses and thus aid in sustainable agriculture.}, }
@article {pmid38969189, year = {2024}, author = {Hasan, M and Kim, J and Liao, X and Ding, T and Ahn, J}, title = {Antibacterial activity of bacteriophage-encoded endolysins against planktonic and biofilm cells of pathogenic Escherichia coli.}, journal = {Microbial pathogenesis}, volume = {193}, number = {}, pages = {106780}, doi = {10.1016/j.micpath.2024.106780}, pmid = {38969189}, issn = {1096-1208}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Escherichia coli/drug effects/genetics ; *Endopeptidases/pharmacology/genetics/metabolism ; *Anti-Bacterial Agents/pharmacology ; Hydrogen-Ion Concentration ; Plankton/drug effects/virology ; Coliphages/genetics/physiology ; Lactic Acid/pharmacology ; Bacteriophages/genetics ; Temperature ; Microbial Sensitivity Tests ; Plasmids/genetics ; Viral Proteins/genetics/pharmacology/metabolism ; }, abstract = {This study was designed to assess the possibility of using bacteriophage-encoded endolysins for controlling planktonic and biofilm cells. The endolysins, LysEP114 and LysEP135, were obtained from plasmid vectors containing the endolysin genes derived from Escherichia coli phages. The high identity (>96 %) was observed between LysEP114 and LysEP135. LysEP114 and LysEP135 were characterized by pH, thermal, and lactic acid stability, lytic spectrum, antibacterial activity, and biofilm eradication. The molecular masses of LysEP114 and LysEP135 were 18.2 kDa, identified as muramidases. LysEP114 and LysEP135 showed high lytic activity against the outer membrane-permeabilized E. coli KCCM 40405 at below 37 °C, between pH 5 to 11, and below 70 mM of lactic acid. LysEP114 and LysEP135 showed the broad rang of lytic activity against E. coli KACC 10115, S. Typhimurium KCCM 40253, S. Typhimurium CCARM 8009, tetracycline-resistant S. Typhimurium, polymyxin B-resistant S. Typhimurium, chloramphenicol-resistant S. Typhimurium, K. pneumoniae ATCC 23357, K. pneumoniae CCARM 10237, and Shigella boydii KACC 10792. LysEP114 and LysEP135 effectively reduced the numbers of planktonic E. coli KCCM by 1.7 and 2.1 log, respectively, when treated with 50 mM lactic acid. The numbers of biofilm cells were reduced from 7.3 to 4.1 log CFU/ml and 2.2 log CFU/ml, respectively, when treated with LysEP114- and LysEP135 in the presence of 50 mM lactic acid. The results suggest that the endolysins in combination with lactic acid could be potential alternative therapeutic agents for controlling planktonic and biofilm cells.}, }
@article {pmid38969185, year = {2024}, author = {Jang, JH and Lee, JE and Kim, KT and Ahn, DU and Paik, HD}, title = {Anti-biofilm effect of enzymatic hydrolysates of ovomucin in Listeria monocytogenes and Staphylococcus aureus.}, journal = {Microbial pathogenesis}, volume = {193}, number = {}, pages = {106771}, doi = {10.1016/j.micpath.2024.106771}, pmid = {38969185}, issn = {1096-1208}, mesh = {*Biofilms/drug effects ; *Listeria monocytogenes/drug effects ; *Staphylococcus aureus/drug effects ; *Anti-Bacterial Agents/pharmacology ; *Ovomucin/pharmacology/metabolism ; Hydrolysis ; Bacterial Adhesion/drug effects ; Papain/metabolism ; Microbial Sensitivity Tests ; Chymotrypsin/metabolism ; Protein Hydrolysates/pharmacology/metabolism ; }, abstract = {Despite modern advances in food hygiene, food poisoning due to microbial contamination remains a global problem, and poses a great threat to human health. Especially, Listeria monocytogenes and Staphylococcus aureus are gram-positive bacteria found on food-contact surfaces with biofilms. These foodborne pathogens cause a considerable number of food poisoning and infections annually. Ovomucin (OM) is a water-insoluble gel-type glycoprotein in egg whites. Enzymatic hydrolysis can be used to improve the bioactive properties of OM. This study aimed to investigate whether ovomucin hydrolysates (OMHs) produced using five commercial enzymes (Alcalase®, Bromelain, α-Chymotrypsin, Papain, and Pancreatin) can inhibit the biofilm formation of L. monocytogenes ATCC 15313, L. monocytogenes H7962, S. aureus KCCM 11593, and S. aureus 7. Particularly, OMH prepared with papain (OMPP; 500 μg/mL) significantly inhibited biofilm formation in L. monocytogenes ATCC 15313, L. monocytogenes H7962, S. aureus KCCM 11593, and S. aureus 7 by 85.56 %, 80.28 %, 91.70 %, and 79.00 %, respectively. In addition, OMPP reduced the metabolic activity, exopolysaccharide production (EPS), adhesion ability, and gene expression associated with the biofilm formation of these bacterial strains. These results suggest that OMH, especially OMPP, exerts anti-biofilm effects against L. monocytogenes and S. aureus. Therefore, OMPP can be used as a natural anti-biofilm agent to control food poisoning in the food industry.}, }
@article {pmid38968915, year = {2024}, author = {Eivazzadeh-Keihan, R and Nokandeh, SM and Aliabadi, HAM and Lalebeigi, F and Kashtiaray, A and Mahdavi, M and Sehat, S and Cohan, RA and Maleki, A}, title = {Unveiling the synergy: Biocompatible alginate-cellulose hydrogel loaded with silk fibroin and zinc ferrite nanoparticles for enhanced cell adhesion, and anti-biofilm activity.}, journal = {International journal of biological macromolecules}, volume = {275}, number = {Pt 1}, pages = {133412}, doi = {10.1016/j.ijbiomac.2024.133412}, pmid = {38968915}, issn = {1879-0003}, abstract = {Combining a biocompatible hydrogel scaffold with the cell-supportive properties of silk fibroin (SF) and the unique functionalities of ZnFe2O4 nanoparticles creates a promising platform for advanced nanobiomaterials. The research is centered on synthesizing a natural hydrogel using cellulose (Cellul) and sodium alginate (SA) combined with SF and zinc ferrite nanoparticles. A range of analytical and biological assays were conducted to determine the biological and physicochemical properties of the nanobiocomposite. The hemolysis and 2,5-diphenyl-2H-tetrazolium bromide (MTT) assays indicated that the SA-Cellul hydrogel/SF/ZnFe2O4 nanobiocomposite was a biocompatible against human dermal fibroblasts (Hu02) and red blood cells (RBC). In addition, aside from demonstrating outstanding anti-biofilm activity, the nanobiocomposite also promotes the Hu02 cells adhesion, showcasing the synergistic effect of incorporating SF and ZnFe2O4 nanoparticle. These promising results show that this nanobiocomposite has potential applications in various biomedical fields.}, }
@article {pmid38967798, year = {2024}, author = {Li, M and Cruz, CD and Ilina, P and Tammela, P}, title = {High-throughput combination assay for studying biofilm formation of uropathogenic Escherichia coli.}, journal = {Archives of microbiology}, volume = {206}, number = {8}, pages = {344}, pmid = {38967798}, issn = {1432-072X}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Uropathogenic Escherichia coli/drug effects/physiology ; *High-Throughput Screening Assays/methods ; *Xanthenes/chemistry ; *Anti-Bacterial Agents/pharmacology ; *Gentian Violet/metabolism ; *Oxazines/pharmacology/metabolism/chemistry ; Microbial Sensitivity Tests ; Urinary Tract Infections/microbiology ; Humans ; }, abstract = {Uropathogenic Escherichia coli, the most common cause for urinary tract infections, forms biofilm enhancing its antibiotic resistance. To assess the effects of compounds on biofilm formation of uropathogenic Escherichia coli UMN026 strain, a high-throughput combination assay using resazurin followed by crystal violet staining was optimized for 384-well microplate. Optimized assay parameters included, for example, resazurin and crystal violet concentrations, and incubation time for readouts. For the assay validation, quality parameters Z' factor, coefficient of variation, signal-to-noise, and signal-to-background were calculated. Microplate uniformity, signal variability, edge well effects, and fold shift were also assessed. Finally, a screening with known antibacterial compounds was conducted to evaluate the assay performance. The best conditions found were achieved by using 12 µg/mL resazurin for 150 min and 0.023% crystal violet. This assay was able to detect compounds displaying antibiofilm activity against UMN026 strain at sub-inhibitory concentrations, in terms of metabolic activity and/or biomass.}, }
@article {pmid38966810, year = {2024}, author = {Wani, MY and Srivastava, V and El-Said, WA and Al-Bogami, AS and Ahmad, A}, title = {Inhibition of apoptosis and biofilm formation in Candida auris by click-synthesized triazole-bridged quinoline derivatives.}, journal = {RSC advances}, volume = {14}, number = {29}, pages = {21190-21202}, pmid = {38966810}, issn = {2046-2069}, abstract = {Candida auris, a recent addition to the Candida species, poses a significant threat with its association to numerous hospital outbreaks globally, particularly affecting immunocompromised individuals. Given its resistance to existing antifungal therapies, there is a pressing need for innovative treatments. In this study, novel triazole bridged quinoline derivatives were synthesized and evaluated for their antifungal activity against C. auris. The most promising compound, QT7, demonstrated exceptional efficacy with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 0.12 μg mL[-1] and 0.24 μg mL[-1], respectively. Additionally, QT7 effectively disrupted mature biofilms, inhibiting them by 81.98% ± 8.51 and 89.57 ± 5.47 at MFC and 2× MFC values, respectively. Furthermore, QT7 induced cellular apoptosis in a dose-dependent manner, supported by various apoptotic markers such as phosphatidylserine externalization, mitochondrial depolarization, and reduced cytochrome c and oxidase activity. Importantly, QT7 exhibited low hemolytic activity, highlighting its potential for further investigation. Additionally, the physicochemical properties of this compound suggest its potential as a lead drug candidate, warranting further exploration in drug discovery efforts against Candida auris infections.}, }
@article {pmid38966782, year = {2024}, author = {Rohilla, A and Kumar, V and Ahire, JJ}, title = {Unveiling the persistent threat: recent insights into Listeria monocytogenes adaptation, biofilm formation, and pathogenicity in foodborne infections.}, journal = {Journal of food science and technology}, volume = {61}, number = {8}, pages = {1428-1438}, pmid = {38966782}, issn = {0022-1155}, abstract = {Listeriosis is a severe disease caused by the foodborne pathogen Listeria monocytogenes, posing a significant risk to vulnerable populations such as the elderly, pregnant women, and newborns. While relatively uncommon, it has a high global mortality rate of 20-30%. Recent research indicates that smaller outbreaks of the more severe, invasive form of the disease occur more frequently than previously thought, despite the overall stable infection rates of L. monocytogenes over the past 10 years. The ability of L. monocytogenes to form biofilm structures on various surfaces in food production environments contributes to its persistence and challenges in eradication, potentially leading to contamination of food and food production facilities. To address these concerns, this review focuses on recent developments in epidemiology, risk evaluations, and molecular mechanisms of L. monocytogenes survival in adverse conditions and environmental adaptation. Additionally, it covers new insights into strain variability, pathogenicity, mutations, and host vulnerability, emphasizing the important events framework that elucidates the biochemical pathways from ingestion to infection. Understanding the adaptation approaches of L. monocytogenes to environmental stress factors is crucial for the development of effective and affordable pathogen control techniques in the food industry, ensuring the safety of food production.}, }
@article {pmid38965339, year = {2024}, author = {Nair, VG and Srinandan, CS and Rajesh, YBRD and Narbhavi, D and Anupriya, A and Prabhusaran, N and Nagarajan, S}, title = {Biogenic amine tryptamine in human vaginal probiotic isolates mediates matrix inhibition and thwarts uropathogenic E. coli biofilm.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {15387}, pmid = {38965339}, issn = {2045-2322}, support = {DST/WOS-B/HN-32/2021//Department of Science and Technology, Ministry of Science and Technology, India/ ; 67/5/2020-DDI/BMS//Indian Council of Medical Research/ ; }, mesh = {*Biofilms/drug effects/growth &amp; development ; Humans ; *Tryptamines/pharmacology ; Female ; *Uropathogenic Escherichia coli/drug effects/physiology ; *Probiotics/pharmacology ; *Vagina/microbiology ; *Lactobacillus/drug effects/metabolism/physiology ; Escherichia coli Infections/microbiology/drug therapy/prevention &amp; control ; Adult ; Anti-Bacterial Agents/pharmacology ; }, abstract = {Probiotics offer a promising prophylactic approach against various pathogens and represent an alternative strategy to combat biofilm-related infections. In this study, we isolated vaginal commensal microbiota from 54 healthy Indian women to investigate their probiotic traits. We primarily explored the ability of cell-free supernatant (CFS) from Lactobacilli to prevent Uropathogenic Escherichia coli (UPEC) colonization and biofilm formation. Our findings revealed that CFS effectively reduced UPEC's swimming and swarming motility, decreased cell surface hydrophobicity, and hindered matrix production by downregulating specific genes (fimA, fimH, papG, and csgA). Subsequent GC-MS analysis identified Tryptamine, a monoamine compound, as the potent bioactive substance from Lactobacilli CFS, inhibiting UPEC biofilms with an MBIC of 4 µg/ml and an MBEC of 8 µg/ml. Tryptamine induced significant changes in E. coli colony biofilm morphology, transitioning from the Red, Dry, and Rough (RDAR) to the Smooth and White phenotype, indicating reduced extracellular matrix production. Biofilm time-kill assays demonstrated a four-log reduction in UPEC viability when treated with Tryptamine, highlighting its potent antibacterial properties, comparable to CFS treatment. Biofilm ROS assays indicated a significant elevation in ROS generation within UPEC biofilms, suggesting a potential antibacterial mechanism. Gene expression studies with Tryptamine-treated samples showed a reduction in expression of curli gene (csgA), consistent with CFS treatment. This study underscores the potential of Tryptamine from probiotic Lactobacilli CFS as a promising antibiofilm agent against UPEC biofilms.}, }
@article {pmid38965139, year = {2024}, author = {Sahin, Z and Ozer, NE and Calı, A}, title = {Biofilm inhibition of denture cleaning tablets and carvacrol on denture bases produced with different techniques.}, journal = {Clinical oral investigations}, volume = {28}, number = {7}, pages = {413}, pmid = {38965139}, issn = {1436-3771}, mesh = {*Biofilms/drug effects ; *Candida albicans/drug effects ; *Denture Bases/microbiology ; *Cymenes/pharmacology ; *Surface Properties ; *Denture Cleansers/pharmacology ; *Materials Testing ; *Microscopy, Electron, Scanning ; Printing, Three-Dimensional ; Tablets ; }, abstract = {OBJECTIVES: This study compares the biofilm inhibition effects of denture cleaning tablets, carvacrol, and their combined use against Candida albicans on denture bases produced with different techniques. Additionally, the surface roughness and contact angles of these denture bases were evaluated.<br><br>MATERIALS AND METHODS: Test samples were prepared from four different denture base materials (cold-polymerized, heat-polymerized, CAD/CAM milling, and 3D-printed). The surface roughness and contact angles of the test samples were measured using a profilometer and goniometer, respectively. For the evaluation of biofilm inhibition, samples were divided into 5 subgroups: Corega and carvacrol, separately and combined treatments, positive (inoculated with C. albicans) and negative control (non-inoculated with C. albicans, only medium). Biofilm mass was determined using the crystal violet method. An additional prepared test sample for each subgroup was examined under scanning electron microscopy (SEM).<br><br>RESULTS: The surface roughness values of the 3D-printed test samples were found to be statistically higher than the other groups (P&#x2009;<&#x2009;.001). The water contact angle of all test materials was not statistically different from each other (P&#x2009;>&#x2009;.001). Corega and carvacrol, separately and combined, significantly decreased the amount of biofilm on all surfaces (P&#x2009;<&#x2009;.0001). Treatment of corega alone and in combination with carvacrol to the 3D-printed material caused less C. albicans inhibition than the other groups (P&#x2009;<&#x2009;.001; P&#x2009;<&#x2009;.05).<br><br>CONCLUSIONS: The surface roughness values of all test groups were within the clinically acceptable threshold. Although Corega and carvacrol inhibited C. albicans biofilms, their combined use did not show a synergistic effect.<br><br>CLINICAL RELEVANCE: Carvacrol may be used as one of the disinfectant agents for denture cleaning due to its biofilm inhibition property.}, }
@article {pmid38965060, year = {2024}, author = {Wu, W and Wang, Y and Yang, H and Chen, H and Wang, C and Liang, J and Song, Y and Xu, S and Sun, Y and Wang, L}, title = {Antibacterial And Biofilm Removal Strategies Based On Micro/nanomotors In The Biomedical Field.}, journal = {ChemMedChem}, volume = {}, number = {}, pages = {e202400349}, doi = {10.1002/cmdc.202400349}, pmid = {38965060}, issn = {1860-7187}, abstract = {Bacterial infection, which can trigger varieties of diseases and tens of thousands of deaths each year, poses serious threats to human health. Particularly, the new dilemma caused by biofilms is gradually becoming a severe and tough problem in the biomedical field. Thus, the strategies to address these problems are considered an urgent task at present. Micro/nanomotors (MNMs), also named micro/nanoscale robots, are mostly driven by chemical energy or external field, exhibiting strong diffusion and self-propulsion in the liquid media, which has the potential for antibacterial applications. In particular, when MNMs are assembled in swarms, they become robust and efficient for biofilm removal. However, there is a lack of comprehensive review discussing the progress in this aspect. Bearing it in mind and based on our own research experience in this regard, the studies on MNMs driven by different mechanisms orchestrated for antibacterial activity and biofilm removal are timely and concisely summarized and discussed in this work, aiming to show the advantages of MNMs brought to this field. In addition, an outlook was proposed, hoping to provide the fundamental guidance for future development in this area.}, }
@article {pmid38964021, year = {2024}, author = {Alves, F and Nakada, PJT and Marques, MJAM and Rea, LDC and Cortez, AA and Pellegrini, VOA and Polikarpov, I and Kurachi, C}, title = {Complete photodynamic inactivation of Pseudomonas aeruginosa biofilm with use of potassium iodide and its comparison with enzymatic pretreatment.}, journal = {Journal of photochemistry and photobiology. B, Biology}, volume = {257}, number = {}, pages = {112974}, doi = {10.1016/j.jphotobiol.2024.112974}, pmid = {38964021}, issn = {1873-2682}, mesh = {*Pseudomonas aeruginosa/drug effects/physiology ; *Biofilms/drug effects/radiation effects ; *Potassium Iodide/pharmacology/chemistry ; *Photosensitizing Agents/pharmacology/chemistry ; Light ; Photochemotherapy ; }, abstract = {Pseudomonas aeruginosa, a gram-negative bacterium, accounts for 7% of all hospital-acquired infections. Despite advances in medicine and antibiotic therapy, P. aeruginosa infection still results in high mortality rates of up to 62% in certain patient groups. This bacteria is also known to form biofilms, that are 10 to 1000 times more resistant to antibiotics compared to their free-floating counterparts. Photodynamic Inactivation (PDI) has been proved to be an effective antimicrobial technique for microbial control. This method involves the incubation of the pathogen with a photosensitizer (PS), then, a light at appropriated wavelength is applied, leading to the production of reactive oxygen species that are toxic to the microbial cells. Studies have focused on strategies to enhance the PDI efficacy, such as a pre-treatment with enzymes to degrade the biofilm matrix and/or an addition of inorganic salts to the PS. The aim of the present study is to evaluate the effectiveness of PDI against P. aeruginosa biofilm in association with the application of the enzymes prior to PDI (enzymatic pre-treatment) or the addition of potassium iodide (KI) to the photosensitizer solution, to increase the inactivation effectiveness of the treatment. First, a range of enzymes and PSs were tested, and the best protocols for combined treatments were selected. The results showed that the use of enzymes as a pre-treatment was effective to reduce the total biomass, however, when associated with PDI, mild bacterial reductions were obtained. Then, the use of KI in association with the PS was evaluated and the results showed that, PDI mediated by methylene blue (MB) in the presence of KI was able to completely eradicate the biofilm. However, when the PDI was performed with curcumin and KI, no additive reduction was observed. In conclusion, out of all strategies evaluated in the present study, the most promising strategy to improve PDI against P. aeruginosa biofilm was the use of KI in association with MB, resulting in eradication with 10[8] log bacterial inactivation.}, }
@article {pmid38963508, year = {2024}, author = {Rouhi, A and Falah, F and Azghandi, M and Alizadeh Behbahani, B and Tabatabaei-Yazdi, F and Ibrahim, SA and Dertli, E and Vasiee, A}, title = {Investigating the Effect of Melittin Peptide in Preventing Biofilm Formation, Adhesion and Expression of Virulence Genes in Listeria monocytogenes.}, journal = {Probiotics and antimicrobial proteins}, volume = {}, number = {}, pages = {}, pmid = {38963508}, issn = {1867-1314}, abstract = {Listeria monocytogenes is a notable food-borne pathogen that has the ability to create biofilms on different food processing surfaces, making it more resilient to disinfectants and posing a greater risk to human health. This study assessed melittin peptide's anti-biofilm and anti-pathogenicity effects on L. monocytogenes ATCC 19115. Melittin showed minimum inhibitory concenteration (MIC) of 100 μg/mL against this strain and scanning electron microscopy images confirmed its antimicrobial efficacy. The OD measurement demonstrated that melittin exhibited a strong proficiency in inhibiting biofilms and disrupting pre-formed biofilms at concentrations ranging from 1/8MIC to 2MIC and this amount was 92.59 ± 1.01% to 7.17 ± 0.31% and 100% to 11.50 ± 0.53%, respectively. Peptide also reduced hydrophobicity and self-aggregation of L. monocytogenes by 35.25% and 14.38% at MIC. Melittin also significantly reduced adhesion to HT-29 and Caco-2 cells by 61.33% and 59%, and inhibited invasion of HT-29 and Caco-2 cells by 49.33% and 40.66% for L. monocytogenes at the MIC value. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) revealed melittin's impact on gene expression, notably decreasing inlB (44%) and agrA (45%) gene expression in L. monocytogenes. flaA and hly genes also exhibited reduced expression. Also, significant changes were observed in sigB and prfA gene expression. These results underscore melittin's potential in combating bacterial infections and biofilm-related challenges in the food industry.}, }
@article {pmid38963393, year = {2024}, author = {Zhou, L and Lai, CY and Wu, M and Guo, J}, title = {Simultaneous Biogas Upgrading and Valuable Chemical Production Using Homoacetogens in a Membrane Biofilm Reactor.}, journal = {Environmental science &amp; technology}, volume = {58}, number = {28}, pages = {12509-12519}, doi = {10.1021/acs.est.4c02021}, pmid = {38963393}, issn = {1520-5851}, mesh = {*Biofuels ; *Bioreactors ; *Biofilms ; RNA, Ribosomal, 16S ; Carbon Dioxide/metabolism ; Acetates/metabolism ; }, abstract = {Biogas produced from anaerobic digestion usually contains impurities, particularly with a high content of CO2 (15-60%), thus decreasing its caloric value and limiting its application as an energy source. H2-driven biogas upgrading using homoacetogens is a promising approach for upgrading biogas to biomethane and converting CO2 to acetate simultaneously. Herein, we developed a novel membrane biofilm reactor (MBfR) with H2 and biogas separately supplied via bubbleless hollow fiber membranes. The gas-permeable hollow fibers of the MBfR enabled high H2 and CO2 utilization efficiencies (∼98% and ∼97%, respectively) and achieved concurrent biomethane (∼94%) and acetate (∼450 mg/L/d) production. High-throughput 16S rRNA gene amplicon sequencing suggested that enriched microbial communities were dominated by Acetobacterium (38-48% relative abundance). In addition, reverse transcription quantitative PCR of the functional marker gene formyltetrahydrofolate synthetase showed that its expression level increased with increasing H2 and CO2 utilization efficiencies. These results indicate that Acetobacterium plays a key role in CO2 to acetate conversion. These findings are expected to facilitate energy-positive wastewater treatment and contribute to the development of a new solution to biogas upgrading.}, }
@article {pmid38962288, year = {2024}, author = {Al Ansari, N and Abid, M}, title = {Enhancing Presurgical Infant Orthopedic Appliances: Characterization, Mechanics, and Biofilm Inhibition of a Novel Chlorhexidine-Halloysite Nanotube-Modified PMMA.}, journal = {International journal of biomaterials}, volume = {2024}, number = {}, pages = {6281972}, pmid = {38962288}, issn = {1687-8787}, abstract = {OBJECTIVES: This in vitro study aimed to develop a novel nanocomposite acrylic resin with inherent antimicrobial properties. This study evaluated its effectiveness against microbial biofilm formation, while also assessing its physical and mechanical properties.<br><br>METHODS: Polymethylmethacrylate (PMMA) was modified with four different concentrations of chlorhexidine halloysite nanotubes (CHX-HNTs): 1%, 1.5%, 3%, and 4.5 wt.% by weight, along with a control group (0 wt.% CHX-HNTs). The biofilm inhibition ability of the modified CHX-HNTs acrylic against Candida albicans, Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus agalactiae was assessed using microtiter biofilm test. In addition, ten samples from each group were then tested for flexural strength, surface roughness, and hardness. Statistical analysis was performed using one-way ANOVA and Tukey's test for comparison (P < 0.05).<br><br>RESULTS: CHX-HNTs effectively reduced the adhesion of Candida albicans and bacteria to the PMMA in a dose-dependent manner. The higher the concentration of CHX-HNTs, the greater the reduction in microbial adhesion, with the highest concentration (4.5 wt.%) showing the most significant effect with inhibition rates &#x2265;98%. The addition of CHX-HNTs at any tested concentration (1%, 1.5%, 3%, and 4.5 wt.%) did not cause any statistically significant difference in the flexural strength, surface roughness, or hardness of the PMMA compared to the control group.<br><br>CONCLUSIONS: The novel integration of CHX-HNT fillers shows promising results as an effective biofilm inhibitor on acrylic appliances. This new approach has the potential to successfully control infectious diseases without negatively affecting the mechanical properties of the acrylic resin. Clinical Relevance. The integration of CHX-HNTs into presurgical infant orthopedic appliances should be thoroughly assessed as a promising preventive measure to mitigate microbial infections. This evaluation holds significant potential for controlling infectious diseases among infants with cleft lip and palate, thereby offering a valuable contribution to their overall well-being.}, }
@article {pmid38961344, year = {2024}, author = {Yu, J and Han, W and Xu, Y and Shen, L and Zhao, H and Zhang, J and Xiao, Y and Guo, Y and Yu, F}, title = {Biofilm-producing ability of methicillin-resistant Staphylococcus aureus clinically isolated in China.}, journal = {BMC microbiology}, volume = {24}, number = {1}, pages = {241}, pmid = {38961344}, issn = {1471-2180}, support = {82202587//The Natural Science Fund of China/ ; }, mesh = {*Methicillin-Resistant Staphylococcus aureus/drug effects/isolation &amp; purification/physiology ; *Biofilms ; China/epidemiology ; *Staphylococcal Infections/epidemiology/microbiology ; Anti-Bacterial Agents/pharmacology ; Genes, Bacterial/genetics ; Humans ; }, abstract = {BACKGROUND: Staphylococcus aureus, a commensal bacterium, colonizes the skin and mucous membranes of approximately 30% of the human population. Apart from conventional resistance mechanisms, one of the pathogenic features of S. aureus is its ability to survive in a biofilm state on both biotic and abiotic surfaces. Due to this characteristic, S. aureus is a major cause of human infections, with Methicillin-Resistant Staphylococcus aureus (MRSA) being a significant contributor to both community-acquired and hospital-acquired infections.<br><br>RESULTS: Analyzing non-repetitive clinical isolates of MRSA collected from seven provinces and cities in China between 2014 and 2020, it was observed that 53.2% of the MRSA isolates exhibited varying degrees of ability to produce biofilm. The biofilm positivity rate was notably high in MRSA isolates from Guangdong, Jiangxi, and Hubei. The predominant MRSA strains collected in this study were of sequence types ST59, ST5, and ST239, with the biofilm-producing capability mainly distributed among moderate and weak biofilm producers within these ST types. Notably, certain sequence types, such as ST88, exhibited a high prevalence of strong biofilm-producing strains. The study found that SCCmec IV was the predominant type among biofilm-positive MRSA, followed by SCCmec II. Comparing strains with weak and strong biofilm production capabilities, the positive rates of the sdrD and sdrE were higher in strong biofilm producers. The genetic determinants ebp, icaA, icaB, icaC, icaD, icaR, and sdrE were associated with strong biofilm production in MRSA. Additionally, biofilm-negative MRSA isolates showed higher sensitivity rates to cefalotin (94.8%), daptomycin (94.5%), mupirocin (86.5%), teicoplanin (94.5%), fusidic acid (81.0%), and dalbavancin (94.5%) compared to biofilm-positive MRSA isolates. The biofilm positivity rate was consistently above 50% in all collected specimen types.<br><br>CONCLUSIONS: MRSA strains with biofilm production capability warrant increased vigilance.}, }
@article {pmid38960353, year = {2024}, author = {Zhang, S and Huang, X and Dong, W and Wang, H and Hu, L and Zhou, G and Zheng, Z}, title = {Potential effects of Cu[2+] stress on nitrogen removal performance, microbial characteristics, and metabolism pathways of biofilm reactor.}, journal = {Environmental research}, volume = {259}, number = {}, pages = {119541}, doi = {10.1016/j.envres.2024.119541}, pmid = {38960353}, issn = {1096-0953}, abstract = {Sequencing batch biofilm reactors (SBBR) were utilized to investigate the impact of Cu[2+] on nitrogen (N) removal and microbial characteristics. The result indicated that the low concentration of Cu[2+] (0.5 mg L[-1]) facilitated the removal of ammonia nitrogen (NH4[+]-N), total nitrogen (TN), nitrate nitrogen (NO3[-]-N), and chemical oxygen demand (COD). In comparison to the average effluent concentration of the control group, the average effluent concentrations of NH4[+]-N, NO3[-]-N, COD, and TN were found to decrease by 40.53%, 17.02%, 10.73%, and 15.86%, respectively. Conversely, the high concentration of Cu[2+] (5 mg L[-1]) resulted in an increase of 94.27%, 55.47%, 22.22%, and 14.23% in the aforementioned parameters, compared to the control group. Low concentrations of Cu[2+] increased the abundance of nitrifying bacteria (Rhodanobacter, unclassified-o-Sacharimonadales), denitrifying bacteria (Thermomonas, Comamonas), denitrification-associated genes (hao, nosZ, norC, nffA, nirB, nick, and nifD), and heavy-metal-resistant genes related to Cu[2+] (pcoB, cutM, cutC, pcoA, copZ) to promote nitrification and denitrification. Conversely, high concentration Cu[2+] hindered the interspecies relationship among denitrifying bacteria genera, nitrifying bacteria genera, and other genera, reducing denitrification and nitrification efficiency. Cu[2+] involved in the N and tricarboxylic acid (TCA) cycles, as evidenced by changes in the abundance of key enzymes, such as (EC:1.7.99.1), (EC:1.7.2.4), and (EC:1.1.1.42), which initially increased and then decreased with varying concentrations of Cu[2+]. Conversely, the abundance of EC1.7.2.1, associated with the accumulation of nitrite nitrogen (NO2[-]-N), gradually declined. These findings provided insights into the impact of Cu[2+] on biological N removal.}, }
@article {pmid38960350, year = {2024}, author = {Ugya, AY and Hasan, DB and Ari, HA and Sheng, Y and Chen, H and Wang, Q}, title = {Antibiotic synergistic effect surge bioenergy potential and pathogen resistance of Chlorella variabilis biofilm.}, journal = {Environmental research}, volume = {259}, number = {}, pages = {119521}, doi = {10.1016/j.envres.2024.119521}, pmid = {38960350}, issn = {1096-0953}, abstract = {Tetracycline (TC) and ciprofloxacin (CF) induce a synergistic effect that alters the biochemical composition, leading to a decrease in the growth and photosynthetic efficiency of microalgae. But the current study provides a novel insight into stress-inducing techniques that trigger a change in macromolecules, leading to an increase in the bioenergy potential and pathogen resistance of Chlorella variabilis biofilm. The study revealed that in a closed system, a light intensity of 167 μmol/m[2]/s causes 93.5% degradation of TC and 16% degradation of CF after 7 days of exposure, hence availing the products for utilization by C. variabilis biofilm. The resistance to pathogens invasion was linked to 85% and 40% increase in the expression level of photosystem II oxygen-evolving enhancer protein 3 (PsbQ), and mitogen activated kinase (MAK) respectively. The results also indicate that a surge in light intensity triggers 49% increase in the expression level of lysophosphatidylcholine (LPC) (18:2), which is an important lipidomics that can easily undergo transesterification into bioenergy. The thermogravimetric result indicates that the biomass sample of C. variabilis biofilm cultivated under light intensity of 167 μmol/m2/s produces a higher residual mass of 45.5% and 57.5 under air and inert conditions, respectively. The Fourier transform infrared (FTIR) indicates a slight shift in the major functional groups, while the energy-dispersive X-ray spectroscopy (SEM-EDS) and X-ray fluorescence (XRF) indicate clear differences in the morphology and elemental composition of the biofilm biomass in support of the increase bioenergy potential of C. variabilis biofilm. The current study provides a vital understanding of a innovative method of cultivation of C. variabilis biofilm, which is resistant to pathogens and controls the balance between fatty acid and TAG synthesis leading to surge in bioenergy potential and environmental sustainability.}, }
@article {pmid38958241, year = {2024}, author = {Zuo, XS and Wang, QY and Wang, SS and Li, G and Zhan, LY}, title = {The role of N-acetylcysteine on adhesion and biofilm formation of Candida parapsilosis isolated from catheter-related candidemia.}, journal = {Journal of medical microbiology}, volume = {73}, number = {7}, pages = {}, doi = {10.1099/jmm.0.001848}, pmid = {38958241}, issn = {1473-5644}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Acetylcysteine/pharmacology ; Humans ; *Candida parapsilosis/drug effects/genetics/physiology ; *Catheter-Related Infections/microbiology ; *Candidemia/microbiology ; Fungal Proteins/genetics/metabolism ; Antifungal Agents/pharmacology ; }, abstract = {Objectives. Anti-fungal agents are increasingly becoming less effective due to the development of resistance. In addition, it is difficult to treat Candida organisms that form biofilms due to a lack of ability of drugs to penetrate the biofilms. We are attempting to assess the effect of a new therapeutic agent, N-acetylcysteine (NAC), on adhesion and biofilm formation in Candida parapsilosis clinical strains. Meanwhile, to detect the transcription level changes of adhesion and biofilm formation-associated genes (CpALS6, CpALS7, CpEFG1 and CpBCR1) when administrated with NAC in C. parapsilosis strains, furthermore, to explore the mechanism of drug interference on biofilms.Hypothesis/Gap statement. N-acetylcysteine (NAC) exhibits certain inhibitory effects on adhesion and biofilm formation in C. parapsilosis clinical strains from CRBSIs through: (1) down-regulating the expression of the CpEFG1 gene, making it a highly potential candidate for the treatment of C. parapsilosis catheter-related bloodstream infections (CRBSIs), (2) regulating the metabolism and biofilm -forming factors of cell structure.Methods. To determine whether non-antifungal agents can exhibit inhibitory effects on adhesion, amounts of total biofilm formation and metabolic activities of C. parapsilosis isolates from candidemia patients, NAC was added to the yeast suspensions at different concentrations, respectively. Reverse transcription was used to detect the transcriptional levels of adhesion-related genes (CpALS6 and CpALS7) and biofilm formation-related factors (CpEFG1 and CpBCR1) in the BCR1 knockout strain, CP7 and CP5 clinical strains in the presence of NAC. To further explore the mechanism of NAC on the biofilms of C. parapsilosis, RNA sequencing was used to calculate gene expression, comparing the differences among samples. Gene Ontology (GO) enrichment analysis helps to illustrate the difference between two particular samples on functional levels.Results. A high concentration of NAC reduces the total amount of biofilm formation in C. parapsilosis. Following co-incubation with NAC, the expression of CpEFG1 in both CP7 and CP5 clinical strains decreased, while there were no significant changes in the transcriptional levels of CpBCR1 compared with the untreated strain. GO enrichment analysis showed that the metabolism and biofilm-forming factors of cell structure were all regulated after NAC intervention.Conclusions. The non-antifungal agent NAC exhibits certain inhibitory effects on clinical isolate biofilm formation by down-regulating the expression of the CpEFG1 gene, making it a highly potential candidate for the treatment of C. parapsilosis catheter-related bloodstream infections.}, }
@article {pmid38955982, year = {2024}, author = {Teixeira, IM and de Moraes Assumpção, Y and Paletta, ACC and Antunes, M and da Silva, IT and Jaeger, LH and Ferreira, RF and de Oliveira Ferreira, E and de Araújo Penna, B}, title = {Investigation on biofilm composition and virulence traits of S. pseudintermedius isolated from infected and colonized dogs.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {38955982}, issn = {1678-4405}, support = {Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado do Rio de Janeiro//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado do Rio de Janeiro/ ; Bill and Melinda Gates Foundation//Bill and Melinda Gates Foundation/ ; }, abstract = {Staphylococcus pseudintermedius, which is part of the skin microbiome of dogs, causes a variety of opportunistic infections. These infections may become more difficult to treat due to the formation of biofilm. The capacity of S. pseudintermedius to form biofilm, as well as the associated genes, has not been elucidated. This study evaluated the production and composition of S. pseudintermedius biofilm. Samples were collected from both infected dogs and asymptomatic dogs. Isolates were identified using mass spectrometry and Multiplex-PCR. Biofilm production and composition were assessed using a quantitative microtiter plate assay. The presence of ica operon genes and sps genes was investigated using conventional PCR. The investigation of Agr type and virulence genes was conducted in silico on 24 sequenced samples. All strains could produce strong biofilms, with most of the isolates presenting a polysaccharide biofilm. 63.6% of the isolates carried the complete ica operon (ADBC). All samples showed the presence of the genes spsK, spsA, and spsL, while the distribution of other genes varied. Agr type III was the most prevalent (52.2%). All sequenced samples carried the cytotoxins hlb, luk-S, luk-F, as well as the exfoliative toxins siet and se_int. No isolate displayed other exfoliative toxins. Only LB1733 presented a set of different enterotoxins (sea, seb, sec_canine, seh, sek, sel, and seq). Our findings suggest that S. pseudintermedius is a strong producer of biofilm and carries virulence genes.}, }
@article {pmid38955904, year = {2024}, author = {Hizlisoy, H and Dishan, A and Bekdik, IK and Barel, M and Koskeroglu, K and Ozkaya, Y and Aslan, O and Yilmaz, OT}, title = {Candida albicans in the oral cavities of pets: biofilm formation, putative virulence, antifungal resistance profiles and classification of the isolates.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {38955904}, issn = {1618-1905}, abstract = {The study aimed to investigate Candida albicans presence, antifungal resistance, biofilm formation, putative virulence genes, and molecular characterization in oral samples of dogs and cats. A total of 239 oral samples were collected from cats and dogs of various breeds and ages at Erciyes University, Faculty of Veterinary Medicine Clinics, between May 2017 and April 2018. Among 216 isolates obtained, 15 (6.95%) were identified as C. albicans, while 8 (3.7%) were non-albicans Candida species. Antifungal susceptibility testing revealed sensitivities to caspofungin, fluconazole, and flucytosine in varying proportions. Molecular analysis indicated the presence of fluconazole and caspofungin resistance genes in all C. albicans isolates. Additionally, virulence genes ALS1, HWP1, and HSP90 showed variable presence. Biofilm formation varied among isolates, with 46.7% strong, 33.3% moderate, and 20% weak producers. PCA analysis categorized isolates into two main clusters, with some dog isolates grouped separately. The findings underscore the significance of oral care and protective measures in pets due to C. albicans prevalence, biofilm formation, virulence factors, and antifungal resistance in their oral cavity, thereby aiding clinical diagnosis and treatment in veterinary medicine.}, }
@article {pmid38955379, year = {2024}, author = {Fang, Y and Li, Z and Wang, G and Xia, Y and Zhang, K and Gong, W and Yu, E and Xie, W and Li, H and Tian, J and Xie, J and Xu, Q}, title = {Effects of two fillers and process conditions on the water treatment efficiency of a continuous packed bed biofilm reactor.}, journal = {Letters in applied microbiology}, volume = {77}, number = {7}, pages = {}, doi = {10.1093/lambio/ovae060}, pmid = {38955379}, issn = {1472-765X}, support = {2022XT0503//CAFS/ ; 2023A1515012748//Guangdong Basic and Applied Basic Research Foundation/ ; 31802348//National Natural Science Foundation of China/ ; }, mesh = {*Biofilms/growth &amp; development ; *Bioreactors/microbiology ; *Water Purification/methods ; *Wastewater/microbiology/chemistry ; *Aquaculture ; Nitrogen/metabolism ; Charcoal/chemistry ; Bacteria/genetics/isolation &amp; purification/metabolism/growth &amp; development ; Biological Oxygen Demand Analysis ; Microbiota ; Waste Disposal, Fluid/methods ; Water Quality ; }, abstract = {This study evaluated the treatment efficiency of two selected fillers and their combination for improving the water quality of aquaculture wastewater using a packed bed biofilm reactor (PBBR) under various process conditions. The fillers used were nanosheet (NS), activated carbon (AC), and a combination of both. The results indicated that the use of combined fillers and the hydraulic retention time (HRT) of 4 h significantly enhanced water quality in the PBBR. The removal rates of chemical oxygen demand, NO2-─N, total suspended solids（TSS）, and chlorophyll a were 63.55%, 74.25%, 62.75%, and 92.85%, respectively. The microbiota analysis revealed that the presence of NS increased the abundance of microbial phyla associated with nitrogen removal, such as Nitrospirae and Proteobacteria. The difference between the M1 and M2 communities was minimal. Additionally, the microbiota in different PBBR samples displayed similar preferences for carbon sources, and carbohydrates and amino acids were the most commonly utilized carbon sources by microbiota. These results indicated that the combination of NS and AC fillers in a PBBR effectively enhanced the treatment efficiency of aquaculture wastewater when operated at an HRT of 4 h. The findings provide valuable insights into optimizing the design of aquaculture wastewater treatment systems.}, }
@article {pmid38955300, year = {2024}, author = {Qiu, Y and Yang, T and Zhang, H and Dai, H and Gao, H and Feng, W and Xu, D and Duan, J}, title = {The application of pH-responsive hyaluronic acid-based essential oils hydrogels with enhanced anti-biofilm and wound healing.}, journal = {International journal of biological macromolecules}, volume = {275}, number = {Pt 2}, pages = {133559}, doi = {10.1016/j.ijbiomac.2024.133559}, pmid = {38955300}, issn = {1879-0003}, abstract = {pH could play vital role in the wound healing process due to the bacterial metabolites, which is one essential aspect of desirable wound dressings lies in being pH-responsive. This work has prepared a degradable hyaluronic acid hydrogel dressing with wound pH response-ability. The aldehyde-modified hyaluronic acid (AHA) was obtained, followed by complex mixture formation of eugenol and oregano antibacterial essential oil in the AHA-CMCS hydrogel through the Schiff base reaction with carboxymethyl chitosan (CMCS). This hydrogel composite presents pH-responsiveness, its disintegration mass in acidic environment (pH = 5.5) is 4 times that of neutral (pH = 7.2), in which the eugenol release rate increases from 37.6 % to 82.1 %. In vitro antibacterial and in vivo wound healing investigations verified that hydrogels loaded with essential oils have additional 5 times biofilm removal efficiency, and significantly accelerate wound healing. Given its excellent anti-biofilm and target-release properties, the broad application of this hydrogel in bacteria-associated wound management is anticipated.}, }
@article {pmid38954220, year = {2024}, author = {Bastos, CG and Livio, DF and de Oliveira, MA and Meira, HGR and Tarabal, VS and Colares, HC and Parreira, AG and Chagas, RCR and Speziali, MG and da Silva, JA and Granjeiro, JM and Millán, RDS and Gonçalves, DB and Granjeiro, PA}, title = {Exploring the biofilm inhibitory potential of Candida sp. UFSJ7A glycolipid on siliconized latex catheters.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {38954220}, issn = {1678-4405}, support = {#APQ-00855-19//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de Minas Gerais/ ; RED-00202-22//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de Minas Gerais/ ; 001//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; }, abstract = {Biosurfactants, sustainable alternatives to petrochemical surfactants, are gaining attention for their potential in medical applications. This study focuses on producing, purifying, and characterizing a glycolipid biosurfactant from Candida sp. UFSJ7A, particularly for its application in biofilm prevention on siliconized latex catheter surfaces. The glycolipid was extracted and characterized, revealing a critical micellar concentration (CMC) of 0.98 mg/mL, indicating its efficiency at low concentrations. Its composition, confirmed through Fourier transform infrared spectroscopy (FT-IR) and thin layer chromatography (TLC), identified it as an anionic biosurfactant with a significant ionic charge of -14.8 mV. This anionic nature contributes to its biofilm prevention capabilities. The glycolipid showed a high emulsification index (E24) for toluene, gasoline, and soy oil and maintained stability under various pH and temperature conditions. Notably, its anti-adhesion activity against biofilms formed by Escherichia coli, Enterococcus faecalis, and Candida albicans was substantial. When siliconized latex catheter surfaces were preconditioned with 2 mg/mL of the glycolipid, biofilm formation was reduced by up to 97% for E. coli and C. albicans and 57% for E. faecalis. These results are particularly significant when compared to the efficacy of conventional surfactants like SDS, especially for E. coli and C. albicans. This study highlights glycolipids' potential as a biotechnological tool in reducing biofilm-associated infections on medical devices, demonstrating their promising applicability in healthcare settings.}, }
@article {pmid38951478, year = {2024}, author = {de Menezes, CLA and Boscolo, M and da Silva, R and Gomes, E and da Silva, RR}, title = {Fungal endo and exochitinase production, characterization, and application for Candida biofilm removal.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {38951478}, issn = {1678-4405}, abstract = {Chitinases are promising enzymes for a multitude of applications, including chitooligosaccharide (COS) synthesis for food and pharmaceutical uses and marine waste management. Owing to fungal diversity, fungal chitinases may offer alternatives for chitin degradation and industrial applications. The rapid reproduction cycle, inexpensive growth media, and ease of handling of fungi may also contribute to reducing enzyme production costs. Thus, this study aimed to identify fungal species with chitinolytic potential and optimize chitinase production by submerged culture and enzyme characterization using shrimp chitin. Three fungal species, Coriolopsis byrsina, Trichoderma reesei, and Trichoderma harzianum, were selected for chitinase production. The highest endochitinase production was achieved in C. byrsina after 168 h cultivation (0.3 U mL[- 1]). The optimal temperature for enzyme activity was similar for the three fungal species (up to 45 and 55 ºC for endochitinases and exochitinases, respectively). The effect of pH on activity indicated maximum hydrolysis in acidic pH (4-7). In addition, the crude T. reesei extract showed promising properties for removing Candida albicans biofilms. This study showed the possibility of using shrimp chitin to induce chitinase production and enzymes that can be applied in different industrial sectors.}, }
@article {pmid38949961, year = {2024}, author = {Guo, T and Yang, L and Zhou, N and Wang, Z and Huan, C and Zhou, J and Lin, T and Bao, G and Hu, J and Li, G}, title = {Subminimum Inhibitory Concentrations Tetracycline Antibiotics Induce Biofilm Formation in Minocycline-Resistant Klebsiella pneumonia by Affecting Bacterial Physical and Chemical Properties and Associated Genes Expression.}, journal = {ACS infectious diseases}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsinfecdis.4c00280}, pmid = {38949961}, issn = {2373-8227}, abstract = {Biofilm formation of Klebsiella pneumoniae can protect bacteria from antibiotics and is difficult to eradicate. Thus, the influence of subinhibitory concentrations of antibiotics on bacteria is becoming increasingly important. Our study showed that subminimum inhibitory concentrations (sub-MICs) of tetracycline antibiotics can increase biofilm formation in minocycline-resistant Klebsiella pneumoniae clinical strains. However, in the bacterial adhesion and invasion experiments, the adhesion and invasion ability decreased and the survival rate of Galleria mellonella increased. Under sub-MICs of tetracycline antibiotics treatment, abnormal stretching of bacteria was observed by scanning electron microscopy. Treatment with sub-MICs of tetracyclines leads to increased surface hydrophobicity and eDNA content and decreased outer membrane permeability. The expression levels of the fimA, luxS, qseB, and qseC genes decreased, the expression level of mrkA increased, and the expression level of acrA was inconsistent under different tetracycline antibiotics treatments. Together, our results suggested that the increase in Klebsiella pneumoniae biofilm formation caused by sub-MICs of tetracycline antibiotics may occur by affecting bacterial physical and chemical properties and associated genes expression.}, }
@article {pmid38949677, year = {2024}, author = {Riahi, A and Mabudi, H and Tajbakhsh, E and Roomiani, L and Momtaz, H}, title = {Optimizing chitosan derived from Metapenaeus affinis: a novel anti-biofilm agent against Pseudomonas aeruginosa.}, journal = {AMB Express}, volume = {14}, number = {1}, pages = {77}, pmid = {38949677}, issn = {2191-0855}, abstract = {Pseudomonas aeruginosa is a commonly found Gram-negative bacterium in healthcare facilities and is renowned for its ability to form biofilms and its virulence factors that are controlled by quorum sensing (QS) systems. The increasing prevalence of multidrug-resistant strains of this bacterium poses a significant challenge in the field of medicine. Consequently, the exploration of novel antimicrobial agents has become a top priority. This research aims to optimize chitosan derived from white shrimp (Metapenaeus affinis) using the Response Surface Methodology (RSM) computational approach. The objective is to investigate chitosan's potential as a solution for inhibiting QS activity and biofilm formation in P. aeruginosa ATCC 10,145. Under optimized conditions, chitin was treated with NaOH (1.41 M) for 15.75 h, HCl (7.49% vol) for 2.01 h, and at a deacetylation temperature of 81.15 °C. The resulting chitosan exhibited a degree of deacetylation (DD%) exceeding 93.98%, as confirmed by Fourier-transform infrared (FTIR) spectral analysis, indicating its high purity. The extracted chitosan demonstrated a significant synergistic antibiotic effect against P. aeruginosa when combined with ceftazidime, enhancing its bactericidal activity by up to 15-fold. In addition, sub-MIC (minimum inhibitory concentration) concentrations of extracted chitosan (10 and 100 µg/mL) successfully reduced the production of pyocyanin and rhamnolipid, as well as the swimming motility, protease activity and biofilm formation ability in comparison to the control group (P < 0.05). Moreover, chitosan treatment downregulated the RhlR and LasR genes in P. aeruginosa when compared to the control group (P < 0.05). The optimized chitosan extract shows significant potential as a coating agent for surgical equipment, effectively preventing nosocomial infections caused by P. aeruginosa pathogens.}, }
@article {pmid38949302, year = {2024}, author = {Kramara, J and Kim, M-J and Ollinger, TL and Ristow, LC and Wakade, RS and Zarnowski, R and Wellington, M and Andes, DR and Mitchell, AG and Krysan, DJ}, title = {Systematic analysis of the Candida albicans kinome reveals environmentally contingent protein kinase-mediated regulation of filamentation and biofilm formation in vitro and in vivo.}, journal = {mBio}, volume = {}, number = {}, pages = {e0124924}, doi = {10.1128/mbio.01249-24}, pmid = {38949302}, issn = {2150-7511}, abstract = {Protein kinases are critical regulatory proteins in both prokaryotes and eukaryotes. Accordingly, protein kinases represent a common drug target for a wide range of human diseases. Therefore, understanding protein kinase function in human pathogens such as the fungus Candida albicans is likely to extend our knowledge of its pathobiology and identify new potential therapies. To facilitate the study of C. albicans protein kinases, we constructed a library of 99 non-essential protein kinase homozygous deletion mutants marked with barcodes in the widely used SN genetic background. Here, we describe the construction of this library and the characterization of the competitive fitness of the protein kinase mutants under 11 different growth and stress conditions. We also screened the library for protein kinase mutants with altered filamentation and biofilm formation, two critical virulence traits of C. albicans. An extensive network of protein kinases governs these virulence traits in a manner highly dependent on the specific environmental conditions. Studies on specific protein kinases revealed that (i) the cell wall integrity MAPK pathway plays a condition-dependent role in filament initiation and elongation; (ii) the hyper-osmolar glycerol MAPK pathway is required for both filamentation and biofilm formation, particularly in the setting of in vivo catheter infection; and (iii) Sok1 is dispensable for filamentation in hypoxic environments at the basal level of a biofilm but is required for filamentation in normoxia. In addition to providing a new genetic resource for the community, these observations emphasize the environmentally contingent function of C. albicans protein kinases.IMPORTANCECandida albicans is one of the most common causes of fungal disease in humans for which new therapies are needed. Protein kinases are key regulatory proteins and are increasingly targeted by drugs for the treatment of a wide range of diseases. Understanding protein kinase function in C. albicans pathogenesis may facilitate the development of new antifungal drugs. Here, we describe a new library of 99 protein kinase deletion mutants to facilitate the study of protein kinases. Furthermore, we show that the function of protein kinases in two virulence-related processes, filamentation and biofilm formation, is dependent on the specific environmental conditions.}, }
@article {pmid38946224, year = {2024}, author = {Benny, AT and Thamim, M and Easwaran, N and Gothandam, KM and Thirumoorthy, K and Radhakrishnan, EK}, title = {Attenuation of Quorum Sensing Mediated Virulence Factors and Biofilm Formation in Pseudomonas aeruginosa PAO1 by Substituted Chalcones and Flavonols.}, journal = {Chemistry &amp; biodiversity}, volume = {}, number = {}, pages = {e202400393}, doi = {10.1002/cbdv.202400393}, pmid = {38946224}, issn = {1612-1880}, abstract = {Flavonoids epitomize structural scaffolds in many biologically active synthetic and natural compounds. They showcase a diverse spectrum of biological activities including anticancer, antidiabetic, antituberculosis, antimalarial, and antibiofilm activities. The antibiofilm activity of a series of new chalcones and flavonols against clinically significant Pseudomonas aeruginosa PAO1 strain was studied. Antivirulence activities were screened by analysing the effect of compounds on the production of virulence factors like pyocyanin, LasA protease, cell surface hydrophobicity, and rhamnolipid. The best ligands towards the quorum sensing proteins LasR, RhlR, and PqsR were recognised using a molecular docking study. The gene expression in P. aeruginosa after treatment with test compounds was evaluated on quorum sensing genes including rhlA, lasB, and pqsE. The antibiofilm potential of chalcones and flavonols was confirmed by the efficient reduction in the production of virulence factors and downregulation of gene expression.}, }
@article {pmid38946115, year = {2024}, author = {Zayed, N and Vertommen, R and Simoens, K and Bernaerts, K and Boon, N and Srivastava, MG and Braem, A and Van Holm, W and Castro, AB and Teughels, W}, title = {How well do antimicrobial mouth rinses prevent dysbiosis in an in vitro periodontitis biofilm model?.}, journal = {Journal of periodontology}, volume = {}, number = {}, pages = {}, doi = {10.1002/JPER.23-0674}, pmid = {38946115}, issn = {1943-3670}, abstract = {BACKGROUND: Periodontal diseases are associated with dysbiosis in the oral microbial communities. Managing oral biofilms is therefore key for preventing these diseases. Management protocols often include over-the-counter antimicrobial mouth rinses, which lack data on their effects on the oral microbiome's ecology, bacterial composition, metabolic activity, and dysbiosis resilience. This study examined the efficacy of antimicrobial mouth rinses to halt dysbiosis in in vitro oral biofilms under periodontitis-simulating conditions.<br><br>METHODS: Multispecies oral biofilms were grown on hydroxyapatite discs (HADs) and rinsed daily with one of six mouth rinses. Positive and negative controls were included. After three rinses, biofilms were analyzed with viability quantitative polymerase chain reaction and visualized using scanning electron microscopy. Supernatants of rinsed biofilms were used for metabolic activity analysis. In addition, human oral keratinocytes were exposed to rinsed biofilms to assess their inflammatory response. All outputs were analyzed for correlation using Spearman coefficient.<br><br>RESULTS: Product-related changes were observed in the rinsed biofilms. Three of the six tested mouth rinses could significantly prevent dysbiosis with &#x2265;30% reduction in pathobiont abundance relative to the control. These biofilms had lower metabolic activity, and the exposed human oral keratinocyte produced less interleukin-8. Interleukin-8 production correlated to both pathobiont quantity and the metabolic activity of the biofilms.<br><br>CONCLUSION: Some mouth rinses could support biofilm resilience and stop dysbiosis evolution in the biofilm model, with a clear product-related effect. Such mouth rinses can be considered for patients under maintenance/supportive periodontal therapy to prevent/delay disease recurrence. Others are more useful for different periodontal therapy stages.}, }
@article {pmid38945827, year = {2024}, author = {Garcia, MT and Namba, AM and do Carmo, PHF and Pedroso, LLC and de Lima, PMN and Gonçale, JC and Junqueira, JC}, title = {Antimicrobial effects of surface pre-reacted glass-ionomer (S-PRG) eluate against oral microcosm biofilm.}, journal = {Biofouling}, volume = {40}, number = {7}, pages = {390-401}, doi = {10.1080/08927014.2024.2371817}, pmid = {38945827}, issn = {1029-2454}, mesh = {*Biofilms/drug effects ; Humans ; *Mouth/microbiology ; Streptococcus mutans/drug effects/growth &amp; development ; Anti-Infective Agents/pharmacology ; Mouthwashes/pharmacology ; Lactic Acid/pharmacology ; Glass Ionomer Cements/pharmacology/chemistry ; Acrylic Resins/pharmacology/chemistry ; Streptococcus/drug effects/physiology ; Surface Properties ; Silicon Dioxide ; }, abstract = {This study investigated the antimicrobial activity of surface pre-reacted glass ionomer eluate (S-PRG) against oral microcosm biofilms collected from the oral cavity of patients. Dental biofilm samples were collected from three volunteers to form microcosm biofilms in vitro. Initially, screening tests were carried out to determine the biofilm treatment conditions with S-PRG eluate. The effects of a daily treatment for 5 min using three microcosm biofilms from different patients was then evaluated. For this, biofilms were formed on tooth enamel specimens for 120 h. Biofilms treated with 100% S-PRG for 5 min per day for 5 days showed a reduction in the number of total microorganisms, streptococci and mutans streptococci. SEM images confirmed a reduction in the biofilm after treatment. Furthermore, S-PRG also reduced lactic acid production. It was concluded that S-PRG eluate reduced the microbial load and lactic acid production in oral microcosm biofilms, reinforcing its promising use as a mouthwash agent.}, }
@article {pmid38945629, year = {2024}, author = {Elafify, M and Liao, X and Feng, J and Ahn, J and Ding, T}, title = {Biofilm formation in food industries: Challenges and control strategies for food safety.}, journal = {Food research international (Ottawa, Ont.)}, volume = {190}, number = {}, pages = {114650}, doi = {10.1016/j.foodres.2024.114650}, pmid = {38945629}, issn = {1873-7145}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Food Safety ; *Food Industry ; *Food Microbiology ; Quorum Sensing/drug effects ; Bacteria/drug effects/growth &amp; development ; Anti-Bacterial Agents/pharmacology ; }, abstract = {Various pathogens have the ability to grow on food matrices and instruments. This grow may reach to form biofilms. Bacterial biofilms are community of microorganisms embedded in extracellular polymeric substances (EPSs) containing lipids, DNA, proteins, and polysaccharides. These EPSs provide a tolerance and favorable living condition for microorganisms. Biofilm formations could not only contribute a risk for food safety but also have negative impacts on healthcare sector. Once biofilms form, they reveal resistances to traditional detergents and disinfectants, leading to cross-contamination. Inhibition of biofilms formation and abolition of mature biofilms is the main target for controlling of biofilm hazards in the food industry. Some novel eco-friendly technologies such as ultrasound, ultraviolet, cold plasma, magnetic nanoparticles, different chemicals additives as vitamins, D-amino acids, enzymes, antimicrobial peptides, and many other inhibitors provide a significant value on biofilm inhibition. These anti-biofilm agents represent promising tools for food industries and researchers to interfere with different phases of biofilms including adherence, quorum sensing molecules, and cell-to-cell communication. This perspective review highlights the biofilm formation mechanisms, issues associated with biofilms, environmental factors influencing bacterial biofilm development, and recent strategies employed to control biofilm-forming bacteria in the food industry. Further studies are still needed to explore the effects of biofilm regulation in food industries and exploit more regulation strategies for improving the quality and decreasing economic losses.}, }
@article {pmid38944284, year = {2024}, author = {Castilla-Sedano, AJ and Zapana-García, J and Valdivia-Del Águila, E and Padilla-Huamantinco, PG and Guerra, DG}, title = {Quantification of early biofilm growth in microtiter plates through a novel image analysis software.}, journal = {Journal of microbiological methods}, volume = {223}, number = {}, pages = {106979}, doi = {10.1016/j.mimet.2024.106979}, pmid = {38944284}, issn = {1872-8359}, mesh = {*Biofilms/growth &amp; development ; *Software ; *Image Processing, Computer-Assisted/methods ; Gentian Violet ; Bacteria/growth &amp; development ; Bacterial Adhesion ; Gentamicins/pharmacology ; }, abstract = {Given the significant impact of biofilms on human health and material corrosion, research in this field urgently needs more accessible techniques to facilitate the testing of new control agents and general understanding of biofilm biology. Microtiter plates offer a convenient format for standardized evaluations, including high-throughput assays of alternative treatments and molecular modulators. This study introduces a novel Biofilm Analysis Software (BAS) for quantifying biofilms from microtiter plate images. We focused on early biofilm growth stages and compared BAS quantification to common techniques: direct turbidity measurement, intrinsic fluorescence detection linked to pyoverdine production, and standard crystal violet staining which enables image analysis and optical density measurement. We also assessed their sensitivity for detecting subtle growth effects caused by cyclic AMP and gentamicin. Our results show that BAS image analysis is at least as sensitive as the standard method of spectrophotometrically quantifying the crystal violet retained by biofilms. Furthermore, we demonstrated that bacteria adhered after short incubations (from 10 min to 4 h), isolated from planktonic populations by a simple rinse, can be monitored until their growth is detectable by intrinsic fluorescence, BAS analysis, or resolubilized crystal violet. These procedures are widely accessible for many laboratories, including those with limited resources, as they do not require a spectrophotometer or other specialized equipment.}, }
@article {pmid38944110, year = {2024}, author = {Di Lodovico, S and Petrini, M and Di Fermo, P and De Pasquale, V and De Martino, L and D'Ercole, S and Nocera, FP and Di Giulio, M}, title = {Staphylococcus pseudintermedius and Pseudomonas aeruginosa Lubbock Chronic Wound Biofilm (LCWB): a suitable dual-species model for in vitro studies.}, journal = {Microbes and infection}, volume = {}, number = {}, pages = {105384}, doi = {10.1016/j.micinf.2024.105384}, pmid = {38944110}, issn = {1769-714X}, abstract = {Antimicrobial treatment of methicillin-resistant Staphylococcus pseudintermedius associated with canine wounds represents an important challenge. The aim of this study was to create a canine wound infection model, Lubbock Chronic Wound Biofilm (LCWB), with a focus on S. pseudintermedius, drawing inspiration from the established human model involving Staphylococcus aureus. Methicillin-resistant S. pseudintermedius 115 (MRSP) and Pseudomonas aeruginosa 700 strains, isolated from dog wounds, were used to set up the LCWB at 24, 48 and 72 h. The LCWBs were evaluated in terms of volume, weight, and microbial CFU/mg. The microbial spatial distribution in the LCWBs was assessed by SEM and CLSM imaging. The best incubation time for the LCWB production in terms of volume (3.38 cm[3] ± 0.13), weight (0.86 gr ± 0.02) and CFU/mg (up to 7.05 × 10[6] CFU/mg ± 2.89 × 10[5]) was 48 h. The SEM and CLSM images showed a major viable microbial colonization at 48 h with non-mixed bacteria with a prevalence of MRSP on the surface and P. aeruginosa 700 in the depth of the wound. The obtained findings demonstrate the capability of S. pseudintermedius to grow together P. aeruginosa in the LCWB model, representing the suitable model to reproduce the animal chronic wound in vitro.}, }
@article {pmid38943910, year = {2024}, author = {Gong, Y and Zhao, X and Yan, X and Zheng, W and Chen, H and Wang, L}, title = {Gold nanoclusters cure implant infections by targeting biofilm.}, journal = {Journal of colloid and interface science}, volume = {674}, number = {}, pages = {490-499}, doi = {10.1016/j.jcis.2024.06.172}, pmid = {38943910}, issn = {1095-7103}, abstract = {The biofilm-mediated implant infections pose a huge threat to human health. It is urgent to explore strategies to reverse this situation. Herein, we design 3-amino-1,2,4-triazole-5-thiol (ATT)-modified gold nanoclusters (AGNCs) to realize biofilm-targeting and near-infrared (NIR)-II light-responsive antibiofilm therapy. The AGNCs can interact with the bacterial extracellular DNA through the formation of hydrogen bonds between the amine groups on the ATT and the hydroxyl groups on the DNA. The AGNCs show photothermal properties even at a low power density (0.5 W/cm[2]) for a short-time (5 min) irradiation, making them highly effective in eradicating the biofilm with a dispersion rate up to 90 %. In vivo infected catheter implantation model demonstrates an exceptional high ability of the AGNCs to eradicate approximately 90 % of the bacteria encased within the biofilms. Moreover, the AGNCs show no detectable toxicity or systemic effects in mice. Our study suggests the great potential of the AGNCs for long-term prevention and elimination of the biofilm-mediated infections.}, }
@article {pmid38943859, year = {2024}, author = {Araujo, TT and Dionizio, A and Carvalho, TS and Debortolli, ALB and Vertuan, M and de Souza, BM and Camara, JVF and Henrique-Silva, F and Chiaratti, M and Santos, A and Alves, L and Ferro, M and Magalhães, AC and Buzalaf, MAR}, title = {Acquired pellicle and biofilm engineering with CaneCPI-5: Insights from proteomic and microbiomics analysis.}, journal = {Archives of oral biology}, volume = {166}, number = {}, pages = {106025}, doi = {10.1016/j.archoralbio.2024.106025}, pmid = {38943859}, issn = {1879-1506}, mesh = {*Biofilms ; *Dental Pellicle/microbiology ; Humans ; *Proteomics ; Microbiota ; Male ; Adult ; RNA, Ribosomal, 16S ; Female ; Cystatins ; Proof of Concept Study ; }, abstract = {OBJECTIVE: In this in vivo proof-of-concept study, acquired pellicle engineering was implemented to promote alterations in the protein composition of the acquired enamel pellicle (AEP) and the bacterial composition of the dental biofilm after treatment with Sugarcane cystatin (CaneCPI-5).<br><br>DESIGN: After prophylaxis, 10 volunteers rinsed (10&#xa0;mL, 1&#xa0;min) with the following solutions: 1) deionized water (H2O- negative control or 2) 0.1&#xa0;mg/mL CaneCPI-5. The AEP and biofilm were formed along 2 or 3&#xa0;h, respectively. The AEP was collected with electrode filter papers soaked in 3&#xa0;% citric acid. After protein extraction, samples were analyzed by quantitative shotgun label-free proteomics. The biofilm microbiome was collected with a dental curette. The DNA was extracted, amplified, and analyzed by 16S-rRNA Next Generation Sequencing (NGS).<br><br>RESULTS: Treatment with CaneCPI-5 increased several proteins with antimicrobial, acid-resistance, affinity for hydroxyapatite, structural and calcium binding properties, such as Cysteine-rich-3 (6-fold-p&#xa0;=&#xa0;0.03), Cystatin-B (5.5-fold-p&#xa0;<&#xa0;0.01), Neutrophil-defensin 1 (4.7-fold-p&#xa0;<&#xa0;0.01), Mucin (3.9-fold-p&#xa0;<&#xa0;0.01), Immunoglobulin-heavy-constant (3.8-fold-p&#xa0;<&#xa0;0.01) and Lactotransferrin (2.8-fold-p&#xa0;<&#xa0;0.01). Microbiome revealed that several commensal bacteria had their abundance increased after rinsing with CaneCPI-5, such as Corynebacterium and Neisseria, while Streptococcus and Prevotella nigrescens were decreased. The results indicate the efficiency of CaneCPI-5 in promoting beneficial changes in the AEP and biofilm, making this phytocystatin a potential target for incorporation into dental products.<br><br>CONCLUSION: Cane demonstrated the capability to alter the protein composition of the acquired enamel pellicle (AEP) and the initial colonizers of the biofilm, enhancing the presence of proteins and bacteria crucial for dental protection.}, }
@article {pmid38942710, year = {2024}, author = {Chen, H and Xu, M and Zhang, B and Yu, S and Weir, MD and Melo, MAS and Masri, RM and Tang, Y and Xu, HHK and Yang, D}, title = {Novel strategy of S. mutans gcrR gene over-expression plus antibacterial dimethylaminohexadecyl methacrylate suppresses biofilm acids and reduces dental caries in rats.}, journal = {Dental materials : official publication of the Academy of Dental Materials}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.dental.2024.06.018}, pmid = {38942710}, issn = {1879-0097}, abstract = {OBJECTIVE: Streptococcus mutans (S. mutans) is a major contributor to dental caries, with its ability to synthesize extracellular polysaccharides (EPS) and biofilms. The gcrR gene is a regulator of EPS synthesis and biofilm formation. The objectives of this study were to investigate a novel strategy of combining gcrR gene over-expression with dimethylaminohexadecyl methacrylate (DMAHDM), and to determine their in vivo efficacy in reducing caries in rats for the first time.<br><br>METHODS: Two types of S. mutans were tested: Parent S. mutans; and gcrR gene over-expressed S. mutans (gcrR OE S. mutans). Bacterial minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were measured with DMAHDM and chlorhexidine (CHX). Biofilm biomass, polysaccharide, lactic acid production, live/dead staining, colony-forming units (CFUs), and metabolic activity (MTT) were evaluated. A Sprague-Dawley rat model was used with parent S. mutans and gcrR OE S. mutans colonization to determine caries-inhibition in vivo.<br><br>RESULTS: Drug-susceptibility of gcrR OE S. mutans to DMAHDM or CHX was 2-fold higher than that of parent S. mutans. DMAHDM reduced biofilm CFU by 3-4 logs. Importantly, the combined gcrR OE S. mutans+&#xa0;DMAHDM dual strategy reduced biofilm CFU by 5 logs. In the rat model, the parent S. mutans group had a higher cariogenicity in dentinal (Dm) and extensive dentinal (Dx) regions. The DMAHDM +&#xa0;gcrR OE group reduced the Dm and Dx caries to only 20&#xa0;% and 0&#xa0;%, those of parent S. mutans +&#xa0;PBS control group (p&#xa0;<&#xa0;0.05). The total caries severity of gcrR OE +&#xa0;DMAHDM group was decreased to 51&#xa0;% that of parent S. mutans control (p&#xa0;<&#xa0;0.05).<br><br>SIGNIFICANCE: The strategy of combining S. mutans gcrR over-expression with antibacterial monomer reducing biofilm acids by 97&#xa0;%, and reduced in vivo total caries in rats by 48&#xa0;%. The gcrR over-expression +&#xa0;DMAHDM strategy is promising for a wide range of dental applications to inhibit caries and protect tooth structures.}, }
@article {pmid38942212, year = {2024}, author = {Hu, Z and Li, J and Qian, J and Liu, J and Zhou, W}, title = {Efficacy and mechanisms of rotating algal biofilm system in remediation of soy sauce wastewater.}, journal = {Bioresource technology}, volume = {406}, number = {}, pages = {131047}, doi = {10.1016/j.biortech.2024.131047}, pmid = {38942212}, issn = {1873-2976}, mesh = {*Biofilms ; *Wastewater/chemistry ; *Soy Foods/microbiology ; Biomass ; Biological Oxygen Demand Analysis ; Phosphorus ; Water Purification/methods ; Nitrogen ; Biodegradation, Environmental ; }, abstract = {This study investigated the efficacy of the rotating algal biofilm (RAB) for treating soy sauce wastewater (SW) and its related treatment mechanisms. The RAB system demonstrated superior nutrient removal (chemical oxygen demand, ammonium nitrogen, total nitrogen, and phosphorus for 92 %, 94 %, 91 %, and 82 %, respectively) and biofilm productivity (14 g m[-2] d[-1]) at optimized 5-day harvest time and 2-day hydraulic retention time. This was mainly attributed to the synergistic interactions within the algae-fungi (Apiotrichum)-bacteria (Acinetobacter and Rhizobia) consortium, which effectively assimilated certain extracellular polymeric substances into biomass to enhance algal biofilm growth. Increased algal productivity notably improved protein and essential amino acid contents in the biomass, suggesting a potential for animal feed applications. This study not only demonstrates a sustainable approach for managing SW but also provides insight into the nutrient removal and biomass conversion, offering a viable strategy for large-scale applications in nutrient recovery and wastewater treatment.}, }
@article {pmid38942052, year = {2024}, author = {Ananda, N and Julia, V and Bachtiar, EW}, title = {Limosilactobacillus reuteri DSM 17938 Inhibition of Biofilm Formation by Prevotella intermedia and Fusobacterium nucleatum Across Salivary pH: An In Vitro Study.}, journal = {European journal of dentistry}, volume = {}, number = {}, pages = {}, doi = {10.1055/s-0044-1786846}, pmid = {38942052}, issn = {1305-7456}, abstract = {OBJECTIVES: This study aims to investigate Limosilactobacillus reuteri DSM 17938's antibiofilm effects on Prevotella intermedia and Fusobacterium nucleatum, common causes of alveolar osteitis. It seeks topical alternatives to prevent this condition posttooth extraction. The secondary objective is to assess these effects under different pH conditions (pH 4.5 and pH 7), mimicking oral cavity saliva pH dynamics.<br><br>MATERIALS AND METHODS: &#x2003;Ethical approval was secured for the saliva collection process involving five healthy adult participants who had undergone wisdom tooth extraction. Saliva samples were diligently collected on the 7th day post-surgery. The unstimulated saliva underwent a series of treatments, including the addition of phenylmethylsulfonyl fluoride (PMSF), pH adjustments, centrifugation, and filtration. The pH levels were re-measured, and subsequent adjustments were made to achieve pH values of 4.5 or 7. Limosilactobacillus reuteri DSM 17938, with a concentration of 1&#xd7;10[8] colony-forming units (CFU) per 5 drops, was utilized in the study. Biofilm testing involved incubating saliva samples with varying pH (4.5 or 7) alongside bacterial suspensions (Prevotella intermedia, Fusobacterium nucleatum, or a mixed species). The Interlac suspension was introduced, and plates were anaerobically incubated for 24 hours. Biofilm results were obtained using a spectrometer. The test is conducted in triplicate.<br><br>STATISTICAL ANALYSIS: &#x2003;To scrutinize the impact of pH on biofilm development, the acquired data underwent a two-way ANOVA test in SPSS as part of the statistical analysis. A significance level of p<0.05 was used to determine statistical significance.<br><br>RESULTS: &#x2003;Limosilactobacillus reuteri DSM 17938 significantly reduced biofilm formation across bacterial strains (p&#x2009;=&#x2009;0.000). Statistical analysis indicated a significant impact of pH on biofilm development (p&#x2009;=&#x2009;0.000) compared to no saliva samples, with higher formation observed under acidic conditions (pH 4.5). However, the pH levels of 4.5 and 7 did not result in significantly different bacterial biofilm formation (p&#x2009;=&#x2009;0.529).<br><br>CONCLUSION: &#x2003;This research highlights Limosilactobacillus reuteri DSM 17938's potency in inhibiting biofilm formation of Prevotella intermedia and Fusobacterium nucleatum. Salivary pH variations significantly influence biofilm development, emphasizing the need to consider pH when assessing probiotic effectiveness. Despite limitations in saliva sample sterilization, this study provides valuable insights into alternative approaches for preventing alveolar osteitis. Further research should explore clinical applications and refine sterilization methods for more accurate results.}, }
@article {pmid38940906, year = {2024}, author = {Zhang, W and Cao, Y and Li, H and Rasmey, AM and Zhang, K and Shi, L and Ge, B}, title = {Membrane protein Bcsdr2 mediates biofilm integrity, hyphal growth and virulence of Botrytis cinerea.}, journal = {Applied microbiology and biotechnology}, volume = {108}, number = {1}, pages = {398}, pmid = {38940906}, issn = {1432-0614}, support = {110202201019(LS-03)//Major Science and Technology Program of China Tobacco Corporation/ ; 32172493//National Natural Science Foundation of China/ ; }, mesh = {*Botrytis/pathogenicity/genetics/growth &amp; development/drug effects ; *Biofilms/growth &amp; development/drug effects ; Virulence ; *Hyphae/growth &amp; development/drug effects ; *Plant Diseases/microbiology ; *Fragaria/microbiology ; *Fungal Proteins/genetics/metabolism ; *Membrane Proteins/genetics/metabolism ; Vitis/microbiology ; Spores, Fungal/growth &amp; development/drug effects/genetics ; Gene Deletion ; }, abstract = {Grey mould caused by Botrytis cinerea is a devastating disease responsible for large losses to agricultural production, and B. cinerea is a necrotrophic model fungal plant pathogen. Membrane proteins are important targets of fungicides and hotspots in the research and development of fungicide products. Wuyiencin affects the permeability and pathogenicity of B. cinerea, parallel reaction monitoring revealed the association of membrane protein Bcsdr2, and the bacteriostatic mechanism of wuyiencin was elucidated. In the present work, we generated and characterised ΔBcsdr2 deletion and complemented mutant B. cinerea strains. The ΔBcsdr2 deletion mutants exhibited biofilm loss and dissolution, and their functional activity was illustrated by reduced necrotic colonisation on strawberry and grape fruits. Targeted deletion of Bcsdr2 also blocked several phenotypic defects in aspects of mycelial growth, conidiation and virulence. All phenotypic defects were restored by targeted gene complementation. The roles of Bcsdr2 in biofilms and pathogenicity were also supported by quantitative real-time RT-PCR results showing that phosphatidylserine decarboxylase synthesis gene Bcpsd and chitin synthase gene BcCHSV II were downregulated in the early stages of infection for the ΔBcsdr2 strain. The results suggest that Bcsdr2 plays important roles in regulating various cellular processes in B. cinerea. KEY POINTS: • The mechanism of wuyiencin inhibits B. cinerea is closely associated with membrane proteins. • Wuyiencin can downregulate the expression of the membrane protein Bcsdr2 in B. cinerea. • Bcsdr2 is involved in regulating B. cinerea virulence, growth and development.}, }
@article {pmid38940862, year = {2024}, author = {Ljaljević Grbić, M and Dimkić, I and Janakiev, T and Kosel, J and Tavzes, &#x10c; and Popović, S and Knežević, A and Legan, L and Retko, K and Ropret, P and Unković, N}, title = {Uncovering the Role of Autochthonous Deteriogenic Biofilm Community: Rožanec Mithraeum Monument (Slovenia).}, journal = {Microbial ecology}, volume = {87}, number = {1}, pages = {87}, pmid = {38940862}, issn = {1432-184X}, support = {451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; 451-03-47/2023-01/200178//Ministry of Education, Science, and Technological Development of the Republic of Serbia/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; BI-RS/20-21-013 and J7-3147//Slovenian Research Agency (ARRS)/ ; }, mesh = {*Biofilms ; *Lichens/microbiology/physiology ; *Calcium Carbonate ; Slovenia ; Ascomycota/physiology ; Mycobiome ; }, abstract = {The primary purpose of the study, as part of the planned conservation work, was to uncover all aspects of autochthonous biofilm pertaining to the formation of numerous deterioration symptoms occurring on the limestone Rožanec Mithraeum monument in Slovenia. Using state-of-the-art sequencing technologies combining mycobiome data with observations made via numerous light and spectroscopic (FTIR and Raman) microscopy analyses pointed out to epilithic lichen Gyalecta jenensis and its photobiont, carotenoid-rich Trentepohlia aurea, as the origin of salmon-hued pigmented alterations of limestone surface. Furthermore, the development of the main deterioration symptom on the monument, i.e., biopitting, was instigated by the formation of typical endolithic thalli and ascomata of representative Verrucariaceae family (Verrucaria sp.) in conjunction with the oxalic acid-mediated dissolution of limestone. The domination of lichenized fungi, as the main deterioration agents, both on the relief and surrounding limestone, was additionally supported by the high relative abundance of lichenized and symbiotroph groups in FUNGuild analysis. Obtained results not only upgraded knowledge of this frequently occurring but often overlooked group of extremophilic stone heritage deteriogens but also provided a necessary groundwork for the development of efficient biocontrol formulation applicable in situ for the preservation of similarly affected limestone monuments.}, }
@article {pmid38939969, year = {2024}, author = {Tian, L and Zhou, P and Su, Z and Graham, N and Yu, W}, title = {Surface Microstructure Drives Biofilm Formation and Biofouling of Graphene Oxide Membranes in Practical Water Treatment.}, journal = {Environmental science &amp; technology}, volume = {58}, number = {27}, pages = {12281-12291}, doi = {10.1021/acs.est.4c03363}, pmid = {38939969}, issn = {1520-5851}, mesh = {*Biofilms ; *Biofouling ; *Water Purification ; *Graphite/chemistry ; Membranes, Artificial ; Oxides/chemistry ; }, abstract = {Significant progress has been made previously in the research and development of graphene oxide (GO) membranes for water purification, but their biofouling behavior remains poorly understood. In this study, we investigated the biofilm formation and biofouling of GO membranes with different surface microstructures in the context of filtering natural surface water and for an extended operation period (110 days). The results showed that the relatively hydrophilic and smooth Fe(OH)3/GO membrane shaped a thin and spatially heterogeneous biofilm with high stable flux. However, the ability to simultaneously mitigate biofilm formation and reduce biofouling was not observed in the weakly hydrophilic and wrinkled Fe/GO and H-Fe(OH)3/GO membranes. Microbial analyses revealed that the hydrophilicity and roughness distinguished the bacterial communities and metabolic functions. The organic matter-degrading and predatory bacteria were more adapted to hydrophilic and smooth GO surfaces. These functional taxa were involved in the degradation of extracellular polymeric substances (EPS), and improved biofilm heterogeneity. In contrast, the weakly hydrophilic and wrinkled GO surfaces had reduced biodiversity, while unexpectedly boosting the proliferation of EPS-secreting bacteria, resulting in increased biofilm formation and aggravated biofouling. Moreover, all GO membranes achieved sustainable water purification during the entire operating period.}, }
@article {pmid38938883, year = {2024}, author = {Zhu, X and Sculean, A and Eick, S}, title = {In-vitro effects of different hyaluronic acids on periodontal biofilm-immune cell interaction.}, journal = {Frontiers in cellular and infection microbiology}, volume = {14}, number = {}, pages = {1414861}, pmid = {38938883}, issn = {2235-2988}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Hyaluronic Acid/pharmacology/metabolism ; Humans ; *Reactive Oxygen Species/metabolism ; *Fibroblasts/drug effects ; *Cytokines/metabolism ; Monocytes/drug effects/immunology/metabolism ; Periodontal Ligament/cytology/microbiology/drug effects ; Cell Line ; Interleukin-1beta/metabolism ; Interleukin-10/metabolism ; }, abstract = {INTRODUCTION: Recent studies have demonstrated a positive role of hyaluronic acid (HA) on periodontal clinical outcomes. This in-vitro study aimed to investigate the impact of four different HAs on interactions between periodontal biofilm and immune cells.<br><br>METHODS: The four HAs included: high-molecular-weight HA (HHA, non-cross-linked), low-molecular-weight HA (LHA), oligomers HA (OHA), and cross-linked high-molecular-weight HA (CHA). Serial experiments were conducted to verify the influence of HAs on: (i) 12-species periodontal biofilm (formation and pre-existing); (ii) expression of inflammatory cytokines and HA receptors in monocytic (MONO-MAC-6) cells and periodontal ligament fibroblasts (PDLF) with or without exposure to periodontal biofilms; (iii) generation of reactive oxygen species (ROS) in MONO-MAC-6 cells and PDLF with presence of biofilm and HA.<br><br>RESULTS: The results indicated that HHA and CHA reduced the bacterial counts in a newly formed (4-h) biofilm and in a pre-existing five-day-old biofilm. Without biofilm challenge, OHA triggered inflammatory reaction by increasing IL-1&#x3b2; and IL-10 levels in MONO-MAC cells and IL-8 in PDLF in a time-dependent manner, whereas CHA suppressed this response by inhibiting the expression of IL-10 in MONO-MAC cells and IL-8 in PDLF. Under biofilm challenge, HA decreased the expression of IL-1&#x3b2; (most decreasing HHA) and increased IL-10 levels in MONO-MAC-6 cells in a molecular weight dependent manner (most increasing CHA). The interaction between HA and both cells may occur via ICAM-1 receptor. Biofilm stimulus increased ROS levels in MONO-MAC-6 cells and PDLF, but only HHA slightly suppressed the high generation of ROS induced by biofilm stimulation in both cells.<br><br>CONCLUSION: Overall, these results indicate that OHA induces inflammation, while HHA and CHA exhibit anti-biofilm, primarily anti-inflammatory, and antioxidant properties in the periodontal environment.}, }
@article {pmid38938878, year = {2024}, author = {Van Nederveen, V and Melton-Celsa, A}, title = {Extracellular components in enteroaggregative Escherichia coli biofilm and impact of treatment with proteinase K, DNase or sodium metaperiodate.}, journal = {Frontiers in cellular and infection microbiology}, volume = {14}, number = {}, pages = {1379206}, pmid = {38938878}, issn = {2235-2988}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Endopeptidase K/pharmacology/metabolism ; *Escherichia coli/drug effects/genetics ; *Deoxyribonucleases/metabolism/pharmacology ; Fimbriae, Bacterial/metabolism ; Bacterial Adhesion/drug effects ; Humans ; Periodic Acid/pharmacology ; }, abstract = {Enteroaggregative E. coli (EAEC) is a major cause of diarrhea worldwide. EAEC are highly adherent to cultured epithelial cells and make biofilms. Both adherence and biofilm formation rely on the presence of aggregative adherence fimbriae (AAF). We compared biofilm formation from two EAEC strains of each of the five AAF types. We found that AAF type did not correlate with the level of biofilm produced. Because the composition of the EAEC biofilm has not been fully described, we stained EAEC biofilms to determine if they contained protein, carbohydrate glycoproteins, and/or eDNA and found that EAEC biofilms contained all three extracellular components. Next, we assessed the changes to the growing or mature EAEC biofilm mediated by treatment with proteinase K, DNase, or a carbohydrate cleavage agent to target the different components of the matrix. Growing biofilms treated with proteinase K had decreased biofilm staining for more than half of the strains tested. In contrast, although sodium metaperiodate only altered the biofilm in a quantitative way for two strains, images of biofilms treated with sodium metaperiodate showed that the EAEC were more spread out. Overall, we found variability in the response of the EAEC strains to the treatments, with no one treatment producing a biofilm change for all strains. Finally, once formed, mature EAEC biofilms were more resistant to treatment than biofilms grown in the presence of those same treatments.}, }
@article {pmid38936698, year = {2024}, author = {Zhao, X and Höfte, M and Spanoghe, P and Rajkovic, A and Uyttendaele, M}, title = {Biofilm-forming Ability of Bacillus thuringiensis Strains from Biopesticides on Polystyrene and their Attachment on Spinach.}, journal = {Journal of food protection}, volume = {87}, number = {8}, pages = {100321}, doi = {10.1016/j.jfp.2024.100321}, pmid = {38936698}, issn = {1944-9097}, mesh = {*Bacillus thuringiensis ; *Spinacia oleracea/microbiology ; *Biofilms ; Polystyrenes ; Food Microbiology ; Food Contamination ; Bacillus cereus ; Humans ; }, abstract = {Bacillus thuringiensis-based commercial products as a biopesticide have been used for more than 60 years in agriculture. However, as one of the species in B. cereus group, B. thuringiensis has been considered as an emerging hazard with the potential to cause food toxico-infections. The present study aimed to evaluate the biofilm-forming ability of B. thuringiensis biopesticide strains and their attachment on spinach, compared to foodborne B. cereus strains. Biofilm formations of tested strains were found to be strain-specific and affected by the nutrient conditions more than the incubation time. Nutrient starvation conditions generally reduced the biofilm formation of tested B. thuringiensis and B. cereus strains, particularly B. thuringiensis ABTS-1857 strain was found as the nonbiofilm former in starvation conditions. It is worth mentioning that B. thuringiensis SA-11 strain showed stronger biofilm-forming ability with more air-liquid interface biofilm than the other two B. thuringiensis biopesticide strains, but no such higher attachment of B. thuringiensis SA-11 to spinach was observed. These results indicate that B. thuringiensis SA-11 strain can enter the food processing lines by the attachment on spinach leaves, and it has the potential to form biofilms throughout the processing lines or the production environment when sufficient nutrients are available. However, more biofilm tests of B. thuringiensis biopesticide strains in the vegetable production chain should be performed. The dry formulation of commercial B. thuringiensis biopesticides enhanced their adhesion on spinach leaves, whereas the strength of adhesion was not improved by the formulation. In addition, 1-2 log reductions of spores after the intensive washing of spinach leaves in the lab were detected. However, the log reduction due to the actual washing done by the food processing companies in large-volume washing baths or by consumers at home would be limited and less than this lab simulation.}, }
@article {pmid38936065, year = {2024}, author = {Zhao, Z and Gao, B and Yang, C and Wu, Y and Sun, C and Jiménez, N and Zheng, L and Huang, F and Ren, Z and Yu, Z and Yu, C and Zhang, J and Cai, M}, title = {Stimulating the biofilm formation of Bacillus populations to mitigate soil antibiotic resistome during insect fertilizer application.}, journal = {Environment international}, volume = {190}, number = {}, pages = {108831}, doi = {10.1016/j.envint.2024.108831}, pmid = {38936065}, issn = {1873-6750}, abstract = {Antibiotic resistance in soil introduced by organic fertilizer application pose a globally recognized threat to human health. Insect organic fertilizer may be a promising alternative due to its low antibiotic resistance. However, it is not yet clear how to regulate soil microbes to reduce antibiotic resistance in organic fertilizer agricultural application. In this study, we investigated soil microbes and antibiotic resistome under black soldier fly organic fertilizer (BOF) application in pot and field systems. Our study shows that BOF could stimulate ARB (antibiotic resistant - bacteria) - suppressive Bacillaceae in the soil microbiome and reduce antibiotic resistome. The carbohydrate transport and metabolism pathway of soil Bacillaceae was strengthened, which accelerated the synthesis and transport of polysaccharides to form biofilm to antagonistic soil ARB, and thus reduced the antibiotic resistance. We further tested the ARB - suppressive Bacillus spp. in a microcosm assay, which resulted in a significant decrease in the presence of ARGs and ARB together with higher abundance in key biofilm formation gene (epsA). This knowledge might help to the development of more efficient bio-fertilizers aimed at mitigating soil antibiotic resistance and enhancing soil health, in particular, under the requirements of global "One Health".}, }
@article {pmid38935316, year = {2024}, author = {Lee, D and Im, J and Kim, AR and Jun, W and Yun, CH and Han, SH}, title = {Enterococcus Phage vB_EfaS_HEf13 as an Anti-Biofilm Agent Against Enterococcus faecalis.}, journal = {Journal of microbiology (Seoul, Korea)}, volume = {}, number = {}, pages = {}, pmid = {38935316}, issn = {1976-3794}, support = {NRF-2018R1A5A2024418//National Research Foundation of Korea/ ; NRF-2022M3A9F3082330//National Research Foundation of Korea/ ; NRF-2023R1A2C1004987//National Research Foundation of Korea/ ; RS-2022-00164722//National Research Foundation of Korea/ ; }, abstract = {Enterococcus faecalis is a Gram-positive bacterium that is frequently found in the periapical lesion of patients with apical periodontitis. Its biofilm formation in root canal is closely related to the development of refractory apical periodontitis by providing increased resistance to endodontic treatments. Phage therapy has recently been considered as an efficient therapeutic strategy in controlling various periodontal pathogens. We previously demonstrated the bactericidal capacities of Enterococcus phage vB_EfaS_HEf13 (phage HEf13) against clinically-isolated E. faecalis strains. Here, we investigated whether phage HEf13 affects biofilm formation and pre-formed biofilm of clinically-isolated E. faecalis, and its combinatory effect with endodontic treatments, including chlorhexidine (CHX) and penicillin. The phage HEf13 inhibited biofilm formation and disrupted pre-formed biofilms of E. faecalis in a dose- and time-dependent manner. Interestingly, phage HEf13 destroyed E. faecalis biofilm exopolysaccharide (EPS), which is known to be a major component of bacterial biofilm. Furthermore, combined treatment of phage HEf13 with CHX or penicillin more potently inhibited biofilm formation and disrupted pre-formed biofilm than either treatment alone. Confocal laser scanning microscopic examination demonstrated that these additive effects of the combination treatments on disruption of pre-formed biofilm are mediated by relatively enhanced reduction in thickness distribution and biomass of biofilm. Collectively, our results suggest that the effect of phage HEf13 on E. faecalis biofilm is mediated by its EPS-degrading property, and its combination with endodontic treatments more potently suppresses E. faecalis biofilm, implying that phage HEf13 has potential to be used as a combination therapy against E. faecalis infections.}, }
@article {pmid38934606, year = {2024}, author = {Huang, Y-L and Huang, C-H and Huang, Y-C and Yen, C-L and Hsu, C-R}, title = {Anti-biofilm activities and antibiotic synergy of naturally occurring compounds against drug-resistant rapidly growing mycobacteria.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0019924}, doi = {10.1128/spectrum.00199-24}, pmid = {38934606}, issn = {2165-0497}, abstract = {UNLABELLED: Some naturally occurring compounds, known for their antimicrobial activities, have been employed as food additives. However, their efficacy in treating infections caused by antibiotic-resistant bacteria is yet to be fully explored. Rapidly growing mycobacteria (RGM), a category within nontuberculous mycobacteria (NTM), are prevalent in various environments and can lead to infections in humans. The rise of antimicrobial resistance within RGM is a documented concern. In this study, we reported that four specific natural compounds effectively inhibited the growth and biofilm formation of three key RGM pathogens M. abscessus, M. fortuitum, and M. chelonae. We screened 12 natural compounds for their effectiveness against antibiotic-resistant clinical strains of RGM. Four compounds showed significant inhibitory effects from the most effective to least: trans-cinnamaldehyde, carvacrol, gentisaldehyde, and phloroglucinaldehyde. In the analysis of time-killing kinetics, gentisaldehyde and phloroglucinaldehyde displayed bactericidal activity while trans-cinnamaldehyde and carvacrol exhibited bacteriostatic effects. At 1× minimal inhibition concentrations, these compounds significantly reduced biofilm formation in all three RGM species to levels between 2.9% and 20.5% relative to controls. Checkerboard assays indicated synergistic interactions between these four compounds and antibiotics such as amikacin, clarithromycin, and linezolid. Of these 12 compound-antibiotic combinations, the pairs of carvacrol-linezolid, carvacrol-amikacin, and gentisaldehyde-clarithromycin demonstrated the most synergy against multiple RGM strains. Moreover, two other compounds citral and geraniol showed synergism with all three test antibiotics. Time-killing assays further confirmed most of synergistic combinations identified in the checkerboard tests. Our research suggests the potential of these essential oils and phenolic aldehydes, both individually and in combination with antibiotics, in treating RGM infections. In addition, this work illuminates applications of these natural compounds in environmental remediation to mitigate bacterial persistence for the control of infectious diseases.<br><br>IMPORTANCE: The emergence of antimicrobial resistance within rapidly growing mycobacteria (RGM) poses a significant threat to public health. This study investigates the potential of naturally occurring compounds to combat infections caused by antibiotic-resistant RGM including M. abscessus, M. fortuitum, and M. chelonae. We identified four specific natural compounds showing impressive inhibitory effects against antibiotic-resistant clinical strains. These compounds not only inhibited the growth and biofilm formation but also exhibited synergistic interactions with antibiotics against key RGM pathogens. Our findings highlight the alternative treatment strategies for RGM infections and potential environmental applications of these natural compounds in mitigating microbial persistence and controlling infectious diseases.}, }
@article {pmid38934251, year = {2024}, author = {Teng, JL and Tang, Y and Wong, SS and Yeung, ML and Cai, JP and Chen, C and Chan, E and Fong, JY and Au-Yeung, RK and Xiong, L and Lau, TC and Lau, SK and Woo, PC}, title = {Mycolyltransferase is important for biofilm formation and pathogenesis of Tsukamurella keratitis.}, journal = {Emerging microbes &amp; infections}, volume = {13}, number = {1}, pages = {2373317}, pmid = {38934251}, issn = {2222-1751}, mesh = {*Biofilms/growth &amp; development ; Animals ; Rabbits ; *Keratitis/microbiology ; *Disease Models, Animal ; Virulence Factors/genetics/metabolism ; Actinomycetales Infections/microbiology/veterinary ; Bacterial Proteins/genetics/metabolism ; Whole Genome Sequencing ; Eye Infections, Bacterial/microbiology ; Genome, Bacterial ; Humans ; }, abstract = {Tsukamurella, a group of multi-drug resistant, Gram-positive, aerobic, and partially acid-fast bacteria, are emerging causes of bacterial conjunctivitis and keratitis. However, the pathogenesis of Tsukamurella keratitis is largely unknown. To address this, we used New Zealand White rabbits to develop the first eye infection model and conducted in vitro tests to study the pathogenesis mechanisms of Tsukamurella. There is increasing evidence that biofilms play a significant role in ocular infections, leading us to hypothesize that biofilm formation is crucial for effective Tsukamurella infection. In order to look for potential candidate genes which are important in biofilm formation and Tsukamurella keratitis. We performed genome sequencing of two ocular isolates, T. pulmonis-PW1004 and T. tyrosinosolvens-PW899, to identify potential virulence factors. Through in vitro and in vivo studies, we characterized their biological roles in mediating Tsukamurella keratitis. Our findings confirmed that Tsukamurella is an ocular pathogen by fulfilling Koch's postulates, and using genome sequence data, we identified tmytC, encoding a mycolyltransferase, as a crucial gene in biofilm formation and causing Tsukamurella keratitis in the rabbit model. This is the first report demonstrating the novel role of mycolyltransferase in causing ocular infections. Overall, our findings contribute to a better understanding of Tsukamurella pathogenesis and provide a potential target for treatment. Specific inhibitors targeting TmytC could serve as an effective treatment option for Tsukamurella infections.}, }
@article {pmid38933776, year = {2024}, author = {Wu, X and Wu, D and Cui, G and Lee, KH and Yang, T and Zhang, Z and Liu, Q and Zhang, J and Chua, EG and Chen, Z}, title = {Association Between Biofilm Formation and Structure and Antibiotic Resistance in H. pylori.}, journal = {Infection and drug resistance}, volume = {17}, number = {}, pages = {2501-2512}, pmid = {38933776}, issn = {1178-6973}, abstract = {BACKGROUND: Persistent infections caused by Helicobacter pylori (H. pylori), which are resistant to antibiotic treatment, pose a growing global public health concern. Biofilm formation is known to be associated with persistent infections due to its role in enhancing antimicrobial resistance and the tolerance of many pathogenic bacteria.<br><br>OBJECTIVE: This study aims to evaluate the biofilm formation of clinical isolates of H. pylori and its impact on antibiotic eradication.<br><br>METHODS: The thickness, morphology, and structure of biofilms derived from nine H. pylori strains were examined using confocal laser scanning microscopy, scanning electron microscopy, and transmission electron microscopy. Subsequently, the susceptibility of both planktonic and biofilm bacteria was assessed through the determination of minimum inhibitory concentration and minimum biofilm eradication concentration for amoxicillin, clarithromycin, levofloxacin, and tetracycline.<br><br>RESULTS: The results revealed varying biofilm thicknesses and densities among the strains, characterised by the presence of numerous filaments intertwining and connecting bacterial cells. Additionally, several cases exhibited susceptibility based on MIC measurements but resistance according to MBEC measurements, with MBEC indicating a higher resistance rate. Pearson Correlation analysis demonstrated a positive correlation between biofilm thickness and MBEC results (0 < r < 1), notably significant for amoxicillin (r = 0.801, P = 0.009) and tetracycline (r = 0.696, P = 0.037).<br><br>CONCLUSION: Different strains of H. pylori exhibit variations in their capacity to release outer membrane vesicles (OMVs) and form biofilms. Biofilm formation can influence the effectiveness of amoxicillin and tetracycline in eradicating susceptible bacterial strains.}, }
@article {pmid38932188, year = {2024}, author = {Alipour-Khezri, E and Moqadami, A and Barzegar, A and Mahdavi, M and Skurnik, M and Zarrini, G}, title = {Bacteriophages and Green Synthesized Zinc Oxide Nanoparticles in Combination Are Efficient against Biofilm Formation of Pseudomonas aeruginosa.}, journal = {Viruses}, volume = {16}, number = {6}, pages = {}, pmid = {38932188}, issn = {1999-4915}, mesh = {*Zinc Oxide/pharmacology ; *Pseudomonas aeruginosa/virology/drug effects/physiology ; *Biofilms/drug effects ; *Metal Nanoparticles/chemistry ; Green Chemistry Technology ; Bacteriophages/physiology ; Anti-Bacterial Agents/pharmacology ; Nanoparticles/chemistry ; }, abstract = {Bacteriophages (phages) are viruses that infect the bacteria within which their reproduction cycle takes place, a process that ends in the lysis and death of the bacterial cell. Some phages are also able to destroy bacterial biofilms. Due to increased antibiotics resistance, Pseudomonas aeruginosa, another biofilm-forming pathogen, is a problem in many parts of the world. Zinc oxide (ZnO) and other metal nanoparticles (NPs) are biologically active and also possess anti-biofilm properties. ZnO-NPs were prepared by the green synthesis method using orange peels. The vibrational peaks of the ZnO-NPs were analyzed using FTIR analysis, and their size and morphological properties were determined using scanning electron microscopy (SEM). The ability of the ZnO-NPs to reduce or eliminate P. aeruginosa biofilm alone or in combination with phages PB10 and PA19 was investigated. The P. aeruginosa cells were effectively killed in the preformed 48 h biofilms during a 24 h incubation with the ZnO-NP-phage combination, in comparison with the control or ZnO-NPs alone. The treatments on growing biofilms were most efficient in the final stages of biofilm development. All five treatment groups showed a significant biofilm reduction compared to the control group (p < 0.0001) at 48 h of incubation. The influence of the ZnO-NPs and phages on the quorum sensing system of P. aeruginosa was monitored by quantitative real-time PCR (qRT-PCR) of the autoinducer biosynthesis gene lasI. While the ZnO-NPs repressed the lasI gene transcription, the phages slightly activated it at 24 and 48 h of incubation. Also, the effect of the ZnO-NPs and phage PA19 on the viability of HFF2 cells was investigated and the results showed that the combination of NPs with PA19 reduced the toxic effect of ZnO-NPs and also stimulated the growth in normal cells.}, }
@article {pmid38932022, year = {2024}, author = {Hwang, JJ and Chen, PY and Luo, KH and Wang, YC and Lai, TY and Balitaan, JNI and Lin, SR and Yeh, JM}, title = {Leaf on a Film: Mesoporous Silica-Based Epoxy Composites with Superhydrophobic Biomimetic Surface Structure as Anti-Corrosion and Anti-Biofilm Coatings.}, journal = {Polymers}, volume = {16}, number = {12}, pages = {}, pmid = {38932022}, issn = {2073-4360}, abstract = {In this study, a series of amine-modified mesoporous silica (AMS)-based epoxy composites with superhydrophobic biomimetic structure surface of Xanthosoma sagittifolium leaves (XSLs) were prepared and applied as anti-corrosion and anti-biofilm coatings. Initially, the AMS was synthesized by the base-catalyzed sol-gel reaction of tetraethoxysilane (TEOS) and triethoxysilane (APTES) through a non-surfactant templating route. Subsequently, a series of AMS-based epoxy composites were prepared by performing the ring-opening polymerization of DGEBA with T-403 in the presence of AMS spheres, followed by characterization through FTIR, TEM, and CA. Furthermore, a nano-casting technique with polydimethylsiloxane (PDMS) as the soft template was utilized to transfer the surface pattern of natural XSLs to AMS-based epoxy composites, leading to the formation of AMS-based epoxy composites with biomimetic structure. From a hydrophilic CA of 69°, the surface of non-biomimetic epoxy significantly increased to 152° upon introducing XSL surface structure to the AMS-based epoxy composites. Based on the standard electrochemical anti-corrosion and anti-biofilm measurements, the superhydrophobic BEAMS3 composite was found to exhibit a remarkable anti-corrosion efficiency of ~99% and antimicrobial efficacy of 82% as compared to that of hydrophilic epoxy coatings.}, }
@article {pmid38931048, year = {2024}, author = {Oalđe Pavlović, M and Kolarević, S and Đorđević Aleksić, J and Vuković-Gačić, B}, title = {Exploring the Antibacterial Potential of Lamiaceae Plant Extracts: Inhibition of Bacterial Growth, Adhesion, Invasion, and Biofilm Formation and Degradation in Pseudomonas aeruginosa PAO1.}, journal = {Plants (Basel, Switzerland)}, volume = {13}, number = {12}, pages = {}, pmid = {38931048}, issn = {2223-7747}, support = {451-03-65/2024-03/200178//Ministry of Education, Science and Technological Development of the Republic of Serbia/ ; 451-03-66/2024-03/200178//Ministry of Education, Science and Technological Development of the Republic of Serbia/ ; 451-03-66/2024-03/200007//Ministry of Education, Science and Technological Development of the Republic of Serbia/ ; 451-03-66/2024-03/200053//Ministry of Education, Science and Technological Development of the Republic of Serbia/ ; }, abstract = {In response to the global rise in antibiotic resistance and the prevalence of bacterial biofilm-related infections, the antibacterial efficacy of methanolic, ethanolic, and aqueous extracts of 18 Lamiaceae plants from Serbia was evaluated. The total coumarins and triterpenes were detected spectrophotometrically, while a microdilution assay measured their effects on bacterial growth. Additionally, the impact of these extracts was assessed on Pseudomonas aeruginosa PAO1 adhesion and invasion in human fibroblasts and biofilm formation and degradation. The alcoholic extracts had the highest phytochemical content, with Teucrium montanum and Lavandula angustifolia being the richest in coumarins and triterpenes, respectively. Gram-positive bacteria, particularly Bacillus subtilis, were more susceptible to the extracts. Hyssopus officinalis ethanolic and Sideritis scardica methanolic extracts inhibited bacterial growth the most efficiently. Although the extracts did not inhibit bacterial adhesion, most ethanolic extracts significantly reduced bacterial invasion. Origanum vulgare and H. officinalis ethanolic extracts significantly inhibited biofilm formation, while Teucrium chamaedrys extract was the most active in biofilm degradation. This study significantly contributes to the literature by examining the antibacterial activity of Lamiaceae extracts, addressing major literature gaps, and underscoring their antibacterial potential, particularly Satureja montana and O. vulgare ethanolic extracts, linking their efficacy to coumarins and triterpenes.}, }
@article {pmid38930580, year = {2024}, author = {Mikziński, P and Kraus, K and Widelski, J and Paluch, E}, title = {Modern Microbiological Methods to Detect Biofilm Formation in Orthopedy and Suggestions for Antibiotic Therapy, with Particular Emphasis on Prosthetic Joint Infection (PJI).}, journal = {Microorganisms}, volume = {12}, number = {6}, pages = {}, pmid = {38930580}, issn = {2076-2607}, abstract = {Biofilm formation is a serious problem that relatively often causes complications in orthopedic surgery. Biofilm-forming pathogens invade implanted foreign bodies and surrounding tissues. Such a condition, if not limited at the appropriate time, often requires reoperation. This can be partially prevented by selecting an appropriate prosthesis material that prevents the development of biofilm. There are many modern techniques available to detect the formed biofilm. By applying them we can identify and visualize biofilm-forming microorganisms. The most common etiological factors associated with biofilms in orthopedics are: Staphylococcus aureus, coagulase-negative Staphylococci (CoNS), and Enterococcus spp., whereas Gram-negative bacilli and Candida spp. also deserve attention. It seems crucial, for therapeutic success, to eradicate the microorganisms able to form biofilm after the implantation of endoprostheses. Planning the effective targeted antimicrobial treatment of postoperative infections requires accurate identification of the microorganism responsible for the complications of the procedure. The modern microbiological testing techniques described in this article show the diagnostic options that can be followed to enable the implementation of effective treatment.}, }
@article {pmid38930479, year = {2024}, author = {Liu, D and Liu, J and Ran, L and Yang, Z and He, Y and Yang, H and Yu, Y and Fu, L and Zhu, M and Chen, H}, title = {Oleanolic Acid Promotes the Formation of Probiotic Escherichia coli Nissle 1917 (EcN) Biofilm by Inhibiting Bacterial Motility.}, journal = {Microorganisms}, volume = {12}, number = {6}, pages = {}, pmid = {38930479}, issn = {2076-2607}, support = {NCTIP-XD/B12, NCTIP-XD/C17; CSTB2023TIAD-LDX0006;2022LYXZ030; SWU-KQ22045//National Center of Technology Innovation for Pigs; Chongqing Technical Innovation and Application Development Special General Project;the Project of Shandong Province on the Transformation of Scientific and Technological Achievements;Fundamental Research/ ; }, abstract = {Probiotic biofilms have been beneficial in the fight against infections, restoring the equilibrium of the host's gut microbiota, and enhancing host health. They are considered a novel strategy for probiotic gut colonization. In this case, we evaluated the effects of various active substances from traditional Chinese medicine on Escherichia coli Nissle 1917 (EcN) to determine if they promote biofilm formation. It was shown that 8-64 μg/mL of oleanolic acid increased the development of EcN biofilm. Additionally, we observed that oleanolic acid can effectively suppress biofilm formation in pathogenic bacteria such as Salmonella and Staphylococcus aureus. Next, we assessed the amount of EcN extracellular polysaccharides, the number of live bacteria, their metabolic activity, the hydrophobicity of their surface, and the shape of their biofilms using laser confocal microscopy. Through transcriptome analysis, a total of 349 differentially expressed genes were identified, comprising 134 upregulated and 215 downregulated genes. GO functional enrichment analysis and KEGG pathway enrichment analysis revealed that oleanolic acid functions are through the regulation of bacterial motility, the iron absorption system, the two-component system, and adhesion pathways. These findings suggest that the main effects of oleanolic acid are to prevent bacterial motility, increase initial adhesion, and encourage the development of EcN biofilms. In addition, oleanolic acid interacts with iron absorption to cooperatively control the production of EcN biofilms within an optimal concentration range. Taking these results together, this study suggests that oleanolic acid may enhance probiotic biofilm formation in the intestines, presenting new avenues for probiotic product development.}, }
@article {pmid38929094, year = {2024}, author = {Kim, JH and Dong, J and Le, BH and Lonergan, ZR and Gu, W and Girke, T and Zhang, W and Newman, DK and Martins-Green, M}, title = {Pseudomonas aeruginosa Activates Quorum Sensing, Antioxidant Enzymes and Type VI Secretion in Response to Oxidative Stress to Initiate Biofilm Formation and Wound Chronicity.}, journal = {Antioxidants (Basel, Switzerland)}, volume = {13}, number = {6}, pages = {}, pmid = {38929094}, issn = {2076-3921}, support = {1 R21 AI156688-01/GF/NIH HHS/United States ; }, abstract = {Pseudomonas aeruginosa (PA) is an opportunistic pathogen frequently isolated from cutaneous chronic wounds. How PA, in the presence of oxidative stress (OS), colonizes chronic wounds and forms a biofilm is still unknown. The purpose of this study is to investigate the changes in gene expression seen when PA is challenged with the high levels of OS present in chronic wounds. We used a biofilm-forming PA strain isolated from the chronic wounds of our murine model (RPA) and performed a qPCR to obtain gene expression patterns as RPA developed a biofilm in vitro in the presence of high levels of OS, and then compared the findings in vivo, in our mouse model of chronic wounds. We found that the planktonic bacteria under OS conditions overexpressed quorum sensing genes that are important for the bacteria to communicate with each other, antioxidant stress genes important to reduce OS in the microenvironment for survival, biofilm formation genes and virulence genes. Additionally, we performed RNAseq in vivo and identified the activation of novel genes/pathways of the Type VI Secretion System (T6SS) involved in RPA pathogenicity. In conclusion, RPA appears to survive the high OS microenvironment in chronic wounds and colonizes these wounds by turning on virulence, biofilm-forming and survival genes. These findings reveal pathways that may be promising targets for new therapies aimed at disrupting PA-containing biofilms immediately after debridement to facilitate the treatment of chronic human wounds.}, }
@article {pmid38928770, year = {2024}, author = {Sung, K and Park, M and Chon, J and Kweon, O and Paredes, A and Khan, SA}, title = {Chicken Juice Enhances C. jejuni NCTC 11168 Biofilm Formation with Distinct Morphological Features and Altered Protein Expression.}, journal = {Foods (Basel, Switzerland)}, volume = {13}, number = {12}, pages = {}, pmid = {38928770}, issn = {2304-8158}, support = {E0735601//United States Food and Drug Administration/ ; }, abstract = {Campylobacter jejuni is the foodborne pathogen causing most gastrointestinal infections. Understanding its ability to form biofilms is crucial for devising effective control strategies in food processing environments. In this study, we investigated the growth dynamics and biofilm formation of C. jejuni NCTC 11168 in various culture media, including chicken juice (CJ), brain heart infusion (BHI), and Mueller Hinton (MH) broth. Our results demonstrated that C. jejuni exhibited a higher growth rate and enhanced biofilm formation in CJ and in 1:1 mixtures of CJ with BHI or MH broth compared to these measures in BHI or MH broth alone. Electron microscopy unveiled distinct morphological attributes of late-stage biofilm cells in CJ, including the presence of elongated spiral-shaped cells, thinner stretched structures compared to regular cells, and extended thread-like structures within the biofilms. Proteomic analysis identified significant alterations in protein expression profiles in C. jejuni biofilms, with a predominance of downregulated proteins associated with vital functions like metabolism, energy production, and amino acid and protein biosynthesis. Additionally, a significant proportion of proteins linked to biofilm formation, virulence, and iron uptake were suppressed. This shift toward a predominantly coccoid morphology echoed the reduced energy demands of these biofilm communities. Our study unlocks valuable insights into C. jejuni's biofilm in CJ, demonstrating its adaptation and survival.}, }
@article {pmid38927396, year = {2024}, author = {Macedo, TT and Malavazi, LM and Vargas, GQ and Gonçalves, FJDS and Gomes, APAP and Bueno, MR and Aguiar da Silva, LD and Figueiredo, LC and Bueno-Silva, B}, title = {Combination of Neovestitol and Vestitol Modifies the Profile of Periodontitis-Related Subgingival Multispecies Biofilm.}, journal = {Biomedicines}, volume = {12}, number = {6}, pages = {}, pmid = {38927396}, issn = {2227-9059}, support = {#2019/19691-0; # 2017/16377-7//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de S&#xe3;o Paulo/ ; # 428984/2018-5//National Council for Scientific and Technological Development/ ; n/a//Coordena&#xe7;&#xe3;o de Aperfeicoamento de Pessoal de N&#xed;vel Superior/ ; #3364/23 and #2878/23//Fund to support teaching, research and extension (FAEPEX - Unicamp)/ ; n/a//Latin American Oral Health Association/ ; }, abstract = {The aim of this study was to evaluate the effect of the combination of neovestitol-vestitol (CNV) compounds obtained from Brazilian red propolis on the microbiological profile of a mature multispecies subgingival biofilm. The biofilm with 32 bacterial species associated with periodontitis was formed for seven days using a Calgary device. Treatment with CNV (1600, 800, 400, and 200 μg/mL), amoxicillin (54 μg/mL), and vehicle control was performed for 24 h on the last day of biofilm formation. Biofilm metabolic activity and DNA-DNA hybridization (checkerboard) assays were performed. The groups treated with CNV 1600 and amoxicillin reduced 25 and 13 species, respectively, compared to the control vehicle treatment (p ≤ 0.05); both reduced P. gingivalis, while only CNV reduced T. forsythia. When the data from the two treatments (CNV and AMOXI) were compared, a statistically significant difference was observed in 13 species, particularly members of Socransky's orange complex. Our results showed that CNV at 1600 μg/mL showed the best results regarding the metabolic activity of mature biofilms and obtained a reduction in species associated with the disease, such as T. forsythia, showing a better reduction than amoxicillin. Therefore, CNV seems to be a promising alternative to eradicate biofilms and reduce their pathogenicity.}, }
@article {pmid38927237, year = {2024}, author = {Iniesta, M and Vasconcelos, V and Sanz, M and Herrera, D}, title = {Supra- and Subgingival Microbiome in Gingivitis and Impact of Biofilm Control: A Comprehensive Review.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {6}, pages = {}, pmid = {38927237}, issn = {2079-6382}, abstract = {This comprehensive review aimed (1) to characterize the sub- and supragingival microbiome in patients with biofilm-induced gingivitis (including experimental gingivitis), (2) to assess its stability and evolution over time, and (3) to assess the impact of biofilm control measures on this stability. An electronic search of the MEDLINE[®]/PubMed[®] database until December 2023 was conducted. NCBI Taxonomy, eHOMD 16S rRNA Reference Sequence, and Tree Version 15.23 databases were used to standardize taxonomic nomenclature. Out of 89 papers initially retrieved, 14 studies were finally included: 11 using experimental gingivitis as a model and three randomized clinical trials evaluating the impact of biofilm control measures. Among them, five characterized the subgingival microbiome, nine the supragingival microbiome, and one both the sub- and supragingival microbiome. In addition, five studies evaluated the effect of toothpaste, and four studies evaluated the effect of mouth rinses. The diversity and structure of the microbiome differed significantly between patients with periodontal health and those with biofilm-induced gingivitis (including experimental gingivitis). Those differences were not reversed through conventional oral hygiene measures. Specific antiseptic agents, especially if delivered as mouth rinses, may have an impact on the supra- and subgingival microbiome in gingivitis.}, }
@article {pmid38927205, year = {2024}, author = {Flores-Vargas, G and Bergsveinson, J and Korber, DR}, title = {Environmentally Relevant Antibiotic Concentrations Exert Stronger Selection Pressure on River Biofilm Resistomes than AMR-Reservoir Effluents.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {6}, pages = {}, pmid = {38927205}, issn = {2079-6382}, abstract = {Freshwater environments are primary receiving systems of wastewater and effluents, which carry low concentrations of antibiotics and antimicrobial-resistant (AMR) bacteria and genes. Aquatic microbial communities are thus exposed to environmentally relevant concentrations of antibiotics (ERCA) that presumably influence the acquisition and spread of environmental AMR. Here, we analyzed ERCA exposure with and without the additional presence of municipal wastewater treatment plant effluent (W) and swine manure run-off (M) on aquatic biofilm resistomes. Microscopic analyses revealed decreased taxonomic diversity and biofilm structural integrity, while metagenomic analysis revealed an increased abundance of resistance, virulence, and mobile element-related genes at the highest ERCA exposure levels, with less notable impacts observed when solely exposed to W or M effluents. Microbial function predictions indicated increased gene abundance associated with energy and cell membrane metabolism and heavy metal resistance under ERCA conditions. In silico predictions of increased resistance mechanisms did not correlate with observed phenotypic resistance patterns when whole communities were exposed to antimicrobial susceptibility testing. This reveals important insight into the complexity of whole-community coordination of physical and genetic responses to selective pressures. Lastly, the environmental AMR risk assessment of metagenomic data revealed a higher risk score for biofilms grown at sub-MIC antibiotic conditions.}, }
@article {pmid38927142, year = {2024}, author = {Offman, EM and Leestemaker-Palmer, A and Fathi, R and Keefe, B and Bibliowicz, A and Raday, G and Bermudez, LE}, title = {Triple-Antibiotic Combination Exerts Effective Activity against Mycobacterium avium subsp. hominissuis Biofilm and Airway Infection in an In Vivo Murine Model.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {13}, number = {6}, pages = {}, pmid = {38927142}, issn = {2079-6382}, support = {001//RedHill Biofarma/ ; }, abstract = {OBJECTIVES: Slow-growing nontuberculous mycobacteria (NTMs) are highly prevalent and routinely cause opportunistic intracellular infectious disease in immunocompromised hosts.<br><br>METHODS: The activity of the triple combination of antibiotics, clarithromycin (CLR), rifabutin (RFB), and clofazimine (CFZ), was evaluated and compared with the activity of single antibiotics as well as with double combinations in an in vitro biofilm assay and an in vivo murine model of Mycobacterium avium subsp. hominissuis (M. avium) lung infection.<br><br>RESULTS: Treatment of 1-week-old biofilms with the triple combination exerted the strongest effect of all (0.12 &#xb1; 0.5 &#xd7; 10[7] CFU/mL) in reducing bacterial growth as compared to the untreated (5.20 &#xb1; 0.5 &#xd7; 10[7]/mL) or any other combination (&#x2265;0.75 &#xb1; 0.6 &#xd7; 10[7]/mL) by 7 days. The treatment of mice intranasally infected with M. avium with either CLR and CFZ or the triple combination provided the greatest reduction in CLR-sensitive M. avium bacterial counts in both the lung and spleen compared to any single antibiotic or remaining double combination by 4 weeks posttreatment. After 4 weeks of treatment with the triple combination, there were no resistant colonies detected in mice infected with a CLR-resistant strain. No clear relationships between treatment and spleen or lung organ weights were apparent after triple combination treatment.<br><br>CONCLUSIONS: The biofilm assay data and mouse disease model efficacy results support the further investigation of the triple-antibiotic combination.}, }
@article {pmid38925646, year = {2024}, author = {De Padua, JC and Tanaka, T and Ueno, K and Dela Cruz, TEE and Ishihara, A}, title = {Isolation of 2,2'-azoxybisbenzyl alcohol from Agaricus subrutilescens and its inhibitory activity against bacterial biofilm formation.}, journal = {Bioscience, biotechnology, and biochemistry}, volume = {}, number = {}, pages = {}, doi = {10.1093/bbb/zbae089}, pmid = {38925646}, issn = {1347-6947}, abstract = {Virulence pathways in pathogenic bacteria are regulated by quorum sensing mechanisms, particularly biofilm formation through autoinducer production and sensing. In this study, the culture filtrate extracted from an edible mushroom, Agaricus subrutilescens, was fractionated to isolate a compound that inhibits biofilm formation. Four gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, and Enterobacter cloacae) and two gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus) were used for the bioassay. The bioassay-guided chromatographic separations of the culture filtrate extract resulted in the isolation of the compound. Further, spectroscopic analyses revealed the identity of the compound as 2,2'-azoxybisbenzyl alcohol (ABA). The minimum inhibitory and sub-inhibitory concentrations of the compound were also determined. ABA was significantly effective in inhibiting biofilm formation in all tested bacteria, with half-maximal inhibitory concentrations of 3-11 µg/mL. Additionally, the bioactivity of ABA was confirmed through the bioassays for the inhibition of exopolysaccharide matrixes and autoinducer activities.}, }
@article {pmid38925344, year = {2024}, author = {Alhariry, J and Kumar, A and Yadav, TC and Yadav, E and Prasad, R and Poluri, KM and Gupta, P}, title = {Tyrosol-gold nanoparticle functionalized acacia gum-PVA nanofibers for mitigation of Candida biofilm.}, journal = {Microbial pathogenesis}, volume = {193}, number = {}, pages = {106763}, doi = {10.1016/j.micpath.2024.106763}, pmid = {38925344}, issn = {1096-1208}, mesh = {*Biofilms/drug effects/growth &amp; development ; *Gold/chemistry/pharmacology ; *Nanofibers/chemistry ; *Phenylethyl Alcohol/analogs &amp; derivatives/pharmacology/chemistry ; *Metal Nanoparticles/chemistry ; *Antifungal Agents/pharmacology ; *Candida/drug effects ; *Gum Arabic/chemistry/pharmacology ; Chitosan/chemistry/pharmacology ; Nanocomposites/chemistry ; Microbial Sensitivity Tests ; Polyvinyl Alcohol/chemistry ; Drug Liberation ; Silver/pharmacology/chemistry ; Ergosterol/chemistry ; Hydrophobic and Hydrophilic Interactions ; }, abstract = {Increasing incidences of fungal infections and prevailing antifungal resistance in healthcare settings has given rise to an antifungal crisis on a global scale. The members of the genus Candida, owing to their ability to acquire sessile growth, are primarily associated with superficial to invasive fungal infections, including the implant-associated infections. The present study introduces a novel approach to combat the sessile/biofilm growth of Candida by fabricating nanofibers using a nanoencapsulation approach. This technique involves the synthesis of tyrosol (TYS) functionalized chitosan gold nanocomposite, which is then encapsulated into PVA/AG polymeric matrix using electrospinning. The FESEM, FTIR analysis of prepared TYS-AuNP@PVA/AG NF suggested the successful encapsulation of TYS into the nanofibers. Further, the sustained and long-term stability of TYS in the medium was confirmed by drug release and storage stability studies. The prepared nanomats can absorb the fluid, as evidenced by the swelling index of the nanofibers. The growth and biofilm inhibition, as well as the disintegration studies against Candida, showed 60-70 % biofilm disintegration when 10 mg of TYS-AuNP@PVA/AG NF was used, hence confirming its biological effectiveness. Subsequently, the nanofibers considerably reduced the hydrophobicity index and ergosterol content of the treated cells. Considering the challenges associated with the inhibition/disruption of fungal biofilm, the fabricated nanofibers prove their effectiveness against Candida biofilm. Therefore, nanocomposite-loaded nanofibers have emerged as potential materials that can control fungal colonization and could also promote healing.}, }
@article {pmid38924949, year = {2024}, author = {Wang, L and Zhang, C and Kang, X and Liu, Y and Qiu, Y and Wanyan, D and Liu, J and Cheng, G and Huang, X}, title = {Establishing mainstream partial nitrification in the membrane aerated biofilm reactor by limiting the oxygen concentration in the biofilm.}, journal = {Water research}, volume = {261}, number = {}, pages = {121984}, doi = {10.1016/j.watres.2024.121984}, pmid = {38924949}, issn = {1879-2448}, abstract = {The proliferation of nitrite oxidizing bacteria (NOB) still remains as a major challenge for nitrogen removal in mainstream wastewater treatment process based on partial nitrification (PN). This study investigated different operational conditions to establish mainstream PN for the fast start-up of membrane aerated biofilm reactor (MABR) systems. Different oxygen controlling strategies were adopted by employing different influent NH4[+]-N loads and oxygen supply strategies to inhibit NOB. We indicated the essential for NOB suppression was to reduce the oxygen concentration of the inner biofilm and the thickness of aerobic biofilm. A higher NH4[+]-N load (7.4 g-N/(m[2]·d)) induced higher oxygen utilization rate (14.4 g-O2/(m[2]·d)) and steeper gradient of oxygen concentration, which reduced the thickness of aerobic biofilm. Employing closed-end oxygen supply mode exhibited the minimum concentration of oxygen to realize PN, which was over 46% reduction of the normal open-end oxygen mode. Under the conditions of high NH4[+]-N load and closed-end oxygen supply mode, the microbial community exhibited a comparative advantage of ammonium oxidizing bacteria over NOB in the aerobic biofilm, with a relative abundance of Nitrosomonas of 30-40% and no detection of Nitrospira. The optimal fast start-up strategy was proposed with open-end aeration mode in the first 10 days and closed-end mode subsequently under high NH4[+]-N load. The results revealed the mechanism of NOB inhibition on the biofilm and provided strategies for a quick start-up and stable mainstream PN simultaneously, which poses great significance for the future application of MABR.}, }
@article {pmid38924874, year = {2024}, author = {Santana, JS and Delbem, ACB and Pessan, JP and Sampaio, C and de Morais, LA and Pereira, TL and Monteiro, DR and Hosida, TY}, title = {Dual-species biofilm of Streptococcus mutans and Candida albicans produces subsurface caries lesions on bovine enamel.}, journal = {Archives of oral biology}, volume = {166}, number = {}, pages = {106029}, doi = {10.1016/j.archoralbio.2024.106029}, pmid = {38924874}, issn = {1879-1506}, mesh = {*Biofilms ; *Candida albicans/physiology ; *Streptococcus mutans/physiology ; *Dental Caries/microbiology ; Animals ; Cattle ; Polysaccharides, Bacterial/metabolism ; Sucrose/pharmacology ; Fluorides/pharmacology ; *Dental Enamel/chemistry/microbiology/pathology ; Models, Animal ; }, abstract = {OBJECTIVES: To develop a protocol for forming subsurface caries lesions on bovine enamel by dual-species biofilms of Streptococcus mutans and Candida albicans in vitro.<br><br>DESIGN: Biofilms were grown on bovine enamel specimens in artificial saliva (AS) for seven days. After 24&#xa0;h of formation, the AS was supplemented or not with fluoride (F) using sodium fluoride (0.005 or 0.008&#xa0;ppm&#xa0;F), and the biofilms were exposed or not to a 20&#xa0;% sucrose solution (reproducing a cariogenic challenge) once/day. On the seventh day, the biofilms were harvested and had their extracellular polysaccharides (EPS) and inorganic components analyzed. The specimens were subjected to computed X-ray microtomography analysis to determine their mineral concentration. Data were compared using two-way analyses of variance, followed by Fisher's LSD or Student-Newman-Keuls tests (p&#xa0;<&#xa0;0.05).<br><br>RESULTS: Biofilms exposed to the cariogenic challenge had significantly higher EPS concentrations than those not exposed, regardless of the presence of F. For biofilms grown with 0.008&#xa0;ppm&#xa0;F, those exposed to the cariogenic challenge had lower F levels than those not exposed. For biofilms exposed to the cariogenic challenge, those grown with 0.008&#xa0;ppm&#xa0;F had lower lesion depths and integrated mineral loss, and higher outer layers than those grown without F.<br><br>CONCLUSIONS: The dual biofilm model assessed was able to create subsurface caries lesions in bovine enamel in vitro, which was influenced by the presence of F in the culture medium and exposure to sucrose.}, }
@article {pmid38924372, year = {2024}, author = {Ballesté, E and Liang, H and Migliorato, L and Sala-Comorera, L and Méndez, J and Garcia-Aljaro, C}, title = {Exploring plastic biofilm formation and Escherichia coli colonisation in marine environments.}, journal = {Environmental microbiology reports}, volume = {16}, number = {3}, pages = {e13308}, pmid = {38924372}, issn = {1758-2229}, support = {PID2019-108957GA-I00//Ministerio de Ciencia e Innovaci&#xf3;n/ ; }, mesh = {*Biofilms/growth &amp; development ; *Escherichia coli/genetics/physiology/isolation &amp; purification/growth &amp; development ; *Plastics ; *Seawater/microbiology ; RNA, Ribosomal, 16S/genetics ; Water Microbiology ; }, abstract = {Microorganisms, including potential pathogens, can colonise plastic surfaces in aquatic environments. This study investigates the colonisation of plastic pellets by Escherichia coli (E. coli) as a proxy for faecal pathogens in aquatic environments. Plastic pellets from a polluted beach were placed in seawater aquaria spiked with E. coli. Diverse bacteria, primarily from the Proteobacteria phylum, rapidly colonised the pellets within 24 h, with notable species known for plastic or hydrocarbon degradation. Over 26 days, biofilms formed on the plastic surfaces, reaching bacterial populations of up to 6.8·10[5] gene copies (gc) of the 16S rRNA mm[-2]. E. coli, was detected in the pellets for up to 7 days using culture methods, exhibiting varying attachment densities regardless of source or environmental factors. The study highlights plastic biofilms as reservoirs for E. coli, contributing to the survival and persistence of faecal bacteria in aquatic systems. These findings deepen our understanding of the risks associated with plastic pollution in marine settings, offering insights into the behaviour of faecal indicators and their implications for water quality assessments, while providing valuable information on potential pathogen dissemination within plastic-associated microbial communities.}, }
@article {pmid38924307, year = {2024}, author = {Liu, JD and VanTreeck, KE and Marston, WA and Papadopoulou, V and Rowe, SE}, title = {Ultrasound-mediated antibiotic delivery to in vivo biofilm infections: A Review.}, journal = {Chembiochem : a European journal of chemical biology}, volume = {}, number = {}, pages = {e202400181}, doi = {10.1002/cbic.202400181}, pmid = {38924307}, issn = {1439-7633}, abstract = {Bacterial biofilms are a significant concern in various medical contexts due to their resilience to our immune system as well as antibiotic therapy. Biofilms often require surgical removal and frequently lead to recurrent or chronic infections. Therefore, there is an urgent need for improved strategies to treat biofilm infections. Ultrasound-mediated drug delivery is a technique that combines ultrasound application, often with the administration of acoustically-active agents, to enhance drug delivery to specific target tissues or cells within the body. This method involves using ultrasound waves to assist in the transportation or activation of medications, improving their penetration, distribution, and efficacy at the desired site. The advantages of ultrasound-mediated drug delivery include targeted and localized delivery, reduced systemic side effects, and improved efficacy of the drug at lower doses. This review scrutinizes recent advances in the application of ultrasound-mediated drug delivery for treating biofilm infections, focusing on in vivo studies. We examine the strengths and limitations of this technology in the context of wound infections, device-associated infections, lung infections and abscesses, and discuss current gaps in knowledge and clinical translation considerations.}, }
@article {pmid38923398, year = {2024}, author = {Nouraei, H and Zare, S and Nemati, M and Amirzadeh, N and Motamedi, M and Shabanzadeh, S and Zomorodian, K and Pakshir, K}, title = {Comparative analysis of enzymatic profiles and biofilm formation in clinical and environmental Candida kefyr isolates.}, journal = {Environmental microbiology reports}, volume = {16}, number = {3}, pages = {e13282}, pmid = {38923398}, issn = {1758-2229}, support = {26387//Vice-Chancellor for Research, Shiraz University of Medical Sciences/ ; 26828//Vice-Chancellor for Research, Shiraz University of Medical Sciences/ ; }, mesh = {*Biofilms/growth &amp; development ; *Candida/isolation &amp; purification/enzymology/physiology/classification ; Humans ; *Candidiasis/microbiology ; *Phospholipases/metabolism ; Esterases/metabolism ; Hemolysin Proteins/metabolism ; Peptide Hydrolases/metabolism ; Environmental Microbiology ; }, abstract = {The global landscape of Candida infections has seen a significant shift. Previously, Candida albicans was the predominant species. However, there has been an emergence of non-albicans Candida species, which are often less susceptible to antifungal treatment. Candida kefyr, in particular, has been increasingly associated with infections. This study aimed to investigate the profiles of enzymatic activity and biofilm formation in both clinical and non-clinical isolates of C. kefyr. A total of 66 C. kefyr isolates were analysed. The activities of proteinase and phospholipase were assessed using bovine serum albumin and egg yolk agar, respectively. Haemolysin, caseinolytic and esterase activities were evaluated using specific methods. Biofilm formation was investigated using crystal violet staining. The findings indicated that biofilm and proteinase activity were detected in 81.8% and 93.9% of all the isolates, respectively. Haemolysin activity was observed with the highest occurrence (95.5%) among normal microbiota isolates. Esterase activity was predominantly identified in dairy samples and was absent in hospital samples. Caseinase production was found with the highest occurrence (18.2%) in normal microbiota and hospital samples. Phospholipase activity was limited, found in only 3% of all the isolates. These findings reveal variations in enzyme activity between clinical and non-clinical C. kefyr isolates. This sheds light on their pathogenic potential and has implications for therapeutic strategies.}, }
@article {pmid38922976, year = {2024}, author = {Bell, RD and Cann, EA and Mishra, B and Valencia, M and Zhang, Q and Huang, M and Yang, X and Carli, A and Bostrom, M and Ivashkiv, LB}, title = {Staphyloccocus aureus biofilm, in absence of planktonic bacteria, produces factors that activate counterbalancing inflammatory and immune-suppressive genes in human monocytes.}, journal = {Journal of orthopaedic research : official publication of the Orthopaedic Research Society}, volume = {}, number = {}, pages = {}, doi = {10.1002/jor.25919}, pmid = {38922976}, issn = {1554-527X}, support = {R01 AI046712/AI/NIAID NIH HHS/United States ; R01AI046712//National Institute of Allergy and Infectious Diseases/ ; T32 AR071302-07/AR/NIAMS NIH HHS/United States ; R01 AR050401/AR/NIAMS NIH HHS/United States ; R01DE019420-14/DE/NIDCR NIH HHS/United States ; R01 DE019420/DE/NIDCR NIH HHS/United States ; }, abstract = {Staphyloccocus aureus (S. aureus) is a major bacterial pathogen in orthopedic periprosthetic joint infection (PJI). S. aureus forms biofilms that promote persistent infection by shielding bacteria from immune cells and inducing an antibiotic-tolerant metabolic state. We developed an in vitro system to study S. aureus biofilm interactions with primary human monocytes in the absence of planktonic bacteria. In line with pre