@article {pmid39779734,
year = {2025},
author = {Wardell, SJT and Yung, DBY and Gupta, A and Bostina, M and Overhage, J and Hancock, REW and Pletzer, D},
title = {DJK-5, an anti-biofilm peptide, increases Staphylococcus aureus sensitivity to colistin killing in co-biofilms with Pseudomonas aeruginosa.},
journal = {NPJ biofilms and microbiomes},
volume = {11},
number = {1},
pages = {8},
pmid = {39779734},
issn = {2055-5008},
mesh = {*Biofilms/drug effects ; *Colistin/pharmacology ; *Pseudomonas aeruginosa/drug effects ; Animals ; *Anti-Bacterial Agents/pharmacology ; *Drug Synergism ; Mice ; *Staphylococcus aureus/drug effects ; *Staphylococcal Infections/drug therapy/microbiology ; *Microbial Sensitivity Tests ; Methicillin-Resistant Staphylococcus aureus/drug effects ; Humans ; Pseudomonas Infections/drug therapy/microbiology ; Daptomycin/pharmacology ; Disease Models, Animal ; Oligopeptides ; },
abstract = {Chronic infections represent a significant global health and economic challenge. Biofilms, which are bacterial communities encased in an extracellular polysaccharide matrix, contribute to approximately 80% of these infections. In particular, pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus are frequently co-isolated from the sputum of patients with cystic fibrosis and are commonly found in chronic wound infections. Within biofilms, bacteria demonstrate a remarkable increase in resistance and tolerance to antimicrobial treatment. We investigated the efficacy of combining the last-line antibiotic colistin with a membrane- and stringent stress response-targeting anti-biofilm peptide DJK-5 against co-biofilms comprised of multidrug-resistant P. aeruginosa and methicillin-resistant S. aureus (MRSA). Colistin lacks canonical activity against S. aureus. However, our study revealed that under co-biofilm conditions, the antibiofilm peptide DJK-5 synergized with colistin against S. aureus. Similar enhancement was observed when daptomycin, a cyclic lipopeptide against Gram-positive bacteria, was combined with DJK-5, resulting in increased activity against P. aeruginosa. The combinatorial treatment induced morphological changes in both P. aeruginosa and S. aureus cell shape and size within co-biofilms. Importantly, our findings also demonstrate synergistic activity against both P. aeruginosa and S. aureus in a murine subcutaneous biofilm-like abscess model. In conclusion, combinatorial treatments with colistin or daptomycin and the anti-biofilm peptide DJK-5 show significant potential for targeting co-biofilm infections. These findings offer promising avenues for developing new therapeutic approaches to combat complex chronic infections.},
}

*Biofilms/drug effects
*Colistin/pharmacology
*Pseudomonas aeruginosa/drug effects
Animals
*Anti-Bacterial Agents/pharmacology
*Drug Synergism
Mice
*Staphylococcus aureus/drug effects
*Staphylococcal Infections/drug therapy/microbiology
*Microbial Sensitivity Tests
Methicillin-Resistant Staphylococcus aureus/drug effects
Humans
Pseudomonas Infections/drug therapy/microbiology
Daptomycin/pharmacology
Disease Models, Animal
Oligopeptides

@article {pmid39778756,
year = {2025},
author = {Zehra, M and Asghar, S and Ilyas, R and Usmani, Y and Khan, RMA and Mirani, ZA and Ahmed, A},
title = {Relationship of biofilm formation with antibiotic resistance, virulence determinants and genetic diversity in clinically isolated Acinetobacter baumannii strains in Karachi, Pakistan.},
journal = {Microbial pathogenesis},
volume = {200},
number = {},
pages = {107283},
doi = {10.1016/j.micpath.2025.107283},
pmid = {39778756},
issn = {1096-1208},
abstract = {Multi-drug resistant (MDR) Acinetobacter baumannii causes nosocomial infections due to a plethora of virulence determinants like biofilm formation which are pivotal to its survival and pathogenicity. Hence, investigation of these mechanisms in currently circulating strains is required for effective infection control and drug development. This study investigates the prevalence of antibiotic resistance and virulence factors and their relationship with biofilm formation in Acinetobacter baumannii strains in Karachi, Pakistan. Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC PCR) was used for observing genetic variations. The results revealed that 100 % A. baumannii strains were MDR and 74.4 % had multiple antibiotic resistance index (MARi) of 0.875-1. There were 27 biofilm forming strains with a moderate correlation between biofilm formation and MARi. A high prevalence of abaI (86.04 %), bfmR (95.3 %), bfmS (97.6 %), csuE (90.69 %), ompA (74.4 %), and pgaA virulence genes (95.3 %) and resistance genes adeF (53.4 %), adeJ (74.4 %), ampC (51.1 %), tem-1 (51.1 %), and vim (65.1 %)) were observed in these strains. ERIC PCR revealed that 5 of 22 genetic types had strong biofilm form strains with similar virulence genes profiles. Conclusively, the study shows escalated resistance and virulence in clinical strains which warrants consistent epidemiological studies to prevent infections spread and future outbreaks.},
}

@article {pmid39777967,
year = {2025},
author = {Mohammed Aggad, FZ and Ilias, F and Elghali, F and Mrabet, R and El Haci, IA and Aifa, S and Mnif, S},
title = {Evaluation of Antibacterial Activity in Some Algerian Essential Oils and Selection of Thymus vulgaris as a Potential Biofilm and Quorum Sensing Inhibitor Against Pseudomonas aeruginosa.},
journal = {Chemistry & biodiversity},
volume = {},
number = {},
pages = {e202402691},
doi = {10.1002/cbdv.202402691},
pmid = {39777967},
issn = {1612-1880},
abstract = {Biofilm formation and virulence factor production by Pseudomonas aeruginosa are identified as the main mechanisms of its antibiotic resistance and pathogenicity. In this context, the study of the chemical composition of three Algerian essential oils (EOs) and the screening of their antibacterial, anti-biofilm and virulence factor inhibitory activities enabled us to select the Thyme EO as the best oil to control the P. aeruginosa strain isolated from hospital environments. This EO composed essentially of thymol (55.82%) associated with carvacrol, had an anti-adhesive activity of 69.8% at a concentration of 5µL/mL, and a biofilm eradication activity of 74.86% at a concentration of 2.5µL/mL. This EO was able to inhibit P. aeruginosa twitching motility by 100% at a concentration of 2.5µL/mL. Pyocyanin was inhibited by 99.33%, at a concentration of 1.25µL/mL. Rhamnolipids were significantly inhibited by 63.33% in the presence of Thyme EO at a concentration of 1.25µL/mL after 24h of incubation. Molecular docking showed that carvacrol and thymol can bind to the three QS receptors in P. aeruginosa, RhlR, LasR, and PqsR, with good affinities, which can inhibit or modulate biofilm formation and the production of certain virulence factors. Keywords antibiofilm, thymol, essential oil, Pseudomonas aeruginosa, pyocyanin, rhamnolipids, in silico study.},
}

@article {pmid39777149,
year = {2024},
author = {Yin, L and Guo, Y and Xv, X and Dai, Y and Li, L and Sun, F and Lv, X and Shu, G and Liang, X and He, C and Xu, Z and Ouyang, P},
title = {Cinnamaldehyde nanoemulsion decorated with rhamnolipid for inhibition of methicillin-resistant Staphylococcus aureus biofilm formation: in vitro and in vivo assessment.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1514659},
pmid = {39777149},
issn = {1664-302X},
abstract = {BACKGROUND: Staphylococcus aureus (S. aureus) biofilm associated infections are prevalent and persistent, posing a serious threat to human health and causing significant economic losses in animal husbandry. Nanoemulsions demonstrate significant potential in the treatment of bacterial biofilm associated infections due to their unique physical, chemical and biological properties. In this study, a novel cinnamaldehyde nanoemulsion with the ability to penetrate biofilm structures and eliminate biofilms was developed.

METHODS: The formulation of cinnamaldehyde nanoemulsion (Cin-NE) combined with rhamnolipid (RHL) was developed by self-assembly, and the efficacies of this formulation in inhibiting S. aureus biofilm associated infections were assessed through in vitro assays and in vivo experiments by a mouse skin wound healing model.

RESULTS: The particle size of the selected Cin-NE formulation was 13.66 ± 0.08 nm, and the Cin-RHL-NE formulation was 20.45 ± 0.25 nm. The selected Cin-RHL-NE formulation was stable at 4, 25, and 37°C. Furthermore, the Minimum Inhibitory Concentration (MIC) value of Cin-RHL-NE against MRSA was two-fold lower than drug solution. Confocal laser scanning microscopy (CLSM) revealed the superior efficacy of Cin-RHL-NE in eradicating MRSA biofilms while maintaining the Cin's inherent functional properties. The efficacy of Cin-RHL-NE in the mouse skin wound healing model was superior to other formulation.

CONCLUSION: These findings highlight the potential of the formulation Cin-RHL-NE for eradicating biofilms, and effective in treating notoriously persistent bacterial infections. The Cin-RHL-NE can used as a dosage form of Cin application to bacterial biofilm associated infections.},
}

@article {pmid39773469,
year = {2025},
author = {Wang, D and Zeng, N and Li, C and Li, C and Wang, Y and Chen, B and Long, J and Zhang, N and Li, B},
title = {Integrative analysis of transcriptome and metabolome profiling uncovers underlying mechanisms of the enhancement of the synthesis of biofilm in Sporobolomyces pararoseus NGR under acidic conditions.},
journal = {Microbial cell factories},
volume = {24},
number = {1},
pages = {9},
pmid = {39773469},
issn = {1475-2859},
support = {31271818//National Natural Science Foundation of China/ ; 2023-01//International Cooperation Project of Universities in Liaoning Province/ ; 2022030673-JH5/104//Liaoning Province Rural Science and Technology Special Action Project/ ; 22-319-2-13//Shenyang Science and Technology Project/ ; CSC202208850002//China Scholarship Council/ ; },
mesh = {*Biofilms ; *Transcriptome ; *Metabolome ; Hydrogen-Ion Concentration ; Gene Expression Profiling ; Burkholderiaceae/metabolism/genetics ; },
abstract = {BACKGROUND: Sporobolomyces pararoseus is a well-studied oleaginous red yeast that can synthesize a variety of high value-added bioactive compounds. Biofilm is one of the important biological barriers for microbial cells to resist environmental stresses and maintain stable fermentation process. Here, the effect of acidic conditions on the biosynthesis of biofilms in S. pararoseus NGR was investigated through the combination of morphology, biochemistry, and multi-omics approaches.

RESULTS: The results showed that the acidic environment was the key factor to trigger the biofilm formation of S. pararoseus NGR. When S. pararoseus NGR was cultured under pH 4.7, the colony morphology was wrinkled, the cells were wrapped by a large amount of extracellular matrix, and the hydrophobicity and anti-oxidative stress ability were significantly improved, and the yield of intracellular carotenoids was significantly increased. Transcriptome and metabolome profiling indicated that carbohydrate metabolism, amino acid metabolism, lipid metabolism, and nucleic acid metabolism in S. pararoseus NGR cells were significantly enriched in biofilm cells under pH 4.7 culture conditions, including 56 differentially expressed genes and 341 differential metabolites.

CONCLUSIONS: These differential genes and metabolites may play an important role in the formation of biofilms by S. pararoseus NGR in response to acidic stress. The results will provide strategies for the development and utilization of beneficial microbial biofilms, and provide theoretical support for the industrial fermentation production of microorganisms to improve their resistance and maintain stable growth.},
}

*Biofilms
*Transcriptome
*Metabolome
Hydrogen-Ion Concentration
Gene Expression Profiling
Burkholderiaceae/metabolism/genetics

@article {pmid39772813,
year = {2024},
author = {Maciel, JG and Gomes, ACG and Sugio, CY and Garcia, AA and Zani, IF and Fernandes, MH and Soares, S and Neppelenbroek, KH},
title = {Denture biofilm increases respiratory diseases in the elderly. A mini-review.},
journal = {American journal of dentistry},
volume = {37},
number = {6},
pages = {288-292},
pmid = {39772813},
issn = {0894-8275},
mesh = {*Biofilms ; Humans ; Aged ; Dentures/microbiology ; Acrylic Resins ; Respiratory Tract Infections/microbiology ; Respiratory Tract Diseases/microbiology ; },
abstract = {PURPOSE: This mini-review discusses the clinical implication of respiratory pathogens in the biofilm on acrylic resin removable dentures in the elderly.

METHODS: A search was conducted using the keywords: "dentures", " acrylic resin", "biofilm", "pneumonia", "elderly", "respiratory pathogens", and "respiratory diseases" in databases PubMed/Medline, Lilacs, SciELO and textbooks between 1999 and 2024.

RESULTS: The elderly are more susceptible to chronic diseases and/or life-threatening infections because of senescence itself and functional and degenerative alterations. Respiratory tract diseases (such as pneumonia) are of greater concern in the elderly because they have been associated with the aspiration of food and oral pathogens and with reflux. This relationship is more aggravating in the presence of removable dentures, common in the elderly after the sixth decade of life, since denture biofilm is a reservoir of respiratory pathogens. Lack of manual dexterity and visual acuity negatively interfere with denture cleaning and favor pathogenic denture biofilm maturation. Reduced salivary flow, a more acidic pH, and a reduced cough reflex associated with poor denture cleaning increase the potential of denture biofilm infections and aspiration pneumonia, which is related to a high mortality rate in the elderly. To prevent respiratory diseases in this population, measures to control denture biofilm should be adopted, such as the superficial or intrinsic modification of the acrylic resin denture bases and the use of effective methods of denture cleaning.

CLINICAL SIGNIFICANCE: Respiratory pathogens colonizing denture biofilm can be aspirated into the respiratory tract, increasing the risk of respiratory infections, especially in the elderly. The knowledge of health professionals on methods of biofilm control can prevent respiratory diseases in elderly denture wearers.},
}

*Biofilms
Humans
Aged
Dentures/microbiology
Acrylic Resins
Respiratory Tract Infections/microbiology
Respiratory Tract Diseases/microbiology

@article {pmid39772812,
year = {2024},
author = {Shamieh, S and Ribeiro, AA and Sulaiman, T and Swift, EJ and Vasconcellos, AB},
title = {Biofilm attachment and mineralizing potential of contemporary restorative materials.},
journal = {American journal of dentistry},
volume = {37},
number = {6},
pages = {279-287},
pmid = {39772812},
issn = {0894-8275},
mesh = {*Biofilms ; *Composite Resins/chemistry ; Humans ; *Dental Restoration, Permanent/methods ; *Resin Cements/chemistry ; Dental Materials/chemistry ; Materials Testing ; Dentin/microbiology ; X-Ray Microtomography ; In Vitro Techniques ; Molar ; },
abstract = {PURPOSE: To evaluate and compare: (1) the effect of the bacterial biofilm on the dentin mineral density at the restoration-tooth interface and (2) the mineralization potential of three resin-based restorative materials (RBRM).

METHODS: 16 extracted human molars free of caries and cracks were collected and stored for disinfection. Each tooth received two standardized Class II preparations with the cervical margin placed in dentin. Teeth were secured into a dentiform with adjacent natural teeth to ensure interproximal contact. All tooth preparations were hybridized using a three-step etch-and-rinse adhesive system (OptiBond FL) and assigned randomly to three experimental groups according to the RBRM (n= 8): Group A - a nanofill resin composite (Filtek Supreme Ultra); Group B - a high-viscosity bulk-fill resin composite (Tetric Powerfill); Group C - a low-viscosity bulk-fill resin composite (SureFil SDR flow+ bulk-fill); and a positive control: Group D - bioactive resin composite (Activa Bioactive-Restorative). All materials were used according to manufacturers' instructions. All specimens were subjected to two distinct challenges: first, thermomechanical cycling was performed within 24 hours of restoring the specimens to simulate 1 year of masticatory function. Subsequently, the specimens were stored for 18 days in a laboratory biofilm model to promote biofilm formation and to mimic the effects of tooth demineralization. Two sessions of micro-CT imaging were conducted: the first immediately after the thermomechanical cycling and the second post-exposure to the biofilm model. All data on mineral profile measurements reconstructed in the Perkin-Elmer Quantum GX-II CT were transferred to Image J software for analysis and interpretation. The ANOVA test (P< 0.05) was used to analyze the mineral density values and mean mineral loss values for each group.

RESULTS: No statistically significant difference in mean mineral loss value (mean ΔZ) was found between the groups (P= 0.209). Regardless, increased mean ΔZ variation was found between SureFil SDR flow+ (-56.95) and the remaining groups, Filtek Supreme Ultra, Tetric Powerfill and Activa Bioactive (-1.17, -1.41, and -7.97, respectively), showing, within the limits of the present laboratory study, the remineralization potential of SureFil SDR flow+. All tested RBRM demonstrated some remineralization capacity under caries risk conditions.

CLINICAL SIGNIFICANCE: The mineralization potential of some resin-based composites under caries-risk conditions can represent a paradigm shift in restorative material selection for moderate-to-high-risk patients.},
}

*Biofilms
*Composite Resins/chemistry
Humans
*Dental Restoration, Permanent/methods
*Resin Cements/chemistry
Dental Materials/chemistry
Materials Testing
Dentin/microbiology
X-Ray Microtomography
In Vitro Techniques
Molar

@article {pmid39770726,
year = {2024},
author = {Mendes, MB and Vidigal, PMP and Soto Lopez, ME and Hungaro, HM},
title = {Combined Effects of the Pijolavirus UFJF_PfSW6 Phage and Sodium Hypochlorite for Reducing Pseudomonas fluorescens Biofilm.},
journal = {Microorganisms},
volume = {12},
number = {12},
pages = {},
pmid = {39770726},
issn = {2076-2607},
support = {Inovaleite Group and Instituto Sua Ciência (ISC)//MilkFund/ ; CAG 00146-22//Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)/ ; 200773/2024-0//Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)/ ; Vicerrectoria de Investigación y Extensión and project entitled BPIN 2020000100697, funden By MinCiencias - Colombia//University of Córdoba/ ; },
abstract = {Pseudomonas are significant spoilage bacteria in raw milk and dairy products, primarily due to their ability to form biofilms and resist disinfection. This study explored the effects of the UFJF_PfSW6 phage combined with sodium hypochlorite in reducing Pseudomonas fluorescens biofilms on stainless steel at various temperatures and ages. Biofilms were formed using P. fluorescens UFV 041 in UHT milk, incubated at 4 °C and 30 °C for 2 and 7 days. Two lytic phages were compared, with UFJF_PfSW6 showing superior activity, reducing cell counts by 0.8 to 2.0 logs CFU/cm[2] depending on conditions. Increasing the contact time of the UFJF_PfSW6 phage from 4 to 8 h did not significantly affect the reduction in mature biofilms. The individual treatments of the phage and sodium hypochlorite (100 mg/L) reduced bacterial counts by 0.9 and 0.6 log CFU/cm[2] at 30 °C, and 1.3 and 1.2 log CFU/cm[2] at 4 °C, respectively. However, their sequential application achieved greater reductions, reaching 1.3 and 1.8 log CFU/cm[2] for biofilms formed at 30 °C and 4 °C, respectively. These findings suggest a promising strategy for controlling P. fluorescens in the food industry. Our findings suggest that the UFJF_PfSW6 phage combined with chlorine improves the removal of P. fluorescens biofilms.},
}

@article {pmid39770699,
year = {2024},
author = {Horgan, C and Baccari, C and O'Driscoll, M and Lindow, SE and O'Sullivan, TP},
title = {BDSF Analogues Inhibit Quorum Sensing-Regulated Biofilm Production in Xylella fastidiosa.},
journal = {Microorganisms},
volume = {12},
number = {12},
pages = {},
doi = {10.3390/microorganisms12122496},
pmid = {39770699},
issn = {2076-2607},
support = {GOIPG/2017/1111//Irish Research Council/ ; GOIPG/2021/227//Irish Research Council/ ; 21/RI/9705/SFI_/Science Foundation Ireland/Ireland ; },
abstract = {Xylella fastidiosa is an aerobic, Gram-negative bacterium that is responsible for many plant diseases. The bacterium is the causal agent of Pierce's disease in grapes and is also responsible for citrus variegated chlorosis, peach phony disease, olive quick decline syndrome and leaf scorches of various species. The production of biofilm is intrinsically linked with persistence and transmission in X. fastidiosa. Biofilm formation is regulated by members of the Diffusible Signal Factor (DSF) quorum sensing signalling family which are comprised of a series of long chain cis-unsaturated fatty acids. This article describes the evaluation of a library of N-acyl sulfonamide bioisosteric analogues of BDSF, XfDSF1 and XfDSF2 for their ability to control biofilm production in X. fastidiosa. The compounds were screened against both the wild-type strain Temecula and an rpfF* mutant which can perceive but not produce XfDSF. Planktonic cell abundance was measured via OD600 while standard crystal violet assays were used to determine biofilm biomass. Several compounds were found to be effective biofilm inhibitors depending on the nature of the sulfonamide substituent. The findings reported here may provide future opportunities for biocontrol of this important plant pathogen.},
}

@article {pmid39770681,
year = {2024},
author = {Niu, B and Sun, Y and Niu, Y and Qiao, S},
title = {Ultrasound Treatment Combined with Rhamnolipids for Eliminating the Biofilm of Bacillus cereus.},
journal = {Microorganisms},
volume = {12},
number = {12},
pages = {},
doi = {10.3390/microorganisms12122478},
pmid = {39770681},
issn = {2076-2607},
support = {No. NL2022013//Henan University of Technology/ ; No. 32100041//the National Natural Science Foundation of China/ ; No. 21420188//the Cultivation Programme for Young Backbone Teachers in Henan University of Technology/ ; No. 2020BS067//Henan University of Technology/ ; No. 231100110300//the Major Science and Technology Project of Henan/ ; },
abstract = {Biofilm formation by Bacillus cereus is a major cause of secondary food contamination, leading to significant economic losses. While rhamnolipids (RLs) have shown effectiveness against Bacillus cereus, their ability to remove biofilms is limited when used alone. Ultrasound (US) is a non-thermal sterilization technique that has been found to enhance the delivery of antimicrobial agents, but it is not highly effective on its own. In this study, we explored the synergistic effects of combining RLs with US for biofilm removal. The minimum biofilm inhibitory concentration (MBIC) of RLs was determined to be 32.0 mg/L. Using a concentration of 256.0 mg/L, RLs alone achieved a biofilm removal rate of 63.18%. However, when 32.0 mg/L RLs were combined with 20 min of US treatment, the removal rate increased to 62.54%. The highest biofilm removal rate of 78.67% was observed with 256.0 mg/L RLs and 60 min of US exposure. Scanning electron microscopy analysis showed that this combined treatment significantly disrupted the biofilm structure, causing bacterial deformation and the removal of extracellular polymeric substances. This synergistic approach not only inhibited bacterial metabolic activity, aggregation, and adhesion but also reduced early biofilm formation and decreased levels of extracellular polysaccharides and proteins. Furthermore, US treatment improved biofilm permeability, allowing better penetration of RLs and interaction with bacterial DNA, ultimately inhibiting DNA synthesis and secretion. The combination of RLs and US demonstrated superior biofilm removal efficacy, reduced the necessary concentration of RLs, and offers a promising strategy for controlling biofilm formation in the food industry.},
}

@article {pmid39770562,
year = {2024},
author = {Tang, D and Liu, Y and Yao, H and Lin, Y and Xi, Y and Li, M and Mao, A},
title = {Transcriptome Analysis Reveals the Mechanism of Y0-C10-HSL on Biofilm Formation and Motility of Pseudomonas aeruginosa.},
journal = {Pharmaceuticals (Basel, Switzerland)},
volume = {17},
number = {12},
pages = {},
doi = {10.3390/ph17121719},
pmid = {39770562},
issn = {1424-8247},
support = {12065001//the Regional Fund of the National Natural Science Foundation of China/ ; 32160025//the Regional Fund of the National Natural Science Foundation of China/ ; 20JR10RA224//the Natural Science Foundation of Gansu Province/ ; },
abstract = {Background:Pseudomonas aeruginosa (P. aeruginosa) is a type of pathogen that takes advantage of opportunities to infect and form biofilm during infection. Inhibiting biofilm formation is a promising approach for the treatment of biofilm-related infections. Methods: Here, Y0-C10-HSL (N-cyclopentyl-n-decanamide) was designed, synthesized, and tested for its effect on biofilm formation, motility, and the Caenorhabditis elegans (C. elegans) survival assay. In addition, the molecular mechanism of Y0-C10-HSL on P. aeruginosa biofilm formation was explored using transcriptome analysis. Results: At a concentration of 200 μmol/L Y0-C10-HSL, biofilm and exopolysaccharides were decreased by 38.5% and 29.3%, respectively; Y0-C10-HSL effectively dispersed the pre-formed biofilm and inhibited the motility ability of P. aeruginosa; and the C. elegans survival assay showed that Y0-C10-HSL was safe and provided protection to C. elegans against P. aeruginosa infection (the survival rates of C. elegans were higher than 74% and increased by 39%, 35.1%, and 47.5%, respectively, when treated with 200 μmol/L Y0-C10-HSL at 24, 48, and 80 h). Transcriptome analysis showed that 585 differentially expressed genes (DEGs) were found after treatment with 200 μmol/L Y0-C10-HSL, including 254 up-regulated DEGs and 331 down-regulated DEGs. The genes involved in the quorum sensing system and biofilm formation were down-regulated. Conclusions: Y0-C10-HSL inhibited the biofilm formation and dispersed the pre-formed biofilm of P. aeruginosa through down-regulated genes related to quorum sensing pathways and biofilm formation. These findings provide a theoretical foundation for the treatment and prevention of antibiotic resistance in clinical and environmental microorganisms such as P. aeruginosa.},
}

@article {pmid39770514,
year = {2024},
author = {Geremia, N and Giovagnorio, F and Colpani, A and De Vito, A and Botan, A and Stroffolini, G and Toc, DA and Zerbato, V and Principe, L and Madeddu, G and Luzzati, R and Parisi, SG and Di Bella, S},
title = {Fluoroquinolones and Biofilm: A Narrative Review.},
journal = {Pharmaceuticals (Basel, Switzerland)},
volume = {17},
number = {12},
pages = {},
doi = {10.3390/ph17121673},
pmid = {39770514},
issn = {1424-8247},
abstract = {Background: Biofilm-associated infections frequently span multiple body sites and represent a significant clinical challenge, often requiring a multidisciplinary approach involving surgery and antimicrobial therapy. These infections are commonly healthcare-associated and frequently related to internal or external medical devices. The formation of biofilms complicates treatment, as they create environments that are difficult for most antimicrobial agents to penetrate. Fluoroquinolones play a critical role in the eradication of biofilm-related infections. Numerous studies have investigated the synergistic potential of combining fluoroquinolones with other chemical agents to augment their efficacy while minimizing potential toxicity. Comparative research suggests that the antibiofilm activity of fluoroquinolones is superior to that of beta-lactams and glycopeptides. However, their activity remains less effective than that of minocycline and fosfomycin. Noteworthy combinations include fluoroquinolones with fosfomycin and aminoglycosides for enhanced activity against Gram-negative organisms and fluoroquinolones with minocycline and rifampin for more effective treatment of Gram-positive infections. Despite the limitations of fluoroquinolones due to the intrinsic characteristics of this antibiotic, they remain fundamental in this setting thanks to their bioavailability and synergisms with other drugs. Methods: A comprehensive literature search was conducted using online databases (PubMed/MEDLINE/Google Scholar) and books written by experts in microbiology and infectious diseases to identify relevant studies on fluoroquinolones and biofilm. Results: This review critically assesses the role of fluoroquinolones in managing biofilm-associated infections in various clinical settings while also exploring the potential benefits of combination therapy with these antibiotics. Conclusions: The literature predominantly consists of in vitro studies, with limited in vivo investigations. Although real world data are scarce, they are in accordance with fluoroquinolones' effectiveness in managing early biofilm-associated infections. Also, future perspectives of newer treatment options to be placed alongside fluoroquinolones are discussed. This review underscores the role of fluoroquinolones in the setting of biofilm-associated infections, providing a comprehensive guide for physicians regarding the best use of this class of antibiotics while highlighting the existing critical issues.},
}

@article {pmid39770495,
year = {2024},
author = {Kabotso, DEK and Neglo, D and Gaba, SE and Danyo, EK and Dayie, AD and Asantewaa, AA and Kotey, FCN and Dayie, NTKD},
title = {In Vitro Evaluation of Rosemary Essential Oil: GC-MS Profiling, Antibacterial Synergy, and Biofilm Inhibition.},
journal = {Pharmaceuticals (Basel, Switzerland)},
volume = {17},
number = {12},
pages = {},
doi = {10.3390/ph17121653},
pmid = {39770495},
issn = {1424-8247},
support = {RZ07//The Fleming Fund/ ; },
abstract = {Background: Antimicrobial resistance (AMR) has become precarious, warranting investments in antimicrobial discovery. Aim: To investigate the antibacterial activity of rosemary essential oil (REO), alone and in combination with selected conventional antibiotics. Methods: REO was subjected to antimicrobial susceptibility testing (including minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) determination) and investigation of anti-pre-biofilm and antibiofilm activities. Results: The phytochemical composition of the REO was eucalyptol (42.68%), bornanone (33.20%), endo-borneol (9.37%), α-terpeneol (7.95%), linalool (2.10%), bornyl acetate (1.81%), caryophyllene (1.09%), 4-terpeneol (0.94%), and anethole (0.87%). The antibacterial inhibition zones generally increased with increasing REO concentration (i.e., 10, 20, 50, 100, and 200 mg/mL). The MIC and MBC ranges of REO for all bacteria were 3.13-6.25 mg/mL and 3.12-12.5 mg/mL, respectively. The MICs (in µg/mL) of ciprofloxacin, chloramphenicol, streptomycin, tetracycline, and ampicillin, respectively, were Escherichia coli (0.98, 3.92, 1.96, 7.81, and 250), Klebsiella pneumoniae (1.25, 7.81, 125, 7.81, and 1000), MRSA (62.5, 7.81, 3.91, 7.81, and 250), Streptococcus mutans and Bacillus subtilis (125, 15.68, 250, 31.25, and 1000), Pseudomonas aeruginosa (125, 31.25, 500, 31.25, and 1000), and Salmonella Typhi (0.98, 15.68, 125, 1.96, and 1000). The MBC-MIC ratios of REO against all bacteria were in the range 1-2, indicating bactericidal effects. Mainly synergy (FICI = 0.16-0.37) was observed between REO and the conventional antibiotics. The IC50 values (in µg/mL) of REO against the bacteria, pre-biofilm vs. biofilm formation, were E. coli (1342.00 vs. 4.00), K. pneumoniae (106.00 vs. 3.00), MRSA (134.00 vs. 6.00), S. mutans (7259.00 vs. 7.00), B. subtilis (120.00 vs. 7.00), P. aeruginosa (4989.00 vs. 7.00), and S. Typhi (10.00 vs. 2.00). Conclusions: Rosemary essential oil had significant bactericidal effects on the bacteria tested, and its MIC and MBC values were low. Overall, it was synergistic with known conventional antibiotics and, thus, has encouraging prospects in combination therapy involving conventional antibiotics, even in the treatment of infections with multidrug-resistant bacteria, including biofilm-forming ones.},
}

@article {pmid39770454,
year = {2024},
author = {Atazhanova, GA and Levaya, YK and Badekova, KZ and Ishmuratova, MY and Smagulov, MK and Ospanova, ZO and Smagulova, EM},
title = {Inhibition of the Biofilm Formation of Plant Streptococcus mutans.},
journal = {Pharmaceuticals (Basel, Switzerland)},
volume = {17},
number = {12},
pages = {},
doi = {10.3390/ph17121613},
pmid = {39770454},
issn = {1424-8247},
support = {АР23488250//MINISTRY OF SCIENCE AND HIGHER EDUCATION OF REPUBLIC OF KAZAKHSTAN/ ; },
abstract = {This review is devoted to a systematic analysis of studies aimed at investigating plant extracts, essential oils and phytochemical compounds capable of inhibiting Streptococcus mutans biofilm formation. This paper investigates the effect of extracts, essential oils and individual plant compounds on inhibiting the biofilm formation of Streptococcus mutans, one of the major pathogens responsible for the development of dental caries. Using cultural microbiology and molecular biology techniques, the authors describe the mechanisms by which plant samples reduce Streptococcus mutans adhesion and growth. The results show that several plant components have antibacterial properties, contributing to the reduction of Streptococcus mutans colony numbers and inhibiting the synthesis of extract-exopolysaccharide matrices required for biofilm formation. This work highlights the potential of botanicals in inhibiting Streptococcus mutans biofilm formation, which can be applied as natural antimicrobial agents in the prevention and treatment of dental diseases. Views on the use of these plant extracts and their components in dental preparations such as toothpastes, rinses and gels aimed at preventing dental caries are evaluated. The review shows the relevance of the research to optimizing the use of plant extracts, essential oils, individual compounds and their active actions in the control of Streptococcus mutans biofilms.},
}

@article {pmid39770033,
year = {2024},
author = {Skeen, TL and Gresham, RL and Agamaite, KA and Molz, OM and Westlake, IF and Kregenow, SM and Romero, AK and Flood, BM and Mazur, LE and Hinkle, RJ and Young, DD},
title = {Elucidation of Antimicrobials and Biofilm Inhibitors Derived from a Polyacetylene Core.},
journal = {Molecules (Basel, Switzerland)},
volume = {29},
number = {24},
pages = {},
doi = {10.3390/molecules29245945},
pmid = {39770033},
issn = {1420-3049},
support = {204-01-23//Commonwealth Health Resource Board/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Polyynes/chemistry/pharmacology ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology/chemistry/chemical synthesis ; Molecular Structure ; Anti-Infective Agents/pharmacology/chemistry ; Structure-Activity Relationship ; Bacteria/drug effects ; },
abstract = {The development of new antibiotics with unique mechanisms of action is paramount to combating the growing threat of antibiotic resistance. Recently, based on inspiration from natural products, an asymmetrical polyacetylene core structure was examined for its bioactivity and found to have differential specificity for different bacterial species based on the substituents around the conjugated alkyne. This research further probes the structural requirements for bioactivity through a systematic synthesis and investigation of new compounds with variable carbon chain length, alkynyl subunits, and alcohol substitution. Furthermore, the research examines the activity of the new compounds towards the inhibition of biofilm formation. Overall, several key new polyyne compounds have been identified in both decreasing bacterial viability and in disrupting pre-formed biofilms. These properties are key in the fight against bacterial infections and will be helpful in the further development of new antibiotic agents.},
}

*Biofilms/drug effects/growth & development
*Polyynes/chemistry/pharmacology
*Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology/chemistry/chemical synthesis
Molecular Structure
Anti-Infective Agents/pharmacology/chemistry
Structure-Activity Relationship
Bacteria/drug effects

@article {pmid39769141,
year = {2024},
author = {Alexa, VT and Fratila, AD and Oancea, R and Galuscan, A and Balean, O and Bolchis, V and Buzatu, BLR and Obistioiu, D and Suleiman, MA and Jumanca, D},
title = {Molecular Docking and Experimental Analysis of Essential Oil-Based Preparations on Biofilm Formation on Orthodontic Archwires.},
journal = {International journal of molecular sciences},
volume = {25},
number = {24},
pages = {},
doi = {10.3390/ijms252413378},
pmid = {39769141},
issn = {1422-0067},
mesh = {*Biofilms/drug effects/growth & development ; *Molecular Docking Simulation ; *Oils, Volatile/pharmacology/chemistry ; *Orthodontic Wires/microbiology ; *Staphylococcus aureus/drug effects ; *Streptococcus mutans/drug effects ; Humans ; Anti-Bacterial Agents/pharmacology/chemistry ; Stainless Steel/chemistry ; },
abstract = {Good oral hygiene is crucial during treatment with fixed appliances, emphasising the need for additional or alternative oral health methods during orthodontic treatment. This study investigates the effect of essential oil (EO)-based preparations on biofilm adhesion to orthodontic archwires. Five identical-sized orthodontic archwires of different materials were tested using therapeutic and preventive applications of essential oils. This study also used molecular docking to explore how essential oil compounds interact with key proteins of common oral pathogens like Staphylococcus aureus and Streptococcus mutans. We found that the constituent materials heavily influence the antimicrobial effects of essential oils on different orthodontic archwires. Stainless steel-based orthodontic archwires demonstrated the highest efficacy in antimicrobial protection against S. mutans strains (maximum BIP = 28.82% on the epoxy-coated SS). Conversely, inhibition effects in preventive applications against S. aureus were observed exclusively with titanium-molybdenum alloy orthodontic archwires across all tested emulsions (maximum BIP = 29.44%). CuNiTi alloys showed ineffectiveness in preventive treatments, as none of the EO mixtures inhibited biofilm development on this material. After biofilm contamination with S. mutans and S. aureuss strains, the ternary emulsion was most effective for four out of five orthodontic archwires. Computational analysis revealed strong binding interactions between essential oil compounds and key proteins of S. aureus and S. mutans, highlighting specific amino acid residues that are critical for these interactions. Based on the results, stainless steel with epoxy coating or TMA archwires, combined with BEO/CEO/OEO ternary mixture, are recommended for optimal antibacterial protection against biofilm formation on orthodontic archwires.},
}

*Biofilms/drug effects/growth & development
*Molecular Docking Simulation
*Oils, Volatile/pharmacology/chemistry
*Orthodontic Wires/microbiology
*Staphylococcus aureus/drug effects
*Streptococcus mutans/drug effects
Humans
Anti-Bacterial Agents/pharmacology/chemistry
Stainless Steel/chemistry

@article {pmid39768840,
year = {2024},
author = {Tsikopoulos, A and Tsikopoulos, K and Sidiropoulos, K and Meroni, G and Triaridis, S and Drago, L and Papaioannidou, P},
title = {Development and Prevention of Biofilm on Cochlear Implants: A Systematic Review.},
journal = {Medicina (Kaunas, Lithuania)},
volume = {60},
number = {12},
pages = {},
doi = {10.3390/medicina60121959},
pmid = {39768840},
issn = {1648-9144},
mesh = {*Biofilms/drug effects ; *Cochlear Implants/standards/adverse effects ; Humans ; Anti-Bacterial Agents/therapeutic use/pharmacology ; Prosthesis-Related Infections/prevention & control ; Staphylococcus aureus/drug effects/physiology ; },
abstract = {Background and Objectives: Biofilm formation on cochlear implants (CIs) poses a major problem for surgeons, leading to a high incidence of explantation and revision surgery. Therefore, developing appropriate and cost-effective biofilm detection and prevention techniques is of the essence. In this systematic review, we sought to investigate the development of biofilm formation on CIs. We also elaborated on experimental preventative biofilm measures. Materials and Methods: We conducted a systematic search of both in vitro and in vivo literature published in PubMed, Scopus, and ScienceDirect, until 15 June 2024, for published studies evaluating the biofilm formation and strategies for inhibiting biofilm formation on CIs. Depending on the type of the included study, we assessed quality with the modified Consolidated Standards of Reporting Trials tool, the Joanna Briggs Institute Case Reports Critical Appraisal Tool, a modified Delphi technique, and the ROBINS-I tool. We synthesized the available information on biofilm formation on CIs and the infection prevention capacity of the included antibiofilm agents. Results: A total of 26 studies were included in this systematic review. Biofilms in CIs are usually localized in their recesses such as their removable magnet pocket as opposed to their smooth surfaces. S. aureus and P. aeruginosa are the most commonly isolated microorganisms, and they tend to be strong biofilm producers. The optimal treatment strategy for a biofilm-infected CI is explantation. Most of the examined biofilm prevention methods in CIs present sufficient antibiofilm activity. Conclusions: Biofilm formation in CIs is considered one of the most dreadful complications. There have been no specific guidelines for the treatment of those cases, with removal and/or replacement of the CI being the treatment of choice. Various experimental prevention methods provide promising antibiofilm activity both in vivo and in vitro.},
}

*Biofilms/drug effects
*Cochlear Implants/standards/adverse effects
Humans
Anti-Bacterial Agents/therapeutic use/pharmacology
Prosthesis-Related Infections/prevention & control
Staphylococcus aureus/drug effects/physiology

@article {pmid39767046,
year = {2024},
author = {Yu, X and Li, Y and Yang, X and He, J and Tang, W and Chai, Y and Duan, Z and Li, W and Zhao, D and Wang, X and Huang, A and Li, H and Shi, Y},
title = {Chlorogenic Acid: A Promising Strategy for Milk Preservation by Inhibiting Staphylococcus aureus Growth and Biofilm Formation.},
journal = {Foods (Basel, Switzerland)},
volume = {13},
number = {24},
pages = {},
doi = {10.3390/foods13244104},
pmid = {39767046},
issn = {2304-8158},
support = {32302259//the National Natural Science Foundation of China/ ; 202005AD160015//Yunnan Province Technology Innovation Talent Training Object/ ; XDYC-QNRC-2023-0413//the "Yunnan Province 'Xingdian Talent Support Plan' for young talent project"/ ; },
abstract = {Chlorogenic acid (CGA), a polyhydroxy phenolic acid, has been extensively studied for its antimicrobial properties. Staphylococcus aureus (S. aureus) threatens food safety by forming biofilms. This study aimed to investigate the mechanism of CGA against S. aureus and its biofilm. The anti-bacterial activity of CGA was assessed using crystal violet staining, TEM, SEM, a CLSM, and using metabolomics and molecular docking to elucidate the mechanism. The results indicated that the minimum inhibitory concentration of CGA against S. aureus was 2.5 mg/mL. CGA disrupts the integrity of bacterial cell membranes, leading to increased hydrophobicity, morphological changes, scattering, and reduced spreading. This disruption decreases biofilm adhesion and bacterial count. Metabolomics and molecular docking analyses revealed that CGA down-regulates key amino acids. It forms hydrogen bonds with penicillin-binding protein 4 (PBP4), Amidase, glutamate synthetase B, and glutamate synthetase A. By inhibiting amino acid metabolism, CGA prevents biofilm formation. CGA interacts with amino acids such as aspartic acid, glutamine, and glutamate through hydroxyl (-OH) and carbonyl (-C=O) groups. This interaction reduces cell viability and biofilm cohesion. The novel findings of this study, particularly the extension of the shelf life of pasteurized milk by inhibiting S. aureus growth, highlight the potential of CGA as a promising anti-biofilm strategy and preservative in the dairy industry.},
}

@article {pmid39766943,
year = {2024},
author = {Unal Turhan, E and Koca, EE},
title = {Predictive Modeling for Inactivation of Escherichia coli Biofilm with Combined Treatment of Thermosonication and Organic Acid on Polystyrene Surface.},
journal = {Foods (Basel, Switzerland)},
volume = {13},
number = {24},
pages = {},
doi = {10.3390/foods13244002},
pmid = {39766943},
issn = {2304-8158},
abstract = {The present study aimed to evaluate the antibiofilm effect of combined sonication treatment with organic acids on polystyrene surfaces and to develop a predictive model for the inactivation of Escherichia coli biofilms. Polystyrene plates containing E. coli biofilms were subjected to sonication using different inactivation solutions (PBS, lactic acid, and acetic acid) at varying temperatures (20 °C, 40 °C, and 50 °C) and durations (2 and 5 min). The effects of temperature, treatment duration, and inactivation solution on E. coli biofilm removal were statistically significant (p < 0.05). The use of organic acids, along with increased treatment time and temperature, led to a significant reduction in viable cell counts (0.43-6.21 log CFU/mL) and optical density (0.13-0.72 at OD600) of E. coli biofilms (p < 0.05). The highest E. coli biofilm inactivation, with a reduction of 6.21 CFU/mL and 0.72 OD, was achieved by combining organic acid and thermosonication at 50 °C for 5 min. A significant positive correlation was observed between test methods based on viable cell count and optical density (OD) measurements. According to multiple linear regression analysis results, the R[2] values of the predictive models for biofilm inactivation, based on viable cell count and OD measurements, were 0.84 and 0.80, respectively. Due to its higher accuracy, the predictive model developed using viable cell count data is recommended for applications in the food industry and processing sectors.},
}

@article {pmid39766622,
year = {2024},
author = {Hofmeisterová, L and Bajer, T and Walczak, M and Šilha, D},
title = {Chemical Composition and Antibacterial Effect of Clove and Thyme Essential Oils on Growth Inhibition and Biofilm Formation of Arcobacter spp. and Other Bacteria.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {12},
pages = {},
doi = {10.3390/antibiotics13121232},
pmid = {39766622},
issn = {2079-6382},
abstract = {Background: In recent years, significant resistance of microorganisms to antibiotics has been observed. A biofilm is a structure that significantly aids the survival of the microbial population and also significantly affects its resistance. Methods: Thyme and clove essential oils (EOs) were subjected to chemical analysis using gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with a flame ionization detector (GC-FID). Furthermore, the antimicrobial effect of these EOs was tested in both the liquid and vapor phases using the volatilization method. The effect of the EOs on growth parameters was monitored using an RTS-8 bioreactor. However, the effect of the EOs on the biofilm formation of commonly occurring bacteria with pathogenic potential was also monitored, but for less described and yet clinically important strains of Arcobacter spp. Results: In total, 37 and 28 compounds were identified in the thyme and clove EO samples, respectively. The most common were terpenes and also derivatives of phenolic substances. Both EOs exhibited antimicrobial activity in the liquid and/or vapor phase against at least some strains. The determined antimicrobial activity of thyme and clove oil was in the range of 32-1024 µg/mL in the liquid phase and 512-1024 µg/mL in the vapor phase, respectively. The results of the antimicrobial effect are also supported by similar conclusions from monitoring growth curves using the RTS bioreactor. The effect of EOs on biofilm formation differed between strains. Biofilm formation of Pseudomonas aeruginosa was completely suppressed in an environment with a thyme EO concentration of 1024 µg/mL. On the other hand, increased biofilm formation was found, e.g., in an environment of low concentration (1-32 µg/mL). Conclusions: The potential of using natural matrices as antimicrobials or preservatives is evident. The effect of these EOs on biofilm formation, especially Arcobacter strains, is described for the first time.},
}

@article {pmid39766618,
year = {2024},
author = {Yang, Z and Khan, SA and Walsh, LJ and Ziora, ZM and Seneviratne, CJ},
title = {Classical and Modern Models for Biofilm Studies: A Comprehensive Review.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {12},
pages = {},
doi = {10.3390/antibiotics13121228},
pmid = {39766618},
issn = {2079-6382},
abstract = {Biofilms are structured microbial communities that adhere to various abiotic and biotic surfaces, where organisms are encased in an exo-polysaccharide matrix. Organisms within biofilms use various mechanisms that help them resist external challenges, such as antibiotics, rendering them more resistant to drugs. Therefore, researchers have attempted to develop suitable laboratory models to study the physical features of biofilms, their resistance mechanisms against antimicrobial agents, and their gene and protein expression profiles. However, current laboratory models suffer from various limitations. In this comprehensive review, we have summarized the various designs that have been used for laboratory biofilm models, presenting their strengths and limitations. Additionally, we have provided insight into improving these models to more closely simulate real-life scenarios, using newly developed techniques in additive manufacturing, synthetic biology, and bioengineering.},
}

@article {pmid39766616,
year = {2024},
author = {Osta-Ustarroz, P and Theobald, AJ and Whitehead, KA},
title = {Microbial Colonization, Biofilm Formation, and Malodour of Washing Machine Surfaces and Fabrics and the Evolution of Detergents in Response to Consumer Demands and Environmental Concerns.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {12},
pages = {},
doi = {10.3390/antibiotics13121227},
pmid = {39766616},
issn = {2079-6382},
support = {N/A//Lubrizol Coporation/ ; },
abstract = {Bacterial attachment and biofilm formation are associated with the contamination and fouling at several locations in a washing machine, which is a particularly complex environment made from a range of metal, polymer, and rubber components. Microorganisms also adhere to different types of clothing fibres during the laundering process as well as a range of sweat, skin particles, and other components. This can result in fouling of both washing machine surfaces and clothes and the production of malodours. This review gives an introduction into washing machine use and surfaces and discusses how biofilm production confers survival properties to the microorganisms. Microbial growth on washing machines and textiles is also discussed, as is their potential to produce volatiles. Changes in consumer attitudes with an emphasis on laundering and an overview regarding changes that have occurred in laundry habits are reviewed. Since it has been suggested that such changes have increased the risk of microorganisms surviving the laundering process, an understanding of the interactions of the microorganisms with the surface components alongside the production of sustainable detergents to meet consumer demands are needed to enhance the efficacy of new antimicrobial cleaning agents in these complex and dynamic environments.},
}

@article {pmid39766538,
year = {2024},
author = {van Leuven, N and Lucassen, R and Dicks, A and Braß, P and Lipski, A and Bockmühl, DP},
title = {Does Antibiotic Use Contribute to Biofilm Resistance in Sink Drains? A Case Study from Four German Hospital Wards.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {12},
pages = {},
doi = {10.3390/antibiotics13121148},
pmid = {39766538},
issn = {2079-6382},
abstract = {Backgound. As biofilms are known to harbour (multi-)resistant species, their presence in health settings must be considered critical. Although there is evidence that bacteria spread from drains to the outside, there is still a lack of research data focusing on drain biofilms from hospitals. Methods. We sampled biofilms from various wards of Helios Hospital Krefeld (Germany), where comprehensive antibiotic consumption data were available. Biofilms were analysed by cell counting, isolation of relevant bacterial groups and genetic and phenotypical resistance parameters. Data were correlated with the prescribed antibiotics of the respective ward. Furthermore, an ex situ biofilm model was employed to investigate the influence of sub-inhibitory antibiotics on the bacterial community and the prevalence of class 1 integrons. Results. Our results show that every ward harboured medically relevant bacterial species. While no significant differences were found in cell counts, the median prevalence of the resistance marker gene intI1 correlated with the amount of prescribed antibiotics. In contrast, phenotypical resistances showed no similar tendency. In addition, melting curve analysis data and changes in intI1 prevalence show that the composition of the bacterial community shifted depending on the biofilm and antibiotic. Conclusions. To the best of our knowledge, our study is the first considering possible correlations between the consumption data of hospital wards and resistances in drain biofilms the way we did. Based on our results, we conclude that sub-inhibitory concentrations of antibiotics have no general effect on biofilms in terms of bacterial community shift and occurrence of antibiotic-resistant species. Amongst other things, the effect depends on the initial composition of the bacterial community, the antibiotic used and the intrinsic bacterial resistance, e.g., prevalence of class 1 integrons.},
}

@article {pmid39766522,
year = {2024},
author = {Kaushik, A and Kest, H and Sood, M and Thieman, C and Steussy, BW and Padomek, M and Gupta, S},
title = {Infective Endocarditis by Biofilm-Producing Methicillin-Resistant Staphylococcus aureus-Pathogenesis, Diagnosis, and Management.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {12},
pages = {},
doi = {10.3390/antibiotics13121132},
pmid = {39766522},
issn = {2079-6382},
abstract = {Infective endocarditis (IE) is a life-threatening condition with increasing global incidence, primarily caused by Staphylococcus aureus, especially methicillin-resistant strains (MRSA). Biofilm formation by S. aureus is a critical factor in pathogenesis, contributing to antimicrobial resistance and complicating the treatment of infections involving prosthetic valves and cardiovascular devices. Biofilms provide a protective matrix for MRSA, shielding it from antibiotics and host immune defenses, leading to persistent infections and increased complications, particularly in cases involving prosthetic materials. Clinical manifestations range from acute to chronic presentations, with complications such as heart failure, embolic events, and neurological deficits. Diagnosis relies on the Modified Duke Criteria, which have been updated to incorporate modern cardiovascular interventions and advanced imaging techniques, such as PET/CT (positron emission tomography, computed tomography), to improve the detection of biofilm-associated infections. Management of MRSA-associated IE requires prolonged antimicrobial therapy, often with vancomycin or daptomycin, needing a combination of antimicrobials in the setting of prosthetic materials and frequently necessitates surgical intervention to remove infected prosthetic material or repair damaged heart valves. Anticoagulation remains controversial, with novel therapies like dabigatran showing potential benefits in reducing thrombus formation. Despite progress in treatment, biofilm-associated resistance poses ongoing challenges. Emerging therapeutic strategies, including combination antimicrobial regimens, bacteriophage therapy, antimicrobial peptides (AMPs), quorum sensing inhibitors (QSIs), hyperbaric oxygen therapy, and nanoparticle-based drug delivery systems, offer promising approaches to overcoming biofilm-related resistance and improving patient outcomes. This review provides an overview of the pathogenesis, current management guidelines, and future directions for treating biofilm-related MRSA IE.},
}

@article {pmid39766503,
year = {2024},
author = {Oh, JW and Shin, MK and Park, HR and Kim, S and Lee, B and Yoo, JS and Chi, WJ and Sung, JS},
title = {PA-Win2: In Silico-Based Discovery of a Novel Peptide with Dual Antibacterial and Anti-Biofilm Activity.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {12},
pages = {},
doi = {10.3390/antibiotics13121113},
pmid = {39766503},
issn = {2079-6382},
support = {NIBRE202411//National Institute of Biological Resources/ ; NIBR202402105//National Institute of Biological Resources/ ; },
abstract = {Background: The emergence and prevalence of antibiotic-resistant bacteria (ARBs) have become a serious global threat, as the morbidity and mortality associated with ARB infections are continuously rising. The activation of quorum sensing (QS) genes can promote biofilm formation, which contributes to the acquisition of drug resistance and increases virulence. Therefore, there is an urgent need to develop new antimicrobial agents to control ARB and prevent further development. Antimicrobial peptides (AMPs) are naturally occurring defense molecules in organisms known to suppress pathogens through a broad range of antimicrobial mechanisms. Methods: In this study, we utilized a previously developed deep-learning model to identify AMP candidates from the venom gland transcriptome of the spider Pardosa astrigera, followed by experimental validation. Results: PA-Win2 was among the top-scoring predicted peptides and was selected based on physiochemical features. Subsequent experimental validation demonstrated that PA-Win2 inhibits the growth of Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and multidrug-resistant P. aeruginosa (MRPA) strain CCARM 2095. The peptide exhibited strong bactericidal activity against P. aeruginosa, and MRPA CCARM 2095 through the depolarization of bacterial cytoplasmic membranes and alteration of gene expression associated with bacterial survival. In addition, PA-Win2 effectively inhibited biofilm formation and degraded pre-formed biofilms of P. aeruginosa. The gene expression study showed that the peptide treatment led to the downregulation of QS genes in the Las, Pqs, and Rhl systems. Conclusions: These findings suggest PA-Win2 as a promising drug candidate against ARB and demonstrate the potential of in silico methods in discovering functional peptides from biological data.},
}

@article {pmid39764613,
year = {2025},
author = {Xiong, T and Ning, F and Chen, Y and Gu, M and Li, M and Chen, X and Wang, L and Fan, J and Peng, X},
title = {Charge Regulation-Enhanced Type I Photosensitizer-Loaded Hydrogel Dressing for Hypoxic Bacterial Inhibition and Biofilm Elimination.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.4c15730},
pmid = {39764613},
issn = {1936-086X},
abstract = {Biofilm-induced chronic bacterial infections represent a significant challenge in modern medicine due to their resistance to conventional antibiotic treatments. Although photodynamic therapy (PDT) has emerged as a promising antibiotic-free antibacterial strategy, the hypoxic condition within biofilms and the lack of an effective local drug delivery system have limited the clinical effectiveness of photosensitizer (PS) agents. Herein, we propose a type of charge regulation-enhanced type I PS-loaded hydrogel dressing for treating biofilm infection. The charge regulation enables the multiple alkylation Nile blue (EB series) to exhibit substantially improved absorbance (∼2-fold), alkaline tolerance, and superoxide anion yield (2.2-4.2-fold) compared to the representative type I PS, sulfur-substituted Nile blue. Specifically, the enhanced electronic push-pull capabilities promote a more efficient electron recycling process, significantly boosting the efficiency of type I PDT. The superior PDT effect and enhanced bacterial uptake via charge regulation render the EB series more pronounced in hypoxic bacterial inhibition under red light or sunlight irradiation. Moreover, the hydrogel, constructed from oxidized dextran and quaternized chitosan, facilitates the localization and sustained retention of type I PSs, accelerating the healing of biofilm-infected wounds. This type I PS-based hydrogel could provide an efficient and user-friendly wound dressing for the clinical treatment and prevention of biofilm infections.},
}

@article {pmid39764404,
year = {2024},
author = {Sengupta, B and Alrubayan, M and Wang, Y and Mallet, E and Torres, A and Solis, R and Wang, H and Pradhan, P},
title = {An AI-directed analytical study on the optical transmission microscopic images of Pseudomonas aeruginosa in planktonic and biofilm states.},
journal = {ArXiv},
volume = {},
number = {},
pages = {},
pmid = {39764404},
issn = {2331-8422},
abstract = {Biofilms are resistant microbial cell aggregates that pose risks to health and food industries and produce environmental contamination. Accurate and efficient detection and prevention of biofilms are challenging and demand interdisciplinary approaches. This multidisciplinary research reports the application of a deep learning-based artificial intelligence (AI) model for detecting biofilms produced by Pseudomonas aeruginosa with high accuracy. Aptamer DNA templated silver nanocluster (Ag-NC) was used to prevent biofilm formation, which produced images of the planktonic states of the bacteria. Large-volume bright field images of bacterial biofilms were used to design the AI model. In particular, we used U-Net with ResNet encoder enhancement to segment biofilm images for AI analysis. Different degrees of biofilm structures can be efficiently detected using ResNet18 and ResNet34 backbones. The potential applications of this technique are also discussed.},
}

@article {pmid39764008,
year = {2024},
author = {Zarate, D and Isenberg, RY and Pavelsky, M and Speare, L and Jackson, A and Mandel, MJ and Septer, AN},
title = {The conserved global regulator H-NS has a strain-specific impact on biofilm formation in Vibrio fischeri symbionts.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2024.12.19.629378},
pmid = {39764008},
issn = {2692-8205},
abstract = {UNLABELLED: Strain-level variation among host-associated bacteria often determines host range and the extent to which colonization is beneficial, benign, or pathogenic. Vibrio fischeri is a beneficial symbiont of the light organs of fish and squid with known strain-specific differences that impact host specificity, colonization efficiency, and interbacterial competition. Here, we describe how the conserved global regulator, H-NS, has a strain-specific impact on a critical colonization behavior: biofilm formation. We isolated a mutant of the fish symbiont V. fischeri MJ11 with a transposon insertion in the hns gene. This mutant formed sticky, moderately wrinkled colonies on LBS plates, a condition not known to induce biofilm in this species. A reconstructed hns mutant displayed the same wrinkled colony, which became smooth when hns was complemented in trans , indicating the hns disruption is causal for biofilm formation in MJ11. Transcriptomes revealed differential expression for the syp biofilm locus in the hns mutant, relative to the parent, suggesting biofilm may in part involve SYP polysaccharide. However, enhanced biofilm in the MJ11 hns mutant was not sufficient to allow colonization of a non-native squid host. Finally, moving the hns mutation into other V. fischeri strains, including the squid symbionts ES114 and ES401, and seawater isolate PP3, revealed strain-specific biofilm phenotypes: ES114 and ES401 hns mutants displayed minimal biofilm phenotypes while PP3 hns mutant colonies were more wrinkled than the MJ11 hns mutant. These findings together define H-NS as a novel regulator of V. fischeri symbiotic biofilm and demonstrate key strain specificity in that role.

IMPORTANCE: This work, which shows how H-NS has strain-specific impacts on biofilm in Vibrio fischeri , underscores the importance of studying multiple strains, even when examining highly conserved genes and functions. Our observation that knocking out a conserved regulator can result in a wide range of biofilm phenotypes, depending on the isolate, serves as a powerful reminder that strain-level variation is common and worthy of exploration. Indeed, uncovering the mechanisms of strain-specific phenotypic differences is essential to understand drivers of niche differentiation and bacterial evolution. Thus, it is important to carefully match the number and type of strains used in a study with the research question to accurately interpret and extrapolate the results beyond a single genotype. The additional work required for multi-strain studies is often worth the investment of time and resources, as it provides a broader view of the complexity of within-species diversity in microbial systems.},
}

@article {pmid39763928,
year = {2024},
author = {Glowacki, RWP and Engelhart, MJ and Till, JM and Kadam, A and Nemet, I and Sangwan, N and Ahern, PP},
title = {Identification of strain-specific cues that regulate biofilm formation in Bacteroides thetaiotaomicron.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2024.12.20.629428},
pmid = {39763928},
issn = {2692-8205},
abstract = {UNLABELLED: Members of the gut microbiome encounter a barrage of host- and microbe-derived microbiocidal factors that must be overcome to maintain fitness in the intestine. The long-term stability of many gut microbiome strains within the microbiome suggests the existence of strain-specific strategies that have evolved to foster resilience to such insults. Despite this, little is known about the mechanisms that mediate this resistance. Biofilm formation represents one commonly employed defense strategy against stressors like those found in the intestine. Here, we demonstrate strain-level variation in the capacity of the gut symbiont Bacteroides thetaiotaomicron to form biofilms. Despite the potent induction of biofilm formation by purified bile in most strains, we show that the specific bile acid species driving biofilm formation differ among strains, and uncover that a secondary bile-acid, lithocholic acid, and its conjugated forms, potently induce biofilm formation in a strain-specific manner. Additionally, we found that the short-chain fatty acid, acetic acid, could suppress biofilm formation. Thus, our data defines the molecular components of bile that promote biofilm formation in B. thetaiotaomicron and reveals that distinct molecular cues trigger the induction or inhibition of this process. Moreover, we uncover strain-level variation in these responses, thus identifying that both shared and strain-specific determinants govern biofilm formation in this species.

IMPORTANCE: In order to thrive within the intestine, it is imperative that gut microbes resist the multitude of insults derived from the host immune system and other microbiome members. As such, they have evolved strategies that ensure their survival within the intestine. We investigated one such strategy, biofilm formation, in Bacteroides thetaiotaomicron , a common member of the human microbiome. We uncovered significant variation in natural biofilm formation in the absence of an overt stimulus among different Bacteroides thetaiotaomicron strains, and revealed that different strains adopted a biofilm lifestyle in response to distinct molecular stimuli. Thus our studies provide novel insights into factors mediating gut symbiont resiliency, revealing strain-specific and shared strategies in these responses. Collectively, our findings underscore the prevalence of strain-level differences that should be factored into our understanding of gut microbiome functions.},
}

@article {pmid39763852,
year = {2024},
author = {Liu, Y and Gates, AD and Liu, Z and Duque, Q and Chen, MY and Hamilton, CD and O'Toole, GA and Haney, CH},
title = {In vitro biofilm formation only partially predicts beneficial Pseudomonas fluorescens protection against rhizosphere pathogens.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2024.12.17.628960},
pmid = {39763852},
issn = {2692-8205},
abstract = {Plant roots form associations with both beneficial and pathogenic soil microorganisms. While members of the rhizosphere microbiome can protect against pathogens, the mechanisms are poorly understood. We hypothesized that the ability to form a robust biofilm on the root surface is necessary for the exclusion of pathogens; however, it is not known if the same biofilm formation components required in vitro are necessary in vivo. Pseudomonas fluorescens WCS365 is a beneficial strain that is phylogenetically closely related to an opportunistic pathogen P. fluorescens N2C3 and confers robust protection against P. fluorescens N2C3 in the rhizosphere. We used this plant-mutualist-pathogen model to screen collections of P. fluorescens WCS365 increased a ttachment m utants (iam) and s urface a ttachment d efective (sad) transposon insertion mutants that form increased or decreased levels of biofilm on an abiotic surface, respectively. We found that while the P. fluorescens WCS365 mutants had altered biofilm formation in vitro , only a subset of these mutants, including those involved in large adhesion protein (Lap) biosynthesis, flagellin biosynthesis and O-antigen biosynthesis, lost protection against P. fluorescens N2C3. We found that the inability of P. fluorescens WCS365 mutants to grow in planta , and the inability to suppress pathogen growth, both partially contributed to loss of plant protection. We did not find a correlation between the extent of biofilm formed in vitro and pathogen protection in planta indicating that biofilm formation on abiotic surfaces may not fully predict pathogen exclusion in planta . Collectively, our work provides insights into mechanisms of biofilm formation and host colonization that shape the outcomes of host-microbe-pathogen interactions.},
}

@article {pmid39761772,
year = {2025},
author = {Padmavathi, AR and Karthikeyan, B and Rao, TS and Senthil Kumar, J and Murthy, PS},
title = {Polydimethylsiloxane loaded capsaicin afflicts membrane integrity, metabolic activity and biofilm formation of nosocomial pathogens.},
journal = {Microbial pathogenesis},
volume = {200},
number = {},
pages = {107282},
doi = {10.1016/j.micpath.2025.107282},
pmid = {39761772},
issn = {1096-1208},
abstract = {Biofilms constitute 80 % of all nosocomial infections associated with invasive medical devices. Polydimethylsiloxane, a highly elastic, inert, non-reactive, biocompatible silicone polymer is widely used as implant biomaterial due to its non-toxic and low-immunogenic nature. Owing to its hydrophobicity, PDMS suffers from microbial adhesion. Inhibition of biofilm formation on PDMS surfaces is imperative to prevent morbidity, mortality and replacement of implants. The present study investigates the efficacy of capsaicin (0.5 % w/v) loaded PDMS as a broad spectrum antimicrobial surface against Staphylococcus aureus, Escherichia coli and Candida albicans. Capsaicin exhibited minimum inhibitory concentration of 1024 μg mL[-1] for S. aureus, E. coli and 256 μg mL[-1] for C. albicans. Capsaicin inhibited biofilms of S. aureus, E. coli and C. albicans at much lower concentrations of 2, 64 and 8 μg mL[-1] respectively. The minimum capsaicin concentrations required for total biofilm eradication was found to be 256, 512, 128 μg mL[-1] for S. aureus, E. coli and C. albicans respectively. Probing sub-lethal concentrations of capsaicin revealed 38, 32, 30 % reduction in metabolic activity of S. aureus, E. coli & C. albicans planktonic cells respectively. Similarly, there was an increase in permeability of cells to propidium iodide compared to control. By reducing the metabolic activity and perturbing membrane integrity, capsaicin could prevent biofilm formation and this was also observed with capsaicin-PDMS surfaces that exhibited 1 log (∼90 %) reduction of viable bacterial counts.},
}

@article {pmid39761771,
year = {2025},
author = {Benahmed, A and Seghir, A and Dergal, F and Chiali, A and Boucherit-Otmani, Z and Ziani-Chérif, C},
title = {Study of interaction in dual-species biofilm of Candida glabrata and Klebsiella pneumoniae co-isolated from peripheral venous catheter using Raman characterization mapping and machine learning algorithms.},
journal = {Microbial pathogenesis},
volume = {199},
number = {},
pages = {107280},
doi = {10.1016/j.micpath.2025.107280},
pmid = {39761771},
issn = {1096-1208},
abstract = {Polymicrobial biofilm infections, especially associated with medical devices such as peripheral venous catheters, are challenging in clinical settings for treatment and management. In this study, we examined the mixed biofilm formed by Candida glabrata and Klebsiella pneumoniae, which were co-isolated from the same peripheral venous catheter. Our results revealed that C. glabrata can form mixed biofilms with K. pneumoniae in vitro on peripheral venous catheters and the bottom of microplate wells, as confirmed by scanning electron microscopy. Additionally, using Raman mapping, we showed the distribution of both species in mono- and dual-species biofilms and suggested the type of microbial interaction in this polymicrobial biofilm. Finally, with the assistance of appropriate machine learning (ML) algorithms, based on identified peaks of bacteria, yeast, catheter, and Microplate mapping spectra, we develop a dedicated Raman database to detect the presence of these elements in an unknown spectrum in the future.},
}

@article {pmid39758814,
year = {2025},
author = {Ribeiro, PDS and Stasko, J and Shircliff, A and Fernandes, LG and Putz, EJ and Andreasen, C and Azevedo, V and Ristow, P and Nally, JE},
title = {Investigations into the growth and formation of biofilm by Leptospira biflexa at temperatures encountered during infection.},
journal = {Biofilm},
volume = {9},
number = {},
pages = {100243},
pmid = {39758814},
issn = {2590-2075},
abstract = {The genus Leptospira comprises unique atypical spirochete bacteria that includes the etiological agent of leptospirosis, a globally important zoonosis. Biofilms are microecosystems composed of microorganisms embedded in a self-produced matrix that offers protection against hostile factors. Leptospires form biofilms in vitro, in situ in rice fields and unsanitary urban areas, and in vivo while colonizing rodent kidneys. The complex three-dimensional biofilm matrix includes secreted polymeric substances such as proteins, extracellular DNA (eDNA), and saccharides. The genus Leptospira comprises pathogenic and saprophytic species with the saprophytic L. biflexa being commonly used as a model organism for the genus. In this study, the growth and formation of biofilms by L. biflexa was investigated not just at 29 °C, but at 37 °C/5 % CO2, a temperature similar to that encountered during host infection. Planktonic free-living L. biflexa grow in HAN media at both 29 °C and 37 °C/5 % CO2, but cells grown at 37 °C/5 % CO2 are longer (18.52 μm ± 3.39) compared to those at 29 °C (13.93 μm ± 2.84). Biofilms formed at 37 °C/5 % CO2 had more biomass compared to 29 °C, as determined by crystal violet staining. Confocal microscopy determined that the protein content within the biofilm matrix was more prominent than double-stranded DNA, and featured a distinct layer attached to the solid substrate. Additionally, the model enabled effective protein extraction for proteomic comparison across different biofilm phenotypes. Results highlight an important role for proteins in biofilm matrix structure by leptospires and the identification of their specific protein components holds promise for strategies to mitigate biofilm formation.},
}

@article {pmid39758150,
year = {2024},
author = {Yadav, P and Shrestha, S and Basyal, D and Tiwari, A and Sah, R and Sah, AK and Yadav, B and Willcox, M and Mishra, SK},
title = {Characterization and Biofilm Inhibition of Multidrug-Resistant Acinetobacter baumannii Isolates.},
journal = {International journal of microbiology},
volume = {2024},
number = {},
pages = {5749982},
pmid = {39758150},
issn = {1687-918X},
abstract = {Multidrug-resistant (MDR) Acinetobacter baumannii poses a significant therapeutic challenge due to its resistance to multiple antibiotics and its ability to form biofilm. This study aimed to characterize MDR A. baumannii isolates for their biofilm-forming capabilities and the presence of common biofilm-related genes at a tertiary care university hospital in Nepal. In addition, it assessed the efficacy of various compounds, particularly essential oils, in inhibiting biofilm formation. Identification and antibiotic sensitivity testing of A. baumannii isolates from clinical specimens were conducted according to the guidelines of the American Society for Microbiology. Isolates were screened for motility profiles, biofilm production in a microtiter plate assay, and the presence of biofilm-related gene(s) by conventional polymerase chain reaction. The ability of cinnamaldehyde, ethylenediaminetetraacetic acid (EDTA), Tween 80, amino acids (glycine and glutamic acid), and natural plant extracts to inhibit biofilm formation was also tested using the microtiter plate system. Out of the total 200 A. baumannii isolates, 195 were MDR, with 192 able to produce biofilms. Among them, 83.1% were strong biofilm producers. In this study, 42.0% and 66.2% of the isolates exhibited twitching motility and surface-associated motility, respectively. Thirty MDR A. baumannii isolates from medical devices contained biofilm-related genes csuE, ompA, bap, and bla PER-1, in 90.0%, 53.3%, 46.6%, and 26.6% of strains, respectively. Cinnamaldehyde (0.875 mg/mL) was the most effective compound, inhibiting biofilm formation by 77.3%, followed by ethanolic extract of onion (77.2%), 0.5% Tween 80 (76.8%), and essential oil of ginger (70.8%). The majority of A. baumannii clinical isolates were strong biofilm producers and often possessed the biofilm-related genes csuE and ompA. Essential oils at 200 mg/L, along with Tween 80, were the most effective (≥ 67%) at inhibiting the formation of biofilms. These findings help to understand biofilm production and provide valuable insights into MDR A. baumannii isolates in this clinical setting.},
}

@article {pmid39757612,
year = {2024},
author = {Banerjee, D and Biswas, P and Mazumder, K and Palai, S and Hossain, CM and Karmakar, S and Biswas, K},
title = {Exploration of Phytochemicals as Anti-biofilm Agents Against Pathogenic Bacteria: Their Potential and Challenges.},
journal = {Infectious disorders drug targets},
volume = {},
number = {},
pages = {},
doi = {10.2174/0118715265324950241204182204},
pmid = {39757612},
issn = {2212-3989},
abstract = {Multicellular surface-attached populations of bacteria embedded in the extracellular matrix are known as biofilms. Bacteria generally preferred to grow as biofilms. Quorum sensing (QS), detection of density of cell population through gene regulation, has been found to play an important role in the production of biofilms. Biofilm formation can increase the severity of infections that can lead to morbidity or mortality. Bacteria living within biofilms have a higher pattern of adaptive resistance to antibiotics. Antibiotic resistance is a barrier in the treatment of biofilmsinduced acute to chronic infections such as post-surgery infections, surgery-associated wound infections, endocarditis, joint infections, burn-related wound infections occurred, ventilator-associated pneumonia, etc. So it is urgent to discover or find out potent new drugs in fight against infectious diseases such as biofilms-associated infections. Medicinal plants or herbs are a rich source for fighting with biofilms-mediated infections. Phytochemicals have exhibited significant effects in the prevention of biofilms formation against different bacteria that are causing infections. Purified compounds such as berberine, tetrandrine, embelin, xanthorrhizol, bakuchiol, etc., exhibited promising biofilm inhibition actions against different pathogenic bacteria. Plant extracts that contain several phytochemicals are evaluated for its biofilm's inhibition property, and have shown significant potential in biofilm formation. Antibiofilm agents act by distinct mechanisms such as inhibiting the adherence of biofilms in a surface, preventing the biofilm formations, disrupting the matured biofilms, etc. This study is intended to reiterate about possibilities of plant extracts and purified compounds in the treatment of the prevention of bacterial biofilms-related infections.},
}

@article {pmid39757571,
year = {2025},
author = {Vaikkathillam, P and Mini, M and Mohan, A and Jayakumar, D and Rajan, PP and Asha, S and Kumar, P},
title = {Anti-biofilm effect of ferulic acid against Enterobacter hormaechei and Klebsiella pneumoniae: in vitro and in silico investigation.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-14},
doi = {10.1080/08927014.2024.2446927},
pmid = {39757571},
issn = {1029-2454},
abstract = {Enterobacter hormaechei and Klebsiella pneumoniae, key members of the ESKAPE group of hospital-acquired pathogens, are driving forces behind numerous infections due to their potent biofilm formation and the growing threat of antimicrobial resistance. Ferulic acid (FA) is known for its strong antioxidant properties and is recognized for its numerous physiological benefits, including anti-inflammatory, antimicrobial, anticancer, and antidiabetic effects. The current investigation delves into the antimicrobial and antibiofilm ability of FA against E. hormaechei and K. pneumoniae. Using different assays, we confirmed that FA inhibits the biofilm formation of these pathogens. Through computational studies involving molecular docking and molecular dynamics simulations, it was found that FA exhibits a strong affinity for binding with MrkB in E. hormaechei and MrkH in K. pneumoniae, crucial proteins involved in biofilm formation. We hypothesise that FA might interfere with adhesion-associated molecules and inhibit biofilms through the c-di-GMP pathway and proves as an effective antibiofilm compound.},
}

@article {pmid39757558,
year = {2025},
author = {Li, C and Xin, W},
title = {Different Disinfection Strategies in Bacterial and Biofilm Contamination on Dental Unit Waterlines: A Systematic Review.},
journal = {International journal of dental hygiene},
volume = {},
number = {},
pages = {},
doi = {10.1111/idh.12899},
pmid = {39757558},
issn = {1601-5037},
support = {220513116490573//Science and Technology Planning Project of Shantou City/ ; 002-181233120//Provincial Quality Engineering Project Dentistry Experimental Teaching Demonstration Centre/ ; },
abstract = {OBJECTIVE: The aim of this systematic review is to explore the effectiveness of different methods of reducing contamination and biofilms in dental unit waterlines (DUWLs) and to provide reference for future standardisation of disinfection practices in dental clinic.

METHODS: This systematic review searched PubMed and Web of Science databases for DUWL disinfection studies from 2013 to 2023, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Synthesis Without Meta-analysis, additional extracting relevant data based on predefined inclusion and exclusion criteria.

RESULTS: The study review identified 8442 articles, with 58 included after rigorous screening. Disinfection methods for DUWLs were categorised into 14 physical and 90 chemical methods. Peroxides, chloramine-based, and biguanide methods were frequently used, often in combination. The effectiveness of these methods varied; for instance, phenolic was effective, while alcohol was not, in reducing bacterial and biofilm contamination. Biguanide, when used alone or combined with chlorine-based or alcohol, showed mixed results. Chlorine-based methods, particularly when combined with quaternary ammonium salt or enzymes, were generally effective. Enzymes and iodophor also demonstrated efficacy, though with some inconsistencies. Mechanical systems, peroxides, quaternary ammonium salts, silver, and tube coatings had varying degrees of success. Other innovative methods, such as Aloe vera and slightly acidic electrolysed water, showed promise in some studies, but the effectiveness of flushing was questioned. This comprehensive analysis highlights the diversity and complexity of disinfection strategies for DUWLs.

CONCLUSION: Future studies should focus on how material composition and tubing design affect biofilm development and the effectiveness of disinfection methods to guide the design of advanced dental units.},
}

@article {pmid39757480,
year = {2025},
author = {Kralj, S and Da Silva, C and Nemec, S and Caf, M and Fourquaux, I and Rols, MP and Golzio, M and Mertelj, A and Kolosnjaj-Tabi, J},
title = {Dynamically Assembling Magnetic Nanochains as New Generation of Swarm-Type Magneto-Mechanical Nanorobots Affecting Biofilm Integrity.},
journal = {Advanced healthcare materials},
volume = {},
number = {},
pages = {e2403736},
doi = {10.1002/adhm.202403736},
pmid = {39757480},
issn = {2192-2659},
support = {ANR-23-CE18-0029-01//French national research agency/ ; P2-0089//Slovenian Research and Innovation Agency/ ; J2-60047//Slovenian Research and Innovation Agency/ ; J2-3043//Slovenian Research and Innovation Agency/ ; J2-3040//Slovenian Research and Innovation Agency/ ; J2-3046//Slovenian Research and Innovation Agency/ ; J3-3079//Slovenian Research and Innovation Agency/ ; J7-4420//Slovenian Research and Innovation Agency/ ; BI-FR/23-24-PROTEUS-005(PR-12039)//Campus France/ ; BI-RS/23-25-030(PR-12782)//Campus France/ ; PHC-PROTEUS-France-Slovenia-48879QJ//Campus France/ ; },
abstract = {Bacterial resistance is gaining ground and novel, unconventional strategies are required to improve antibiotic treatments. As a synthetic analog of planktonic bacilli, the natural bacterial swimmers that can penetrate bacterial biofilms, ultra-short propelling magnetic nanochains are presented as bioinspired magnetic nanorobots, enhancing the antibiotic treatment in biofilm-forming Staphylococcus epidermidis. Propelling nanochains, activated by a low intensity (<20 mT) and low frequency (<10 Hz) rotating magnetic field (RMF), prompt the otherwise resistant biofilm-forming bacteria to become sensitive to methicillin, resulting in the killing of 99.99% of bacteria. While magnetic force-driven spherical magnetic nanoparticles were previously reported as unidirectional biofilm channel diggers, propelling nanochains emerge as second-generation magnetic nanorobots, which, due to their magnetic core, shape anisotropy, and negative zeta potential, combine magnetic responsiveness, torque-driven movement, and attractive electrostatic interactions to attach to bacterial aggregates and multi-directionally protrude throughout the biofilm, indulging mechanical forces. These synergistic effects, in combination with an antibiotic drug, destroy the bacterial extracellular matrix and eradicate the formed biofilm, as confirmed with several complementary techniques.},
}

@article {pmid39756997,
year = {2025},
author = {Chen, YS and Chien, AS and Li, CC and Lin, CC and Wu, RJ},
title = {Effects of Commonly Used Vegetable Oils on Skin Barrier Function and Staphylococcus aureus Biofilm.},
journal = {Journal of oleo science},
volume = {74},
number = {1},
pages = {97-106},
doi = {10.5650/jos.ess24032},
pmid = {39756997},
issn = {1347-3352},
mesh = {*Biofilms/drug effects ; *Staphylococcus aureus/drug effects ; Animals ; *Filaggrin Proteins ; Mice ; *Plant Oils/pharmacology ; NIH 3T3 Cells ; *Keratinocytes/drug effects ; *Skin/drug effects ; *Wound Healing/drug effects ; Fibroblasts/drug effects ; Collagen/metabolism ; Sodium Dodecyl Sulfate/pharmacology ; Sunflower Oil ; Olive Oil/pharmacology/chemistry ; Surface-Active Agents/pharmacology ; Dose-Response Relationship, Drug ; },
abstract = {Adding of vegetable oils to skincare products or the use of plant oils for oil care is a current trend. Therefore, the safety and functionality of vegetable oils are of great concern to consumers and cosmetics manufacturers. This study focused on three types of vegetable oils: sunflower oil (SO), andiroba oil (AO) and hydrogenated olive oil (HOO). We conducted a comprehensive evaluation of the oils, which encompassed their ability to protect mouse skin keratinocytes (XB-2) and mouse fibroblasts (NIH 3T3) from damage caused by the surfactant sodium lauryl sulfate (SLS), their influence on the levels of filaggrin and collagen, their potential to aid in wound healing, and their effectiveness in anti-Staphylococcus aureus biofilm formation. The results showed that SO, AO and HOO at a concentration of 1.5 × 10[-4] % (v/v) have the ability to defend against SLS-induced cell damage, increase wound healing ability and the filaggrin and collagen content to XB-2 or NIH 3T3 cells. SO, AO and HOO at a concentration of 3.75 × 10[-3] % also have the anti-biofilm ability. Among the oils, AO can inhibit S. aureus biofilm composed of either polysaccharides or proteins. Therefore, the tested vegetable oils and can be applied to the cosmetics field as ingredients to repair damaged skin and preserve skin barrier stability.},
}

*Biofilms/drug effects
*Staphylococcus aureus/drug effects
Animals
*Filaggrin Proteins
Mice
*Plant Oils/pharmacology
NIH 3T3 Cells
*Keratinocytes/drug effects
*Skin/drug effects
*Wound Healing/drug effects
Fibroblasts/drug effects
Collagen/metabolism
Sodium Dodecyl Sulfate/pharmacology
Sunflower Oil
Olive Oil/pharmacology/chemistry
Surface-Active Agents/pharmacology
Dose-Response Relationship, Drug

@article {pmid39756524,
year = {2025},
author = {Upadhyay, A and Jaiswal, N and Kuamr, A},
title = {Biofilm battle: New transformative tactics to tackle the bacterial biofilm infections.},
journal = {Microbial pathogenesis},
volume = {199},
number = {},
pages = {107277},
doi = {10.1016/j.micpath.2025.107277},
pmid = {39756524},
issn = {1096-1208},
abstract = {Bacterial biofilm infections are the root cause of persistent infections and the prevalence of resistance to specific or multiple antibiotics. Biofilms have unique features that provide a protective environment for bacteria under various stress conditions and contribute significantly to the pathogenesis of chronic infections. They cover bacterial cells with a self-produced extracellular polymeric matrix, effectively hiding the bacterial cells and their targets. Conventional therapies cannot effectively treat and control bacterial biofilm infections. Therefore, advanced therapeutic means like microneedles, targeted tissue therapy, phage therapy, nanodrug therapy, combination drug therapy, microbial therapy, and immune cell hijacking therapy are needed to tackle the complex issue. These advanced therapies have shown promising results not only in bacterial biofilm infections but also in diseases such as cancer and genetic disorders. Due to their unique features and mechanisms, they significantly contribute to preventing bacterial infections by disrupting biofilm. This article aims to serve as a comprehensive overview of the ongoing battle against biofilms with transformative therapies. This article compiles advancements in new therapies that have demonstrated effective roles in the disruption of bacterial biofilms. We also discuss the current developments and Food and Drug Administration-approved status of these therapies. Additionally, this article summarizes the limitations and future steps needed for these therapies in the field of bacterial biofilm prevention. Thus, these therapies represent the future of preventing bacterial biofilm infections and could be also effective in the reversal of resistance.},
}

@article {pmid39756377,
year = {2025},
author = {Vimalanathan, V and Hasan, H and Kunasegaran, V and Sarawanan, K and Ilangovan, M and Sandrasaigaran, P},
title = {Rice husk and lemongrass-derived eco-enzymes as potential food contact surface disinfectants against biofilm-forming foodborne pathogens.},
journal = {FEMS microbiology letters},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsle/fnae116},
pmid = {39756377},
issn = {1574-6968},
abstract = {This study aims to evaluate the rice husk (EE-R) and lemongrass (EE-L) derived-eco-enzymes (EE) as alternatives to chemical-based disinfectants. The EE-R and EE-L's antimicrobial activity were tested against Pseudomonas aeruginosa, Salmonella Typhimurium, and Staphylococcus aureus using a broth microdilution method. The antibiofilm activities of EE were determined using crystal violet staining. Lastly, the minimal contact time of EE for effectively reducing biofilm-forming pathogens (<25 CFU/mL) was assessed on various food contact surfaces (wood, glass, plastic, stainless steel, and marble). The results show that EE-R at 25-50% concentration significantly inhibited P. aeruginosa and S. aureus while reducing the initial biofilm formation by 61% and 58%, respectively. Contrarily, EE-L inhibited S. Typhimurium at 12.5-50% and P. aeruginosa at 25-50% concentration, with a strong preformed biofilm inhibition noticed for S. Typhimurium (70%). For the minimal contact time, EE-R superiorly inhibited P. aeruginosa (60 s) and S. aureus (120 s) on all contact surfaces, and contrarily, EE-L needed 120 s to reduce P. aeruginosa and S. Typhimurium. These outcomes were comparable to sodium hypochlorite (NaOCl-2.5%). The study's outcomes implicate the potential application of EE-R and EE-L as surface disinfectants against biofilm-forming bacteria, thus promoting safer food processing practices while minimising environmental impacts.},
}

@article {pmid39755609,
year = {2025},
author = {Shao, Y and Zhu, W and Liu, S and Zhang, K and Sun, Y and Liu, Y and Wen, T and Zou, Y and Zheng, Q},
title = {Cordycepin affects Streptococcus mutans biofilm and interferes with its metabolism.},
journal = {BMC oral health},
volume = {25},
number = {1},
pages = {25},
pmid = {39755609},
issn = {1472-6831},
support = {2019byyfyyq07//the First Affiliated Hospital of Bengbu Medical College Science Fund for Outstanding Young Scholars/ ; GXXT-2021-056//the University Synergy Innovation Program of Anhui Province/ ; KJ2020A0574//Key Science Research Project Funding of Education Department of Anhui Province/ ; },
mesh = {*Biofilms/drug effects ; *Streptococcus mutans/drug effects ; *Deoxyadenosines/pharmacology ; *Microbial Sensitivity Tests ; Humans ; Microscopy, Confocal ; Real-Time Polymerase Chain Reaction ; Keratinocytes/drug effects ; Metabolomics ; Anti-Bacterial Agents/pharmacology ; Biomass ; Tetrazolium Salts ; },
abstract = {BACKGROUND: Streptococcus mutans (S. mutans) contributes to caries. The biofilm formed by S. mutans exhibits greater resistance to drugs and host immune defenses than the planktonic form of the bacteria. The objective of this study was to evaluate the anti-biofilm effect of cordycepin from the perspective of metabolomics.

METHODS: The minimum inhibitory concentration (MIC) was determined to evaluate the antimicrobial effect of cordycepin on planktonic S. mutans. The 24-h biofilm was treated with 128 µg/mL of cordycepin for 10 min at the 8- or 20-h time points. Biofilm biomass and metabolism were assessed using crystal violet and MTT assays and cordycepin cytotoxicity was evaluated in human oral keratinocytes (HOK) using CCK-8 assays. The live bacterial rate and the biofilm volume were assessed by confocal laser scanning microscopy. Metabolic changes in the biofilm collected at different times during with cordycepin were analyzed by metabolomics and verified by quantitative real-time PCR.

RESULTS: The results showed that treatment with 128 µg/mL cordycepin reduced both the biomass and metabolic activity of the biofilm without killing the bacteria, and cordycepin at this concentration showed good biocompatibility. Metabolomics analysis showed that differentially abundant metabolites following cordycepin treatment were mainly related to purine and nucleotide metabolism. After immediate treatment with cordycepin, genes related to purine and nucleotide metabolism were downregulated, and the levels of various metabolites changed significantly. However, the effect was reversible. After continuing culture for 4 h, the changes in genes and most metabolites were reversed, although the levels of 2'-deoxyadenosine, 2'-deoxyinosine, and adenine remained significantly different.

CONCLUSIONS: Cordycepin has the effect of anti-biofilm of S. mutans, mainly related to purine and nucleotide metabolism.},
}

*Biofilms/drug effects
*Streptococcus mutans/drug effects
*Deoxyadenosines/pharmacology
*Microbial Sensitivity Tests
Humans
Microscopy, Confocal
Real-Time Polymerase Chain Reaction
Keratinocytes/drug effects
Metabolomics
Anti-Bacterial Agents/pharmacology
Biomass
Tetrazolium Salts

@article {pmid39753671,
year = {2025},
author = {Vaidya, S and Saha, D and Rode, DKH and Torrens, G and Hansen, MF and Singh, PK and Jelli, E and Nosho, K and Jeckel, H and Göttig, S and Cava, F and Drescher, K},
title = {Bacteria use exogenous peptidoglycan as a danger signal to trigger biofilm formation.},
journal = {Nature microbiology},
volume = {},
number = {},
pages = {},
pmid = {39753671},
issn = {2058-5276},
support = {TMCG-3_213801//Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (Swiss National Science Foundation)/ ; 51NF40_180541//Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (Swiss National Science Foundation)/ ; TMCG-3_213801//Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (Swiss National Science Foundation)/ ; TMCG-3_213801//Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (Swiss National Science Foundation)/ ; 51NF40_180541//Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (Swiss National Science Foundation)/ ; DR 982/5-1//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; DR 982/6-1//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; TARGET-Biofilms//Bundesministerium für Bildung und Forschung (Federal Ministry of Education and Research)/ ; TARGET-Biofilms//Bundesministerium für Bildung und Forschung (Federal Ministry of Education and Research)/ ; 716734//EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council)/ ; 716734//EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council)/ ; 716734//EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council)/ ; IMPRS-Mic//Max-Planck-Gesellschaft (Max Planck Society)/ ; IMPRS-Mic//Max-Planck-Gesellschaft (Max Planck Society)/ ; IMPRS-Mic//Max-Planck-Gesellschaft (Max Planck Society)/ ; },
abstract = {For any organism, survival is enhanced by the ability to sense and respond to threats in advance. For bacteria, danger sensing among kin cells has been observed, but the presence or impacts of general danger signals are poorly understood. Here we show that different bacterial species use exogenous peptidoglycan fragments, which are released by nearby kin or non-kin cell lysis, as a general danger signal. Using microscopy and gene expression profiling of Vibrio cholerae, we find that even brief signal exposure results in a regulatory response that causes three-dimensional biofilm formation, which protects cells from a broad range of stresses, including bacteriophage predation. A diverse set of species (Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecalis) also respond to exogenous peptidoglycan by forming biofilms. As peptidoglycan from different Gram-negative and Gram-positive species triggered three-dimensional biofilm formation, we propose that this danger signal and danger response are conserved among bacteria.},
}

@article {pmid39747199,
year = {2025},
author = {Vávrová, P and Janďourek, O and Diepoltová, A and Nachtigal, P and Konečná, K},
title = {The appropriate nutrient conditions for methicillin-resistant Staphylococcus aureus and Candida albicans dual-species biofilm formation in vitro.},
journal = {Scientific reports},
volume = {15},
number = {1},
pages = {183},
pmid = {39747199},
issn = {2045-2322},
support = {NU21-05-00482//Ministerstvo Zdravotnictví Ceské Republiky/ ; SVV 260 664//Charles University/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Methicillin-Resistant Staphylococcus aureus/drug effects/physiology ; *Candida albicans/drug effects/physiology ; *Culture Media/pharmacology ; Humans ; Nutrients/metabolism ; Animals ; Sheep ; Microbial Sensitivity Tests ; Anti-Bacterial Agents/pharmacology ; },
abstract = {Polymicrobial biofilms, the reason for most chronic wound infections, play a significant role in increasing antibiotic resistance. The in vivo effectiveness of the new anti-biofilm therapy is conditioned by the profound evaluation using appropriate in vitro biofilm models. Since nutrient availability is crucial for in vitro biofilm formation, this study is focused on the impact of four selected cultivation media on the properties of methicillin-resistant Staphylococcus aureus and Candida albicans dual-species biofilms. To reflect the wound environment, Tryptic soy broth, RPMI 1640 with and without glucose, and Lubbock medium were supplemented with different amounts of host effector molecules present in human plasma or sheep red blood cells. The study demonstrates that the Lubbock medium provided the most appropriate amount of nutrients regarding the biomass structure and the highest degree of tolerance to selected antimicrobials with the evident contribution of the biofilm matrix. Our results allow the rational employment of nutrition conditions within methicillin-resistant Staphylococcus aureus and Candida albicans dual-species biofilm formation in vitro for preclinical research. Additionally, one of the potential targets of a complex antibiofilm strategy, carbohydrates, was revealed since they are prevailing molecules in the matrices regardless of the cultivation media.},
}

*Biofilms/drug effects/growth & development
*Methicillin-Resistant Staphylococcus aureus/drug effects/physiology
*Candida albicans/drug effects/physiology
*Culture Media/pharmacology
Humans
Nutrients/metabolism
Animals
Sheep
Microbial Sensitivity Tests
Anti-Bacterial Agents/pharmacology

@article {pmid39745428,
year = {2024},
author = {Cao, L and Mi, J and He, Y and Xuan, G and Wang, J and Li, M and Tong, Y},
title = {Quorum sensing inhibits phage infection by regulating biofilm formation of P. aeruginosa PAO1.},
journal = {Journal of virology},
volume = {},
number = {},
pages = {e0187224},
doi = {10.1128/jvi.01872-24},
pmid = {39745428},
issn = {1098-5514},
abstract = {UNLABELLED: Quorum sensing (QS) can regulate diverse critical phenotypic responses in Pseudomonas. aeruginosa (P. aeruginosa), enabling bacterial adaptation to external environmental fluctuations and optimizing population advantages. While there is emerging evidence of QS's involvement in influencing phage infections, our current understanding remains limited, necessitating further investigation. In this study, we isolated and characterized a novel phage designated as BUCT640 that infected P. aeruginosa PAO1. This phage belonged to class Caudoviricetes, genus Bruynoghevirus, with a podovirus morphology, and its adsorption was dependent on Psl polysaccharides, a repeating pentamer used to support biofilm structure. Leveraging phage BUCT640 as a model, we analyzed the role of both rhl QS and las QS in bacteria-phage interactions. Based on its distinctive plaque formation performances on different QS-related mutants, we investigated the variations of phage sensitivity to these strains and ultimately elucidated the mechanism underlying how QS inhibited phage infection to PAO1. Specifically, we unveiled that the las QS could inhibit phage adsorption, which is related to the thickness change caused by biofilm differentiation. Our findings suggest that the inhibition of QS may enhance phage infectivity, potentially facilitating advanced phage therapy combined with QS interference.

IMPORTANCE: Phage therapy is a powerful solution to combat drug-resistant pathogenic bacterial infections and has earned remarkable success in clinical treatment. However, recent insights underscore the potential impact of bacterial QS on phage infection dynamics. Here, we reported a unique phenomenon wherein QS, particularly in the las QS pathway, showed distinctive plaque formation behaviors by enlarging halos around plaques in mutant strains. In addition to this, we first elucidated the correlation between biofilm formation and phage infection. Notably, the las QS could inhibit phage adsorption, an effect closely related to biofilm thickness. Such research could be the evidence to steer bacterial QS toward favorable therapeutical outcomes. Therefore, our work can extend the comprehension of the interactions between bacteria and phages influenced by QS, thereby providing new perspectives on leveraging QS interference to enhance the efficacy of phage therapy for clinical applications.},
}

@article {pmid39745385,
year = {2024},
author = {Kim, M-J and Mitchell, AP},
title = {Strain-limited biofilm regulation through the Brg1-Rme1 circuit in Candida albicans.},
journal = {mSphere},
volume = {},
number = {},
pages = {e0098024},
doi = {10.1128/msphere.00980-24},
pmid = {39745385},
issn = {2379-5042},
abstract = {UNLABELLED: Prominent virulence traits of Candida albicans include its ability to produce filamentous hyphal cells and grow as a biofilm. These traits are under control of numerous transcription factors (TFs), including Brg1 and Rme1. In the reference strain SC5314, a brg1Δ/Δ mutant has reduced levels of biofilm/filament production; a brg1Δ/Δ rme1Δ/Δ double mutant has wild-type levels of biofilm/filament production. Here, we asked whether this suppression relationship is preserved in four additional strain backgrounds: P76067, P57055, P87, and P75010. These strains represent diverse clades and biofilm/filament production abilities. We find that a rme1Δ/Δ mutation restores biofilm/filament production in a brg1Δ/Δ mutant of P76067, but not in brg1Δ/Δ mutants of P57055, P87, and P75010. We speculate that variation in activities of two functionally related TFs, Nrg1, and Ume6, may cause the strain-limited impact of the rme1Δ/Δ mutation.

IMPORTANCE: Candida albicans is a widespread fungal pathogen. The regulatory circuitry underlying virulence traits is well studied in the reference strain background, but not in other clinical isolate backgrounds. Here, we describe a pronounced example of strain variation in the control of two prominent virulence traits, biofilm formation and filamentation.},
}

@article {pmid39745371,
year = {2024},
author = {Pickens, CP and Wang, D and Pan, C and De León, KB},
title = {Absence of biofilm adhesin proteins changes surface attachment and cell strategy for Desulfovibrio vulgaris Hildenborough.},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {e0037924},
doi = {10.1128/jb.00379-24},
pmid = {39745371},
issn = {1098-5530},
abstract = {UNLABELLED: Ubiquitous in nature, biofilms provide stability in a fluctuating environment and provide protection from stressors. Biofilms formed in industrial processes are exceedingly problematic and costly. While biofilms of sulfate-reducing bacteria in the environment are often beneficial because of their capacity to remove toxic metals from water, in industrial pipelines, these biofilms cause a major economic impact due to their involvement in metal and concrete corrosion. The mechanisms by which biofilms of sulfate-reducing bacteria form, however, are not well understood. Our previous work identified two proteins, named by their gene loci DVU1012 and DVU1545, as adhesins in the model sulfate-reducing bacterium, Desulfovibrio vulgaris Hildenborough. Both proteins are localized to the cell surface and the presence of at least one of the proteins, with either being sufficient, is necessary for biofilm formation to occur. In this study, differences in cell attachment and early biofilm formation in single deletion mutants of these adhesins were identified. Cells lacking DVU1012 had a different attachment strategy from wild-type (WT) and ΔDVU1545 cells, more often attaching as single cells than aggregates, which indicated that DVU1012 was more important for cell-to-cell attachment. ΔDVU1545 cells had increased cell attachment compared to WT cells when grown in static cultures. To date, comparisons of the D. vulgaris Hildenborough have been made to the large adhesion protein system in environmental pseudomonads. Yet, we and others have shown distinct mechanistic differences in the systems. We propose to name these proteins in D. vulgaris Hildenborough biofilm formation system to facilitate comparisons.

IMPORTANCE: Biofilms of sulfate-reducing bacteria contribute to biocorrosion, costing the United States hundreds of millions of dollars annually. In contrast, these biofilms can be used to bioremediate toxic heavy metals and to generate bioelectricity. As one of the most abundant groups of organisms on Earth, it is pertinent to better understand mechanistically how the biofilms of sulfate-reducing bacteria form so we may use this knowledge to help in efforts to mitigate biocorrosion, to promote bioremediation, and to produce clean energy. This study shows that the absence of either one of two biofilm adhesins impacts surface colonization by a sulfate-reducing bacterium, and that these two biofilm adhesins differ in their effect on cell attachment compared to other well-documented bacteria such as Pseudomonas species.},
}

@article {pmid39745211,
year = {2024},
author = {Kizilyildirim, S and Köksal, F},
title = {[Examination of Capsule Genotypes, Antibiotic Susceptibility Profiles and Biofilm Forming Abilities of Group B Streptococcus Isolates Isolated from Pregnant Women].},
journal = {Mikrobiyoloji bulteni},
volume = {58},
number = {4},
pages = {380-392},
doi = {10.5578/mb.20249663},
pmid = {39745211},
issn = {0374-9096},
mesh = {Humans ; *Streptococcus agalactiae/drug effects/genetics/isolation & purification/classification ; *Biofilms/drug effects ; Female ; Pregnancy ; *Streptococcal Infections/microbiology ; *Genotype ; *Anti-Bacterial Agents/pharmacology ; *Microbial Sensitivity Tests ; *Pregnancy Complications, Infectious/microbiology ; *Bacterial Capsules/genetics ; Erythromycin/pharmacology ; Drug Resistance, Bacterial/genetics ; Adult ; },
abstract = {Group B Streptococcus (GBS) or Streptococcus agalactiae is a pathogen that causes infections during pregnancy. The aim of this study was to investigate the antibiotic sensitivity profiles, capsule genotypes and biofilm forming capabilities of GBS isolates obtained from pregnant women . The study included 252 pregnant women who applied to Adana Gynecology and Children's Hospital between 2018 and 2023. The disk diffusion method was used to test antibiotic susceptibility. The multiplex polymerase chain reaction method was used to examine capsule genotypes (Ia-IX) and the genes responsible for resistance to erythromycin (ermB, ermTR, and mefA), clindamycin (linB) and tetracycline (tetM and tetO). The polystyrene microplate method was used to determine the presence of biofilm production. As a result of the study; It was observed that GBS isolates consisted of 44.8% III, 29% Ib, 20.6% Ia, 2.4% V, 1.6% IV, 1.2% II and 0.4% VI genotypes, respectively. All of the isolates were found be susceptible to cefotaxime, ampicillin, vancomycin, penicillin, and linezolid; however, 42.5% of the isolates were resistant to tetracycline, 33.3% to erythromycin and 24.2% to clindamycin. Erythromycin and tetracycline resistance genes were mostly detected in the capsule III genotype. It was observed that 6.3% of GBS isolates produced strong biofilm, 56% produced moderate biofilm and 37.7% produced weak biofilm. In the study, the distribution of capsule genotypes and changes in antibiotic susceptibility profiles of GBS isolates over the years were revealed. The results of this study contributed to the epidemiological studies on GBS infections by providing data.},
}

Humans
*Streptococcus agalactiae/drug effects/genetics/isolation & purification/classification
*Biofilms/drug effects
Female
Pregnancy
*Streptococcal Infections/microbiology
*Genotype
*Anti-Bacterial Agents/pharmacology
*Microbial Sensitivity Tests
*Pregnancy Complications, Infectious/microbiology
*Bacterial Capsules/genetics
Erythromycin/pharmacology
Drug Resistance, Bacterial/genetics
Adult

@article {pmid39745063,
year = {2025},
author = {Palomares-Navarro, JJ and Bernal-Mercado, AT and González-Pérez, CJ and Martínez-Tellez, MA and Gonzalez-Aguilar, GA and Ortega-Ramirez, LA and Ayala-Zavala, JF},
title = {Inhibition of Salmonella Typhimurium biofilm and polysaccharide production via eugenol-glucosyltransferase interactions.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-18},
doi = {10.1080/08927014.2024.2446928},
pmid = {39745063},
issn = {1029-2454},
abstract = {This study hypothesizes that eugenol, due to its structural properties, can inhibit glucosyltransferase activity, thereby reducing polysaccharide synthesis in Salmonella Typhimurium biofilms. It was found that eugenol exhibited minimum inhibitory and bactericidal concentrations of 0.6 mg mL[-1] and 0.8 mg mL[-1], respectively, against planktonic S. Typhimurium growth. It also demonstrated minimum biofilm eradication and inhibition concentrations of 1.8 mg mL[-1] and 0.7 mg mL[-1], respectively. At 0.3 mg mL[-1], eugenol reduced biofilm formation and affected polysaccharide production. Moreover, eugenol reduced glucosyltransferase activity. Computational analysis indicated strong interactions between eugenol and the enzyme's active site residues with affinity energy -8.5 kcal mol[-1]. Real-time PCR revealed a significant increase in bcsA gene expression in the presence of eugenol. These findings suggest that eugenol's ability to inhibit glucosyltransferase activity effectively reduces biofilm formation and polysaccharide content.},
}

@article {pmid39745056,
year = {2025},
author = {Aragão, MGB and Aires, CP and Corona, SAM and He, X},
title = {Effects of epigallocatechin gallate on the development of matrix-rich Streptococcus mutans biofilm.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-10},
doi = {10.1080/08927014.2024.2446932},
pmid = {39745056},
issn = {1029-2454},
abstract = {In this study, we evaluated the impact of Epigalocatechin-3-gallate (EGCG) on S. mutans biofilm development for 24 and 46 h using high-resolution confocal laser scanning microscopy. EGCG treatment led to the formation of interspaced exopolysaccharide (EPS)-microcolony complexes unevenly distributed on the surface of hydroxyapatite disc, forming a thinner and less complex biofilm structure with significantly reduced biomass, matrix volume, and thickness compared to the NaCl treated group (negative control). At 46 h, the biofilm of the EGCG-treatment group failed to form the bacterial-EPS superstructures which is characteristic of the biofilm in the negative control group. EGCG treatment seems to significantly delay biofilm development, with the 46 h biofilm in the EGCG treatment group resembling the negative control group at 24 h. EGCG topical treatments impaired S. mutans biofilm initial growth and maturation, suggesting its potential to be used as a preventive agent against dental caries.},
}

@article {pmid39744154,
year = {2024},
author = {Liu, X and Li, J and Wu, R and Bai, L},
title = {Characterization of glycogen-related glycoside hydrolase glgX and glgB from Klebsiella pneumoniae and their roles in biofilm formation and virulence.},
journal = {Frontiers in cellular and infection microbiology},
volume = {14},
number = {},
pages = {1507332},
pmid = {39744154},
issn = {2235-2988},
mesh = {*Biofilms/growth & development ; *Klebsiella pneumoniae/genetics/pathogenicity/enzymology/metabolism/growth & development ; Virulence ; *Glycogen/metabolism ; *Glycoside Hydrolases/metabolism/genetics ; Animals ; Temperature ; Hydrogen-Ion Concentration ; Klebsiella Infections/microbiology ; Mice ; Bacterial Proteins/genetics/metabolism ; Gene Deletion ; Virulence Factors/genetics/metabolism ; },
abstract = {Glycogen is a polymer used by bacteria to store excess glucose, playing a crucial role in bacterial growth, stress resistance, biofilm formation, and virulence. In bacteria, the glycoside hydrolase family 13 protein are involved in the synthesis and metabolism of glycogen, respectively. The absence of these enzymes leads to changes in bacterial glycogen content, thereby affecting the growth metabolism of the strain. To date, research on the roles of these glycogen-related glycoside hydrolase genes in the synthesis metabolism and bacterial phenotypes of Klebsiella pneumoniae has been limited. In this study, we characterized the glycogen-related glycoside hydrolase genes glgB and glgX of K. pneumoniae. We found that both enzymes exhibited significant degradation activity against glycogen substrates and were capable of degrading amylopectin, amylose, and pullulan. The optimal temperatures for GlgB and GlgX were both in the range of 35-40°C, with optimal pH values of 7.5 and 7.0, respectively, and they exhibited high stability at 37°C. Subsequently, we deleted the glgB and glgX genes in K. pneumoniae. The deletion of the glgB gene resulted in a decrease in the growth rate of the bacteria and defected glycogen synthesis. In contrast, the deletion of the glgX gene slightly accelerated the growth rate and led to continuous glycogen accumulation. In terms of biofilm formation and virulence, defects in glycogen synthesis impeded biofilm formation and virulence, while continuous glycogen accumulation did not affect biofilm formation but slightly increased virulence. In conclusion, the glgB and glgX genes are essential for the glycogen synthesis and metabolism in K. pneumoniae and further influence the biofilm formation capacity and virulence.},
}

*Biofilms/growth & development
*Klebsiella pneumoniae/genetics/pathogenicity/enzymology/metabolism/growth & development
Virulence
*Glycogen/metabolism
*Glycoside Hydrolases/metabolism/genetics
Animals
Temperature
Hydrogen-Ion Concentration
Klebsiella Infections/microbiology
Mice
Bacterial Proteins/genetics/metabolism
Gene Deletion
Virulence Factors/genetics/metabolism

@article {pmid39744121,
year = {2024},
author = {Miao, Y and Shuang, W and Qianwei, Q and Xin, L and Wei, P and Hai, Y and Yonghui, Z and Xinbo, Y},
title = {Proteomic study of the inhibitory effects of tannic acid on MRSA biofilm.},
journal = {Frontiers in pharmacology},
volume = {15},
number = {},
pages = {1413669},
pmid = {39744121},
issn = {1663-9812},
abstract = {INTRODUCTION: The mechanism of tannic acid (TA) intervention on methicillin-resistant Staphylococcus aureus (MRSA, USA 300) biofilm formation was explored using proteomics.

METHODS: The minimum inhibitory concentration (MIC) of TA against the MRSA standard strain USA 300 was determined by two-fold serial dilution of the microbroth. The effects of TA were studied using crystal violet staining. The morphology of TA-treated USA 300 cells was observed by scanning electron microscopy and confocal laser scanning microscopy. Differentially expressed proteins (DEPs) were screened using proteomic and biological information analyses, and their transcriptional levels were verified using real-time quantitative polymerase chain reaction.

RESULTS: The MIC of TA was 0.625 mg/mL, whereas 1/2 MIC (0.3125 mg/mL) of TA significantly inhibited biofilm formation without affecting the bacterial growth (p < 0.01) and prevented the formation of a complete three-dimensional biofilm structure. Using 1/2 MIC of TA, 208 DEPs were identified, of which 127 were upregulated and 81 were downregulated. The transcriptional levels of the genes corresponding to five randomly selected DEPs (glnA, ribD, clpB, gap, and lukE) were consistent with the proteomics data (p < 0.05). Bioinformatic analysis showed that the changes in the MRSA strains after TA intervention primarily involved pyrimidine and purine metabolisms, arginine biosynthesis, and the citric acid cycle.

CONCLUSION: TA exerts an antibacterial effect on MRSA and can be used as a potential candidate for the development of anti-biofilm drugs, thereby laying a foundation for the treatment of MRSA biofilm-induced infections.},
}

@article {pmid39743153,
year = {2024},
author = {Tai, ZS and Sun, Y and Dulatre Medriano, CA and Fu, Y and Jiang, Y and Lei, F and Liu, K and Yan, T and Xin Eve, LJ and Bae, SW and Hoon Elaine, QP and Chue, PW and Hui Lennis, SK and Wong, JJ and Ong, SL and Hu, J},
title = {Exploring water quality variations and biofilm growth in a drinking water distribution system via a biofilm annular reactor series system and predictive modelling of residual chlorine.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {144048},
doi = {10.1016/j.chemosphere.2024.144048},
pmid = {39743153},
issn = {1879-1298},
abstract = {The hydraulic conditions vary significantly across different segments of the drinking water distribution system (DWDS), leading to distinct variations in water quality throughout the system. Understanding these changes in water quality and biofilm development over time is crucial for enhancing drinking water management efficiency. This study focused on replicating the hydraulic conditions found in transmission and distribution pipelines within a specific pipeline path of the DWDS in Singapore using a biofilm annular reactor series system (BARSS). The BARSS experiment revealed that the total residual chlorine (TRC) concentration in water was greatly influenced by both flow velocity and the amount of biofilm present. TRC decay occurred more rapidly at higher flow velocity and was influenced by bacterial growth under fast flow conditions. Furthermore, UV254 levels in the water decreased with extended water age in the BARSS, due to the degradation of organic matters into smaller molecules. The study also found that higher TRC concentrations had a more pronounced inhibitory effect on biofilm formation and the proliferation of minor taxa. In the last part of the study, a predictive model for TRC concentration was developed using water quality parameters from preceding stages in the BARSS. This model demonstrated excellent prediction accuracy for TRC concentration, with a mean square error (MSE) of 0.0110 and R[2] of 0.9893.},
}

@article {pmid39743100,
year = {2024},
author = {Sun, X and Chen, X and Wang, S and Gu, H and Bao, H and Ning, Z and Feng, X and Chen, Y},
title = {Oxygenous and biofilm-targeted nanosonosensitizer anchored with Pt nanozyme and antimicrobial peptide in the gelatin/sodium alginate hydrogel for infected diabetic wound healing.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {139356},
doi = {10.1016/j.ijbiomac.2024.139356},
pmid = {39743100},
issn = {1879-0003},
abstract = {Sonodynamic therapy is an emerging therapeutic approach for combating bacterial infections. However, the characteristics of hypoxia, high H2O2 microenvironment, and the formation of persistent biofilms in diabetic wound sites limit its efficacy in this field. To address these issues, we developed a multifunctional antibacterial hydrogel dressing PPCN@Pt-AMPs/HGel with the cross-linked gelatin and sodium alginate as the matrix, where the nanosonosensitizer PCN-224 was decorated with the oxygen-generating Pt nanoenzyme and further coupled with a biofilm-targeting antimicrobial peptide via an interacting polydopamine layer. This nano-composite hydrogel displayed improved mechanical properties as well as good biocompatibility and biodegradability. The catalase-like activity of the nanoparticles facilitated the ultrasound-induced generation of the singlet oxygen due to the catalytic decomposition of the H2O2 into O2. In vitro results showed that the hydrogel dressing exhibited excellent antimicrobial ability under low-intensity ultrasound stimulation, which could effectively inhibit the newly formed biofilm and eliminate the full-grown biofilms. In the infected diabetic wound of rats, PPCN@Pt-AMPs/HGel significantly enhanced the wound healing rate under low-intensity ultrasound stimulation and improved the regeneration outcomes by promoting granulation tissue formation, angiogenesis, and type III collagen deposition. In conclusion, our study provides a novel and effective antibacterial hydrogel dressing for sonodynamic treatment of diabetic wounds.},
}

@article {pmid39743066,
year = {2024},
author = {Rath, S and Das, S},
title = {Stress response proteins within biofilm matrixome protect the cell membrane against heavy metals-induced oxidative damage in a marine bacterium Bacillus stercoris GST-03.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {139397},
doi = {10.1016/j.ijbiomac.2024.139397},
pmid = {39743066},
issn = {1879-0003},
abstract = {Biofilm formation is a key adaptive response of marine bacteria towards stress conditions. The protective mechanisms of biofilm matrixome proteins against heavy metals (Pb and Cd) induced oxidative damage in the marine bacterium Bacillus stercoris GST-03 was investigated. Exposure to heavy metals resulted in significant changes in cell morphology, biofilm formation, and matrixome composition. Biofilm-encased cells showed lower oxidative damage. Biofilm matrixome protein exhibited major conformational changes, with 100 % α-helix turned to 62.33 % and 69.64 % of random coil under Pb and Cd stress, respectively. Fluorescence quenching kinetics revealed slow interactions between biofilm matrixome proteins and heavy metals (Kq values < 2.0 × 10[10]). Thermodynamic analysis showed negative ∆G (-16.02 kJ/mol for Pb and -17.45 kJ/mol for Cd) and binding dissociation constant (KD) (1530 ± 157 μM for Pb and 875 ± 97.4 μM for Cd), indicating a stronger binding affinity of biofilm matrixome to heavy metals. Pb stress led to overproduction of detoxification proteins (YnaI, KhtS, Bacillopeptidase F), competence and sporulation proteins (RapF, CSSF, XkdP), while Cd exposure leads to overproduction of proteins involved in protein misfolding repair (YlxX, cysteine-tRNA ligase, YacP), DNA repair (YfkN), and redox balance (cysteine synthase, YdiK). The findings highlight the resilience of B. stercoris GST-03 to heavy metal stress in biofilm mode.},
}

@article {pmid39742762,
year = {2024},
author = {Chang, BZ and Huang, XL and Chen, DZ and Jin, RC and Yang, GF},
title = {How biofilm and granular sludge cope with dissolved oxygen exposure in anammox process: Performance, bioaccumulation characteristics and bacterial evolution.},
journal = {Journal of environmental management},
volume = {373},
number = {},
pages = {123986},
doi = {10.1016/j.jenvman.2024.123986},
pmid = {39742762},
issn = {1095-8630},
abstract = {In order to study the resistance mechanisms of biofilm and granular sludge to various dissolved oxygen (DO) exposures in anaerobic ammonium oxidation (anammox) process, a biofilm - granular sludge anammox reactor was established and operated. Experimental results showed that DO levels of ≤0.41 mg L[-1] hardly affected the total nitrogen removal efficiency (TNRE). Higher DO levels of 1.96-2.08 mg L[-1] promoted biomass disintegration and decreased specific anammox activity and extracellular polymeric substance (EPS) levels in granular sludge, but did not decrease EPS significantly in biofilm. The relative abundance of anammox genus Candidatus Kuenenia in granular sludge and biofilm decreased to 13.93% and 1.93%, respectively. NO3[-]-N was accumulated due to the increased NOB genus Nitrospira in granular sludge and biofilm. The inhibition effects of 1.96-2.08 mg L[-1] DO on anammox system were reversible, and the TNRE was quickly restored to (82.21 ± 2.39)% with AnAOB accumulation after removing aeration. This study provided theoretical support for the development of coupled biological nitrogen removal system based on anammox with other aerobic processes.},
}

@article {pmid39742531,
year = {2024},
author = {Chougule, S and Basrani, S and Gavandi, T and Patil, S and Yankanchi, S and Jadhav, A and Karuppayil, SM},
title = {Zingerone effect against Candida albicans growth and biofilm production.},
journal = {Journal de mycologie medicale},
volume = {35},
number = {1},
pages = {101527},
doi = {10.1016/j.mycmed.2024.101527},
pmid = {39742531},
issn = {1773-0449},
abstract = {BACKGROUND: The increasing resistance of Candida albicans biofilms underscores the urgent need for effective antifungals. This study evaluated the efficacy of zingerone and elucidated its mode of action against C. albicans ATCC 90028 and clinical isolate C1.

EXPERIMENTAL PROCEDURE: Minimum inhibitory concentrations (MICs) of zingerone were determined using CLSI methods against planktonic cells, biofilm formation, and yeast-to-hyphal transition. The mode of action was investigated through fluorescent microscopy, ergosterol assays, cell cycle analysis, and RT-PCR for gene expression.

KEY RESULTS: Zingerone inhibited planktonic growth and biofilm formation at in C. albicans ATCC 90028 and clinical isolate C1 at 2 mg/mL 4 mg/mL and 1 mg/mL and 2 mg/mL respectively. Treatment with the MIC concentration caused significant cell cycle arrest at the G0/G1 phase, halting proliferation in both the strains. Propidium iodide Staining revealed compromised membrane integrity in both the strains. Also, acridine orange and ethidium bromide dual staining showed increased dead cell proportions in C. albicans ATCC 90028. RT-PCR studies showed downregulation of BCY1, PDE2, EFG1, and upregulation of negative regulators NRG1, TUP1 disrupting growth and virulence pathways. Zingerone induced elevated reactive oxygen species (ROS) levels, triggering apoptosis, evidenced by DNA fragmentation and upregulation of apoptotic markers. It also inhibited ergosterol synthesis in a concentration-dependent manner, crucial for membrane integrity. Importantly, zingerone exhibited minimal hemolytic activity. In an in vivo silkworm model, zingerone demonstrated significant antifungal efficacy, protecting silkworms from infection. It also modulated stress response genes, highlighting its multifaceted action.

CONCLUSIONS: In vitro and in vivo findings confirm the potent antifungal efficacy of zingerone against C. albicans ATCC 90028 and clinical isolate C1, suggesting its promising potential as a therapeutic agent that warrants further exploration.},
}

@article {pmid39742298,
year = {2024},
author = {Fan, S and Qin, P and Lu, J and Wang, S and Zhang, J and Wang, Y and Cheng, A and Cao, Y and Ding, W and Zhang, W},
title = {Bioprospecting of culturable marine biofilm bacteria for novel antimicrobial peptides.},
journal = {iMeta},
volume = {3},
number = {6},
pages = {e244},
pmid = {39742298},
issn = {2770-596X},
abstract = {Antimicrobial peptides (AMPs) have become a viable source of novel antibiotics that are effective against human pathogenic bacteria. In this study, we construct a bank of culturable marine biofilm bacteria constituting 713 strains and their nearly complete genomes and predict AMPs using ribosome profiling and deep learning. Compared with previous approaches, ribosome profiling has improved the identification and validation of small open reading frames (sORFs) for AMP prediction. Among the 80,430 expressed sORFs, 341 are identified as candidate AMPs with high probability. Most potential AMPs have less than 40% similarity in their amino acid sequence compared to those listed in public databases. Furthermore, these AMPs are associated with bacterial groups that are not previously known to produce AMPs. Therefore, our deep learning model has acquired characteristics of unfamiliar AMPs. Chemical synthesis of 60 potential AMP sequences yields 54 compounds with antimicrobial activity, including potent inhibitory effects on various drug-resistant human pathogens. This study extends the range of AMP compounds by investigating marine biofilm microbiomes using a novel approach, accelerating AMP discovery.},
}

@article {pmid39742058,
year = {2024},
author = {Sowmya, BR and Nayak, A and Kottrashetti, VS and Ingalagi, P and Harish, G},
title = {Determination of the antibiofilm property of aqueous extract of the Amorphophallus paeoniifolius on some early and late colonizers in an artificially synthesized dental biofilm - An in vitro study.},
journal = {Journal of Indian Society of Periodontology},
volume = {28},
number = {3},
pages = {325-331},
pmid = {39742058},
issn = {0972-124X},
abstract = {BACKGROUND: Mechanical therapy along with adjunctive therapy, using agents like chlorhexidine digluconate mouthwash helps to disrupt the plaque biofilm. Recently, herbs with medicinal value have been tested for their antimicrobial properties. The present study was designed to assess the anti-biofilm activity of Amorphophallus paeoniifolius against some periodontal pathogens in an artificially synthesized dental biofilm.

MATERIALS AND METHODS: The aqueous extract of A. paeoniifolius was constituted and its minimum inhibitory concentration (MIC) against standard strains of some periodontal pathogens was determined. A total of 21 biofilm samples were synthesized on extracted teeth and microtiter plates, and these were divided into two groups of 10 samples each. One group was treated with the predetermined MIC values of A. paeoniifolius, while the other group was treated with chlorhexidine. The anti-biofilm activity of both compounds was assessed by calculating colony-forming units (CFUs) for the extracted teeth and optical density (OD) values for the microtiter plates.

RESULTS: The mean CFU at baseline was 55,000/μl while posttreatment with chlorhexidine digluconate and aqueous extract of A. paeoniifolius was 23,280 ± 5274.00 and 28,560 ± 4509.545/μl, respectively. The mean OD value (at 595 nm) posttreatment with chlorhexidine digluconate was 0.9876 ± 0.49179 and A. paeoniifolius was 1.4990 ± 0.37851. Results indicate that the aqueous extract of A. paeoniifolius showed an inhibitory effect on biofilm obtained on microtiter plates and the one constituted on extracted teeth.

CONCLUSION: Anti-biofilm activity of aqueous extract of A. paeoniifolius was appreciable and also comparable to that of chlorhexidine digluconate, both on extracted teeth and microtiter plates.},
}

@article {pmid39741867,
year = {2024},
author = {de Araújo, LGS and Rodrigues, THS and Rates, ERD and Alencar, LMR and Rosa, MF and Ponte Rocha, MV},
title = {Production of Cellulose Nanoparticles from Cashew Apple Bagasse by Sequential Enzymatic Hydrolysis with an Ultrasonic Process and Its Application in Biofilm Packaging.},
journal = {ACS omega},
volume = {9},
number = {51},
pages = {50671-50684},
pmid = {39741867},
issn = {2470-1343},
abstract = {Cellulose nanostructures obtained from lignocellulosic biomass via enzymatic processes may offer advantages in terms of material properties and processing sustainability. Thus, in this study, cellulose nanoparticles with a spherical morphology were produced through the enzymatic hydrolysis of cashew apple bagasse (CAB). CAB was previously subjected to alkaline and acid-alkali pretreatment, and the pretreated solids were labeled as CAB-PTA and CAB-PT-HA, respectively. The enzymatic hydrolysis was carried out using two different enzymatic loadings (7.5 and 12 FPU/gcellulose) of the Trichoderma reesei cellulase complex, and the formation of nanostructures occurred only at 7.5 FPU/gcellulose. The results indicated the production of nanocellulose using only CAB-PT-HA as the precursor, obtaining nanosphere structures with a yield of 65.1 ± 2.9% and a diameter range of 57.26-220.66 nm. The nanocellulose showed good thermal and colloidal stability and was subsequently used for biofilm production. Biofilms were prepared using different percentages of nanocellulose (5 and 7% w/v), and they showed a greater water retention capacity and higher biodegradability compared to the control film, indicating potential for application in food packaging and cosmetic masks. Thus, it highlights the potential for developing new biodegradable plastics incorporated with nanocellulose obtained from CAB through a more sustainable process.},
}

@article {pmid39739329,
year = {2024},
author = {Nguyen, VT and Le, TN and Huynh, DD and Le, VA and Do, QH and Vo, TD},
title = {Maximizing nutrient removal: unveiling the influence of biomass retention time in revolving algae biofilm reactor.},
journal = {Environmental technology},
volume = {},
number = {},
pages = {1-11},
doi = {10.1080/09593330.2024.2445325},
pmid = {39739329},
issn = {1479-487X},
abstract = {This study introduces a novel Revolving Algae Biofilm reactor for synthetic wastewater treatment, examining the influence of various biomass retention times (BRTs) on nutrient removal performance. The study reveals complex interactions between microalgae and bacteria, emphasizing their symbiotic functions in oxygen provision, nutrient absorption, and floc creation. This research contributes to the advancement of sustainable wastewater treatment methods, showing promise for large-scale nutrient removal in industrial settings. The biomass retention time of 3 days (BRT-3) emerges as the most suitable condition for efficient nutrient removal. Specifically, in the BRT-3 period, the reactor can remove up to 97% of NH4-N, 94% of total phosphorus, and 92% of COD. NH4-N was also effectively assimilated to NO2-N and NO3-N, underscoring the efficiency of the nitrification process. While BRT-7 exhibits a noteworthy algae growth rate when it reaches the maximum rate of 3 mg/L.day. Continual investigation into the interplay between microalgae and bacteria is essential for enhancing system efficiency in future wastewater treatment applications.},
}

@article {pmid39739165,
year = {2024},
author = {Pathoor, NN and Ganesh, PS and Anshad, AR and Gopal, RK and Ponmalar, EM and Suvaithenamudhan, S and Rudrapathy, P and Shankar, EM},
title = {3-Hydroxybenzoic acid inhibits the virulence attributes and disrupts biofilm production in clinical isolates of Acinetobacter baumannii.},
journal = {European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology},
volume = {},
number = {},
pages = {},
pmid = {39739165},
issn = {1435-4373},
abstract = {PURPOSE: Acinetobacter baumannii (A. baumannii) is an emerging global public health threat owing to its ability to form biofilms. Here, we evaluated 3-hydroxybenzoic acid (3-HBA), a promising organic compound, for its ability to disrupt biofilm formation and virulence attributes in clinical isolates of A. baumannii.

MATERIALS AND METHODS: The effect of 3-HBA on A. baumannii was assessed by determining the minimum inhibitory concentration (MIC) and certain other in vitro investigations viz., extracellular polymeric substance (EPS) estimation, crystal violet staining assay, motility assay, and the hydrogen peroxide (H2O2) assay to examine its impact on bacterial virulence. Biofilm formation was also evaluated at the air-liquid interface. In situ visualization investigations were employed to confirm biofilm dispersion at the lowest effective concentration. The cytotoxic effects of 3-HBA on MCF-7 cells were investigated using the MTT assay.

RESULTS: At a sub-inhibitory concentration of 0.078 mg/mL, 3-HBA reduced biofilm formation in A. baumannii LSAB-04 and A. baumannii LSAB-06 by 61.22% and 59.21%, respectively, and decreased EPS production by 64% in LSAB-04 and 58.31% in LSAB-06. Microscopic examination confirmed significant biofilm dispersion. 3-HBA also significantly impaired swarming motility and increased their sensitivity to H2O2. The MTT assay showed a dose-dependent decrease in MCF-7 cell viability (43.67%) at a concentration of 0.078 mg/mL.

CONCLUSION: Our findings underscore the likely role of 3-HBA as a promising A. baumannii biofilm-disrupting agent. Further, by downplaying against the virulence factors of A. baumannii, 3-HBA could be a compelling alternative to conventional antibiotics that however requires to be investigated.},
}

@article {pmid39739119,
year = {2024},
author = {Li, J and Wang, J and Wu, J and Wang, X},
title = {Matrix-producing cells' orientation order facilitates Bacillus subtilis biofilm self-healing.},
journal = {Archives of microbiology},
volume = {207},
number = {1},
pages = {19},
pmid = {39739119},
issn = {1432-072X},
support = {12372321 and 11972074//National Natural Science Foundation of China/ ; },
mesh = {*Bacillus subtilis/physiology/metabolism/genetics ; *Biofilms/growth & development ; },
abstract = {During the self-healing process of Bacillus subtilis biofilms on a solid MSgg substrate, large-scale ordered clusters emerge within the biofilm, providing an invasive advantages. To investigate the self-healing mechanism, an agent-based model is employed to simulate the self-healing processes of biofilms at two ages. The study reveals that a uniform cell distribution facilitates the healing of biofilm incisions. The nutrient diffusion rate within the biofilm and the elastic modulus (comprising cell and EPS) play a dominant role in the healing of circumferential incisions, while the diffusion rate outside the biofilm governs the healing of radial and penetrating incisions. These influencing factors can adjust cellular ordering, providing valuable insights for controlling the self-healing of Bacillus subtilis biofilms.},
}

*Bacillus subtilis/physiology/metabolism/genetics
*Biofilms/growth & development

@article {pmid39737751,
year = {2025},
author = {Benny, AT and Radhakrishnan, EK},
title = {Assessing the antibiofilm activity of flavonol esters against Pseudomonas aeruginosa PAO1 biofilm: an in vitro, molecular docking, and molecular dynamics study.},
journal = {Journal of biomolecular structure & dynamics},
volume = {43},
number = {2},
pages = {813-829},
doi = {10.1080/07391102.2023.2283811},
pmid = {39737751},
issn = {1538-0254},
mesh = {*Biofilms/drug effects ; *Pseudomonas aeruginosa/drug effects ; *Molecular Dynamics Simulation ; *Flavonols/pharmacology/chemistry ; *Molecular Docking Simulation ; *Esters/chemistry/pharmacology ; *Anti-Bacterial Agents/pharmacology/chemistry ; Microbial Sensitivity Tests ; Virulence Factors/metabolism ; Bacterial Proteins/metabolism/chemistry ; Hydrophobic and Hydrophilic Interactions ; Glycolipids/chemistry/pharmacology/metabolism ; Quorum Sensing/drug effects ; Pyocyanine/metabolism ; Gene Expression Regulation, Bacterial/drug effects ; },
abstract = {Pseudomonas aeruginosa is one of the opportunistic pathogens that may cause serious health problems and can produce several virulence factors, which are responsible for various infections, particularly in immunocompromised patients. They are responsible for producing infections on indwelling medical devices by attaching on to them and forming a biofilm. Antibiofilm, antivirulence, and gene expression studies of P. aeruginosa biofilm treated with esters of flavonols were evaluated. Pyocyanin, cell surface hydrophobicity, LasA protease estimation, rhamnolipid estimation, and pyoverdine estimation were performed to evaluate the antivirulence activities of the test compounds against P. aeruginosa. Previous studies on the antivirulence activity of flavonoids against P. aeruginosa demonstrate that even if they can inhibit bacterial growth, relatively high concentrations of the compound are generally required for the inhibition of virulence factors. The esters showed more than 40% inhibition in all the tested virulence factors at their sub minimum inhibitory concentration. The gene expression studies of selected esters toward lasB and rhlA genes show downregulation of rhlA which suggests the inhibition in biofilm formation through rhamnolipid inhibition, quorum sensing inhibition, or biofilm formation inhibition.Communicated by Ramaswamy H. Sarma.},
}

*Biofilms/drug effects
*Pseudomonas aeruginosa/drug effects
*Molecular Dynamics Simulation
*Flavonols/pharmacology/chemistry
*Molecular Docking Simulation
*Esters/chemistry/pharmacology
*Anti-Bacterial Agents/pharmacology/chemistry
Microbial Sensitivity Tests
Virulence Factors/metabolism
Bacterial Proteins/metabolism/chemistry
Hydrophobic and Hydrophilic Interactions
Glycolipids/chemistry/pharmacology/metabolism
Quorum Sensing/drug effects
Pyocyanine/metabolism
Gene Expression Regulation, Bacterial/drug effects

@article {pmid39736993,
year = {2024},
author = {Migliaccio, A and Stabile, M and Triassi, M and Dé, E and De Gregorio, E and Zarrilli, R},
title = {Inhibition of biofilm formation and preformed biofilm in Acinetobacter baumannii by resveratrol, chlorhexidine and benzalkonium: modulation of efflux pump activity.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1494772},
pmid = {39736993},
issn = {1664-302X},
abstract = {INTRODUCTION: The persistence of Acinetobacter baumannii in the contaminated environment is sustained by tolerance to biocides and ability to growth as biofilm. The aim of the study was to analyze the susceptibility of A. baumannii biofilms to chlorhexidine (CHX) and benzalkonium (BZK) biocides and the ability of natural monomeric stilbenoid resveratrol (RV) to modulate the phenomenon.

METHODS: Biofilm formation and preformed biofilm were tested by Crystal violet and tetrazolium salt reduction assay, respectively. Analysis of efflux pump (EP) expression during biofilm growth was performed by Real-time RT-PCR assays.

RESULTS: CHX and BZK at ¼ and ½ MICs alone or in combination inhibited biofilm growth of A. baumannii ATCC 19606, 4190, and 3909 strains. RV at 32 mg/L and CHX and BZK at ¼ or ½ MICs showed a synergistic effect and completely inhibited biofilm formation in all A. baumannii strains. Similarly, RV at 32 mg/L and CHX and BZK at ½ MIC significantly inhibited air-liquid biofilm formation of A. baumannii ATCC 19606, 4190 and 3909 strains. The inactivation of AdeB and AdeJ RND EPs in A. baumannii ATCC19606 increased the susceptibility to CHX and BZK alone or in the presence of 32 mg/L RV. Concordantly, carbonyl cyanide m-chlorophenylhydrazine (CCCP) increased the susceptibility to CHX, BZK and RV and dose-dependently inhibited biofilm formation in A. baumannii ATCC 19606, 4190 and 3909 strains. RV at 32 mg/L inhibited basal and CHX-induced EP genes expression, while increased EP gene expression in the presence of BZK during A. baumannii ATCC19606 biofilm growth. In addition, CHX and BZK alone or in combination dose-dependently reduced preformed biofilm of all A. baumannii strains. The combination of RV with CHX and BZK additively decreased minimal biofilm eradicating concentrations in A. baumannii strains.

CONCLUSION: These results demonstrate that: (i) CHX and BZK alone or in the presence of RV inhibit biofilm growth and preformed biofilm in A. baumannii; (ii) tolerance to CHX and BZK during biofilm growth is dependent on the activation of AdeB and AdeJ EPs; and (iii) the inhibitory effect of RV on biofilm growth is mediated by the inhibition of EP genes expression in A. baumannii.},
}

@article {pmid39736437,
year = {2024},
author = {Zhai, T and Zhang, L and Zhang, F and Su, X and Chen, P and Xing, Z and Liu, H and Zhao, T},
title = {Characteristics of biofilm layer in a bio-doubling reactor and their impact on aerobic denitrifying bacteria enrichment.},
journal = {Environmental research},
volume = {267},
number = {},
pages = {120730},
doi = {10.1016/j.envres.2024.120730},
pmid = {39736437},
issn = {1096-0953},
abstract = {Microbial loss significantly affects wastewater treatment efficiency. This study simulated the inoculation area of a self-developed biological doubling reactor (BDR) to evaluate the retention efficiency of seven different fillers for aerobic denitrifying bacteria. Over 90 days of continuous operation, the porous filler R3 demonstrated excellent performance, with OD600 values consistently exceeding 1.0 and minimal fluctuation. On day 90, the seed liquid amplified with R3 achieved removal efficiencies of 100% for ammonia nitrogen, 97.75% for total nitrogen, and 96.4% for chemical oxygen demand, outperforming other fillers. Scanning electron microscopy and microscopic analysis revealed that R3's large large specific surface area and volume formed a unique meshed biofilm structure, enhancing oxygen and nutrient transport while minimizing detachment. This promoted effective enrichment and retention of aerobic denitrifying bacteria. Microbial diversity analysis confirmed that Acinetobacter, a key genus involved in aerobic denitrification, dominated the network biofilm on R3, accounting for an average of 35.63%. while granular fillers, due to oxygen limitation, promoted the growth of anaerobic ammonium-oxidizing Alcaligenes. The use of BDR-enhanced MBBR for treating synthetic wastewater resulted in a 29.6% increase in TN removal efficiency, with stable system operation. The use of porous fillers with a high specific volume supports stable biofilm formation and consistent seed liquid output, providing a viable solution to microbial loss in wastewater treatment processes.},
}

@article {pmid39736338,
year = {2024},
author = {Xia, L and Wu, B and Cui, X and Ran, T and Li, Q and Zhou, Y},
title = {Machine learning-based prediction of non-aeration linear alkylbenzene sulfonate mineralization in an oxygenic microalgal-bacteria biofilm.},
journal = {Bioresource technology},
volume = {419},
number = {},
pages = {132028},
doi = {10.1016/j.biortech.2024.132028},
pmid = {39736338},
issn = {1873-2976},
abstract = {Microalgal-bacteria biofilm shows great potential in low-cost greywater treatment. Accurately predicting treated greywater quality is of great significance for water reuse. In this work, machine learning models were developed for simulating and predicting linear alkylbenzene sulfonate (LAS) removal using 152-days collected data from a battled oxygenic microalgal-bacteria biofilm reactor (MBBfR). By using nine variables including influent LAS, hydraulic retention time (HRT), biofilm density and thickness, specific oxygen production and consumption rates, microalgae and bacteria concentrations, and dissolved oxygen (DO), the support vector machine (SVM) model enabled the accurate LAS removal prediction (training set: R[2] = 0.995, (root mean square error, RMSE) = 0.076, (mean absolute error, MAE) = 0.069; testing set: R[2] = 0.961, RMSE = 0.251, MAE = 0.153). SVM can be also successfully applied for MBBfR operation optimization (HRT = 4.28 h, DO = 0.25 mg/L) that achieving accurate prediction of LAS mineralization.},
}

@article {pmid39736219,
year = {2024},
author = {Kong, L and Hu, X and Xia, D and Wu, J and Zhao, Y and Guo, H and Zhang, S and Qin, C and Wang, Y and Li, L and Su, Z and Zhu, C and Xu, S},
title = {Janus PEGylated CuS-engineered Lactobacillus casei combats biofilm infections via metabolic interference and innate immunomodulation.},
journal = {Biomaterials},
volume = {317},
number = {},
pages = {123060},
doi = {10.1016/j.biomaterials.2024.123060},
pmid = {39736219},
issn = {1878-5905},
abstract = {Bacterial implant-associated infections predominantly contribute to the failure of prosthesis implantation. The local biofilm microenvironment (BME), characterized by its hyperacidic condition and high hydrogen peroxide (H2O2) level, inhibits the host's immune response, thereby facilitating recurrent infections. Here, a Janus PEGylated CuS nanoparticle (CuPen) armed engineered Lactobacillus casei (L. casei) denoted as LC@CuPen, is proposed to interfere with bacterial metabolism and arouse macrophage antibiofilm function. Once LC@CuPen reached the BME, NIR irradiation-activated mild heat damages L. casei and biofilm structure. Meanwhile, the BME-responsive LC@CuPen can catalyze local H2O2 to produce toxic •OH, whereas in normal tissues, the effect of •OH production is greatly reduced due to the higher pH and lower H2O2 concentration. The released bacteriocin from damaged L. casei can destroy the bacterial membrane to enhance the penetration of •OH into damaged biofilm. Excessive •OH interferes with normal bacterial metabolism, resulting in reduced resistance of bacteria to heat stress. Finally, under the action of mild heat treatment, the bacterial biofilm lysed and died. Furthermore, the pathogen-associated molecular patterns (PAMPs) in LC@CuPen can induce M1 polarization of macrophages through NF-κB pathway and promote the release of inflammatory factors. Inflammatory factors enhance the migration of macrophages to the site of infection and phagocytose bacteria, thereby inhibiting the recurrence of infection. Generally, this engineered L. casei program presents a novel perspective for the treatment of bacterial implant-associated infections and serves as a valuable reference for future clinical applications of engineered probiotics.},
}

@article {pmid39734766,
year = {2024},
author = {Nazari, M and Hemmati, J and Asghari, B},
title = {Comprehensive Analysis of Virulence Genes, Antibiotic Resistance, Biofilm Formation, and Sequence Types in Clinical Isolates of Klebsiella pneumoniae.},
journal = {The Canadian journal of infectious diseases & medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale},
volume = {2024},
number = {},
pages = {1403019},
pmid = {39734766},
issn = {1712-9532},
abstract = {Background: The rise in multidrug-resistant pathogens poses a formidable challenge in treating hospital-acquired infections, particularly those caused by Klebsiella pneumoniae. Biofilm formation is a critical factor contributing to antibiotic resistance, enhancing bacterial adherence and persistence. K. pneumoniae strains vary in virulence factors, influencing their pathogenicity and resistance profiles. This study aimed to comprehensively analyze virulence factors, antibiotic resistance patterns, and biofilm formation in clinical isolates of K. pneumoniae from Hamadan hospitals. Moreover, the study explored the molecular epidemiological relationships among isolates using multilocus sequence typing (MLST) to uncover the genetic diversity associated with resistance and virulence. Materials and Methods: Between December 2022 and April 2024, 402 K. pneumoniae isolates were collected from clinical samples, including urine, tracheal aspirates, blood, wounds, and abscesses, in teaching hospitals in Hamadan. Initial culturing was performed on blood agar and MacConkey agar, and isolates were identified using biochemical tests. Antimicrobial susceptibility testing followed CLSI, employing the Kirby-Bauer disk diffusion method with 10 antibiotics. Biofilm formation was assessed using the microtiter plate method, and virulence genes were detected by PCR. MLST analysis was conducted on 10 selected isolates based on their virulence gene profiles and resistance patterns. Result: Of the 456 clinical isolates analyzed, 402 (88.15%) were identified as K. pneumoniae, predominantly isolated from tracheal samples (251/402, 62.44%), followed by urine (105/402, 26.12%), blood (30/402, 7.46%), wounds (15/402, 3.73%), and abscesses (1/402, 0.25%). Antibiotic resistance rates revealed high resistance to cefepime (356/402, 88.55%), imipenem (345/402, 85.82%), and ceftazidime (305/402, 75.87%), while resistance to amikacin (165/402, 41.04%) and piperacillin-tazobactam (75/402, 18.65%) was comparatively lower. Biofilm formation varied among the isolates, with 17/402 (4.22%) forming strong biofilms, 104/402 (25.87%) moderate biofilms, 180/402 (44.78%) weak biofilms, and 101/402 (25.12%) showing no biofilm production. Virulence gene analysis indicated high prevalence rates for mrkD (396/402, 98.50%), fimH1 (351/402, 87.31%), and entB (402/402, 100%), while genes like irp-1 (151/402, 37.56%) and irp-2 (136/402, 33.83%) were less common, and hylA and cnf-1 were absent. MLST analysis of 10 selected isolates identified sequence types ST147 (5/10, 50%), ST11 (3/10, 30%), and ST15 (2/10, 20%). Conclusion: K. pneumoniae demonstrates notable biofilm-associated antibiotic resistance, supported by a significant association with XDR strains, along with a diverse array of virulence gene profiles. The study underscores the importance of understanding molecular epidemiology for effective management of hospital infections, emphasizing the need for targeted surveillance and infection control measures.},
}

@article {pmid39734628,
year = {2024},
author = {Li, H and Staxäng, K and Ladak, HM and Agrawal, S and Rask-Andersen, H},
title = {Middle ear biofilm and sudden deafness - a light and transmission electron microscopy study.},
journal = {Frontiers in neurology},
volume = {15},
number = {},
pages = {1495893},
pmid = {39734628},
issn = {1664-2295},
abstract = {BACKGROUND: There still exists controversy about whether the healthy human middle ear mucosa is sterile or if it may harbor a diverse microbiome. Considering the delicacy of the human round window membrane (RWM), different mechanisms may exist for avoiding inner ear pathogen invasion causing sensorineural deafness. We re-analyzed archival human RWMs using light and transmission electron microscopy after decalcification to determine if bacteria are present in clinically normal human middle ears. We also searched for the presence of inborn immune defensive mechanisms within the round window niche (RWN), as previously reported in non-human primate ears.

MATERIALS AND METHODS: Five round window niches, removed and directly fixed at transcochlear petroclival meningioma surgery, were re-investigated after ethical permission using light and transmission electron microscopy. The morphology of the RWM, including its bony attachment and pseudomembrane outline, was analyzed. Moreover, 64 human temporal bones were investigated using synchrotron phase-contrast imaging (SR-PCI) aiming to identify potentially "hidden" spaces, including the RWN potentially harboring infectious material.

RESULTS: Histologic evidence of free-living bacteria and biofilm was found in 40% of RWNs in seemingly "healthy" middle ears. The RWM in these ears was pathologically changed with repealed epithelial and intercellular junctional integrity. Putative membranous defense machinery consisted of a lymphatic drainage system together with free phagocytic cells seemingly serving to protect the inner ear from alleged pathogens. Synchrotron analyses showed that a pseudomembrane was present in the human round window niche (RWN) in 80% of the specimens, of which 20% were complete. In 3%, the RWN contained dense tissue or serous fluid plugs partly obstructing the RWN. Infralabyrinthic clefts and tympanomeningeal fissures (Hyrtl's fissure) were occasionally enclosed by delicate membranes near the round window. These may represent predilection sites for "hidden" infections potentially endangering inner ear function, particularly in connection with round window surgery.

CONCLUSION: Considering the fragility of the normal human RWM, we speculate that occult colonies of biofilm may be a factor in surgeries involving the RWM, sensorineural hearing loss, and hearing preservation/fibrosis following cochlear implantation, and more controversially in hidden perilymph leaks causing sudden deafness and labyrinthine pathology.},
}

@article {pmid39734361,
year = {2024},
author = {Lange, A and Kutwin, M and Zawadzka, K and Ostrowska, A and Strojny-Cieślak, B and Nasiłowska, B and Bombalska, A and Jaworski, S},
title = {Impaired Biofilm Development on Graphene Oxide-Metal Nanoparticle Composites.},
journal = {Nanotechnology, science and applications},
volume = {17},
number = {},
pages = {303-320},
pmid = {39734361},
issn = {1177-8903},
abstract = {PURPOSE: Biofilms are one of the main threats related to bacteria. Owing to their complex structure, in which bacteria are embedded in the extracellular matrix, they are extremely challenging to eradicate, especially since they can inhabit both biotic and abiotic surfaces. This study aimed to create an effective antibiofilm nanofilm based on graphene oxide-metal nanoparticles (GOM-NPs).

METHODS: To create nanofilms, physicochemical analysis was performed, including zeta potential (Zp) (and the nanocomposites stability in time) and size distribution measurements, scanning transmission electron microscopy (STEM), energy dispersive X-ray analysis (EDX), and atomic force microscopy (AFM) of the nanofilm surfaces. During biological analysis, reactive oxygen species (ROS) and antioxidant capacity were measured in planktonic cells treated with the nanocomposites. Thereafter, biofilm formation was checked via crystal violet staining, biofilm thickness was assessed by confocal microscopy using double fluorescent staining, and biofilm structure was analyzed by scanning electron microscopy.

RESULTS: The results showed that two of the three nanocomposites were effective in reducing biofilm formation (GOAg and GOZnO), although the nanofilms were characterized by the roughest surface, indicating that high surface roughness is unfavorable for biofilm formation by the tested bacterial species (Staphylococcus aureus (ATCC 25923), Salmonella enterica (ATCC 13076), Pseudomonas aeruginosa (ATCC 27853)).

CONCLUSION: The performed analysis indicated that graphene oxide may be a platform for metal nanoparticles that enhances their properties (eg colloidal stability, which is maintained over time). Nanocomposites based on graphene oxide with silver nanoparticles and other types of nanocomposites with zinc oxide were effective against biofilms, contributing to changes throughout the biofilm structure, causing a significant reduction in the thickness of the structure, and affecting cell distribution. A nanocomposite consisting of graphene oxide with copper nanoparticles inhibited the biofilm, but to a lesser extent.},
}

@article {pmid39734057,
year = {2024},
author = {Soulaimani, B and Abbad, I and Dumas, E and Gharsallaoui, A},
title = {Enhanced antimicrobial and biofilm disruption efficacy of the encapsulated Thymus pallidus and Lavandula stoechas essential oils and their mixture: A synergistic approach.},
journal = {International journal of pharmaceutics},
volume = {},
number = {},
pages = {125144},
doi = {10.1016/j.ijpharm.2024.125144},
pmid = {39734057},
issn = {1873-3476},
abstract = {The antimicrobial and antibiofilm properties of plant essential oils (EOs) have aroused significant interest for their potential as effective alternatives or supplements in combating microbial infections and biofilm-associated challenges. For these applications, EOs must be encapsulated to overcome some key technical limitations, including high volatility, poor stability, and low solubility. This study aimed to develop microencapsulated EOs derived from two valuable Moroccan medicinal plants, Lavandula stoechas L. and Thymus pallidus Batt., both individually and in combination, using the spray drying method. The antimicrobial and antibiofilm effects of these encapsulated EOs were evaluated against various pathogenic microorganisms using microdilution and crystal violet assays. Key physico-chemical characteristics of the EO microcapsules, including optimal particle size, favorable zeta potential, low water content, and high encapsulation yield and efficiency were observed, indicating strong stability and effective encapsulation. The major chemical compounds identified in the studied EOs were thymol (26.72 %), γ-terpinene (23.26 %), and p-cymene (19.07 %) in T. pallidus EO; and camphor (47.67 %), fenchone (20.78 %), and 1.8-cineole (12.17 %) in L. stoechas EO. The results from antimicrobial assays demonstrated that the encapsulated T. pallidus EO exhibited stronger inhibitory and microbicidal effects against all tested strains, with MIC and MMC values ranging from 0.312 mg/mL to 2.50 mg/mL. The encapsulated EOs combination demonstrated interesting antimicrobial effect, with varying type of interactions depending on the target microorganisms. Additionally, the antibiofilm activity of the microencapsulated EOs combination, evaluated against Staphylococcus aureus, Klebsiella pneumoniae and Bacillus subtilis, showed significant biofilm inhibition with percentages reaching up to 92.68 % at MIC concentration and BIC50 ranging from 0.05 ± 0.00 mg/mL to 0.17 ± 0.01 mg/mL. The eradication of preformed biofilms was also measured, showing a notable effect with eradication rates exceeding 78 % at concentrations of 4MIC, and BEC50 values ranging from 0.16 ± 0.02 mg/mL to 1.30 ± 0.37 mg/mL. Overall, these finding indicate that the encapsulated EO combination derived from these two Moroccan medicinal plants presents a promising formulation capable of overcoming the limitations associated with free EOs and contributing to the fight against antimicrobial resistance and biofilm-related challenges.},
}

@article {pmid39733752,
year = {2024},
author = {Feng, B and Chen, J and Wang, C and Wang, P and You, G and Lin, J and Gao, H},
title = {Removal of ofloxacin and inhibition of antibiotic resistance gene spread during the aerobic biofilm treatment of rural domestic sewage through the micro-nano aeration technology.},
journal = {Journal of hazardous materials},
volume = {486},
number = {},
pages = {137020},
doi = {10.1016/j.jhazmat.2024.137020},
pmid = {39733752},
issn = {1873-3336},
abstract = {Micro-nano aeration (MNA) has great potential for emerging contaminant removal. However, the mechanism of antibiotic removal and antibiotic resistance gene (ARG) spread, and the impact of the different aeration conditions remain unclear. This study investigated the adsorption and biodegradation of ofloxacin (OFL) and the spread of ARGs in aerobic biofilm systems under MNA and conventional aeration (CVA) conditions. Results showed that the MNA increased OFL removal by 17.27 %-40.54 % and decreased total ARG abundance by 36.37 %-54.98 %, compared with CVA. MNA-induced biofilm rough morphology, high zeta potential, and reduced extracellular polymeric substance (EPS) secretion enhanced OFL adsorption. High dissolved oxygen and temperature, induced by MNA-enriched aerobic bacteria and their carrying OFL-degrading genes, enhanced OFL biodegradation. MNA inhibited the enrichment of ARG host bacteria, which acquired ARGs possibly via horizontal gene transfer (HGT). Functional profiles involved in the HGT process, including reactive oxygen species production, membrane permeability, mobile genetic elements (MGEs), adenosine triphosphate synthesis, and EPS secretion, were down-regulated by MNA, inhibiting ARG spread. Partial least-squares path modeling revealed that MGEs might be the main factor inhibiting ARG spread. This study provides insights into the mechanisms by which MNA enhances antibiotic removal and inhibits ARG spread in aerobic biofilm systems.},
}

@article {pmid39733448,
year = {2024},
author = {Zhu, X and Chang, W and Kong, Y and Cai, Y and Huang, Z and Wu, T and Zhang, M and Nie, H and Wang, Y},
title = {Effects of low temperature on the microbial community of MBBR filler biofilm.},
journal = {Water science and technology : a journal of the International Association on Water Pollution Research},
volume = {90},
number = {12},
pages = {3166-3179},
pmid = {39733448},
issn = {0273-1223},
mesh = {*Biofilms ; *Bioreactors/microbiology ; Bacteria/genetics/classification/metabolism ; Cold Temperature ; Waste Disposal, Fluid/methods ; Temperature ; Microbiota ; },
abstract = {Moving bed biofilm reactors can purify urban domestic sewage through microbial biodegradation. High-throughput sequencing was used to study the response mechanism of the biofilm microbial community to temperature. The effluent quality of the reactor declined with the decrease in temperature. Proteobacteria, Bacteroidota, and Nitrospirota were the dominant bacteria, accounting for 59.2, 11.9, and 9.4%, respectively. Gammaproteobacteria (38.3%), Alphaproteobacteria (23.2%), and Bacteroidia (12.4%) were the dominant bacteria at the class level. Low temperature had an obvious directional domestication effect on microbial flora, and the composition of the bacterial community was more similar. Pseudomonas was one of the dominant bacterial groups at 5 °C. Nitrospira (p < 0.001) and Trichococcus (p < 0.05) were significantly negatively correlated with effluent ammonia nitrogen and significantly positively correlated with NO3[-] (p < 0.05) at low temperature. Functional bacteria related to chemoheterotrophy (25.88%) and aerobic_chemoheterotrophy (21.56%) accounted for a relatively high proportion. The bacteria related to nitrate reduction only accounted for 2.62%. Studies have shown that low temperatures can inhibit the growth of nitrogen-cycling bacteria, and few domesticated and selected nitrogen-cycling bacteria play a major role in the removal and transformation of ammonia nitrogen. The degradation of chemical oxygen demand can still be achieved through the adsorption and degradation of dominant functional bacteria.},
}

*Biofilms
*Bioreactors/microbiology
Bacteria/genetics/classification/metabolism
Cold Temperature
Waste Disposal, Fluid/methods
Temperature
Microbiota

@article {pmid39732630,
year = {2024},
author = {Olana, MD and Asrat, D and Swedberg, G},
title = {Antimicrobial resistance profile, biofilm forming capacity and associated factors of multidrug resistance in Pseudomonas aeruginosa among patients admitted at Tikur Anbessa Specialized Hospital and Yekatit 12 Hospital Medical College in Addis Ababa, Ethiopia.},
journal = {BMC infectious diseases},
volume = {24},
number = {1},
pages = {1472},
pmid = {39732630},
issn = {1471-2334},
mesh = {*Biofilms/drug effects/growth & development ; Ethiopia/epidemiology ; Humans ; *Pseudomonas aeruginosa/drug effects/isolation & purification ; *Drug Resistance, Multiple, Bacterial ; Cross-Sectional Studies ; Male ; *Pseudomonas Infections/microbiology/epidemiology ; *Anti-Bacterial Agents/pharmacology ; Female ; Adult ; Middle Aged ; *Microbial Sensitivity Tests ; Young Adult ; Adolescent ; Cross Infection/microbiology/epidemiology ; Child ; Aged ; Hospitals/statistics & numerical data ; Child, Preschool ; Prevalence ; Infant ; },
abstract = {BACKGROUND: Pseudomonas aeruginosa is one of the leading causes of nosocomial infections and the most common multidrug-resistant pathogen. This study aimed to determine antimicrobial resistance patterns, biofilm-forming capacity, and associated factors of multidrug resistance in P. aeruginosa isolates at two hospitals in Addis Ababa, Ethiopia.

METHODS: A cross-sectional study was conducted from August 2022 to August 2023 at Tikur Anbessa Specialized Hospital and Yekatit 12 Hospital Medical College. Culture and identification of P. aeruginosa were done using standard microbiological methods. An antimicrobial susceptibility test was done by Kirby-Bauer disk diffusion according to CLSI recommendations. The microtiter plate assay method was used to determine biofilm-forming capacity. SPSS version 25 was used for data analysis. Bivariate and multivariable logistic regression were used to assess factors associated with multidrug resistance in P. aeruginosa. The Spearman correlation coefficient (rs = 0.266)) was performed to evaluate the relationship between biofilm formation and drug resistance.

RESULTS: The overall prevalence of P. aeruginosa was 19.6%. High levels of resistance were observed for ciprofloxacin (51.8%), ceftazidime (50.6%), and cefepime (48.2%). The level of multidrug-resistance was 56.6%. The isolates showed better susceptibility to ceftazidime-avibactam (95.2%) and imipenem (79.5%). Overall, 95.2% of P. aeruginosa were biofilm-producing isolates, and 27.7% and 39.8% of isolates were strong and moderate biofilm producers, respectively. A positive correlation and statistically significant relationship was observed between resistance to multiple drugs and the level of biofilm formation (rs = 0.266; p-value = 0.015). Previous history of exposure to ciprofloxacin (OR, 5.1; CI, 1.12-24.7, p-value, 0.032) was identified as an independent associated factor for multidrug resistance in P. aeruginosa.

CONCLUSION: The present study indicates an association between multidrug resistance in P. aeruginosa and its biofilm formation capabilities. Additionally, over half of the isolates were resistant to multiple drugs, with prior use of ciprofloxacin linked to the development of multidrug-resistance. These findings suggest that antibiotic stewardship programs in hospital settings may be beneficial in addressing resistance.},
}

*Biofilms/drug effects/growth & development
Ethiopia/epidemiology
Humans
*Pseudomonas aeruginosa/drug effects/isolation & purification
*Drug Resistance, Multiple, Bacterial
Cross-Sectional Studies
Male
*Pseudomonas Infections/microbiology/epidemiology
*Anti-Bacterial Agents/pharmacology
Female
Adult
Middle Aged
*Microbial Sensitivity Tests
Young Adult
Adolescent
Cross Infection/microbiology/epidemiology
Child
Aged
Hospitals/statistics & numerical data
Child, Preschool
Prevalence
Infant

@article {pmid39732619,
year = {2024},
author = {Jeong, SY and Lee, JW and Kim, EJ and Lee, CW and Kim, TG},
title = {Comparison of crystal violet staining, microscopy with image analysis, and quantitative PCR to examine biofilm dynamics.},
journal = {FEMS microbiology letters},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsle/fnae115},
pmid = {39732619},
issn = {1574-6968},
abstract = {Crystal-violet staining, microscopy with image analysis, and quantitative PCR (qPCR) were compared to examine biofilm dynamics. Biofilms of 30 polycultures comprising 15 bacterial species were monitored for 14 days. Collectively, qPCR (representing population) revealed a different growth pattern compared to staining (biomass) and microscopy (colonization): biomass and colonization gradually increased over time, whereas population increased rapidly for the first seven days and leveled off. Temporal forms were categorized into two growth patterns: continuous increase (CI) and non-continuous increase (NCI). Staining and microscopy showed similar odds of detecting the CI pattern (27 and 23 polycultures, respectively) across polycultures, greater than that of qPCR (14 polycultures) (P < 0.05). All three methods revealed the identical patterns for 13 polycultures. Staining with microscopy, staining with qPCR, and microscopy with qPCR found the same patterns in 22, 15, and 19 polycultures, respectively. Additionally, staining was quantitatively agreed with microscopy (P < 0.05; R2 > 0.50), whereas neither staining nor microscopy strongly agreed with qPCR (P < 0.05; R2 ≤ 0.22). Collectively, staining was more compatible with microscopy than qPCR in characterizing biofilm dynamics and quantifying biofilms owing to the difference between population growth and biofilm expansion. The concurrent use of qPCR with biomass estimations allows for accurate and comprehensive biofilm quantification.},
}

@article {pmid39732373,
year = {2024},
author = {Yin, S and Wang, YX and Hou, C and Wang, J and Xu, J and Jiang, X and Chen, D and Mu, Y and Shen, J},
title = {Deciphering the key role of biofilm and mechanisms in high-strength nitrogen removal within the anammox coupled partial S[0]-driven autotrophic denitrification system.},
journal = {Bioresource technology},
volume = {419},
number = {},
pages = {132020},
doi = {10.1016/j.biortech.2024.132020},
pmid = {39732373},
issn = {1873-2976},
abstract = {Anammox coupled partial S[0]-driven autotrophic denitrification (PS[0]AD) technology represents an innovative approach for removing nitrogen from wastewater. The research highlighted the crucial role of biofilm on sulfur particles in the nitrogen removal process. Further analysis revealed that sulfur-oxidizing bacteria (SOB) are primarily distributed in the inner layer of the biofilm, while anammox bacteria (AnAOB) are relatively evenly distributed in inner and outer layers, with Thiobacillus and Candidatus Brocadia being the dominant species, respectively. Except for anammox and PS[0]AD processes, [15]N isotope labeling tests determined that sulfur reshaped nitrogen metabolism pathways, providing solid evidence for the occurrence of sulfammox process. SOB and AnAOB collaborate in nitrogen and sulfur conversion, with SOB-drived PS[0]AD processes reducing nitrate to nitrite for AnAOB to remove ammonia. Conversely, the nitrate produced from anammox process can be reused by SOB. Metagenomic analyses verified that SOB drove the PS[0]AD process through encoding soxBYZ gene, while AnAOB might play an important role in simultaneously driving the anammox and sulfammox processes. These findings underscore the importance of biofilm and clarify the nitrogen-sulfur cycle mechanisms within the coupled system.},
}

@article {pmid39732217,
year = {2024},
author = {Li, L and Zhang, J and Zhang, Y and Zhao, R and Yang, F and Yan, Y and Wang, Q and Xie, M},
title = {Biofilm-modified Prussian blue improves memory function in late-stage Alzheimer's disease mice with triple therapy.},
journal = {International journal of pharmaceutics},
volume = {670},
number = {},
pages = {125112},
doi = {10.1016/j.ijpharm.2024.125112},
pmid = {39732217},
issn = {1873-3476},
abstract = {Alzheimer's disease (AD) is a neurodegenerative disease that is significantly characterized by cognitive and memory impairments, which worsen significantly with age. In the late stages of AD, metal ion disorders and an imbalance of reactive oxygen species (ROS) levels occur in the brain microenvironment, which causes abnormal aggregation of β-amyloid (Aβ), leading to a significant worsening of the AD symptoms. Therefore, we designed a composite nanomaterial of macrophage membranes-encapsulated Prussian blue nanoparticles (PB NPs/MM). Prussian blue nanoparticles (PB NPs) are capable of chelating Cu[2+] and reducing ROS. Macrophage membranes (MM) have advantages over liposomal and erythrocyte membrane carriers, including inflammatory targeting capabilities and more effective immune evasion. Concurrently, the excellent photothermal ability of PB NPs can briefly open the blood-brain barrier (BBB) under near-infrared laser irradiation, which improves the transport efficiency of PB NPs/MM across the BBB and ablates Aβ deposition, thus achieving optimal therapeutic efficacy. In vitro experiments demonstrated that PB NPs/MM is a multifunctional nanosystem, which can effectively inhibit Cu[2+]-induced Aβ monomers aggregation, photothermally depolymerize Aβ fibrils, and attenuate oxidative stress through the combined treatment of chelating metals, photothermal therapy and scavenging ROS. In behavioral experiments, it also significantly improved the cognitive and learning deficits in late-stage APP/PS1 mice, thereby providing new ideas for the treatment of late-stage AD and other neurodegenerative diseases.},
}

@article {pmid39731595,
year = {2024},
author = {Yazdanpanah, S and Shafiekhani, M and Emami, M and Khodadadi, H and Pakshir, K and Zomorodian, K},
title = {Exploring the anti-biofilm and gene regulatory effects of anti-inflammatory drugs on Candida albicans.},
journal = {Naunyn-Schmiedeberg's archives of pharmacology},
volume = {},
number = {},
pages = {},
pmid = {39731595},
issn = {1432-1912},
abstract = {Researchers have repurposed several existing anti-inflammatory drugs as potential antifungal agents in recent years. So, this study aimed to investigate the effects of anti-inflammatory drugs on the growth, biofilm formation, and expression of genes related to morphogenesis and pathogenesis in Candida albicans. The minimum inhibitory concentration (MIC) of anti-inflammatory drugs was assessed using the broth microdilution method. Biofilm formation in C. albicans was evaluated using XTT reduction assay following exposure to different concentrations of drugs. Additionally, the expression of adhesin-related genes (ALS1, ALS3), hyphal cell wall specific genes (EAP1, HWP1), secreted aspartyl proteinase (SAP4, SAP6), and morphogenesis pathway regulatory gene (EFG1) was analyzed using quantitative RT-PCR. Betamethasone and dexamethasone markedly inhibited C. albicans biofilm formation by up to 80% at a concentration of 2 mg/mL. Moreover, the inhibition of C. albicans biofilm formation was significant at concentrations ranging from 0.6 to 10 mg/mL for piroxicam and from 0.75 to 12 mg/mL for diclofenac. The expression of key genes involved in biofilm formation including EFG1, HWP1, and ALS3 was all downregulated under hyphae-inducing conditions. Moreover, the expression proteinase genes of C. albicans were upregulated following exposure with corticosteroids. The data obtained provides valuable insights into the antifungal potential of anti-inflammatory drugs. Our novel findings indicate the downregulation of several Candida genes that are crucial for morphogenesis, pathogenesis, and biofilm formation. However, further research is necessary to fully elucidate the clinical applications and effectiveness of anti-inflammatory drugs as alternative or adjunctive therapies for Candida infections.},
}

@article {pmid39729737,
year = {2024},
author = {Dey, S and Nayak, AK and Rajaram, H and Das, S},
title = {Exploitative stress within Bacillus subtilis biofilm determines the spatial distribution of pleomorphic cells.},
journal = {Microbiological research},
volume = {292},
number = {},
pages = {128034},
doi = {10.1016/j.micres.2024.128034},
pmid = {39729737},
issn = {1618-0623},
abstract = {Bacteria commonly live in a spatially organized biofilm assemblage. The metabolic activity inside the biofilm leads to segmented physiological microenvironments. In nature, bacteria possess several pleomorphic forms to withstand certain ecological alterations. We hypothesized that pleomorphism also exists within the biofilm, which can be considered as the fundamental niche for bacteria. We report a distinct pattern of cell size variation throughout the biofilm of Bacillus subtilis. Cell size heterogeneity was observed in biofilm development, wherein the frequency of long cells is higher in outer regions, whereas lower in inner regions. Moreover, compared to planktonic cells, bacteria in the biofilm mode reduce their geometric ratio from 8.34 to 3.69 and 2.65 in the outer and inner regions, respectively. There were no significant differences observed in nutrient diffusion from the outer to the inner region, and more than 73 % of cells in the inner region were viable. However, the inner and middle regions were more acidic than the outer of the biofilm. Conclusively, growth rate-independent cell size reduction at low pH suggests that the resulting phenotype switching within biofilm was observed due to the pH gradient of neutral to acidic from the outer to the core of the biofilm. This gradient of H[+] ions concentration may create exploitative stress within the biofilm, which could favor specific pleomorphic cells to thrive in their specialized niches. By understanding the cell size variation in response to the local environment, we propose a model of biofilm formation by pleomorphic cells.},
}

@article {pmid39727871,
year = {2024},
author = {Wu, W and Hong, H and Lin, J and Yang, D},
title = {Antimicrobial Responses to Bacterial Metabolic Activity and Biofilm Formation Studied Using Microbial Fuel Cell-Based Biosensors.},
journal = {Biosensors},
volume = {14},
number = {12},
pages = {},
pmid = {39727871},
issn = {2079-6374},
support = {2021J01313//Natural Science Foundation of Fujian Province/ ; },
mesh = {*Biofilms/drug effects ; *Biosensing Techniques ; *Bioelectric Energy Sources ; *Pseudomonas aeruginosa/drug effects ; *Silver/pharmacology ; *Metal Nanoparticles ; Anti-Bacterial Agents/pharmacology ; },
abstract = {Simultaneous monitoring of antimicrobial responses to bacterial metabolic activity and biofilm formation is critical for efficient screening of new anti-biofilm drugs. A microbial fuel cell-based biosensor using Pseudomonas aeruginosa as an electricigen was constructed. The effects of silver nanoparticles (AgNPs) on the cellular metabolic activity and biofilm formation of P. aeruginosa in the biosensors were investigated and compared with the traditional biofilm detection method. The crystal violet staining results showed that the concentration of AgNPs being increased to 20 and 40 μg/mL had a slight and obvious inhibitory effect on biofilm formation, respectively. In comparison, the detection sensitivity of the biosensor was much higher. When the concentration of AgNPs was 5 μg/mL, the output voltage of the biosensor was suppressed, and the inhibition gradually increased with the AgNPs dose. AgNPs inhibited the activity of planktonic cells in the anolyte and the formation of biofilm on the anode surface, and it had a dose-dependent effect on the secretion of phenazine in the anolyte. The biosensor could monitor the impacts of AgNPs not only on biofilm formation but also on cell activity and metabolic activity. It provides a new and sensitive method for the screening of anti-biofilm drugs.},
}

*Biofilms/drug effects
*Biosensing Techniques
*Bioelectric Energy Sources
*Pseudomonas aeruginosa/drug effects
*Silver/pharmacology
*Metal Nanoparticles
Anti-Bacterial Agents/pharmacology

@article {pmid39727743,
year = {2024},
author = {Matsumoto, S and Tatsuoka, H and Yoshii, M and Nagao, T and Shimizu, T and Shingubara, S and Tanaka, S and Ito, T},
title = {Anti-Biofilm Performance of Resin Nanopillars Inspired from Cicada Wing Surface for Staphylococcus spp.},
journal = {Biomimetics (Basel, Switzerland)},
volume = {9},
number = {12},
pages = {},
pmid = {39727743},
issn = {2313-7673},
support = {21H01773//Japan Society for the Promotion of Science/ ; },
abstract = {The increase in infections derived from biofilms from Staphylococcal spp. prompted us to develop novel strategies to inhibit biofilm development. Nanoscale protrusion structures (nanopillars) observed on the wings of dragonflies and cicadas have recently gained notable attention owing to their physical, antimicrobial, and bactericidal properties. Thus, they are not only expected to reduce the damage caused by chemical antimicrobial agents to human health and the environment, but also to serve as a potential countermeasure against the emergence of antimicrobial-resistant bacteria (ARB). In this study, we evaluated the anti-biofilm effects of cyclo-olefin polymer (COP) nanopillars by changing the wettability of surfaces ranging in height from 100 to 500 nm against Staphylococcus spp., such as Staphylococcus aureus NBRC 100910 (MSSA), Staphylococcus aureus JCM 8702 methicillin-resistant S. aureus (MRSA), and Staphylococcus epidermidis ATCC 35984. The results clearly show that the fabricated nanopillar structures exhibited particularly strong biofilm inhibition against MRSA, with inhibition rates ranging from 51.2% to 62.5%. For MSSA, anti-biofilm effects were observed only at nanopillar heights of 100-300 nm, with relatively low hydrophobicity, with inhibition rates ranging from 23.9% to 40.8%. Conversely, no significant anti-biofilm effect was observed for S. epidermidis in any of the nanopillar structures. These findings suggest that the anti-biofilm properties of nanopillars vary among bacteria of the same species. In other words, by adjusting the height of the nanopillars, selective anti-biofilm effects against specific bacterial strains can be achieved.},
}

@article {pmid39726405,
year = {2024},
author = {Sakava, P and Nyemb, JN and Matchawe, C and Kumcho, MP and Tagatsing, MF and Nsawir, BJ and Talla, E and Atchadé, AT and Laurent, S and Henoumont, C},
title = {Chemical constituents and antibacterial activities of Cameroonian dark brown propolis against potential biofilm-forming bacteria.},
journal = {Natural product research},
volume = {},
number = {},
pages = {1-14},
doi = {10.1080/14786419.2024.2437024},
pmid = {39726405},
issn = {1478-6427},
abstract = {Propolis is a resinous material collected by different bee species from various plant exudates and used to seal holes in honeycombs, smoothen the internal walls, embalm intruders, improve health and prevent diseases. From its n-hexane extract, eight compounds were isolated and characterised as: mangiferonic acid (1); 1-hydroxymangiferonic acid (2), new natural product; mangiferolic acid(3); 27-hydroxymangiferolic acid (4), reported here for the first time as propolis constituent; 27-hydroxymangiferonic acid (5); α-amyrin (6); β-amyrin (7) and lupeol (8). The chemical structures of the isolated compounds were elucidated using spectroscopic methods, such as 1D and 2D-NMR, mass spectrometry and comparison with previous published reports. Compounds 6-8 and n-hexane extract were tested against Gram-negative and Gram-positive bacteria strains using agar disc diffusion and macrodilution techniques. Interestingly, n-hexane extract and compounds 6-8 had good inhibitory activities against Methicillin Resistant Staphylococcus aureus (MRSA) and the clinical Klebsiella pneumoniae isolates. The biological effects of n-hexane extract and its fraction against K. pneumoniae 12 CM and MRSA revealed in the present study suggest that the Cameroonian dark brown propolis could be a potential alternative management of biofilms on medical devices and respiratory skin or infections.},
}

@article {pmid39725043,
year = {2024},
author = {Mumin, YM and Yüksel, G and Özad Düzgün, A},
title = {Investigation of virulence factor genes and biofilm formation of antibiotic resistant clinical E.coli isolates.},
journal = {Microbial pathogenesis},
volume = {199},
number = {},
pages = {107257},
doi = {10.1016/j.micpath.2024.107257},
pmid = {39725043},
issn = {1096-1208},
abstract = {PURPOSE: The aim of this study is to investigate the antibiotic sensitivity, presence of virulence genes and biofilm formation capacity of 90 clinical E. coli isolates.

METHODS: The presence of virulence genes in E.coli isolates were investigated by PCR. Ninety clinical isolates of E.coli were subjected to biofilm quantitative analysis using the semi-quantitative crystal violet staining method.

RESULTS: it was observed that the isolates were resistant to quinolone, cephalosporin, aminoglycoside, carbapenem and penicillin group antibiotics. The presence of virulence factor genes were observed in a total of 86/90 E. coli. The highest rate of fim (92.2 %) virulence factor gene was detected in the strains. Afa, pap, cnf, sfa, hly were detected in 30 %, 13 %, 13 %, 3.3 %, 2.2 % respectively. Also, 13 different virulence factor gene patterns were determined in 90 E. coli isolates. Of the 90 E. coli isolates whose biofilm-forming capacities were evaluated, 42 were found to have biofilm-forming capacity. Of these 26 (28.8 %) the weak, 12 (13.3 %) moderate and 4 (4.4 %) strong biofilm-forming. Also, statistical analysis was performed to investigate the relationship between virulence factor genes and biofilm formation, and none of the 7 genes analyzed showed a significant relationship with biofilm formation.

CONCLUSION: since pathogenic E. coli is an important public health problem, investigating antibiotic resistance, virulence factor genes and biofilm formation in bacterial pathogens is important for better treatment options.},
}

@article {pmid39723739,
year = {2024},
author = {Wang, JL and Pan, X and Li, X and Liu, KM and Yao, M and An, JY and Wan, Y and Yu, XQ and Feng, S and Wu, MY},
title = {Photoimmunologic Therapy of Stubborn Biofilm via Inhibiting Bacteria Revival and Preventing Reinfection.},
journal = {Advanced materials (Deerfield Beach, Fla.)},
volume = {},
number = {},
pages = {e2411468},
doi = {10.1002/adma.202411468},
pmid = {39723739},
issn = {1521-4095},
support = {22177094//National Natural Science Foundation of China/ ; 22174117//National Natural Science Foundation of China/ ; YJ202419//Fundamental Research Funds for the Central Universities/ ; },
abstract = {Stubborn biofilm infections pose serious threats to public health. Clinical practices highly rely on mechanical debridement and antibiotics, which often fail and lead to persistent and recurrent infections. The main culprits are 1) persistent bacteria reviving, colonizing, and rejuvenating biofilms, and 2) secondary pathogen exposure, particularly in individuals with chronic diseases. Addressing how to inhibit persistent bacteria revival and prevent reinfection simultaneously is still a major challenge. Herein, an oligo-ethylene glycol-modified lipophilic cationic photosensitizer (PS), TBTCP-PEG7, is developed. It effectively eradicates Methicillin-Resistant Staphylococcus aureus (MRSA) under light irradiation. Furthermore, TBTCP-PEG7-mediated photodynamic therapy (PDT) not only conquers stubborn biofilm infections by downregulating the two-component system (TCS), quorum sensing (QS), and virulence factors, thereby reducing intercellular communication, inhibiting persistent bacterial regrowth and biofilm remodeling but also prevents reinfection by upregulating heat shock protein-related genes to induce immunogenetic cell death (ICD) and establish immune memory. In vivo, TBTCP-PEG7 efficiently eradicates MRSA biofilm adhered to medical catheters, stimulates angiogenesis, reduces inflammatory factor expression, and accelerates wound healing. Furthermore, ICD promotes short-term immune and long-term immunological memory for coping with secondary infections. This two-pronged strategy not only effectively overcomes stubborn, persistent and recurrent biofilm infection, but also provides theoretical guidance for designing the next generation of antibacterial materials.},
}

@article {pmid39723738,
year = {2024},
author = {Yao, K and Cheung, SW and Tang, Y and Dong, J and Feng, S and Xu, J and Xiang, L and Zhou, X},
title = {Photoelectron Therapy Preventing the Formation of Bacterial Biofilm on Titanium Implants.},
journal = {Small (Weinheim an der Bergstrasse, Germany)},
volume = {},
number = {},
pages = {e2409824},
doi = {10.1002/smll.202409824},
pmid = {39723738},
issn = {1613-6829},
support = {82370996//National Natural Science Foundation of China/ ; 22108179//National Natural Science Foundation of China/ ; 82170997//National Natural Science Foundation of China/ ; YJ202081//Fundamental Research Funds for the Central Universities in China/ ; 2024NSFSC0537//Sichuan Province Science and Technology Support Program/ ; },
abstract = {The exogenous bacterial infection and formation of biofilm on the surface of titanium implants can affect the adhesion, proliferation, and differentiation of cells associated with osteogenesis, ultimately leading to surgical failure. This study focuses on two critical stages for biofilm formation: i) bacterial adhesion and aggregation, ii) growth and proliferation. The titanium with well-organized titania nanotube arrays is first modified by nitrogen dopants, then loaded with CuFeSe2 nanoparticles to form a p-n heterojunction. Such heterojunction can effectively separate the electrons and holes generated by CuFeSe2 under NIR excitation, where CuFeSe2 serves as an electron acceptor from adherent bacteria, thus disrupting the respiratory chain and eventually affecting the metabolism. Combined with the released ions in solution and photothermal effect, the formation of bacterial biofilm on the surface of titanium implants is prevented on both stages.},
}

@article {pmid39723056,
year = {2024},
author = {Quradha, MM and Tamfu, AN and Duru, ME and Kucukaydin, S and Iqbal, M and Qahtan, AMF and Khan, R and Ceylan, O},
title = {Evaluation of HPLC Profile, Antioxidant, Quorum Sensing, Biofilm, Swarming Motility, and Enzyme Inhibition Activities of Conventional and Green Extracts of Salvia triloba.},
journal = {Food science & nutrition},
volume = {12},
number = {12},
pages = {10716-10733},
pmid = {39723056},
issn = {2048-7177},
abstract = {The current study aims to prepare a green extract using a new method in addition to conventional extraction methods including; methanolic and ultrasonic extraction of Salvia triloba, to compare their phenolic composition utilizing high-performance liquid chromatograph equipped with a diode array detector (HPLC-DAD), anti-bacterial, anti-oxidant, and enzyme inhibition activities. The results of HPLC-DAD analysis showed that Rosmarinic acid was found the highest amount in the methanolic extract followed by ultrasonic and green extracts as 169.7 ± 0.51, 135.1 ± 0.40, and 28.58 ± 0.46 μg/g respectively. The Trans-cinnamic acid (4.40 ± 0.09 μg/g) was found exclusively in ultrasonic extract. For bioactivities, the green extract exhibited the highest biofilm inhibition against Enterococcus faecalis compared to other extracts, while the methanolic extract outperformed both ultrasonic-assisted and green extract against Staphylococcus aureus and Escherichia coli strains at minimum inhibitory concentration. The methanolic and green extract exhibited considerable quorum sensing inhibition against Chromobacterium violaceum CV026, while no activity was recorded from ultrasonic-assisted extract. The methanolic and ultrasonic-assisted extracts of S. triloba recorded moderate butyrylcholinesterase inhibition; each extract demonstrated limited inhibitory effects on the urease enzyme. Similarly, each extract of S. triloba demonstrated significant antioxidant activity, with the highest activity exhibited by methanolic extract as β-carotene-linoleic acid assay (IC50 = 10.29 ± 0.36 μg/mL), DPPH[•] assay (IC50 = 27.77 ± 0.55 μg/mL), ABTS[•+] assay (IC50 = 15.49 ± 0.95 μg/mL), metal chelating assay (IC50 = 57.80 ± 0.95 μg/mL), and CUPRAC (assay A 0.50 = 32.54 ± 0.84 μg/mL). Furthermore, the methanolic extract exhibited antioxidant activity better than α-tocopherol (Standard used). The current study demonstrated the potential of green solvent(s) as eco-friendly alternative for extractin phenolic compounds from S. triloba and evaluated their biological activities for the first time.},
}

@article {pmid39723028,
year = {2024},
author = {López-García, E and Benítez-Cabello, A and Arroyo-López, FN},
title = {Effects of Phenolic Compounds on Biofilm Formation by Table Olive-Related Microorganisms.},
journal = {Food science & nutrition},
volume = {12},
number = {12},
pages = {10924-10932},
pmid = {39723028},
issn = {2048-7177},
abstract = {The process of biofilm formation during table olive fermentation is crucial to turning this fermented vegetable into a probiotic food. Some phenolic compounds have been described as important quorum-sensing molecules during biofilm development. The present in vitro study examined the effects of three phenolic compounds widely found in table olive fermentations (Oleuropein 0-3000 ppm, Hydroxytyrosol 0-3000 ppm, and Tyrosol 0-300 ppm) on the development of single biofilm by diverse microorganisms isolated from table olives (Lactiplantibacillus pentosus 13B4, Lp119, and LPG1; Lactiplantibacillus plantarum Lp15 and LAB23; and yeasts Wickerhamomyces anomalus Y12, Candida boidinii Y13, and Saccharomyces cerevisiae Y18). Biofilm formation was quantified in vitro by crystal violet staining in microtiter plates after incubation at 30°C for 96 h. A clear tendency to decrease the biofilm production was observed for the L. plantarum strains when any of the three phenolic compounds were added to the medium, which was statistically significant (p ≤ 0.05) for certain concentrations and phenols. In the case of yeasts, no statistical influence on biofilm formation was noticed when the phenolic compounds were dosed to the culture medium. Finally, the effects of the phenolic compounds on the L. pentosus strains were dependent on the strain assayed. Thereby, addition of phenolic compounds on 13B4 or Lp119 strains did not have statistical influence on biofilm production. On the contrary, the probiotic LPG1 strain noticed a statistical increase in biofilm production when a low concentration of tyrosol (50 ppm) was added to the medium. Results obtained in this work could be useful to control the biofilm formation process on olive epidermis during table olive fermentation to include beneficial microorganisms.},
}

@article {pmid39722993,
year = {2024},
author = {Jaisal, S and Singh, A and Verma, RK and Ram, VS and Verma, SK and Yadav, H and Prakash, V},
title = {Evaluation of biofilm formation and carbapenem resistance in Klebsiella pneumoniae isolated from clinical samples at a rural hospital in western Uttar Pradesh.},
journal = {Journal of family medicine and primary care},
volume = {13},
number = {11},
pages = {4894-4900},
pmid = {39722993},
issn = {2249-4863},
abstract = {INTRODUCTION: Klebsiella pneumoniae commonly causes healthcare-associated infections and shows multidrug resistance. K. pneumoniae can produce biofilm. Carbapenem resistance in K. pneumoniae is due to the production of carbapenemases mainly. This study was done to evaluate the formation of biofilm and carbapenemase resistance in K. pneumoniae isolates.

MATERIAL AND METHODS: A total of 110 K. pneumoniae isolated from various clinical samples were taken, the antibiotic susceptibility test was done by the Kirby disk diffusion method, and biofilm detection was done by the tissue culture plate method. All the carbapenem-resistant isolates were confirmed by multiplex real-time PCR (mPCR). Those found positive for any of the carbapenemase genes were tested by the modified Hodge test (MHT), modified carbapenem inactivation method (mCIM), and ethylenediamine tetraacetic acid (EDTA)-modified carbapenem inactivation method (eCIM).

RESULTS: Out of 110 isolates, 66% (72/110) were carbapenem-resistant (suggestive of carbapenemase producers) by Kirby-Bauer disk diffusion but 58% (42/72) of Klebsiella isolates were confirmed for carbapenemase production by mPCR. Maximum number of carbapenemase gene were New Delhi metallo-β-lactamase (NDM) 52% (N = 22), 29% (N = 12) coproducers (NDM+OXA-48), and lowest in oxacillinase (OXA-48), 19% (N = 8). The overall sensitivity of MHT and mCIM+eCIM was 62% and 93%, and specificity was 88% and 97%, respectively. Our study showed that moderate biofilm producers were 51% (N = 56) K. pneumoniae isolates, strong biofilm producers 27% (N = 30), and 22% (N = 30) were weak/non-biofilm producers. We also found the correlation between biofilm formation and carbapenem-resistant K. pneumoniae (CR-KP) genes was statistically significant with a P value of 0.01*<0.05.

CONCLUSION: Most isolates of K. pneumoniae demonstrated a wide range of antibiotic resistance and were biofilm producers. Our results indicated that the combination of mCIM with eCIM showed high sensitivity and specificity to detect CR-KP compared with MHT.},
}

@article {pmid39722480,
year = {2024},
author = {Lekkala, VV and SirigiReddy, B and Lomada, D and Reddy, MC},
title = {Synthesis and Characterization of Silver and Zinc Nanoparticles from Vitex altissima: Comparative Analysis of Anti-oxidant, Anti-inflammatory, Anti-bacterial and Anti-biofilm Activities.},
journal = {Chemistry & biodiversity},
volume = {},
number = {},
pages = {e202402166},
doi = {10.1002/cbdv.202402166},
pmid = {39722480},
issn = {1612-1880},
abstract = {Metal nanoparticles have attained much popularity due to their low toxicity, economic feasibility, and eco-friendly nature. The present study focuses on the synthesis of silver and zinc nanoparticles from Vitex altissima leaf extract, further characterized by UV/Vis spectral analysis, Powder-XRD, FE-SEM, FTIR, TEM, DLS, and Zeta potential. Synthesized silver and zinc nanoparticles were screened for anti-oxidant, anti-inflammatory, anti-bacterial, and anti-biofilm activities. AgNPs exhibited moderate anti-oxidant activities compared to ZnNPs which were studied using DPPH and ABTS assays. The anti-inflammatory effect was assessed using membrane stabilization and human red blood cell methods. Furthermore, both nanoparticles AgNPs and ZnNPs exhibited antibiofilm activity against four MDR bacterial strains Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia and Pseudomonas aeruginosa. Synthesized nanoparticles show anti-bacterial activity. Our data suggest that silver nanoparticles exhibited moderate activity compared to ZnNPs. These nanoparticles could act as potential anti-oxidant, anti-inflammatory, anti-bacterial and anti-inflammatory agents.},
}

@article {pmid39722442,
year = {2024},
author = {Huang, Y and Yu, S and Liu, S and Zhao, X and Chen, X and Wei, X},
title = {Autophagy Activated by Atg1 Interacts With Atg9 Promotes Biofilm Formation and Resistance of Candida albicans.},
journal = {Journal of basic microbiology},
volume = {},
number = {},
pages = {e2400603},
doi = {10.1002/jobm.202400603},
pmid = {39722442},
issn = {1521-4028},
support = {//This work was supported by the National Natural Science Foundation of China (grant number 81970945). The recipient of this fund is Xin Wei./ ; },
abstract = {Autophagy regulates the development of Candida albicans (C. albicans) biofilms and their sensitivity to antifungals. Atg1, a serine/threonine protein kinase, recruits autophagy-related proteins for autophagosome formation. Atg9, the only transmembrane protein, is phosphorylated by Atg1 during autophagy. The specific roles of Atg1 and Atg9 in biofilm formation and resistance of C. albicans remain unclear. The study used RT-qPCR and Western blotting to assess the correlation between Atg1, Atg9 and biofilm formation, XTT reduction assays to evaluate biofilm formation and antifungal resistance, commercial kits to detect reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and autophagy activity, transmission electron microscopy (TEM) to study the morphological changes, protein-protein interaction (PPI) analysis to analyze the interaction between Atg1 and Atg9. Results demonstrated that Atg1 and Atg9 were highly expressed in biofilms than planktonic cells. Biofilm formation, antifungal resistance, MMP and autophagy activity decreased and ROS increased in atg1Δ/Δ and atg9Δ/Δ. TORC1 inhibition with rapamycin rescued the reduced biofilm formation of atg1Δ/Δ and increased antifungal resistance of atg1Δ/Δ and atg9Δ/Δ. PPI analysis and TEM observation indicated that Atg1 interacted with Atg9, which was certified by RT-qPCR and Western blotting. This study suggested that Atg1 interacts with Atg9, activates the autophagy regulating the formation and sensitivity of C. albicans biofilms.},
}

@article {pmid39721302,
year = {2024},
author = {Taha, AB},
title = {Bacteriological profile, antibiotic susceptibility, and biofilm formation in children with chronic suppurative otitis media.},
journal = {International journal of pediatric otorhinolaryngology},
volume = {188},
number = {},
pages = {112208},
doi = {10.1016/j.ijporl.2024.112208},
pmid = {39721302},
issn = {1872-8464},
abstract = {BACKGROUND: Chronic suppurative otitis media is predominantly caused by aerobic bacterial infections, complicated by antibiotic-resistant strains and biofilm formation. This study aims to identify the aerobic bacterial pathogens in chronic suppurative otitis media among children and assess their antibiotic susceptibility patterns. The potential link between biofilm formation and antibiotic resistance is also evaluated.

METHODS: A cross-sectional study was conducted on 457 children with chronic suppurative otitis media. Middle ear discharge samples were collected and aerobic bacteria were isolated and identified using standard microbiological methods. Antibiotic susceptibility was determined by the agar dilution method, and biofilm formation was assessed using the microtiter plate assay.

RESULTS: Of the 457 cases, 89.72 % were monomicrobial infections. The most prevalent Gram-negative bacterium was Pseudomonas aeruginosa (35.71 %), while Staphylococcus aureus (26.27 %) was the leading Gram-positive pathogen. Pseudomonas aeruginosa demonstrated high resistance, with 96.77 % resistant to cefuroxime and 92.26 % to amoxicillin/clavulanic acid. Similarly, Staphylococcus aureus showed significant resistance to ampicillin (83.33 %) and amoxicillin (78.07 %). A strong correlation (p < 0.001) was observed between biofilm formation and antibiotic resistance, with Gram-negative bacteria resisting an average of 4.24 ± 1.769 antibiotics and Gram-positive bacteria resisting 5.13 ± 1.535 antibiotics.

CONCLUSION: A high prevalence of antibiotic-resistant pathogens has been observed in children with chronic suppurative otitis media, with a significant association between biofilm formation and antibiotic resistance.},
}

@article {pmid39720794,
year = {2024},
author = {González, JF and Laipply, B and Sadowski, VA and Price, M and Gunn, JS},
title = {Functional role of the biofilm regulator CsgD in Salmonella enterica sv. Typhi.},
journal = {Frontiers in cellular and infection microbiology},
volume = {14},
number = {},
pages = {1478488},
pmid = {39720794},
issn = {2235-2988},
mesh = {*Biofilms/growth & development ; *Bacterial Proteins/genetics/metabolism ; *Gene Expression Regulation, Bacterial ; Salmonella typhi/genetics/metabolism/physiology ; Humans ; Typhoid Fever/microbiology ; Fimbriae, Bacterial/metabolism/genetics ; },
abstract = {INTRODUCTION: Typhoid fever is an infectious disease primarily caused by Salmonella enterica sv. Typhi (S. Typhi), a bacterium that causes as many as 20 million infections and 600,000 deaths annually. Asymptomatic chronic carriers of S. Typhi play a major role in the transmission of typhoid fever, as they intermittently shed the bacteria and can unknowingly infect humans in close proximity. An estimated 90% of chronic carriers have gallstones; biofilm formation on gallstones is a primary factor in the establishment and maintenance of gallbladder carriage. CsgD is a central biofilm regulator in Salmonella, but the S. Typhi csgD gene has a mutation that introduces an early stop codon, resulting in a protein truncated by 8 amino acids at the C-terminus. In this study, we investigate the role of role of CsgD in S. Typhi.

METHODS: We introduced a fully functional copy of the csgD gene from S. Typhimurium into S. Typhi under both a native and a constitutive promoter and tested for red, dry, and rough (Rdar) colony morphology, curli fimbriae, cellulose, and biofilm formation.

RESULTS AND DISCUSSION: We demonstrate that although CsgD-regulated curli and cellulose production were partially restored, the introduction of the S. Typhimurium csgD did not induce the Rdar colony morphology. Interestingly, we show that CsgD does not have a significant role in S. Typhi biofilm formation, as biofilm-forming capacities depend more on the isolate than the CsgD regulator. This data suggests the presence of an alternative biofilm regulatory process in this human-restricted pathogen.},
}

*Biofilms/growth & development
*Bacterial Proteins/genetics/metabolism
*Gene Expression Regulation, Bacterial
Salmonella typhi/genetics/metabolism/physiology
Humans
Typhoid Fever/microbiology
Fimbriae, Bacterial/metabolism/genetics

@article {pmid39720018,
year = {2024},
author = {Doi, H and Mishima, A and Ikeda, R},
title = {Spencermartinsiella japonica f.a., sp. nov., a novel yeast species isolated from biofilm in a reverse osmosis system.},
journal = {Mycoscience},
volume = {65},
number = {5},
pages = {224-227},
pmid = {39720018},
issn = {1618-2545},
abstract = {Novel Spencermartinsiella strains, JCM 35526[T] and 261-2C, were isolated from biofilm formed on a reverse osmosis membrane in the phosphate recovery system of a semiconductor factory. Morphological, biochemical, physiological, and chemotaxonomic analyses as well as sequence analysis of the concatenated internal transcribed spacer region and D1/D2 domains of the large subunit of the rRNA gene confirmed that strains JCM 35526[T] and 261-2C, were distinct from all currently known Spencermartinsiella species. The holotype and isotype strains of the new species, which is named Spencermartinsiella japonica, are JCM 35526[T] and MUCL 58310[I], respectively.},
}

@article {pmid39719371,
year = {2025},
author = {Meza-Torres, J and Tinevez, JY and Crouzols, A and Mary, H and Kim, M and Hunault, L and Chamorro-Rodriguez, S and Lejal, E and Altamirano-Silva, P and Groussard, D and Gobaa, S and Peltier, J and Chassaing, B and Dupuy, B},
title = {Clostridioides difficile binary toxin CDT induces biofilm-like persisting microcolonies.},
journal = {Gut microbes},
volume = {17},
number = {1},
pages = {2444411},
doi = {10.1080/19490976.2024.2444411},
pmid = {39719371},
issn = {1949-0984},
mesh = {*Biofilms/drug effects/growth & development ; *Clostridioides difficile/genetics/drug effects/growth & development/physiology/metabolism ; Animals ; Mice ; *Clostridium Infections/microbiology ; *Bacterial Proteins/metabolism/genetics ; Bacterial Toxins/metabolism/genetics ; Humans ; Anti-Bacterial Agents/pharmacology ; Vancomycin/pharmacology ; Colon/microbiology ; Mice, Inbred C57BL ; Cecum/microbiology ; Female ; Disease Models, Animal ; ADP Ribose Transferases ; },
abstract = {Clinical symptoms of Clostridioides difficile infection (CDI) range from diarrhea to pseudomembranous colitis. A major challenge in managing CDI is the high rate of relapse. Several studies correlate the production of CDT binary toxin by clinical strains of C. difficile with higher relapse rates. Although the mechanism of action of CDT on host cells is known, its exact contribution to CDI is still unclear. To understand the physiological role of CDT during CDI, we established two hypoxic relevant intestinal models, Transwell and Microfluidic Intestine-on-Chip systems. Both were challenged with the epidemic strain UK1 CDT[+] and its isogenic CDT[-] mutant. We report that CDT induces mucin-associated microcolonies that increase C. difficile colonization and display biofilm-like properties by enhancing C. difficile resistance to vancomycin. Importantly, biofilm-like microcolonies were also observed in the cecum and colon of infected mice. Hence, our study shows that CDT induces biofilm-like microcolonies, increasing C. difficile persistence and risk of relapse.},
}

*Biofilms/drug effects/growth & development
*Clostridioides difficile/genetics/drug effects/growth & development/physiology/metabolism
Animals
Mice
*Clostridium Infections/microbiology
*Bacterial Proteins/metabolism/genetics
Bacterial Toxins/metabolism/genetics
Humans
Anti-Bacterial Agents/pharmacology
Vancomycin/pharmacology
Colon/microbiology
Mice, Inbred C57BL
Cecum/microbiology
Female
Disease Models, Animal
ADP Ribose Transferases

@article {pmid39718087,
year = {2024},
author = {Piletić, K and Mežnarić, S and Keržić, E and Oder, M and Gobin, I},
title = {Comparison of different disinfection protocols against contamination of ceramic surfaces with Klebsiella pneumoniae biofilm.},
journal = {Arhiv za higijenu rada i toksikologiju},
volume = {75},
number = {4},
pages = {289-296},
pmid = {39718087},
issn = {1848-6312},
mesh = {*Klebsiella pneumoniae/drug effects ; *Biofilms/drug effects ; *Disinfection/methods ; *Ceramics ; *Disinfectants/pharmacology ; Ozone/pharmacology ; Citric Acid/pharmacology ; Benzalkonium Compounds/pharmacology ; Equipment Contamination/prevention & control ; Humans ; },
abstract = {Environmental contamination with Klebsiella pneumoniae biofilm can be a source of healthcare-associated infections. Disinfection with various biocidal active substances is usually the method of choice to remove contamination with biofilm. In this study we tested 13 different disinfection protocols using gaseous ozone, citric acid, and three working concentrations of benzalkonium chloride-based professional disinfecting products on 24-hour-old biofilms formed by two K. pneumoniae strains on ceramic tiles. All tested protocols significantly reduced total bacterial counts compared to control, varying from a log10 CFU reduction factor of 1.4 to 5.6. Disinfection combining two or more biocidal active substances resulted in significantly better anti-biofilm efficacy than disinfection with single substances, and the most effective combination for both strains was that of citric acid, gaseous ozone, and benzalkonium chloride. This follow up study is limited to K. pneumoniae alone, and to overcome this limitation, future studies should include more bacterial species, both Gram-positive and Gramnegative, and more samples for us to find optimal disinfection protocols, applicable in real hospital settings.},
}

*Klebsiella pneumoniae/drug effects
*Biofilms/drug effects
*Disinfection/methods
*Ceramics
*Disinfectants/pharmacology
Ozone/pharmacology
Citric Acid/pharmacology
Benzalkonium Compounds/pharmacology
Equipment Contamination/prevention & control
Humans

@article {pmid39716908,
year = {2024},
author = {Wu, X and Pan, B and Chu, C and Zhang, Y and Ma, J and Xing, Y and Ma, Y and Zhu, W and Zhong, H and Alimu, A and Zhou, G and Liu, S and Chen, W and Li, X and Sheng, P},
title = {CXCL16/CXCR6/TGF-β Feedback Loop Between M-MDSCs and Treg Inhibits Anti-Bacterial Immunity During Biofilm Infection.},
journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)},
volume = {},
number = {},
pages = {e2409537},
doi = {10.1002/advs.202409537},
pmid = {39716908},
issn = {2198-3844},
support = {82372424//National Natural Science Foundation of China/ ; 82203677//National Natural Science Foundation of China/ ; GZC20233275//Postdoctoral Fellowship Program of CPSF/ ; 82302716//Young Scientists Fund of the National Natural Science Foundation of China/ ; 2024M753776//China Postdoctoral Science Foundation/ ; 2023M744048//China Postdoctoral Science Foundation/ ; 2023A1515140147//Basic and Applied Basic Research Foundation of Guangdong Province/ ; },
abstract = {Staphylococcus aureus (S. aureus) is a leading cause of Periprosthetic joint infection (PJI), a severe complication after joint arthroplasty. Immunosuppression is a major factor contributing to the infection chronicity of S. aureus PJI, posing significant treatment challenges. This study investigates the relationship between the immunosuppressive biofilm milieu and S. aureus PJI outcomes in both discovery and validation cohorts. This scRNA-seq analysis of synovium from PJI patients reveals an expansion and heightened activity of monocyte-related myeloid-derived suppressor cells (M-MDSCs) and regulatory T cells (Treg). Importantly, CXCL16 is significantly upregulated in M-MDSCs, with its corresponding CXCR6 receptor also elevated on Treg. M-MDSCs recruit Treg and enhance its activity via CXCL16-CXCR6 interactions, while Treg secretes TGF-β, inducing M-MDSCs proliferation and immunosuppressive activity. Interfering with this cross-talk in vivo using Treg-specific CXCR6 knockout PJI mouse model reduces M-MDSCs/Treg-mediated immunosuppression and alleviates bacterial burden. Immunohistochemistry and recurrence analysis show that PJI patients with CXCR6[high] synovium have poor prognosis. This findings highlight the critical role of CXCR6 in Treg in orchestrating an immunosuppressive microenvironment and biofilm persistence during PJI, offering potential targets for therapeutic intervention.},
}

@article {pmid39716676,
year = {2024},
author = {Tang, T and Zhao, Z},
title = {Deciphering the internal mechanism of nitrogen removal from sludge and biofilm under low temperature from the perspective of microbial function metabolism.},
journal = {Environmental research},
volume = {267},
number = {},
pages = {120688},
doi = {10.1016/j.envres.2024.120688},
pmid = {39716676},
issn = {1096-0953},
abstract = {Nitrogen emissions up to the standard are a major challenge for wastewater treatment plants in alpine and high-altitude areas. The dosing of carriers can improve the nitrogen removal efficiency of the system at low temperatures; however, the mechanism of action of sludge and biofilm in nitrogen removal remains unclear. This study elucidated the internal mechanism of nitrogen removal via the function of microbial metabolism in sludge and biofilm at low temperatures. At low temperatures, the biofilm facilitated the enrichment of nitrifying bacteria (5.21%-6.62%) and nitrifying functional genes (amoABC); the average removal efficiency of NH4[+]-N peaked at 94.14%. The denitrification performance of biofilm (14.34-20.67 mg N/(gMLVSS·h) was weaker than that of sludge (27-30.95 mg N/(gMLVSS·h) at low temperatures. The relative abundance of chemical oxygen demand-degrading, denitrifying bacteria, and denitrification functional genes (napAB, nirS, norB, and nosZ) in the sludge was higher than in the biofilm. With a decrease in temperature, the upregulation of carbon metabolism and quorum-sensing functional genes improved the adaptability of sludge to low temperatures. The enhancement of c-type cytochromes and cyclic dimeric guanosine monophosphate functional genes promoted nitrogen removal by endorsing extracellular electron transfer between microorganisms and releasing extracellular polymeric substances at low temperatures. This study offers new insights into improving the mechanism of nitrogen removal from sludge and biofilm at low temperatures.},
}

@article {pmid39716652,
year = {2024},
author = {Ghadimi, N and Asadpour, L and Mokhtary, M},
title = {Enhanced Antimicrobial, Anti-Biofilm, and Efflux Pump Inhibitory Effects of Ursolic Acid-Conjugated Magnetic Nanoparticles Against Clinical Isolates of Multidrug-Resistant Pseudomonas aeruginosa.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107241},
doi = {10.1016/j.micpath.2024.107241},
pmid = {39716652},
issn = {1096-1208},
abstract = {OBJECTIVES: In the present study, we investigate the effect of Fe3O4 nanoparticles conjugated with ursolic acid (Fe3O4NPs@UA) on inhibiting the growth, biofilm-forming ability and efflux pump activity in clinical isolates of Pseudomonas aeruginosa with multiple drug resistance.

METHODS: Iron oxide NPs conjugated with ursolic acid (Fe3O4NPs@UA) were synthesized. Physicochemical features of the NPs were studied by FT-IR, XRD, EDAX, and TEM. The antibacterial and antibiofilm effects of Fe3O4NPs@UA against P. aeruginosa isolates were determined by broth microdilution and microtiter plate methods, respectively. The efflux pump inhibitory effect of Fe3O4NPs@UA was determined using Cartwheel method and through determining the expression level of efflux pump genes, including mexA and oprD in selected P. aeruginosa isolates treated with sub-MIC concentration of Fe3O4NPs@UA by real-time PCR.

RESULTS: In investigating the antimicrobial effect of Fe3O4NPs@UA, the MIC of these nanoparticles varied between 0.19-0.78 mg/mL and in the study of the anti-biofilm effect of Fe3O4NPs@UA, it caused a 68-75% decrease in biofilm formation compared to the control. Moreover, in the Cartwheel test, the anti-efflux effect of these nanoparticles was confirmed at 1/4-MIC concentrations, and the expression of mexA and oprD genes was reduced in bacteria treated with Fe3O4NPs@UA compared to the control.

CONCLUSION: According to the results, the use of Fe3O4NPs@UA can provide a basis for the development of new treatments against drug-resistant bacteria in P. aeruginosa. This substance can improve the concentration of antibiotics in bacterial cells and increase their effectiveness by inhibiting the efflux in P. aeruginosa isolates.},
}

@article {pmid39716060,
year = {2024},
author = {Fatih, HJ and Ashengroph, M and Sharifi, A and Zorab, MM},
title = {Green-synthesized α-Fe2O3-nanoparticles as potent antibacterial, anti-biofilm and anti-virulence agent against pathogenic bacteria.},
journal = {BMC microbiology},
volume = {24},
number = {1},
pages = {535},
pmid = {39716060},
issn = {1471-2180},
mesh = {*Biofilms/drug effects ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Microbial Sensitivity Tests ; *Ferric Compounds/chemistry/pharmacology ; *Green Chemistry Technology ; Gram-Positive Bacteria/drug effects ; Gram-Negative Bacteria/drug effects ; Nanoparticles/chemistry ; Bacillus/drug effects ; Virulence/drug effects ; X-Ray Diffraction ; Spectroscopy, Fourier Transform Infrared ; Bacteria/drug effects ; },
abstract = {BACKGROUND: Antimicrobial resistance (AMR) presents a serious threat to health, highlighting the urgent need for more effective antimicrobial agents with innovative mechanisms of action. Nanotechnology offers promising solutions by enabling the creation of nanoparticles (NPs) with antibacterial properties. This study aimed to explore the antibacterial, anti-biofilm, and anti-virulence effects of eco-friendly synthesized α-Fe2O3 nanoparticles (α-Fe2O3-NPs) against pathogenic bacteria.

METHODS: The α-Fe2O3-NPs were synthesized using a green synthesis method that involved Bacillus sp. GMS10, with iron sulfate as a precursor. The NPs were characterized through ultraviolet-visible (UV-Vis) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), Dynamic Light Scattering (DLS), Zeta Potential Analysis, X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FT-IR). Their antimicrobial activity was assessed against Gram-positive and Gram-negative bacteria. The study also evaluated the effect of the α-Fe2O3-NPs on bacterial cell membrane disruption, biofilm formation, efflux pump inhibition, and swarming motility.

RESULTS: The UV-Visible spectrum showed a peak at 228 nm, indicating plasmon absorbance of the α-Fe2O3-NPs. FESEM revealed spherical NPs (~ 30 nm), and DLS confirmed a hydrodynamic size of 36.3 nm with a zeta potential of -25.1 mV, indicating good stability. XRD identified the rhombohedral α-Fe2O3 phase, and FTIR detected O-H, C-H, C = O, and Fe-O functional groups, suggesting organic capping for stability. Antibacterial assays demonstrated that the α-Fe2O3-NPs had MIC values ranging from 0.625 to 5 µg/mL and MBC values between 5 and 20 µg/mL, with a strong effect against Gram-positive bacteria. The NPs significantly increased membrane permeability, inhibited biofilm formation in S. aureus and E. coli, and disrupted efflux pumps in S. aureus SA-1199B (a fluoroquinolone-resistant strain overexpressing norA). Additionally, the α-Fe2O3-NPs inhibited P. aeruginosa swarming motility.

CONCLUSION: The bacteria-synthesized α-Fe2O3-NPs demonstrated significant antimicrobial activity, particularly against Gram-positive bacteria, and exhibited strong potential for inhibiting biofilm formation and efflux pump activity, offering a promising strategy to address AMR. Focus on further evaluating their therapeutic potential in clinical settings and conducting comprehensive assessments of their safety profiles to ensure their applicability in medical treatments.

CLINICAL TRIAL NUMBER: Not applicable.},
}

*Biofilms/drug effects
*Anti-Bacterial Agents/pharmacology/chemistry
*Microbial Sensitivity Tests
*Ferric Compounds/chemistry/pharmacology
*Green Chemistry Technology
Gram-Positive Bacteria/drug effects
Gram-Negative Bacteria/drug effects
Nanoparticles/chemistry
Bacillus/drug effects
Virulence/drug effects
X-Ray Diffraction
Spectroscopy, Fourier Transform Infrared
Bacteria/drug effects