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Bibliography on: Biofilm

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ESP: PubMed Auto Bibliography 01 Jan 2026 at 01:41 Created: 

Biofilm

Wikipedia: Biofilm A biofilm is any group of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPS). The EPS components are produced by the cells within the biofilm and are typically a polymeric conglomeration of extracellular DNA, proteins, and polysaccharides. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, biofilms are frequently described metaphorically as cities for microbes. Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single-cells that may float or swim in a liquid medium. Biofilms can be present on the teeth of most animals as dental plaque, where they may cause tooth decay and gum disease. Microbes form a biofilm in response to many factors, which may include cellular recognition of specific or non-specific attachment sites on a surface, nutritional cues, or in some cases, by exposure of planktonic cells to sub-inhibitory concentrations of antibiotics. When a cell switches to the biofilm mode of growth, it undergoes a phenotypic shift in behavior in which large suites of genes are differentially regulated.

Created with PubMed® Query: ( biofilm[title] NOT 28392838[PMID] NOT 31293528[PMID] NOT 29372251[PMID] ) NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2025-12-31

Macedo MJP, Hamann PRV, I Polikarpov (2025)

Revisiting the endo and exo mode of action of dextran hydrolyzing enzymes, and their significance for Streptococcus mutans biofilm eradication.

World journal of microbiology & biotechnology, 42(1):15.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Bhandari R, Amatya NM, Bogati P, et al (2025)

Unveiling Hidden Threats: Bacterial Contamination of Frequently Touched Objects and the Biofilm Property of Staphylococcus aureus as a Threat to Antibiotic Success.

The Canadian journal of infectious diseases & medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale, 2025:9929263.

BACKGROUND: Frequently touched objects within hospital premises acts as a potential reservoir for healthcare-associated infections (HCAIs), significantly amplifying the risk when biofilm-producing bacteria are involved. These bacteria often exhibit multidrug-resistant (MDR) patterns, complicating the antimicrobial treatments. So, this study intended to determine the bacterial contamination level on frequently touched objects and their antibiotic susceptibility patterns and to determine the relation between biofilm-producing Staphylococcus aureus and multidrug resistance patterns.

METHODS: A hospital-based cross-sectional study was conducted at different intensive care units (NICU and MICU) and operation theatre of Frontline Hospital, Kathmandu, Nepal. Aseptically, 297 swab samples were collected and cultured, and the isolated bacteria were identified using standard microbiological procedures. Antibiotics susceptibility test done by the Kirby-Bauer disc diffusion method, and biofilm detection was done by the microtiter plate method at 570 nm by using an ELISA reader. For data analysis, SPSS Version 23 was used.

RESULTS: Of total 297 swab samples processed, 31.3% (93/297) showed bacterial growth, yielding a total of 108 isolates. Mixed growth was reported on 16.1% (15/93) samples. The frequency of Gram-positive and Gram-negative bacteria was 95.4% (103/108) and 4.6% (5/108), respectively. The main isolates were coagulase-negative staphylococci (CoNS) 50.9%, followed by S. aureus (36.1%), Gram-positive bacilli (8.3%), Pseudomonas species (2.8%), and Klebsiella species (1.9%). Out of 39 S. aureus isolates, 53.8% (21/39) were MDR and 25 (64.10%) were biofilm producers. Similarly, 35.9% (14/39) were methicillin-resistant S. aureus (MRSA), among which majority 71.4% (10/14) of MRSA recovered as biofilm producers.

CONCLUSION: A frequently touched object within different intensive care units and operation theatre was found to be contaminated with potential pathogens and normal flora. Bacterial contamination of such objects can contribute to HCAIs and the hands of health professionals can be the mode of cross-contamination.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Díaz-Navarro M, Irigoyen Á, Palomo M, et al (2025)

Corrigendum to "In vitro study to assess modulation of Candida biofilm by Escherichia coli from vaginal strains" [Biofilm 5 (2023) 100116].

Biofilm, 10:100297 pii:S2590-2075(25)00045-0.

[This corrects the article DOI: 10.1016/j.bioflm.2023.100116.].

RevDate: 2025-12-31
CmpDate: 2025-12-31

Barbosa A, Azevedo NF, Goeres DM, et al (2025)

Erratum to "Ecology of Legionella pneumophila biofilms: The link between transcriptional activity and the biphasic cycle" [Biofilm 7 100196].

Biofilm, 10:100291 pii:S2590-2075(25)00039-5.

[This corrects the article DOI: 10.1016/j.bioflm.2024.100196.].

RevDate: 2025-12-31
CmpDate: 2025-12-31

Kozłowska A, Piłat-Rożek M, Raczkiewicz A, et al (2025)

Application of biofilm community structure analysis for assessing the impact of a stormwater system on the aquatic environment.

Annals of agricultural and environmental medicine : AAEM, 32(4):461-468.

INTRODUCTION AND OBJECTIVE: Industrial, agricultural and construction development has brought improvements in living conditions, but have also increased the amount of pollution in the environment. Atmospheric precipitation collects pollutants from urban surfaces, which then end up in stormwater systems, contaminating surface waters. These pollutants are also linked to the similar effects of agriculture, as biogenic pollutants originate from over-fertilized crops. Contaminated surface water forces flora and fauna to adapt to new conditions, and affecting the structure and extent of ecosystems. Monitoring the environment with bio-indication methods is important because it enables identification of the areas in need of protection, in an inexpensive and environmentally harmless way. The aim of this study was to evaluate the possibility of using biocenotic indices to assess the impact of a stormwater system on the aquatic environment.

MATERIAL AND METHODS: Bio-indicative studies were conducted on periphyton sampled at 4 points on the Bystrzyca River in Lublin, eastern Poland, under the influence of stormwater discharge and 1 reference point localized before the stormwater system outflow. The quantitative data concerning the number of chosen algae species was analyzed using indices for the examination of community structure.

RESULTS: Considered the indices, i.e. taxonomic richness, Shannon, MacArthur, Menhinick and McIntosh were calculated, evaluated, and shown in various types of graphs showing the fluctuation of indices at measurement points.

CONCLUSIONS: The use of bioindication and classic biocenotic indices allowed for the description, analysis of changes in the periphyton biocenosis under the influence of point source stormwater discharges, and linking measurements from tested samples with environmental conditions and biodiversity in the analyzed study sites and periods.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Musilová I, Kozlová K, D Šilha (2025)

Biofilm Formation in Arcobacter butzleri and Arcobacter cryaerophilus: Phenotypic and Genotypic Characterization of Food and Environmental Isolates.

Microorganisms, 13(12):.

Arcobacter butzleri and Arcobacter cryaerophilus are emerging foodborne and waterborne pathogens associated with enteritis and extraintestinal infections in humans. Their persistence in the environment and resistance to antimicrobial treatment are closely related to their ability to form biofilms, which provide protection against adverse conditions and support survival on food contact surfaces. This study evaluated both the genotypic and phenotypic aspects of biofilm formation among A. butzleri and A. cryaerophilus isolates from food and environmental sources. Six biofilm-associated genes (flaA, flaB, fliS, luxS, pta, and spoT) were detected by multiplex PCR, and biofilm production was assessed using the Christensen microtiter plate assay and Congo Red Agar (CRA) test. All A. cryaerophilus isolates carried the same gene set as A. butzleri, suggesting conserved genetic determinants of motility and Quorum sensing. However, phenotypic assays revealed interspecific variability: while most A. butzleri isolates formed strong biofilms, 70% of A. cryaerophilus strains showed moderate to strong formation despite all being CRA-negative. No direct correlation between gene presence and biofilm intensity was observed, indicating complex regulation of biofilm development. This study provides a comparative overview of biofilm formation in A. butzleri and A. cryaerophilus and highlights their adaptive potential and persistence in food-related environments.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Hindieh P, Yaghi J, Assaf JC, et al (2025)

Emerging Multimodal Strategies for Bacterial Biofilm Eradication: A Comprehensive Review.

Microorganisms, 13(12):.

Bacterial biofilms pose significant challenges in clinical, industrial, and environmental settings due to their inherent resistance to antimicrobial agents and host immune responses. Encased within a self-produced extracellular polymeric substance (EPS) matrix, these structured microbial communities demonstrate exceptional resilience, resisting conventional antimicrobial treatments and adapting to, as well as recovering from, environmental and therapeutic stresses, necessitating the development of novel anti-biofilm strategies. This review provides a comprehensive synthesis of biofilm formation, resistance mechanisms, and current and emerging approaches for controlling biofilms, with a primary focus on advancements made over the last decade. Chemical, physical, and biological strategies, including enzymatic degradation, natural compounds, chelating agents, nanoparticles, photodynamic therapy, and probiotics, have demonstrated promising antibiofilm activity. Additionally, combination therapies and targeted drug delivery systems have emerged as viable solutions to enhance the eradication of biofilms. Despite these advancements, challenges such as cytotoxicity, bacterial adaptation, and clinical applicability remain. Addressing these hurdles requires interdisciplinary research to refine existing strategies and develop innovative solutions for effective biofilm management.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Belfihadj F, Elkolli M, Boussoualim N, et al (2025)

Emergence of Multidrug-Resistant and Biofilm-Producing Staphylococcus aureus from Raw Poultry in Algeria: Implications for Public Health.

Microorganisms, 13(12):.

Staphylococcus aureus is a common foodborne pathogen, posing significant concern due to the emergence of its multidrug-resistant (MDR) strains. The aim of this study was to assess the antibiotic resistance profiles in S. aureus isolated from raw poultry, the associated resistance genes, and their ability to form biofilms. S. aureus was isolated and identified using conventional microbiological methods. Antimicrobial susceptibility profiles were assessed using the disk diffusion method, and biofilm-forming ability was evaluated using the microtiter plate assay. The presence of antimicrobial resistance genes was determined by PCR. A total of 45 isolates were isolated. High resistance rates were observed against penicillin (88.9%), tetracycline (86.7%) and doxycycline (66.7%). Of the isolates, 71.1% were classified as multidrug-resistant (MDR) organisms, and 60% exhibited a multiple antibiotic resistance index greater than 0.2. PCR analysis revealed the presence of the resistance genes blaZ (86.7%), mecA (27.3%), tet(M) (46.2%), tet(K) (35.9%), tet(S) (59%), erm(B) (51.9%), and erm(C) (59.3%). A total of 44 isolates were biofilm producers: 46.7% were weak producers, 46.7% were moderate producers, and 4.4% were strong producers. These findings highlight a significant public health concern, emphasizing the need for stringent hygiene practices and continuous monitoring to limit the spread of resistant pathogens through the food chain.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Jotic A, Cirkovic I, Jovicic N, et al (2025)

Biofilm Formation and Its Relationship with the Microbiome in Pediatric Otitis Media.

Microorganisms, 13(12):.

Otitis media is among the most common pediatric illnesses globally, constituting a leading cause of antimicrobial prescriptions, recurrent medical consultations, and preventable hearing loss in early childhood. Traditionally regarded as a sterile cavity intermittently invaded by pathogens, the middle ear is now recognized as a dynamic ecological niche influenced by anatomical immaturity of the Eustachian tube, host immune development, and the composition of resident microbial communities. Increasing evidence demonstrates that microbial dysbiosis and the establishment of biofilms are central to the persistence and recurrence of disease. This review synthesizes current knowledge of the pediatric middle ear microbiome, highlighting how commensal organisms contribute to mucosal resilience and colonization resistance, whereas pathogenic bacteria exploit ecological disruption to establish biofilm communities. Biofilm formation provides bacteria with enhanced survival through immune evasion, altered microenvironments, and antibiotic tolerance, thereby transforming acute otitis media into recurrent or chronic states. Furthermore, studies demonstrate how adenoids act as reservoirs of biofilm-forming organisms, seeding the middle ear and perpetuating infection. The emerging ecological perspective emphasizes the limitations of conventional antibiotic-centered management and directs attention toward innovative strategies, including microbiome-preserving interventions, probiotic or live biotherapeutic approaches, and antibiofilm agents. By defining pediatric otitis media as a disorder of disrupted host-microbe equilibrium, future research may pave the way for precision-based preventive and therapeutic strategies aimed at reducing the global burden of this pervasive disease.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Hernández-Huerta MT, Pérez-Campos E, Pérez-Campos Mayoral L, et al (2025)

Proactive Strategies to Prevent Biofilm-Associated Infections: From Mechanistic Insights to Clinical Translation.

Microorganisms, 13(12):.

Biofilms are structured microbial communities that adhere to biotic and abiotic surfaces embedded in an autonomous extracellular matrix. These structures contribute to persistent infections, especially in patients with indwelling medical devices, due to their resistance to antimicrobial agents; they have evolved to evade host immune responses. Despite advances in antimicrobial therapies, biofilm-associated infections remain a major challenge in clinical infectious diseases. This perspective explores the underlying mechanisms of biofilm resilience and immune evasion, emphasizing the limitations of conventional treatments and the need to develop pre-emptive measures that focus on preventing biofilm formation rather than implementing a treatment. This work discusses emerging strategies, such as quorum-sensing inhibition, hormonal modulation, matrix-degrading enzymes, anti-adhesive surface modifications, and nanotechnology-based drug delivery, that offer promising avenues to disrupt biofilm formation and maturation. Also offers a shift from the paradigm, looking into proactive prevention rather than treatment, emphasizing clinical translation, scalability, and biocompatibility. Embedding these strategies into routine care could significantly reduce healthcare-associated infections, improve patient outcomes, and mitigate the development of antimicrobial resistance. Our analysis highlights biofilm prevention as a critical frontier in the future of infectious disease management.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Zheng J, Li Y, Wei Y, et al (2025)

HtrA Contributes to Biofilm Formation in Mycobacterium smegmatis by Downregulating the Cell Wall Amidase Ami3.

Microorganisms, 13(12):.

Mycobacterium tuberculosis, the causative agent of tuberculosis, utilizes biofilm formation as a key mechanism to withstand host-derived stresses. To identify novel factors involved in this process, we performed a CRISPRi screen in the model organism Mycobacterium smegmatis. This screen identified trypsin HtrA as a critical factor for growth and biofilm formation. Deletion of htrA led to a profound upregulation of the cell wall amidase Ami3. We demonstrated that Ami3 is a crucial negative regulator of biofilm formation, as overexpression of ami3 recapitulated the biofilm and growth defects of the ΔhtrA strain. Furthermore, we found that the essential role of periplasmic protease HtrA for normal growth could be suppressed by novel mutations in pmt, a gene encoding a phosphomyoinositol mannosyltransferase, at residues F53 and N55, distinct from the previously reported D68 site. Our findings establish a novel regulatory pathway in which HtrA modulates mycobacterial biofilm formation by controlling the levels of Ami3 and reveal new genetic interactions within this network.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Kiousi DE, Kyriakou S, Efstathiou C, et al (2025)

Lacticaseibacillus casei Combats Biofilm Formation and Exhibits Antibacterial Activity Against Clinical Isolates of Staphylococcus aureus, Salmonella enterica, and Escherichia coli.

Microorganisms, 13(12):.

Biofilm-forming pathogens are a major cause of persistent infections, showing limited response to antibiotic treatment. The search for alternative strategies has therefore driven extensive research into the antimicrobial potential of beneficial microorganisms. In the present study, the antibacterial and antibiofilm activity of the commercial probiotic strain Lacticaseibacillus casei ATCC 393 (Lc393) was examined against clinical isolates of Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Enteritidis and Escherichia coli. Lc393 reduced pathogen viability and attachment to the colon adenocarcinoma cell line HT-29, with maximal effects recorded against S. aureus. Confocal microscopy visualization of the lactobacilli-pathogens-host interface revealed that Lc393 binds loosely to both host cells and pathogens. The Lc393 cell-free culture supernatant (CFCS) significantly reduced planktonic growth, biofilm mass, and viability of cells in biofilm (>2 logCFU reduction, p < 0.05) and downregulated genes involved in the early stages of biofilm formation in S. aureus (i.e., icaA, fnbpA, eno). In silico analysis of the Lc393 genome identified two bacteriocin clusters, along with genes related to ethanol and organic acid production. Based on in silico predictions and a bacteriocin zymogram, the strain cannot produce functional antimicrobial peptides. Untargeted metabolomics based on UPLC/MS further revealed the presence of putative antimicrobial metabolites. Collectively, our findings highlight the antimicrobial potential of Lc. casei ATCC 393 and support its further investigation for combating clinically relevant human pathogens.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Tkaczyk M (2025)

Biofilm as a Key Element in the Bacterial Pathogenesis of Forest Trees: A Review of Mechanisms and Ecological Implications.

Microorganisms, 13(12):.

Bacterial diseases of forest trees represent an increasing threat to ecosystem health and the sustainability and resilience of forest management, particularly under changing climate conditions. One of the key yet still insufficiently understood adaptive mechanisms of pathogens is biofilm formation-a structured community of bacterial cells embedded in a matrix of extracellular polymeric substances (EPS), which provides protection against stress factors, biocides, and the host's defensive responses such as antimicrobial compounds or immune reactions. This paper presents a comprehensive review of current knowledge on the role of biofilms in the bacterial pathogenesis of forest trees, covering their formation mechanisms, molecular regulation, and ecological significance. Four key stages of biofilm development are discussed-adhesion, microcolony formation, EPS production, and dispersion-along with the roles of quorum sensing systems and c-di-GMP-based signaling in regulating these processes. Examples of major tree pathogens are presented, including Pseudomonas syringae, Erwinia amylovora, Xylella fastidiosa, the Brenneria-Gibbsiella complex associated with Acute Oak Decline (AOD) and Lonsdalea populi. Biofilm formation is shown to play a crucial role in the colonization of xylem, leaf surfaces, and tissues undergoing necrosis, where biofilms may stabilize decomposition zones and support saprophytic-pathogenic transitions. In the applied section, the concept of "biofilm-targeted control" is discussed, encompassing both chemical and biological strategies for disrupting biofilm structure-from quorum-sensing inhibitors and EPS-degrading enzymes to the use of biosurfactants and antagonistic microorganisms. The need for in situ research in forest environments and the adaptation of advanced imaging (CLSM, micro-CT) and metagenomic analyses to tree systems is also emphasized. This review concludes that biofilms are not merely a physiological form of bacterial organization but a complex adaptive system essential for the survival and virulence of pathogens in forest ecosystems. Understanding their functions is fundamental for developing sustainable and ecologically safe phytosanitary strategies for forest protection.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Niedźwiadek K, Polak-Berecka M, A Waśko (2025)

Innovations in Biofilm Prevention and Eradication in Medical Sector: An Integrative Review.

Pathogens (Basel, Switzerland), 14(12): pii:pathogens14121242.

BACKGROUND: Biofilm-associated infections remain a major challenge in modern medicine due to their high resistance to antibiotics and immune defences. Advances in materials science, chemistry, and nanotechnology have led to the development of innovative, non-antibiotic approaches to prevent or eradicate biofilms.

METHODS: This review summarises antibiofilm strategies reported between 2020 and 2025, grouped into chemical, enzymatic, physical-photonic, nanomaterial-based, and biological hybrid categories.

RESULTS: Chemical methods such as silver-based chemical systems, nitric oxide donors, and biosurfactants disrupt bacterial membranes, generate reactive oxygen species, and inhibit quorum sensing. Enzymatic coatings with DNase I or lysostaphin effectively reduce Staphylococcus aureus and S. epidermidis biofilms, showing stability after sterilisation and high biocompatibility. Physical-photonic techniques, including photocatalytic and light-activated coatings, provide controllable and renewable antibacterial activity. Nanomaterials such as silver nanomaterials, chitosan-based carriers, magnetic ferrites, and catalytic nanozymes enable targeted, ROS-mediated biofilm disruption. Biologically derived systems, including bacteriophage hydrogels and plant metabolites, offer eco-friendly, biocompatible alternatives.

CONCLUSIONS: Recent antibiofilm innovations mark a transition from conventional antibiotics to multifunctional and adaptive systems integrating chemical, enzymatic, and physical mechanisms for effective biofilm control on medical surfaces.

RevDate: 2025-12-31
CmpDate: 2025-12-31

Vegas-Bustamante E, Toledano-Serrabona J, Sánchez-Garcés MÁ, et al (2025)

Cytocompatibility and Microbiological Effects of Ti6Al4V Particles Generated During Implantoplasty on Human Fibroblasts, Osteoblasts, and Multispecies Oral Biofilm.

Materials (Basel, Switzerland), 18(24):.

OBJECTIVES: This study aimed to evaluate the cytotoxic effects of Ti6Al4V particles and implantoplasty (IP)-treated surfaces on human fibroblasts and osteoblasts, and to investigate the influence of these particles on multispecies oral biofilm formation.

METHODS: Ti6Al4V particles generated during implantoplasty were collected. Human fibroblasts (HFF-1) and osteoblast-like cells (SaOs-2) were used to assess cytotoxicity through indirect lactate dehydrogenase (LDH) assays. Multispecies biofilms composed of Streptococcus oralis, Actinomyces viscosus, Veillonella parvula and Porphyromonas gingivalis were evaluated based on colony-forming units (CFUs) and metabolic activity. Fibroblasts and osteoblasts were co-cultured with biofilm-contaminated particles for 2, 4 and 6 h. Cell morphology and biofilm association were examined by phase-contrast microscopy, while metabolic activity was measured spectrophotometrically.

RESULTS: IP-treated surfaces showed no significant cytotoxicity (metabolic activity > 92%, LDH < 20%). Ti6Al4V particles selectively promoted A. viscosus and V. parvula growth (metabolic activity increases of ≈192% and ≈203%; CFU significantly higher versus controls, p < 0.05). Co-culture with biofilm-contaminated particles drastically reduced cell activity (fibroblasts < 25%, osteoblasts < 10%), whereas bacteria-free particles did not.

CONCLUSIONS: Biofilm-contaminated particles released during implantoplasty markedly impair fibroblast and osteoblast cytocompatibility and selectively alter bacterial growth, whereas IP-treated surfaces per se are biocompatible. Minimizing particle dissemination and bacterial contamination during IP is therefore crucial.

RevDate: 2025-12-30

Greve NB, Fei X, Håkansson AP, et al (2025)

Identification of a novel gene associated with group B Streptococcus persister cell formation and biofilm production.

Scientific reports pii:10.1038/s41598-025-34333-4 [Epub ahead of print].

RevDate: 2025-12-30

Shirato M, Lehrkinder A, Nakamura K, et al (2025)

Impact of hydrogen peroxide photolysis on viable bacterial count and composition of in vivo dental biofilm-an ex vivo study.

BMC oral health pii:10.1186/s12903-025-07588-6 [Epub ahead of print].

RevDate: 2025-12-30

Mao MY, Zhang YJ, ZZ Huang (2025)

[Effects of pleiotropic regulator catabolite control protein A in prompting the biofilm formation of cariogenic Streptococcus mutans].

Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology, 61(1):64-73 [Epub ahead of print].

Objective: To explore the effects of pleiotropic regulator, catabolite control protein A (CcpA), on the biofilm formation of Streptococcus mutans (Sm). Methods: The CcpA knockout strain ΔccpA and complementation strain ΔccpA/pDL278-ccpA were constructed. The cell morphologies and growth curves of UA159 and ΔccpA cells were detected. The pH meter and acid tolerance assay were conducted to evaluate the effect of CcpA on the acid-producing and acid resistance capacity of Sm, respectively. Crystal violet assay (CVS), anthrone-sulfuric method, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were conducted to evaluate the characteristics of Sm biofilms. Moreover, real-time fluorescence quantitative PCR (RT-qPCR) and electrophoretic mobility shift assay (EMSA) were employed to explore the molecular mechanism of CcpA in prompting the biofilm formation at transcriptional level. Results: Growth curve analysis indicated that ΔccpA demonstrated slightly reduced growth rate compared with UA159, while the final yield showed no significant difference. SEM observation showed ΔccpA bacteria formed loose biofilm architectures and exhibited a reduced capacity in synthesizing extracellular matrix, and these findings were further confirmed by CVS that ΔccpA (0.55±0.11) exhibited decreased biomass relative to UA159 (0.82±0.01) (P<0.01), while no significant difference between ΔccpA/pDL278-ccpA and UA159 (P>0.05). CLSM observation exhibited a reduced capacity to synthesize exopolysaccharides of ΔccpA strain, and these findings were further confirmed by data of anthrone-sulfuric method that ΔccpA exhibited decreased water-soluble glucans (0.10±0.01) and water-insoluble glucans (0.08±0.00) relative to UA159 (0.14±0.02, 0.20±0.03) (all P<0.01), while there was no significant difference between ΔccpA/pDL278-ccpA and UA159 (all P>0.05). RT-qPCR showed the expression levels of gtfB/C/D genes were markedly downregulated in ∆ccpA strain with different carbon resources (all P<0.05). Specifically, the promoter regions of gtfB and gtfC were directly regulated by CcpA. Conclusions: In summary, CcpA can trigger transcription of biofilm-formation genes via direct binding. Our study supports a role for CcpA as a crucial regulator that exploit the nuanced control of Sm biofilm formation.

RevDate: 2025-12-30

Zhou Y, Song X, Li W, et al (2025)

Revealing the optimal ratio of aged-to-fresh carbon in BAC filtration: linking biofilm development, iDNA/eDNA community dynamics, and purification performance.

Water research, 291:125248 pii:S0043-1354(25)02149-9 [Epub ahead of print].

Ozone-biological activated carbon (O3-BAC) filtration has been widely employed for water purification, yet guidance on appropriate strategies for carbon media renewal remains unclear. A pair of full-scale O3-BAC filters located at a water treatment plant in eastern China (new: 3 years; aged: 11 years) was investigated and verified with a 90-day lab-scale test comprising four columns spanning 0-100% fresh carbon to decipher adsorption-biodegradation interactions and microbial succession. In the full-scale system, the newer filter removed 21.99% of dissolved organic carbon (DOC) and reduced UV254 by 20.14%, whereas the aged filter, despite its weaker adsorption, removed more assimilable organic carbon (AOC, 22.67%) consistent with a mature biofilm but released more cells to the effluent (up to 2.2 × 10[5] mL[-1]). In the laboratory, beds filled only with fresh carbon showed strong early adsorption but slower onset of nitrification and a delayed decline in AOC, while beds filled only with aged carbon provided immediate biodegradation but higher start-up cell release. Critically, intermediate replacement synchronized adsorption and biodegradation: the 75% fresh + 25% aged configuration stabilized fastest, drove residual AOC towards about 20 µg L[-1] by day 90, and maintained effluent cell concentrations on the order of 10[3]-10[4] mL[-1] while developing dense, diverse biofilms. Microbial analysis showed that hybrid beds preserved nitrifiers and aromatic degraders from aged media while recruiting pioneer colonizers on fresh carbon, enabling broad-spectrum removal of protein-like and humic-like organics confirmed by three-dimensional fluorescence spectroscopy. These findings indicate that partial rather than full replacement, optimally 50-75% fresh carbon, can maximize organic pollutant removal and minimize microbial risks when BAC operation maintains low and stable AOC, low and steady effluent TCC/ICC, and concurrent declines in UV254 and DOC, providing a practical basis for sustainable BAC management under stringent drinking water standards.

RevDate: 2025-12-30

Li Y, Yan S, Song H, et al (2025)

Calcium-Powered Probiotics Reconfigure the Intestinal Niche via Biofilm Transformation.

Advanced materials (Deerfield Beach, Fla.) [Epub ahead of print].

Excessive Desulfovibrio (Des) forms biofilm to enable dominant occupation of the intestinal niche, representing a common pathogenic driver of multiple inflammatory bowel disease (IBD) types. Colonization resistance constitutes the primary barrier to antagonistic probiotic efficacy, and this is driven by the pathogen-favorable microenvironment established by Des. Here, probiotic Lactiplantibacillus (Lap) is modified by calcium ions (Ca[2+]) and calcium-regulative polyphenol (kaempferol-3-O-rutinoside, KAE) via coordinate interaction to achieve intestinal niche reconfiguration. Targeting the tripartite mechanisms of Des-mediated colonization resistance, the Ca[2+]/KAE@Lap platform optimized niche competition through Ca[2+]-bridged interfacial binding with directional bactericidal activity, and this enables bacterial replacement at occupied sites. Ca[2+]/KAE@Lap reestablishes calcium homeostasis disrupted by Des via synergistic Ca[2+]/KAE regulation, dually restoring epithelial energy metabolism and mucus layer reconstitution, counteracting Des-induced colonized sites contraction and regenerated site impairment. This drives phenotypic shift in biofilm composition from Des-dominated to Lap-enriched consortia, which is concomitant with the redirection of intestinal colonization resistance from a pathogen-permissive to a probiotic-favored state. This calcium-based biofilm transformation strategy overcomes the transient colonization limitation inherent in conventional probiotic therapies by effectively disrupting colonization resistance in IBD treatment.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Zhang J, Wang HL, Ding T, et al (2025)

L-serine-O-sulfate alters cellular ultrastructure and mitigates the capacity of biofilm formation in Streptococcus mutans UA159 via interfering with glutamate racemase.

Current research in microbial sciences, 9:100427.

Dental caries, primarily caused by Streptococcus mutans (S. mutans), remains a significant global health challenge. Conventional treatments often disrupt commensal oral flora, necessitating targeted antimicrobial strategies. This study investigated L‑serine-O-sulfate (LSOS), a substrate analog of glutamate racemase (MurI), as a potential agent for interfering with S. mutans UA159 virulence. Computational docking predicted LSOS binding to MurI, while circular dichroism spectroscopy confirmed LSOS-induced structural perturbations in recombinant MurI. LSOS exhibited concentration-dependent bactericidal effects, with 5.0 mM completely suppressing growth and 2.5 mM significantly extending doubling time (11.37 hrs vs. 5.68 hrs in controls). Transmission electron microscopy revealed progressive ultrastructural damage, characterized by membrane blebs and cell wall disintegration. Biofilm formation was severely impaired, with 63 % reduction in biomass and significant disruption of extracellular matrix integrity. Microarray-based gene expression analysis identified 119 differentially expressed genes, predominantly downregulated (111/119), affecting translation machinery, metabolic pathways, and transmembrane transport. Biosafety evaluation in L929 fibroblasts showed reduced proliferation (67.59 % of control at 2.5 mM after 48 hrs) with both G1-phase reduction and S-phase cell cycle accumulation. Caenorhabditis elegans demonstrated uncompromised survival and early development at concentrations <10 mM, with developmental toxicity emerging only at higher doses (≥20 mM). These findings establish LSOS as a promising anti-virulence agent targeting MurI in S. mutans UA159, with favorable biosafety profiles that warrant further investigation for dental caries prevention and treatment.

RevDate: 2025-12-30

Alimata B, Ablassé R, Moussa C, et al (2025)

Anti-biofilm, anti-quorum sensing potential, cytotoxicity, and UPLC-UV/DAD-MS/MS/QTOF profiling of Prosopis Africana (Guill. & Perr.) Taub. leaves and stems extracts: benefits of a traditional medicine in dental care.

BMC complementary medicine and therapies, 25(1):445.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Frolov NA, Seferyan MA, Detusheva EV, et al (2025)

In Pursuit of a Better Biocide Composition: Synergistic and Additive Effects of QAC-Based Formulations Against Planktonic and Biofilm Cultures.

International journal of molecular sciences, 26(24): pii:ijms262412098.

Managing bacterial infections and the spread of microbial resistance is one of the most critical and complex tasks of modern healthcare infrastructures. Antiseptics and disinfectants such as biocides play a significant role in controlling microbial resistance by reducing the microbial load on surfaces, skin, and environments, thereby limiting the opportunity for pathogens to proliferate and develop resistance. Herein, we tested the different interactions of quaternary ammonium compound (QAC)-based biocide compositions in pursuit of a better antimicrobial performance. An extensive microbiological analysis was conducted for 12 selected compositions of various combinations of mono-QACs, bis-QACs, and alcohols on 17 strains of bacteria of the ESKAPEE group and fungi, including 11 clinical highly resistant varieties, highlighting synergistic or additive dynamics. The evaluation showed noticeable improvements in activity, with up to 16-fold MBC and 32-fold MBEC reductions for alcohol-based compositions of lead QAC. Moreover, synergistic interactions were detected and confirmed via an optimized checkerboard assay for pyridinium QAC combinations against planktonic Gram-positive S. aureus with a fractional inhibitory concentration index (FICI) and fractional bactericidal concentration index (FBCI) of 0.39-0.5 and Gram-negative A. baumannii biofilms. The studied biocides demonstrated the long-term preservation of antimicrobial efficiency without resistance development during a 40-day period and do not induce QAC-associated cross-resistance for four commercially available antibiotics with similar mechanisms of action.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Andrzejczuk S, Sozoniuk M, D Sugier (2025)

Preliminary Assessment of Arnica montana L. Extract: Antimicrobial Activity Against Acinetobacter baumannii and Biofilm-Related Gene Expression Profiling.

Genes, 16(12): pii:genes16121473.

Background/Objectives: Arnica montana L. is widely recognized for its diverse biological activities, including antimicrobial effects. This study aimed to evaluate the antimicrobial and antibiofilm activity of A. montana L. extracts against Acinetobacter baumannii, a pathogen of urgent public health concern due to its increasing antibiotic resistance and capacity for biofilm formation. Methods: The antimicrobial activity of ethanolic (EtE) and aqueous (AqE) extracts of A. montana flowers was evaluated via the broth microdilution method. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), and the MBC/MIC ratio were used. The effects of EtE on A. baumannii biofilm formation were assessed via a crystal violet assay. Additionally, transcriptional profiling of biofilm-associated genes following exposure to sub-MIC levels of the extract was conducted via RT-qPCR. Results: The anti-Acinetobacter activity of EtE was demonstrated (MIC = 234.4 and 468.75 µg/mL for A. baumannii ATCC BAA-3252 and ATCC 19606, respectively). The EtE exhibited bactericidal activity against both strains, whereas the AqE showed no activity. Additionally, EtE inhibited biofilm formation and significantly downregulated the expression of key biofilm-associated genes, including those of the csu operon and ompA. Conclusions: Arnica montana EtE demonstrated antimicrobial and antibiofilm activities against A. baumannii and inhibited biofilm development by suppressing the transcription of genes involved in pilus assembly and surface adherence, highlighting their essential role in biofilm formation.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Yang H, Jiang X, Nychas GE, et al (2025)

Role of the PhoP/PhoQ Two-Component Regulatory System in Biofilm Formation in Acid-Adapted Salmonella typhimurium.

Foods (Basel, Switzerland), 14(24): pii:foods14244344.

Salmonella typhimurium is a global foodborne pathogen, and controlling its persistence is critical for public health. This study investigated the regulatory role of the PhoP/PhoQ two-component system (TCS) in biofilm formation under the acid adaptation condition. A phoP deletion strain (ΔphoP) was constructed and compared with the wild type (WT) after acid induction (pH 5.4). Without acid adaptation, ΔphoP and WT showed similar acid tolerance and biofilm formation. However, after acid induction, ΔphoP exhibited markedly reduced biofilm formation, swimming ability, metabolic activity, and extracellular polymer production. RNA-seq analysis further revealed defects in ΔphoP under acid-induced conditions: (i) first leads to downregulation of lipopolysaccharide biosynthesis, peptidoglycan synthesis, and cationic antimicrobial peptide resistance pathways, thereby weakening the bacteria's envelope modification capacity and structural stability; (ii) it also disrupts signal regulations in acidic environments, further impairing energy metabolism, flagellar function, and chemotaxis, thereby affecting bacterial adhesion capacity and environmental adaptability. These results demonstrate that under acid adaptation, the PhoP/PhoQ TCS is critical for coordinating cell envelope remodelling, energy metabolism, and motility to support biofilm formation in S. typhimurium. Understanding the contribution of this system to biofilm formation is essential for addressing the stress resistance and persistence of Salmonella in the food industry.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Zhang M, Hu J, T Xue (2025)

clpC-Mediated Translational Control Orchestrates Stress Tolerance and Biofilm Formation in Milk-Originated Staphylococcus aureus RMSA24.

Foods (Basel, Switzerland), 14(24): pii:foods14244333.

Staphylococcus aureus is an important pathogen that can cause widespread infections as well as severe outbreaks of food poisoning. Recent studies have drawn attention to foodborne pathogens such as S. aureus endowed with the ability to form biofilms and increase resistance to antimicrobial agents as well as environmental stress, posing challenges to food safety. The Clp (caseinolytic protease) protein complex plays a crucial role in energy-dependent protein hydrolysis processes. This mechanism is a common way to maintain intracellular homeostasis and regulation in both prokaryotic and eukaryotic cells, especially under stress conditions. In S. aureus, multiple genes encoding Clp ATPase homologues have been identified: clpC, clpB, clpY, clpX, and clpL. This study investigated the roles of clpC in stress tolerance and biofilm formation of foodborne S. aureus RMSA24 isolated from raw milk. Our results showed that the deletion of the clpC gene significantly reduced the bacterium's tolerance to heat, desiccation, hydrogen peroxide, and high osmotic pressure compared to wild type (WT). Furthermore, the clpC knockout mutant also exhibited a marked decrease in biofilm formation using Crystal Violet Staining (CVS) and Scanning Electron Microscopy (SEM). Finally, compared to WT, there was a total of 102 DEGs (differentially expressed genes), with a significant downregulation of genes related to biofilm formation (isaA and spa) and heat-shock response (clpP and danJ). These findings suggest that clpC regulates environmental tolerance in S. aureus by modulating the expression of stress- and biofilm-related genes, positioning it as a potential biomarker and a novel target for controlling contamination in the food industry.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Yao P, Kang M, ME Effarizah (2025)

Characterization of Biofilm-Forming Lactic Acid Bacteria from Traditional Fermented Foods and Their Probiotic Potential.

Foods (Basel, Switzerland), 14(24): pii:foods14244299.

A biofilm is a self-protective material formed by microorganisms to resist adverse environments. As an important group of microorganisms in the food industry and the human intestine, lactic acid bacteria (LAB) demonstrate enhanced probiotic activity in their biofilm state. In this study, a total of 90 LAB isolates from various traditional fermented foods across China were evaluated for their biofilm-forming capacity using the crystal violet staining method. Of these, eight isolates showed strong biofilm-forming capacity. These eight isolates were further evaluated for environmental stress responses, including tolerance to high acid and high bile salt concentrations, resistance to simulated gastrointestinal conditions, and adherence to Caco-2 cells. Four isolates with strong resistance to these stresses and adhesion to Caco-2 cells were selected for comparison between their planktonic and biofilm forms. Among these, the two isolates demonstrating the highest biofilm production capacity were AQ-4 and SY1-3, which were isolated from fermented pear juice and apple juice, respectively. Isolate AQ-4 was then identified as Lactiplantibacillus plantarum based on 16S rDNA sequencing. By integrating biofilm-forming capacity with key biological properties, including stress tolerance and epithelial adhesion, this study focuses on L. plantarum AQ-4, which exhibits distinct microstructural differences between planktonic and biofilm states, as revealed by scanning electron microscopy. The findings suggest that L. plantarum AQ-4 could be used to investigate the differential mechanisms in the planktonic and biofilm states and to act as the theoretical basis for the application of LAB biofilms in the food industry.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Ahn JM, Kim YH, Rhim JW, et al (2025)

Onion-Peel Carbon Quantum Dots: Antimicrobial Effect and Biofilm Control on Food Contact Surfaces.

Foods (Basel, Switzerland), 14(24): pii:foods14244296.

As by-products rich in flavonoids and phenolic compounds, onion peels are globally undervalued and often discarded. This study reports the synthesis of carbon quantum dots (CQDs) from onion peels and evaluates their antimicrobial effectiveness against key foodborne pathogens and biofilms on common food contact surfaces, including plastic, stainless steel, and rubber. The CQDs exhibited a quasi-spherical shape with particle sizes ranging from 1.7 to 9.0 nm and contained abundant oxygen- and nitrogen-functional groups, as confirmed by FT-IR and XPS analyses. The CQDs showed significant antimicrobial activity, with minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) against Salmonella typhimurium, Escherichia coli O157: H7, Listeria monocytogenes, and Staphylococcus aureus of 2200/2800 µg/mL, 1400/2000 µg/mL, 1200/1800 µg/mL, and 400/600 µg/mL, respectively. Time-kill assays confirmed these results. In biofilm tests, S. typhimurium formed biofilms more easily than L. monocytogenes. Washing with CQD solution for 5 min reduced biofilm presence by 81.6-91.5% for S. typhimurium and over 74% for L. monocytogenes, with more than 94% reduction after 10 min of treatment (over 94% for S. typhimurium; 95.8-98.8% for L. monocytogenes) across all surfaces, especially on plastic and stainless steel. These findings indicate that onion peel-derived CQDs are promising, eco-friendly agents for disrupting biofilms and turning undervalued waste into valuable products.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Azirar R, Ouagajjou Y, da Costa F, et al (2025)

Effect of Stocking Density and Biofilm-Based Microalgae on Larvae and Post-Larvae Growth and Settlement Patterns of the Clam Ruditapes decussatus (Linnaeus, 1758) in Captivity.

Animals : an open access journal from MDPI, 15(24): pii:ani15243557.

Larval rearing is a critical phase in shellfish-hatchery production. Thus, optimizing larval survival, growth, and settlement is essential for reliable seed output. This study investigated the effect of rearing density on larvae and settlement performances of the carpet shell clam Ruditapes decussatus in captivity. Furthermore, the influence of natural biofilm-based microalgae on larvae settlement and post-larvae performance was also investigated herein. Three larval rearing densities (10, 20, and 40 larvae mL[-1]) were studied during larvae development, and four settlement densities (35, 70, 100, and 140 larvae cm[-2]) were tested during larvae settlement and metamorphosis. The effect of biofilm-based microalgae on larvae settlement and post-larvae pattern was tested at a standard settlement density (70 larvae cm[-2]). High larval density significantly reduced survival (18% at 40 larvae mL[-1]) compared with lower densities (26% and 23% at 20 and 10 larvae mL[-1], respectively). Significantly higher settlement rate (36% and 33%) and spat yield were observed at 35 and 70 larvae cm[-2], respectively, compared to high densities (100 and 140 larvae cm[-2]). Remarkably, post-larvae reared under the biofilm treatment showed faster growth performances compared to untreated (control) ones. These findings indicated that lower larval and settlement densities enhance survival and settlement rates. Natural biofilm promoted post-larval growth, and therefore, its use can be an effective strategy to improve R. decussatus hatchery outcomes.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Nurmohamed FRHA, Allen KJH, Malo ME, et al (2025)

Pathogen-Specific Actinium-225 and Lutetium-177 Labeled Antibodies for Treatment of Biofilm-Associated Implant Infections: Initial In Vivo Proof-of-Concept.

Antibiotics (Basel, Switzerland), 14(12): pii:antibiotics14121283.

BACKGROUND: the primary challenge with implant infections is the formation of biofilm, which harbors dormant bacteria that reduce the effectiveness of antibiotics and amplify antibiotic resistance, exacerbating the global antimicrobial resistance crisis. A potential novel treatment strategy is radioimmunotherapy, which uses antibodies linked to radioisotopes to deliver targeted radiation to the bacteria and biofilm. We describe the first in vivo use of targeted radiation therapy, employing Actinium-225 (α-radiation) and Lutetium-177 (β-radiation) labeled antibodies to treat a Staphylococcus aureus biofilm-associated intramedullary implant infection. Untargeted radiation in the form of unbound radionuclide treatment was also evaluated.

METHODS: to assess therapeutic efficacy, bacterial counts were performed on implant and surrounding bone after seven days of follow-up. Biodistribution was evaluated using SPECT/CT and ex vivo gamma counting.

RESULTS: radioimmunotherapy using an antibody against wall teichoic acid which was labeled with Actinium-225 and Lutetium-177 achieved bacterial reductions between 45% and 93% on the implant and surrounding bone. Surprisingly, a similar antimicrobial effect was observed with unbound Actinium-225 treatment reducing the bacterial load by 80% on the implant and 98% in the surrounding bone. Indications of maximum tolerated dose (MTD) with Lutetium-177 labeled antibodies were observed through hepatic and renal function evaluations.

CONCLUSIONS: These results should be interpreted in the context of the study's constraints, particularly the limited animal sample size. Nonetheless, the results suggest that in vivo applied radiation may help reduce a biofilm-associated infection at the implant site as well as in the surrounding bone. These findings encourage further investigation into the use of targeted and non-targeted radiation, potentially combined with antibiotics, to develop effective strategies for eradicating biofilm-associated implant infections.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Erdoğan Deniz N, Akkaya Y, İH Kılıç (2025)

Biofilm Production, Distribution of ica Genes, and Antibiotic Resistance in Clinical Coagulase-Negative Staphylococci Isolates.

Antibiotics (Basel, Switzerland), 14(12): pii:antibiotics14121215.

Backgrounds/Objectives: This study aimed to quantify biofilm production and characterize the distribution of the biofilm-associated ica genes (icaA, icaD, icaB, icaC, icaR) in coagulase-negative staphylococci (CoNS) isolates, and to assess the association between these genes and antibiotic resistance profiles. Methods: A total of 121 CoNS isolates collected at Ümraniye Training and Research Hospital between 1 January and 30 August 2024 were identified by VITEK 2 Compact and MALDI-TOF MS. Biofilm production was quantified using the microtiter plate assay, and the presence of ica genes was determined by quantitative real-time PCR (qPCR). Antimicrobial susceptibility testing (AST) was performed with the VITEK 2 Compact (bioMérieux), and minimum inhibitory concentrations (MICs) were interpreted according to EUCAST criteria. Results:S. epidermidis was found to have the highest biofilm production capacity among the CoNS isolates, followed by S. haemolyticus. The icaA gene was detected in 99.17% of isolates, followed by icaR (70.24%), icaD (55.37%), and both icaB and icaC (28.92% each). The highest resistance rates were observed for oxacillin (85.8%) and erythromycin (85.1%), while all isolates remained susceptible to linezolid, daptomycin, and vancomycin. Conclusions: The high prevalence of ica genes in CoNS isolates indicates that biofilm formation plays a critical role in the pathogenesis of these species. The findings reveal that CoNS have a strong biofilm production potential, which is a decisive factor in their pathogenicity. However, the high methicillin resistance rates emerge as one of the main factors limiting the effectiveness of current treatment options. Therefore, future studies need to focus on the development of anti-biofilm approaches and alternative therapeutic strategies.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Zeng D, Jiao F, Yang Y, et al (2025)

Correction: Zeng et al. Myricetin Potentiates Antibiotics Against Resistant Pseudomonas aeruginosa by Disrupting Biofilm Formation and Inhibiting Motility Through FimX-Mediated c-di-GMP Signaling Interference. Biology 2025, 14, 859.

Biology, 14(12): pii:biology14121660.

Error in Figure [...].

RevDate: 2025-12-30
CmpDate: 2025-12-30

Aziz W, Sultana H, Kumar V, et al (2025)

The Relationship Between NETosis and Biofilm Formation in Chronic Infections.

Biomolecules, 15(12): pii:biom15121692.

Chronic infections pose significant clinical challenges due to their persistent nature, heightened resistance to conventional therapies, and association with biofilm formation. Neutrophil extracellular traps (NETs), released through a unique form of cell death known as NETosis, serve as an innate immune defense mechanism by trapping and neutralizing pathogens. However, accumulating evidence reveals a complex and paradoxical relationship between NETs and microbial biofilms. While NETs can immobilize and kill planktonic microbes, the extracellular DNA and associated proteins often contribute to biofilm stability, immune evasion, and chronic infection persistence. This review explores the bidirectional interactions between NETosis and biofilm formation, with a focus on their synergistic roles in the pathogenesis of chronic infections such as cystic fibrosis lung disease, diabetic foot ulcers, periodontitis, and implant-associated infections. We outline the molecular mechanisms governing NETosis, the structural and functional dynamics of biofilms, and how these processes intersect to form recalcitrant infection niches. Emerging therapeutic strategies aimed at disrupting this pathogenic interplay including DNase-based treatments, PAD4 inhibitors, and combination therapies are critically evaluated. By illuminating the pathogenic synergy between NETs and biofilms, this review underscores the need for integrated immunomodulatory and anti-biofilm interventions to effectively manage chronic infectious diseases and improve patient outcomes.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Jeyachandran S, S Sekar (2025)

Natural Anti-Biofilm Agents: A Comprehensive Review and Future Perspectives.

Current microbiology, 83(2):115.

Biofilms, complex microbial communities embedded in extracellular polymeric substances (EPS), pose significant challenges across medical, industrial and environmental sectors due to their enhanced resistance to antibiotics and chemical agents. Traditional treatments often fail to combat biofilm-associated infections, leading to increased healthcare costs and mortality rates. This comprehensive review explores the potential of natural anti-biofilm agents derived from plants, microorganisms, marine organisms and other natural sources as alternative strategies. Plant-derived compounds, microbial products and marine bioactive substances exhibit promising anti-biofilm properties through various mechanisms, including inhibition of microbial adhesion, quorum sensing (QS) interference and EPS disruption. The review highlights the efficacy of these agents in both in vitro and in vivo studies and discusses their potential applications in industries such as medicine, food processing and water treatment. Despite the promising results, challenges such as standardization, biocompatibility and environmental impact remain. Future research should focus on optimizing these natural agents and exploring synergistic combinations to enhance their efficacy. This review underscores the importance of sustainable and interdisciplinary approaches in developing effective, eco-friendly anti-biofilm strategies for diverse applications.

RevDate: 2025-12-29
CmpDate: 2025-12-29

Li T, Shen W, Zhou Y, et al (2026)

Simultaneous removal of manganese and nitrate by manganese redox driven moving bed biofilm reactor: Characteristic, biological community and mechanism.

Journal of environmental sciences (China), 161:858-871.

This study investigated the effects of different manganese forms (MnCl2 and MnO2) on the nitrogen and phosphorus removal performance of moving bed biofilm reactor (MBBR). Compared to the control without manganese, the addition of MnCl2 and MnO2 increased NO3[-]-N removal efficiency by 11.47 % and 9.54 %, and total nitrogen (TN) removal efficiency by 17.91 % and 15.45 %, respectively. The average accumulation of NO2[-]-N decreased from 3.02 to 0.04 mg/L and 0.18 mg/L, respectively. The manganese redox system induced by MnCl2 enhanced total phosephorus (TP) removal efficiency by approximately 3.5 times, while MnO2 reduced TP removal efficiency by 2.94 %. After discontinuing MnCl2 and MnO2 supplementation, denitrification efficiency significantly declined, and Mn(II) reduced by BioMnOx could not sustain the manganese cycling process long-term. Extracellular polymeric substances (EPS) analysis revealed that MnCl2 and MnO2 stimulated the production of uronic acids, amide III, and secondary amides in proteins. High-throughput sequencing indicated that Proteobacteria, Bacteroidetes, Chloroflexi, and Acidobacteria were the dominant phyla involved in denitrification, but different manganese sources altered the microbial community composition. The relative abundance of Proteobacteria generally decreased, while Bacteroidetes increased by 16.29 % and 4.14 % with MnCl2 and MnO2. MnCl2 was more conducive to the Bacteroidetes growth. This study provides a practical framework for applying manganese-enhanced MBBR system in wastewater treatment plants to improve nitrogen removal efficiency and operational stability.

RevDate: 2025-12-30
CmpDate: 2025-12-30

Guo X, Liu S, Zhou L, et al (2025)

Effective disposal and remediation of chemical agents with designer living biofilm materials in soil and water.

Fundamental research, 5(6):2571-2579.

Chemical agents (CAs) and their analogues, as representative persistent organic pollutants, are of serious global concerns and can have devastating impacts on environments and human beings. Enzymes used for decontamination of such chemical pollutions often lack high efficacy and robustness against environmental pressures, thereby limiting their practical application in bioremediation. Here, we report living materials based on genetically engineered biofilms that exhibit remarkable enzymatic activities, superior environmental tolerance, self-regeneration, recyclable usage, and tunable functionality. We show that the designer living materials can degrade CAs and pesticides with high efficacy in an eco-friendly manner, and our systems enable actual elimination of CAs pollution in water and soil. The degradation capacity of the designer living materials can achieve more than 95% for 5 mg/ml HD, 5 mg/ml GD and 5 mg/ml VX within 60 min under laboratory conditions, and the turnover numbers of the designer living materials for HD, GD, and VX have increased by more than 1.3 times compared with free enzymes. In addition, the relative activities of the designer living materials remained almost unchanged after 5 recycles, retaining over 95% of their initial catalytic activities even after the final cycle. Combining the adhesive engineered biofilm living materials with electropositive granule media to form a bifunctional composite material, we further demonstrate coinstantaneous removal of biological and chemical pollutants in environmental water. Our work thus establishes a general approach to improve the robustness of enzymes against environmental pressures and provides a sustainable method for decontamination of chemical and biological pollutions.

RevDate: 2025-12-29

Qi WY, Zhou JY, Guan SN, et al (2025)

Protective behavior of bacterial biofilm at high Temperatures: Corrosion control strategies for thermal system Pipes.

Bioresource technology pii:S0960-8524(25)01860-7 [Epub ahead of print].

Corrosion in the water-heat interaction systems shortens facility lifespan of transportation pipelines, leading to extensive perforation accidents and economic losses. This study investigates the impact of Geobacillus stearothermophilus on carbon steel corrosion, validated through the separate and combined application of biocide and biofilm dispersant. In high-temperature aqueous environments, the inoculation of this bacterium mitigates corrosion, as evidenced by a 33 % reduction in weight loss, a decrease in pitting depth from 16.2 to 0.8 μm, and an increase in Fe(Ⅱ): Fe(Ⅲ) of corrosion products. The addition of biocide (from 0 to 0.5 ppm) weakens the protective effect, while the combined use of both biocide and dispersant nearly abolishes the inhibition of corrosion. The local "anaerobic microenvironment" created by bacterial internal oxygen consumption and biofilm isolation of external oxygen alters corrosion products and directly inhibits aerobic corrosion. These findings provide a theoretical basis for the in-situ anti-corrosion of high-temperature pipelines by thermophiles.

RevDate: 2025-12-29
CmpDate: 2025-12-29

Zhu Z, Zhan Y, Sun H, et al (2025)

Exploring the Dynamic Culture System of biofilm-forming Bifidobacterium Adolescentis BL-8: from System establishment, Formation Mechanisms Analysis To Application in freeze-dried Probiotic Powder.

Current microbiology, 83(2):110.

Biofilm formation provides probiotics with a natural barrier against harsh conditions and increases their bioavailability. The dynamic culture system could effectively promote probiotic biofilm formation. In view of the excellent probiotic properties and biofilm-forming ability of Bifidobacterium adolescentis BL-8, a dynamic culture system for this strain was constructed in this study and utilized to carry out in-depth mechanistic and potential application research. The results showed that innovatively establishing this system with physical-biological synergies for B. adolescentis BL-8, using oat bran as the carrier, achieved a 46.6% increase in the biofilm-forming rate and reduced the formation time by 12 h. This enhancement was attributed to carrier-strain interactions that this system strengthened bacterial initial aggregation during reversible adhesion through electrostatic/hydrophilic force regulation. Transcriptome analysis during irreversible adhesion and growth maturation phase further discovered that this system controls two-component signaling systems to boost nitrogen assimilation and c-di-GMP pathways to suppress flagella assembly, collectively promoting bacterial growth and morphological transitions. Dynamic cultivation also regulated the quorum-sensing system, prolonged biofilm growth, and stimulated extracellular polymeric substance synthesis. These modulations reinforced the biofilm's structural integrity, enabling increased bacterial resistance to freeze-drying and gastrointestinal stress and the storage time of the freeze-dried probiotic powder. This dynamic culture system with physical-biological synergies effectively promoted B. adolescentis BL-8 biofilm formation through enhanced initial adhesion, bacterial proliferation and morphological transformations, and prolonged biofilm formation, exhibiting great potential for applications. This study provides an important theoretical basis and new insights for the development of probiotic biofilm-modulation technology and its industrial applications.

RevDate: 2025-12-29

Chatterjee S, Dube A, SK Majumder (2025)

Evaluation of antibacterial photodynamic efficacy of a novel cationic near infrared chlorophyll derivative against planktonic and biofilm-borne methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa.

Photochemistry and photobiology [Epub ahead of print].

Antibacterial photodynamic therapy (aPDT) is a promising approach for inactivation of antibiotic-resistant bacteria; however, its effectiveness is compromised, particularly when bacteria hide within biofilm and if infection spreads deeper in tissue. To overcome this limitation, photosensitizers having absorption in the near-infrared region (NIR) (650-800 nm), where light penetrates deeper in tissue, need to be developed. We report aPDT efficacy of Cycloimide Purpurin-18 betaine hydrazide conjugate (CIPp-18-BH), a cationic chlorophyll derivative, against Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PAO). CIPp-18-BH was synthesized by conjugating CIPp-18 to betaine hydrazide (BH) using a carbodiimide coupling reaction. CIPp-18-BH, as compared to CIPp-18, exhibited lower lipophilicity; thereby, it did not aggregate in aqueous conditions and generated a substantial amount of singlet oxygen upon photo-excitation with red light. CIPp-18-BH exhibited no fluorescence in water and substantial fluorescence in less polar solvents. CIPp-18-BH bound to planktonic bacteria did not show fluorescence; whereas remarkable fluorescence was seen in biofilms, indicating it lies on the surface of bacteria and accumulates within the apolar micro-environment of biofilms. PDT of planktonic MRSA and PAO with 40 μM CIPp-18-BH led to ~7 log and ~2.5 log reduction in cell viability, respectively. Confocal microscopy showed that PDT led to substantial bacterial inactivation within MRSA and PAO biofilms, resulting in inhibition of biofilm growth by ~50% and ~20%, respectively. Results demonstrate that CIPp-18-BH is a promising photosensitizer for photodynamic inactivation of planktonic and biofilm-borne bacteria.

RevDate: 2025-12-29
CmpDate: 2025-12-29

Shi S, Tang G, Wei J, et al (2025)

Organosilicone double-long-chain diquaternary ammonium salt acts as a biofilm scavenger to ameliorate colitis induced by dextran sulfate sodium salt.

Frontiers in immunology, 16:1644433.

OBJECTIVE: The treatment of ulcerative colitis (UC) remains challenging due to limited efficacy and significant side effects. Organosilicone Double-Long-Chain Diquaternary Ammonium Salt (JUC Spray Dressing) exhibits antibacterial, anti-inflammatory, and wound-healing properties. This study aimed to evaluate the therapeutic effects of JUC Spray Dressing in a Dextran Sulfate Sodium Salt (DSS)-induced UC mouse model and explore its potential mechanisms of action.

METHODS: A UC model was induced in mice using 3% DSS, followed by JUC Spray Dressing enema treatment. Disease activity index (DAI), histological scores, bacterial biofilms on the intestinal mucosa, and tight junction integrity were assessed. Inflammatory cytokine levels in peripheral blood were measured, and 16S rDNA amplicon sequencing was performed to analyze cecal microbiota composition.

RESULTS: JUC Spray Dressing significantly alleviated UC symptoms and reduced colonic congestion, with no significant difference compared to other treatment groups (P > 0.05). All treatments significantly decreased the expression of inflammatory cytokines in peripheral blood (P < 0.0001), with no significant differences among the groups. Additionally, all treatments effectively reduced biofilm thickness and bacterial abundance, improving intestinal barrier integrity. JUC Spray Dressing inhibited harmful bacteria such as Bacteroides spp. without significantly altering overall microbial composition.

CONCLUSIONS: JUC Spray Dressing effectively removes intestinal bacterial biofilms, reduces inflammation, and enhances barrier function to alleviate UC symptoms. Its efficacy appeared comparable to conventional treatments, suggesting potential as an alternative therapeutic option; however, the present study did not assess mucosal safety, and dedicated toxicology studies are required to establish safety for intraluminal use.

RevDate: 2025-12-29
CmpDate: 2025-12-29

Barel M, Koskeroglu K, Koca FD, et al (2026)

Colistin and Biofilm-Related Genes of Positive Escherichia coli O157:H7 in Cattle (Bos taurus) Carcasses Antibiotic Resistance Profiles, Biofilm and Molecular Characterisation of Isolates.

Veterinary medicine and science, 12(1):e70730.

Antimicrobial resistance in various infectious agents represents a public health threat. Therefore, the use of antimicrobials reveals new resistance mechanisms, and these resistance mechanisms are spreading globally. In this study, the aim was to isolate Escherichia coli from samples by conventional culture method and to identify the E. coli isolates obtained by PCR analysis. As a result of the culture method, 120 of 300 samples (40%) were isolated as suspected E. coli. However, the detection of the trpA gene only in 90 (75%) of the isolates allowed for the confirmation that it was, in fact, E. coli. According to PCR results, a total of 10 (11%) isolates were identified as E. coli subgroups. Eight (80%) of these isolates were found to be E. coli O157:H7 positive, while two (20%) were found to be E. coli O157 positive. In addition, five (50%) isolates were found to be H7 positive. Antimicrobial effect (Enzyme-Linked Immuno Sorbent Assay) was determined using the ELISA method. The results show that the CuONPs at 0.085 µg/mL had antibacterial properties against all strains. Antibiotic susceptibility was tested using the disc diffusion method. Nine (10%), 6 (6%), 28 (31%), 24 (26%), 5 (5%), 8 (8.8%), 4 (4%) and 6 (6%) tetracyclines, erythromycin, gentamicin, azithromycin, imipenem, ampicillin and nalidixic acid were found to be resistant, respectively. According to the results of the analysis, 1 and mcr 5 gene levels were found in 10 (11%) and 2 (2.2%) isolates, respectively. Also, in the isolates, E. coli O157:H7 had mcr 1 and mcr 5 genes in levels 3 (37.5) and 2 (25%). Nonetheless, 2 (100%) E. coli O157 isolates carried the mcr 1 gene, while 4 (80%) H7 isolates carried the mcr 1 gene. In this study, virulence genes were detected in all E. coli O157:H7 isolates. According to Congo red agar, two E. coli isolates were found to have strong biofilm formation ability, while three E. coli isolates were found to have moderate biofilm formation ability. The results of this study, due to the antimicrobial resistance, virulence genes and biofilm formation abilities of the strains, emphasize that these strains pose a significant risk to public health because they are associated with foodborne diseases and that this situation poses a danger of spreading the resistance gene in the environment.

RevDate: 2025-12-29
CmpDate: 2025-12-29

Deari S, Gothwal M, Gränicher K, et al (2025)

The Effect of Pellicle on Biofilm Formation in a Supragingival Biofilm Model.

Clinical and experimental dental research, 11(6):e70276.

OBJECTIVES: Oral biofilms initiate with the formation of an acquired pellicle on dental surfaces, a thin layer of salivary glycoproteins that provides a substrate for microbial adhesion. This study aimed to assess the necessity of a preformed pellicle for biofilm growth in vitro by analyzing the development of a standardized six-species biofilm, comprising Actinomyces oris, Veillonella dispar, Fusobacterium nucleatum, Streptococcus sobrinus, Streptococcus oralis, and Candida albicans.

MATERIALS AND METHODS: Biofilms were cultivated on bovine enamel discs under two conditions: (1) precoated with human saliva to simulate a pellicle and (2) without a preformed pellicle. Colony-forming units (CFUs) of each microbial species were quantified after incubation in either human saliva or a NaCl-based medium at 16 and 64 h.

RESULTS: The analysis revealed no significant differences in CFU counts between discs with or without a preformed pellicle, regardless of whether biofilms were grown in human saliva or NaCl medium, with one exception: S. oralis in pellicle/NaCl (6.7 Log10) medium at 16 h showed a slight decrease in the absence of a pellicle (5.9 Log10).

CONCLUSIONS: These findings suggest that microbial adhesion and subsequent biofilm development occurred independently of an initial pellicle. The preformed salivary pellicle does not seem to play a significant role in the initial development of this in vitro biofilm model. Biofilm testing in laboratory settings, especially for studies on antimicrobial efficacy, could be simplified, as pellicle formation may not be an essential requirement. Although no significant differences in biofilm development were observed between pellicle and no-pellicle conditions, the growth medium may have influenced pellicle interactions, warranting further investigation of media effects on pellicle formation. Existing assumptions about pellicle dependence in biofilm formation are challenged, and suggest that in vitro models without a pellicle may still provide valid platforms for studying biofilms and testing antimicrobial agents effectively.

RevDate: 2025-12-29

Bai S, Chen L, Xiang L, et al (2025)

Novel Sulfonamide Derivatives Containing the α-Aminophosphonate Backbone: A Biofilm Inhibitor for Preventing and Treating Citrus Bacterial Canker.

Journal of agricultural and food chemistry [Epub ahead of print].

The formation of bacterial biofilms enhances pathogen resistance, reducing the efficacy of traditional antibacterial agents. Consequently, developing new and efficient biofilm inhibitors is critical. Herein, a series of sulfonamide derivatives containing α-aminophosphonate fragments were designed, synthesized, and evaluated for antimicrobial activities. In vitro bioassay revealed the superior efficacy of compound A20 (EC50 = 26.6 μg mL[-1]) over the commercial bactericide thiodiazole copper (EC50 = 82.5 μg mL[-1]) against Xanthomonas axonopodis pv. citri (Xac). Further studies demonstrated that A20 effectively inhibited Xac biofilm formation and reduced multiple virulence factors, including extracellular enzyme activity, motility, and extracellular polysaccharide (EPS) production. These excellent properties are undoubtedly transmitted to in vivo activity, yielding preventive efficacies of 75.32% and 50.28% against citrus bacterial canker at 200 μg mL[-1], surpassing those of thiodiazole copper (57.52% and 43.83%). These findings indicate that inhibiting biofilm formation represents a promising strategy for developing novel antibacterial agents to manage persistent plant bacterial diseases.

RevDate: 2025-12-29

Albanell-Fernández M, Soriano Á, Herrera S, et al (2025)

Real-world experience with rezafungin for the treatment of biofilm-forming Candida infections.

Future microbiology [Epub ahead of print].

Biofilm eradication remains a significant challenge in clinical practice and contributes substantially to healthcare costs. Medical devices serve as a common substrate for biofilm formation and are implicated in a considerable proportion of invasive candidiasis cases. Rezafungin, a next-generation echinocandin, exhibits broad-spectrum fungicidal activity against Candida spp. and in vitro studies have confirmed its efficacy against Candida biofilms. A literature review up to July 2025 was conducted, including PubMed, Embase, Web of Science, and gray literature, focusing on the real-world use of rezafungin for device-related and other biofilm-associated Candida infections. Real-world data may suggest its clinical effectiveness in managing complex fungal infections frequently associated with biofilms, such as implant-associated infections, endocarditis, or osteoarticular infections, particularly in co-morbid patients. Among the 18 reviewed cases, mostly coming from Europe and the United States, a successful outcome was reported in 83.3% of patients after a median treatment duration of over 3 months, with no serious drug-related adverse events reported. Although these findings should be interpreted cautiously, given the limited sample size and heterogeneity of cases, they support rezafungin as a potential therapeutic option for biofilm-associated fungal infections.

RevDate: 2025-12-28
CmpDate: 2025-12-28

Farah H, Kadhim-Abosaoda M, Mohaisen-Mousa H, et al (2026)

Nanomedicine Strategies Against Biofilm-Associated Infections: Advances, Challenges, and Translational Barriers.

MicrobiologyOpen, 15(1):e70210.

Antimicrobial resistance continues to rise globally, with biofilm-associated infections intensifying the clinical burden through persistent tolerance to antibiotics and evasion of immune responses. Biofilms, structured microbial communities embedded in a protective extracellular matrix, underlie many chronic and recurrent infections, including endocarditis, urinary tract infections, cystic fibrosis lung disease, and device-related infections. Conventional antibiotics often fail in these contexts, and the discovery pipeline for novel agents remains limited. Nanotechnology has therefore emerged as a promising alternative, offering unique physicochemical features that enable enhanced penetration into biofilm matrices, improved drug stability, and targeted delivery of therapeutic agents. Diverse nanosystems, including metallic, polymeric, lipid-based, and ligand-functionalized platforms, have shown encouraging results in vitro and in vivo, demonstrating superior biofilm disruption and bacterial eradication compared with conventional therapies. Nevertheless, translating these advances into clinical practice remains challenging. Key barriers include complex and costly synthesis, scalability under good manufacturing practices, limited drug loading efficiencies, variability of preclinical biofilm models, regulatory uncertainties, and the risks of nanoparticle (NP)-induced toxicity, unpredictable biodistribution, and potential resistance development. Moreover, the dynamic interactions between NPs, host fluids, and biofilm extracellular matrices complicate pharmacokinetic and pharmacodynamic predictability. Addressing these obstacles requires coordinated efforts to refine manufacturing processes, standardize biofilm models, and implement nanospecific regulatory frameworks. With careful optimization, nanomedicine holds the potential to redefine the therapeutic landscape for biofilm-related infections.

RevDate: 2025-12-28
CmpDate: 2025-12-28

Alrashidi A, Husin BAEH, Alazmi M, et al (2025)

Modulatory effects of Mentha longifolia and Mentha spicata essential oils on Candida albicans biofilm formation.

Cellular and molecular biology (Noisy-le-Grand, France), 71(12):1-9.

Mentha longifolia (horsemint) and Mentha spicata (spearmint) are economically valuable aromatic plants widely utilized in food, cosmetic, and pharmaceutical industries due to their rich reservoir of bioactive compounds. This study investigated the antifungal and antibiofilm properties of essential oils extracted from these species against various Candida strains, particularly Candida albicans, a major opportunistic pathogen responsible for oral and systemic infections. Essential oils were extracted via hydrodistillation using a Clevenger apparatus and chemically characterized through GC-MS, revealing that M. longifolia oil was predominantly composed of pulegone (29.7%), menthone (26%), and eucalyptol (17.8%), while M. spicata oil was mainly enriched in pulegone (68.5%), eucalyptol (5.2%), and thymol (3.5%). The antifungal activity, evaluated by agar-well diffusion and broth microdilution assays, showed inhibition zones ranging from 9-14 mm for M. longifolia and 9-12 mm for M. spicata, with corresponding minimal inhibitory concentrations (MICs) of 0.39-6.25 mg/mL and fungicidal concentrations (MFCs) of 12.5-100 mg/mL. Both oils markedly reduced biofilm biomass in a concentration-dependent manner, with up to 90% inhibition observed at 4× MIC. The potent biofilm disruption was attributed to the high terpenoid content, capable of altering fungal membrane integrity. Overall, these findings demonstrate that the essential oils of M. longifolia and M. spicata possess significant antifungal and antibiofilm potential, highlighting their possible application as natural, plant-derived therapeutic agents for controlling Candida-associated oral and biomedical infections.

RevDate: 2025-12-27

Hanna RS, Sebak M, Sayed AM, et al (2025)

Mechanistic insights into Rottlerin's inhibition of MrkH-mediated biofilm and capsule formation in Klebsiella pneumoniae.

BMC microbiology pii:10.1186/s12866-025-04582-4 [Epub ahead of print].

BACKGROUND: Klebsiella pneumoniae is a notoriously aggressive opportunistic pathogen within the Enterobacteriaceae family, with virulence factors, including polysaccharide capsules, lipopolysaccharide (LP>S), siderophores, and biofilm formation, serving as essential determinants of the pathogenicity. Biofilms in particular are associated with substantial nosocomial and community-acquired illnesses; moreover, the capsule enveloping K. pneumoniae's surface further contributes to its viscous phenotype and virulence. This study explores the possible anti-virulence properties of the plant-derived compound Rottlerin using molecular docking aimed at a crucial protein implicated in biofilm formation in Klebsiella pneumoniae. Here, we investigate the molecular foundation of ligand-specific modulation of MrkH, a c-di-GMP-responsive transcriptional activator essential for biofilm development in Klebsiella pneumoniae. Utilizing a comprehensive methodology that encompasses molecular docking, dynamic modeling, and structural analysis, we evaluated the native c-di-GMP dimer-MrkH complex against the binding orientation and conformational impacts of the plant-derived chemical Rottlerin.

RESULTS: The sub-MIC of Rottlerin shows an inhibitory effect against some virulence factors, leading to a 57.6% decrease in biofilm formation, and a reduction in capsule size by 85.6% was observed; moreover, Rottlerin also significantly downregulated genes associated with these virulence factors. Through extensive molecular modeling (e.g., inverse docking, molecular dynamics simulation, and structural analysis), the c-di-GMP dimer was found to bind to rottlerin with a remarkable specificity, establishing stabilizing hydrogen bonds and distinctive π-cation interactions with Arg107 and Arg111, securing MrkH in an activation-ready configuration. Conversely, Rottlerin binds to the same pocket mainly via dual π-cation interactions with Arg107 and supplementary localized contacts; however, it is deficient in the extensive interaction network necessary for complete allosteric activation. Dynamic profiling by RMSF and PCA indicate that Rottlerin-bound MrkH exhibits an intermediate level of flexibility between the totally stable c-di-GMP-bound state and the highly dynamic apo form.

CONCLUSION: These results substantiate the function of Rottlerin as a non-activating competitive binder, providing mechanistic insight into its potential as an anti-biofilm agent and building a foundation for the rational design of small-molecule inhibitors aimed at c-di-GMP regulatory pathways. Our findings demonstrate that Rottlerin is a potent and efficient sub-MIC inhibitor of K. pneumoniae's ability to form biofilms and capsules.

RevDate: 2025-12-27

Hou G, Zhang R, Zhao T, et al (2025)

In situ biofilm development on microplastics and its impact on PFAS adsorption in aquatic environment.

Water research, 291:125240 pii:S0043-1354(25)02142-6 [Epub ahead of print].

Microplastics (MPs) in aquatic environments are rapidly colonized by microorganisms, leading to biofilm formation that alters their physicochemical properties and pollutant interactions. This process strongly affects the transport, transformation, and fate of coexisting contaminants, raising ecological concerns given the widespread abundance of MPs in natural waters. In this study, in situ exposure experiments were conducted in the Chishui River (Southwest China) to examine biofilm development on polypropylene (PP) and polystyrene (PS) over 60 days. Biofilm colonization significantly modified MP surface hydrophobicity, charge distribution, and functional groups, with biomass increasing by 4.40-5.70-fold. PS exhibited stronger microbial attachment and colonization, likely due to its rougher morphology and aromatic structure. Biofilm growth also enhanced the adsorption of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), increasing uptake by 1.12-1.45 and 1.16-1.39 times, with maximum capacities of 1.48-3.35 µg/g and 2.00-5.36 µg/g, respectively. Mechanistic analyses indicated hydrophobic and electrostatic interactions as dominant drivers, complemented by hydrogen bonding and surface complexation. Overall, these findings provide field-based evidence that biofilm development markedly strengthens MP-pollutant interactions, underscoring the ecological risks of biofilm-mediated contaminant transport in natural waters.

RevDate: 2025-12-27

Carvalho CG, Câmara JVF, Méndez DAC, et al (2025)

In vitro antibiofilm and anti-caries effects of polyhexamethylene biguanide under a microcosm biofilm model.

Journal of dentistry pii:S0300-5712(25)00761-4 [Epub ahead of print].

OBJECTIVE: To evaluate the in vitro antimicrobial effect of polyhexamethylene biguanide (PHMB) solution compared to chlorhexidine digluconate (CHX) on the viability and vitality of microcosm biofilm.

MATERIAL AND METHODS: Biofilm was produced from the saliva of 3 volunteers, under 0.2% sucrose exposure for 5 days. 180 enamel specimens were treated for 2 min with distilled water, 0.1% PHMB, 0.2% PHMB, 0.06% CHX and 0.12% CHX, once a day, for 5 days. The metabolic activity, viability of microorganisms and the vitality of biofilms were determined by resazurin, colony forming unit counts (CFU) and confocal scanning laser microscopy (CSLM), respectively (immediate and mediate analysis). Statistical analysis was conducted by Kruskal Wallis and Dunn's post-hoc tests (α = 0.05).

RESULTS: Only CHX significantly reduced biofilm metabolic activity, with 0.06% CHX showing an immediate effect and both CHX concentrations being effective in the mediate analysis. CFU analysis revealed that 0.06% CHX had the strongest immediate antimicrobial effect against Lactobacillus sp. (p = 0.0043) and Streptococcus mutans (p = 0.0159), while PHMB showed no significant reductions in viable counts. Confocal microscopy demonstrated no immediate effects on whole-biofilm vitality; however, 0.2% PHMB reduced vitality in the outer biofilm layer (p = 0.0349). PHMB further showed selective effects on biofilm structure, including an immediate reduction of β-polysaccharides (p = 0.0442) and live-cell volume (p = 0.0259), whereas CHX exerted more pronounced effects in the mediate analysis.

CONCLUSIONS: PHMB demonstrated antibiofilm activity characterized by modulation of biofilm viability and extracellular matrix components, particularly in the immediate phase.

RevDate: 2025-12-27

Lin Z, Ren G, Guo Y, et al (2025)

Microbial biofilm-based hydrovoltaic system for degradating organic pollutants.

Water research, 291:125256 pii:S0043-1354(25)02157-8 [Epub ahead of print].

Electron donors are the central drivers of microbial biodegradation, yet conventional sources-derived from light (photoelectrons), electrodes (bias-injected electrons), or chemical substrates (valence electrons)-are scarce in oligotrophic or lightless environments, limiting their environmental applicability. Here, we report the first microbial biofilm-based hydrovoltaic system (mBio-HS) that harnesses the hydrovoltaic effect of water evaporation to provide a sustainable electron source for pollutant degradation. The mBio-HS, constructed simply with electroactive microorganisms, continuously generates a stable electron flow (∼20 μA, ∼0.3 V) solely through the hydrovoltaic effect, without any external energy input. These water-evaporation-induced hydrovoltaic electrons (WEH-e) perform dual functions: sustaining microbial metabolism to form a self-sufficient community and directly reducing organic pollutants. Using methyl orange (MO) as a model azo dye, the system achieved efficient azo-bond cleavage and 90% decolorization within 72 h. This work not only presents the first prototype of a simple biofilm-based hydrovoltaic pollutant-degradation system, but also establishes a mechanistic foundation for harnessing the ubiquitous hydrovoltaic effect in microbial biofilms to power redox reactions-offering a practical route toward zero-energy, environmentally adaptive bioremediation.

RevDate: 2025-12-27

Sarkar P, Das S, Bandyopadhyay S, et al (2025)

Beta Carboline Alkaloid Harmine as Biofilm Inhibitor: In vitro, in Silico and in Vivo Studies Suppressing Growth and Virulence-Related Factors Against Resistant Staphylococcus Aureus.

Applied biochemistry and biotechnology [Epub ahead of print].

Screening plant-based alkaloids is one of the alternate therapeutic approaches to control antibiotic-resistant micro-pathogens. Our research highlighted beta carboline alkaloids as one of the most promising small molecules to established anti-virulent and anti-biofilm efficacy to regulate resistant bacterial infection. In vitro, in vivo assay and molecular docking were employed. Result Among six different bacterial strains, harmine showed 160 ± 2.07 µg/ml as the minimum inhibitory concentrations (MIC), followed by harmalol (190 ± 2.46) and harmaline (270 ± 3.04) against Staphylococcus aureus 96 (SA 96). Methicillin-resistant Staphylococcus aureus MRSA strain also showed inhibition of growth (MIC) by harmine, harmalol and harmaline at 250 ± 3.10, 320 ± 3.39 and 390 ± 4.90 µg/ml, respectively. MRSA is a prominent source of nosocomial infections, forming biofilms. The growth of biofilm got decreased with exposure to the sub-MIC concentrations (60, 80 and 100 µg/mL) of harmine, suppressing protein, targeting EPS and inhibiting extracellular protease. Harmine promote biofilm cell detachment by targeting cell surface hydrophobicity. Harmine causes depolarization of bacteria's cell membrane. Bacterial cell viability was further studied by propidium iodide (PI), DNA leakage and Acridine Orange (A/O)-Ethidium Bromide (EtBr) assay. Harmine treatment leads to increased reactive oxygen species (ROS) levels in biofilm cells. The binding affinities by molecular docking and dynamics indicated highest affinity with AgrC (-6.17 kcal/mol). Harmine treatment (32.0 mg/ kg bw, IP for five days) further recovered MRSA infected lungs in BALB/c mice. The findings revealed that among the three beta carboline alkaloids, harmine might be employed as a potential antibiofilm and antimicrobial agent for successful control of clinical S. aureus infection.

RevDate: 2025-12-27
CmpDate: 2025-12-27

Guo D, Tao Y, Sun L, et al (2026)

Betulinic Acid Eradicates Implant-Associated Infections by Disrupting the S. aureus Biofilm Matrix and Potentiating Host Immune Clearance.

Microbial biotechnology, 19(1):e70293.

Staphylococcus aureus biofilms are major contributors to chronic and recurrent infections due to their intrinsic tolerance to antibiotics and host immune clearance, highlighting the urgent need for safe and effective antibiofilm strategies. This study evaluated the inhibitory effects and underlying mechanisms of betulinic acid (BA), the principal active constituent of the traditional Chinese medicine Liquidambaris fructus, against S. aureus biofilms. In vitro assays demonstrated that the minimum biofilm inhibitory concentration (MBIC) of BA was 32 μg/mL, which was markedly lower than its minimum inhibitory concentration (MIC, 512 μg/mL), indicating preferential activity against biofilm formation. Serial passage experiments revealed no detectable induction of drug resistance. Mechanistic studies revealed that BA suppressed early biofilm adhesion and aggregation, downregulated the expression of adhesion-related genes (clfA, clfB, fnbpA and fnbpB), and reduced the production of extracellular polysaccharide (EPS) and extracellular DNA (eDNA). BA further disrupted mature biofilm architecture, promoted macrophage infiltration, enhanced bacterial clearance and attenuated the expression of immune evasion factors (scin, chip, lukE and nuc). In vivo, BA significantly alleviated implant-associated infections, mitigated local inflammatory responses and facilitated tissue repair. Collectively, these findings reveal that BA inhibits S. aureus biofilms through multiple coordinated mechanisms, with a low propensity for resistance development and favourable biosafety, supporting its potential as a promising lead compound for the development of novel antibiofilm therapeutics.

RevDate: 2025-12-26

Ragab AE, Al-Madboly LA, Al-Ashmawy GM, et al (2025)

SIRT1 mediated autophagy enhancement by Lactobacillus fermentum derived oligosaccharides accelerates wound healing in biofilm associated infection.

Scientific reports pii:10.1038/s41598-025-30280-2 [Epub ahead of print].

The present study explores the structural elucidation, antimicrobial properties, and wound-healing potential of a novel oligosaccharide, OligoF, derived from Lactobacillus fermentum. Structural analysis using paper chromatography, and 1D & 2D NMR spectroscopy indicated that OligoF is a linear tetrasaccharide comprising β-D-glucose, α-L-rhamnose, and D-glucuronic acid in a defined sequence. This structural elucidation was further confirmed by key chemical shifts, coupling constants, and glycosidic linkage assignments. OligoF exhibited potent antibacterial activity against multidrug-resistant Pseudomonas aeruginosa isolates, demonstrating inhibition zones of 60-63 mm, a minimum inhibitory concentration (MIC) of 16 µg/mL, and a minimum bactericidal concentration (MBC) of 32 µg/mL. Biofilm eradication assays revealed a significant reduction in biofilm viability by ~ four-fold at sub-MIC concentrations, as evidenced by scanning electron microscopy. OligoF-treated biofilms displayed notable disruption of extracellular matrix and severe bacterial cell distortion compared to untreated controls. In vivo wound-healing assays in rats showed that OligoF significantly reduced wound area and enhanced skin repair compared to untreated controls. Treatment with OligoF notably increased the concentration and gene expression of SIRT1 as well as upregulated the gene expression of beclin1 and ATG5 which are critical regulators of autophagy and cellular repair processes. Histopathological analysis corroborated these findings, revealing enhanced re-epithelialization, granulation tissue formation, and vascularized connective tissue deposition in OligoF-treated wounds. These findings underscore the potential of OligoF as a multifunctional agent with antibacterial and wound-healing properties, paving the way for its application in managing multidrug-resistant infections and promoting tissue repair.

RevDate: 2025-12-26

Patil TV, Randhawa A, Park H, et al (2025)

Spatiotemporally activated gelatin/unzipped carbon nanotubes/chitosan-based conductive hydrogel via dual stimuli for robust methicillin-resistant Staphylococcus aureus biofilm eradication.

International journal of biological macromolecules pii:S0141-8130(25)10402-9 [Epub ahead of print].

Antibiotic-resistant bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), pose a significant global health risk because they can form biofilms that are highly resistant to standard treatments. Even with considerable progress in antibacterial materials, reliance on passive antimicrobial agents may still lead to the emergence of resistance over time. We introduce a dual-action approach by developing a gelatin/glycerol/conductive chitosan (GGCC) hydrogel that demonstrates bactericidal properties both naturally and by external stimulation. We chemically modified chitosan with unzipped CNTs to impart conductivity (~4.2 S/m) and NIR responsiveness, then blended it with gelatin to enhance its biocompatibility and skin regeneration capabilities. The antibacterial activity was enhanced via NIR (~92.23 %) and electrical stimulation (~99.85 %). Moreover, robust biofilm was also ~100 % eliminated upon electrical stimulation. To clarify the fundamental mechanisms, we performed RNA sequencing on MRSA treated with hydrogel, with and without electrical stimulation. Pathways in oxidative stress, replication, biofilm formation, and peptidoglycan synthesis were triggered, resulting in strong antibacterial and anti-biofilm properties. Electrical exposure restricts bacterial adaptability, reducing the likelihood of resistance development. Our findings indicate that integrating of conductive chitosan with electrical stimulation offers a potential, resistance-resistant approach for addressing chronic bacterial infections.

RevDate: 2025-12-26

Li C, Liu K, Wu X, et al (2025)

Mechanisms of enhanced synergistic pollution reduction and carbon fixation induced by microalgal-bacterial interactions within different biofilm structures.

Journal of environmental management, 398:128412 pii:S0301-4797(25)04388-9 [Epub ahead of print].

Microalgae can achieve simultaneous pollutant removal and carbon fixation in wastewater treatment. However, unimicrobial algal systems face challenges of limited performance and poor biofilm adhesion. This study introduced bacteria as mediators and examined the mechanisms involved in different spatial structures of microalgal-bacterial biofilms. Results showed that, compared to the unimicrobial microalgal biofilm (UMB), the hybrid microalgal-bacterial biofilm (HMBB) and stratified microalgal-bacterial biofilm (SMBB) enhanced CO2 fixation from 20.04 % to 31.50 % and 35.30 %, respectively, with biomass increasing from 62.1 mg/g to 77.6 mg/g and 93.0 mg/g. The SMBB system exhibited the strongest enhancement, particularly in microalgal photosynthetic activity and total EPS. Protein (PN) and polysaccharide (PS) concentrations reached 57.28 mg/L and 26.45 mg/L, which were 43.27 % and 17.45 % higher than those in HMBB, respectively. The increased PN improved hydrophobicity, thereby enhancing biofilm formation and biomass accumulation in the microalgal-bacterial systems, with a bacterial-to-microalgal biomass ratio of 1:1.19, compared to 1:1.01 in HMBB. The microalgal-bacterial interaction comprised: (i) microalgae facilitating the enrichment of pollutant-degrading bacteria (e.g., Acinetobacter and Pseudomonas); and bacterial modulation of algal metabolism through (ii) upregulation of key genes associated with photosynthetic carbon fixation (e.g., GOT1, 12.57-fold), (iii) stimulation of hydrophobic amino acid synthesis (e.g., ilvE, 12.56-fold), and (iv) activation of pathways related to nitrogen-phosphorus metabolism and the TCA cycle. In general, bacterial inoculation contributes three main advantages for microalgal: enhanced biofilm adhesion, increased carbon sequestration, and improved pollutant removal efficiency, and the stratified microalgal-bacterial biofilm (SMBB) provides the most pronounced improvement.

RevDate: 2025-12-26
CmpDate: 2025-12-26

Song J, Liu M, Yasen Y, et al (2025)

Naringin as a non-antibiotic agent for multi-species oral biofilm control: in vitro antimicrobial mechanisms and in vivo safety in a rat caries model.

Frontiers in microbiology, 16:1722083.

INTRODUCTION: Dental caries is driven by dysbiosis of oral biofilms. Conventional antibiotics easily disrupt oral commensal balance, creating an urgent need for natural, non-antibiotic agents that can target cariogenic biofilms without causing ecological collapse.

METHODS: The antimicrobial and antibiofilm efficacy of Naringin was evaluated in vitro against planktonic and biofilm states of Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis (mono-species), and their multi-species consortium. Minimum inhibitory/bactericidal concentrations (MIC/MBC) and minimum biofilm inhibitory/reduction concentrations (MBIC/MBRC) were determined. Effects on acid production, extracellular polysaccharide (EPS) synthesis, and bacterial adhesion to hydroxyapatite (HAP) were mechanistically investigated. In vivo, a rat caries model induced by the multi-species consortium was topically treated with Naringin (2 × MIC, MIC, 1/2 × MIC) for 4 weeks. Caries lesions were evaluated using Keyes scoring and micro-computed tomography. Oral microbiota, serum biochemistry, and histopathology were analyzed for safety assessment.

RESULTS: Naringin exhibited potent, concentration-dependent antimicrobial activity. MICs were 1.00 mg/mL for S. mutans and S. sanguinis, 0.50 mg/mL for S. sobrinus, and 0.50 mg/mL for the multi-species consortium. Naringin at MBIC (2 mg/mL for multi-species) significantly disrupted biofilm architecture, reduced viable bacteria, and inhibited EPS synthesis. It maintained biofilm pH above 5.5 (the critical threshold for enamel demineralization), inhibited lactate production, and reduced multi-species bacterial adhesion to HAP by 68.3% at MIC. In vivo, Naringin (MIC) significantly reduced Keyes scores on smooth and sulcal surfaces by over 60%, preserved enamel integrity, and rebalanced the oral microbiota without inducing mucosal irritation or systemic toxicity.

DISCUSSION: Naringin, a natural non-antibiotic agent, effectively inhibits the "adhesion-biofilm-acid-EPS" cascade of multi-species cariogenic biofilms. Its selective efficacy against pathogens and favorable in vivo safety profile position it as a promising ecological agent for caries prevention by addressing oral dysbiosis at its root.

RevDate: 2025-12-26
CmpDate: 2025-12-26

Gade N, Scholz KJ, Kopp L, et al (2025)

Cerium chloride pretreatment reduces initial biofilm attachment on hydroxyapatite: a scanning electron microscopy study.

Frontiers in oral health, 6:1734138.

The incorporation of cerium instead of calcium into the crystal lattice of hydroxyapatite appears to increase the resistance of dental hard tissues to caries lesion initiation and progression. The effect on initial biofilm formation is yet unknown. The aim of this study was to assess the effect of cerium(III)chloride (50%CeCl3) pretreatment of hydroxyapatite (HA) discs on subsequent growth of an initial 3 species caries-biofilm. Twelve 9.5 mm diameter hydroxyapatite discs were divided into three groups (n = 4) and treated for 1 min with either 50% CeCl3, ultrapure water (Control), or 0.02% chlorhexidine gluconate (CHX) and washed twice in ultrapure water for 1 min. Samples were incubated in artificial saliva (21 °C, 120 min) for pellicle formation and then placed in an active attachment caries biofilm model comprising Actinomyces naeslundii, Schaalia odontolytica, and Streptococcus mutans, cultured anaerobically at 37 °C for 4 h before being fixed in 2.5% glutaraldehyde and examined using scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDX) in high-vacuum mode. SEM-micrographs at up to 50,000× showed net-like or spherical precipitates on the surface of all CeCl3-samples but not on the Control or CHX-samples. CeCl3-samples also showed signs of acid attack possibly due to the low pH (2.6) of the CeCl3 solution. Rods and cocci were found on all Control, but only on 2 of 4 CHX samples. On CeCl3 samples, only one harbored isolated cocci but no rods were observed. EDX-analyses confirmed the presence of Cerium in all CeCl3 samples with atomic percent (At%) ranging from 0.1 to 0.4 for areas without visible precipitates and up to 4.1 for areas with precipitates. CeCl3-treatment before pellicle formation results in the development of precipitates on the surface of HA and appears to have potential to inhibit initial biofilm growth on HA compared to CHX treated or untreated controls.

RevDate: 2025-12-26
CmpDate: 2025-12-26

Bai Y, Shang Z, Hu R, et al (2025)

Study on the antibacterial effect of the new anti-biofilm inhibitor ICAC on Escherichia coli.

Frontiers in cellular and infection microbiology, 15:1710407.

The rise of bacteria antibiotics resistance has bacome increasingly severe, and the development of natural compounds with antibacterial activity represents a promising approach to combat this issue. The efficacy and mechanisms of the plant-derived phenolic compound isochlorogenic acid C (ICAC) as an antibacterial and antibiofilm agent against E. coli were investigated. The study utilized a comprehensive approach encompassing crystal violet staining, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), the ruthenium red method, semi-solid agar motility assays, and quantitative real-time PCR (qRT-PCR) to elucidate the inhibitory effects and their underlying mechanisms. Results revealed that ICAC exhibited significant antibacterial and antibiofilm activity against E. coli. The results demonstrated that ICAC could inhibit the biofilm formation of E. coli, reduce the biomass of preformed biofilms, and decrease the production of extracellular polysaccharides (EPS) and extracellular proteins, as well as bacterial motility. Moreover, qRT-PCR results showed that ICAC downregulated genes associated with c-di-GMP synthesis while upregulating those involves in c-di-GMP degradation, thereby inhibiting biofilm formation and bacterial motility. In summary, ICAC shows potential as an effective anti-c-di-GMP agent and a novel antibacterial candidate for the treatment of E. coli infections.

RevDate: 2025-12-26
CmpDate: 2025-12-26

Gao C, Fu L, Wang J, et al (2025)

Aggregation-Induced Emission Ionic Liquids for Bacterial Imaging, Biofilm Inhibition, and Mixed Bacterial Infection Wound Healing.

Chemical & biomedical imaging, 3(12):837-848.

The excessive utilization of antibiotics escalates the susceptibility to bacterial infections in the general populace. The misuse of antibiotics and the emergence of bacterial resistance can be effectively regulated through the implementation of bacterial detection technology. Therefore, the construction of a multifunctional platform for bacterial detection and removal holds immense significance. In this research, we have effectively developed an imidazolium ionic liquid (TPE-IL) based on the tetraphenylethylene (TPE) structure with aggregation-induced emission (AIE), enabling effective bacterial imaging, biofilm inhibition, and mixed bacterial infection wound healing. TPE-IL effectively targets and penetrates bacterial surfaces via the electrostatic interactions of its imidazole groups and the hydrophobic interactions of its alkyl chains. This dual-action mechanism not only enhances fluorescence emission from the bacterial surface, enabling precise bacterial imaging, but also exhibits significant bactericidal activity. TPE-IL revealed superior antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The in vitro anti-biofilm experiments demonstrated that TPE-IL exhibited remarkable inhibitory effects on biofilms formed by S. aureus and E. coli. The in vivo antibacterial experiments confirmed the potent in vivo bactericidal activity of TPE-IL, which significantly reduced inflammatory responses, enhanced collagen deposition, and promoted wound healing without inducing organ damage in mice. Moreover, TPE-IL displayed low cytotoxicity and hemolysis rate. This work has successfully developed a safe and effective platform for bacterial identification and antimicrobial treatment, thereby offering significant implications in addressing the challenges associated with antibiotic resistance and misuse.

RevDate: 2025-12-26
CmpDate: 2025-12-26

Qi P, Liu H, Li Y, et al (2025)

Discovering a green pesticide candidate for controlling bacterial plant disease: 1,2,3,4-tetrahydro-β-carboline as a potential biofilm inhibitor.

RSC advances, 15(59):51110-51119.

Xanthomonas oryzae pv. Oryzae, result in rice bacterial blight, is the most severe bacterial disease affecting rice, and in certain regions, it is considered the most critical disease overall, with the potential to reduce yields by as much as 50%. It is difficult to control rice bacterial blight and lacking of pesticides. 1,2,3,4-Tetrahydro-β-carboline (THC) and their analogues show a diverse range of activities; however, research specifically focusing on THC remains limited, particularly concerning its antibacterial properties. Given its promising characteristics, THC holds potential for development as an environmentally friendly green pesticide. These outcomes reveal that THC signally inhibits both the cell growth and biofilm formation, thereby reducing its pathogenicity. Consequently, THC holds promise as a novel green pesticide aimed at targeting bacterial biofilms to effectively manage rice bacterial leaf blight.

RevDate: 2025-12-25

Nagai de Lima PM, Abbasi A, LaMastro V, et al (2025)

Methylene Blue-Loaded Liposomal Nanocarriers Enhance the Efficacy of Photodynamic Therapy against Candida auris Biofilm.

ACS infectious diseases [Epub ahead of print].

Candida auris poses a significant healthcare challenge, particularly within immunosuppressed patients. This pathogen can colonize the skin and develop biofilms associated with increased antifungal drug resistance that are difficult to treat with a limited antifungal repertoire. Some adjuvant treatments have been investigated, such as photodynamic therapy (PDT), which employs a photosensitizer (PS) irradiated by light. However, most PSs available suffer from poor biofilm penetration. In this in vitro study, a nanocarrier system was proposed as a possible strategy to facilitate the methylene blue (MB) photosensitizer penetration into biofilm and improve PDT action against C. auris. For this, positively (MB-P) and negatively (MB-N) charged liposomes encapsulating MB were successfully fabricated. In the PDT results, both liposome formulations eradicated planktonic cells of C. auris at minimum fungicidal concentrations (MFC) equivalent to those of free MB. MB-loaded liposomes showed enhanced penetration within biofilms and reduced C. auris biofilm burden ∼2× more compared to free MB. Additionally, biofilm biomass was reduced up to 37% with MB-loaded liposomes, while free MB only achieved ∼3% reduction. Furthermore, PDT mediated by MB-P or MB-N led to the production of reactive oxygen species (ROS) 2× higher than free MB, leading to greater oxidative damage toward C. auris biofilms. Finally, the biocompatibility of MB-loaded liposomes was examined against mammalian fibroblasts; MB-loaded liposomes maintained ∼80% cell viability compared to ∼58% viability for free MB. Promisingly, MB-P and MB-N liposomes were able to enhance the in vitro activity of PDT on C. auris biofilms, inciting the development of in vivo studies to validate their efficacy and safety.

RevDate: 2025-12-25

Qi X, Huo P, Gu Y, et al (2025)

Role of Extracellular Electrical Signal Transfer on Sensitivity in Electrochemically Active Biofilm Sensors for Signaling Water Acute-Toxicity Exposure.

Environmental science & technology [Epub ahead of print].

Electrochemically active biofilm (EAB) sensors have been widely used for real-time monitoring of water biotoxicity. Although extracellular electron transfer (EET) drives the electrical signal output of EAB sensors, its relationship with sensitivity is poorly understood. This raises two critical questions: (1) Do toxicants affect EET performance? (2) What is the relationship between EET performance and sensitivity. Herein, we employed a double-electrode-controlled electrochemical gating method (EGM) to evaluate the effects of different toxicants on EET performance across multiple biological scales, ranging from mixed- and purified-species biofilms to isolated OmcA proteins. Results indicated that five representative toxicants (0.02% formaldehyde, 5 mg/L NO2[-], 5 mg/L tobramycin, 5 mg/L Cu[2+], and 5 mg/L SDS) rarely impacted EET performance directly. On this basis, we probed the link between EET performance and sensitivity using riboflavin (RF) and anthraquinone-2,7-disulfonate (AQDS). After a 30 min toxicity exposure, the inhibition ratios were ranked as follows: AQDS-EABs > Control > RF-EABs. Although RF observably reduced the resistance, the high capacitance weakened the sensitivity. It is suggested that reducing resistance alone could not result in a higher sensitivity, and capacitance effects cannot be overlooked through modeling and electrochemical analysis. This study, therefore, proposes the time constant as a suitable metric for evaluating the relationship between the EET performance and sensitivity.

RevDate: 2025-12-25

Amirfard KD, Amarasiri M, D Sano (2025)

Energy allocation trade-offs among conjugative transfer, biofilm formation, and heavy metal resistance: a dynamic energy budget theory perspective.

Water research, 291:125216 pii:S0043-1354(25)02119-0 [Epub ahead of print].

Plasmid-mediated bacterial conjugation is a significant driver of antimicrobial resistance (AMR) dissemination in the environment, particularly within surface-attached biofilms, where spatial proximity facilitates gene exchange. Environmental stressors, such as heavy metals, can influence both the structural development of biofilms and the frequency of conjugation, imposing metabolic burdens that force bacteria to reprioritize their energy use. In this study, we used a simplified Dynamic Energy Budget (DEB)-based modeling framework to evaluate energy allocation in a single-strain bacterial population exposed to varying concentrations of zinc oxide (ZnO; 0-0.1 g/L). The model incorporates substrate assimilation, reserve dynamics, and energy partitioning toward growth, maintenance, metal resistance, biofilm formation, and conjugation. Experimental data were collected every 12 h for 48 h, including total organic carbon (TOC, mg/L), biomass (CFU/mL), intracellular adenosine triphosphate (ATP, mol/mL), conjugation frequency (transconjugants/donor), and biofilm density (OD550). Ordinary Differential Equation (ODE)-based simulations over 60 h showed that at 0.1 g/L ZnO, reserve energy and substrate declined approximately 3.1- and 1.9-fold, respectively (vs around 5- and 2.9-fold in control), indicating reduced depletion. Discrete-time-point flux models revealed conjugation demanded 17% of total energy at 36 h under 0.01 g/L ZnO, and 10% under 0.1 g/L at 60 h, while energy allocated to biofilm formation remained ≤ 3% under the highest ZnO concentration. Overall, the model reveals key trade-offs in bacterial energy allocation and provides mechanistic insight into how metal stress may shape biofilm formation and conjugation dynamics. Its modular and data-driven structure offers a basis for understanding microbial adaptation and AMR propagation in metal-contaminated environments.

RevDate: 2025-12-25

Sarwar W, Iqbal I, Ali Q, et al (2025)

Prospecting the Antibiofilm Potential of Bioactive Secondary Metabolites of Fungal Endophyte Cephalotheca foveolata (N11) Against Biofilm-Forming Bacteria.

Microscopy research and technique [Epub ahead of print].

Biofilms are found in diverse environmental settings and are considered to be responsible for various recalcitrant infections. One characteristic feature of biofilms is resistance to antibiotics, which is the leading cause of recurrent infections and treatment failure. Eradicating the biofilms necessitates the need for agents with promising anti-biofilm potentials. In the present study, the secondary metabolites of the fungal endophyte Cephalotheca foveolata (N11) isolated from the woody tissues of the medicinal plant Teucrium stocksianum were investigated for their antibiofilm potential against the test organisms. For evaluating the antibiofilm activities, in vitro assays including biofilm inhibition and eradication assays were employed. The bioactive metabolites of the N11 strain exhibited the highest biofilm inhibition and eradication potential of 87.62% and 79.22% respectively against Staphylococcus epidermidis. The results were further validated by light microscopy and confocal laser scanning microscope which revealed considerable distortion of the biofilm architecture by test agents. Besides, the effect of secondary metabolites on biofilms of test strain was also observed using Raman spectroscopy. The Raman spectra of treated biofilms exhibited a significant reduction in the intensities of the peaks indicating the denaturation and conformational changes in biomolecules. Furthermore, the partial purification of antibiofilm metabolites of N11 was carried out using solvent extraction following TLC and silica column with further characterization done using FTIR. These findings highlight the remarkable potential of bioactive secondary metabolites of endophytic fungi associated with T. stocksianum in disrupting the biofilms thus suggesting that these metabolites can be exploited for manufacturing effective agents against biofilm-associated complications.

RevDate: 2025-12-25
CmpDate: 2025-12-25

Pauer H, Nasiri S, Magalhães NS, et al (2025)

Enterocloster citroniae and related gut microbiome species modulate Vibrio cholerae biofilm formation through the production of bioactive small molecules.

bioRxiv : the preprint server for biology pii:2025.12.15.694346.

UNLABELLED: Cholera is a diarrheal disease that affects millions of people globally. Although the causative agent, Vibrio cholerae , has been extensively studied in isolation, investigation of its interactions with the gut microbiota started relatively recently. We and others previously showed that microbiota-derived metabolites significantly influence V. cholerae behavior. By investigating how an organic extract of human feces affects V. cholerae gene expression, we showed that gut metabolites strongly suppress swimming motility, a trait important for host colonization. Interestingly, extracts of pure cultures of a gut commensal, Enterocloster citroniae , recapitulated this inhibition. Here, we present a comprehensive examination of the effect of small molecules produced by E. citroniae and related species on V. cholerae behavior. We show that E. citroniae small molecules inhibit motility by various V. cholerae strains, and that several phylogenetically related species produce this activity, although the magnitude of the effect varies between strains. Using biofilm formation assays in static and flow conditions, we show that V. cholerae strongly induces biofilm formation in response to E. citroniae metabolites. Transcriptome and reporter analyses showed that several genes involved in synthesis of an extracellular polysaccharide are induced by E. citroniae metabolites. Lastly, we show that V. cholerae interactions with host cells are also modulated by this commensal. These findings advance our understanding of microbiome-pathogen interactions and how commensal bacteria influence V. cholerae virulence through the production of small molecules. In the future, this knowledge may be used to design novel microbiome-based therapeutic approaches to combat cholera and other infections.

IMPORTANCE: The human gut is home to a dense and rich community of microbes termed microbiota. This community has critical functions for host health, including protection against enteric pathogens. Despite this important role, we have only recently scratched the surface of the interactions that occur between members of the microbiota and pathogenic invaders. Cholerae is a disease that still causes significant morbidity and mortality worldwide. Studying how the causative agent, Vibrio cholerae , interacts with the microbiota will have implications not only for our understanding of this important microbial community, but may also lead to the development of new therapeutic strategies against cholera and potentially other infectious diseases.

RevDate: 2025-12-25
CmpDate: 2025-12-25

Lane JR, Mauser H, Santana-Krímskaya SE, et al (2025)

Biofilm formation during pneumococcal carriage imprints naturally acquired humoral immunity.

bioRxiv : the preprint server for biology pii:2025.12.17.694863.

UNLABELLED: Streptococcus pneumoniae (Spn) colonization of the nasopharynx is a prerequisite for transmission and invasive disease. To investigate how repeated asymptomatic colonization shapes immunity and influences bacterial traits, we developed the Repeated Asymptomatic Murine Pneumococcal Colonization (RAMPC3) model using strains belonging to serotypes: 2 (D39), 3 (WU2), and 4 (TIGR4). Sequential colonization revealed strain- and exposure-order-dependent effects on bacterial burden, with initial colonization yielding robust carriage and subsequent exposures resulting in diminished burden and rapid clearance. Humoral profiling demonstrated antigenic imprinting: the first colonizing strain largely determined IgG and IgA specificity, with minimal diversification after repeated exposures. Reactivity was strongest for biofilm-associated antigens correlating with each strain's biofilm-forming capacity. Using TIGR4 mutants deficient in biofilm formation, we confirmed that in vivo aggregate formation drives humoral responses. Human sera from naturally colonized adults mirrored these findings, favoring biofilm antigens independent from capsule. Protection was demonstrated as triple-colonized mice exhibited reduced mortality and bacteremia following pneumococcal pneumonia challenge. Moreover, the initial colonizing strain influenced protection against heterologous infection, underscoring the lasting imprint of the biofilm phenotype on immunity. Finally, IgA responses in nasal-associated lymphoid tissue paralleled serum IgA patterns, validating systemic measurements as a proxy for mucosal immunity. Collectively, these results reveal that biofilm formation during colonization is a key determinant of humoral immunity and protection, providing insight into pneumococcal biology and informing strategies to design next-generation interventions.

AUTHOR SUMMARY: Streptococcus pneumoniae (Spn) is a leading cause of pneumonia, meningitis, and sepsis, yet its primary lifestyle is asymptomatic colonization of the nasopharynx. Understanding how colonization shapes immunity and bacterial physiology is critical for predicting disease risk and improving future vaccines. Using a novel murine model of repeated colonization and human sera from naturally colonized adults, we show that humoral immunity is strongly biased toward antigens expressed during biofilm growth, the predominant mode of Spn in the nasopharynx, rather than planktonic forms. This response is strain-dependent and imprinted by the first colonizing strain, influencing subsequent exposures and protection against pneumonia. Importantly, biofilm formation, not capsule, drives immune recognition revealing a key link between bacterial physiology and host immunity. These findings provide fundamental insight into pneumococcal biology and the host response, suggesting that targeting biofilm-associated antigens may improve vaccine design or strategies to prevent transmission and invasive disease.

RevDate: 2025-12-25
CmpDate: 2025-12-25

Palma F, Díaz-Navarro M, Visedo A, et al (2025)

Correction: Assessment of the anti-biofilm effect of UV-C irradiation (254 nm) against healthcare associated infections related microorganisms.

Frontiers in microbiology, 16:1741013.

[This corrects the article DOI: 10.3389/fmicb.2025.1570334.].

RevDate: 2025-12-24

Valdivia C, P Domingo-Calap (2025)

Directed evolution of a staphylophage under biofilm and planktonic conditions.

NPJ biofilms and microbiomes pii:10.1038/s41522-025-00893-6 [Epub ahead of print].

The rise of multidrug-resistant bacteria, particularly biofilm-forming pathogens such as Staphylococcus epidermidis, highlights the urgent need for alternative antimicrobial strategies. Phage therapy, which uses phages to selectively infect and lyse bacterial cells, offers a promising solution. In this study, we evolved the lytic phage vB_Sep_Steph1 under both biofilm and planktonic conditions, using varying initial phage inoculum titers. Whole-genome sequencing of evolved populations revealed recurrent condition-dependent mutations in holins and structural genes with putative depolymerase activity-critical for host recognition and biofilm degradation. Phenotypic improvements in traits such as antibacterial efficacy and replicative fitness were observed to be highly dependent on both the presence of biofilm and the initial phage titer during evolution. Furthermore, some evolved phage lineages could delay bacterial resistance better than the ancestral strain. These findings support the utility of directed phage evolution to improve therapeutic efficacy and robustness, particularly against biofilm-associated infections.

RevDate: 2025-12-24

Leng J, Yang W, Yao Q, et al (2025)

Escherichia coli immobilized fermentation for continuous 3-fucosyllactose production via manipulating biofilm formation.

Bioresource technology pii:S0960-8524(25)01824-3 [Epub ahead of print].

3-Fucosyllactose (3-FL), a representative human milk oligosaccharide, is witnessing rapidly increasing demand. Establishing an immobilized fermentation system using microbial cell factories presents a promising strategy for continuous 3-FL production. In this study, the effects of nine biofilm-related genes on biofilm-forming capacity and 3-FL synthesis in Escherichia coli were systematically evaluated. Among them, pslA from Pseudomonas aeruginosa driven by a constitutive promoter demonstrated the best performance. Subsequently, the strategy of "prioritizing biofilm formation, following product synthesis" was implemented to develop an E. coli biofilm-based immobilized fermentation based on cotton fiber. In repeated-batch fermentation, BZJP05-JpslA exhibited higher cell density, improved cellular viability, and a 38.4% increase in average 3-FL yield. Furthermore, transcriptional level analysis revealed that pslA overexpression promoted glycerol metabolism, TCA cycle, fluxes toward 3-FL biosynthesis pathway, and expression of key genes involved in stress response. These findings provide an effective strategy and mechanism insights for optimizing E. coli cell-factory platforms.

RevDate: 2025-12-24

Li Y, Chen Z, Xia T, et al (2025)

Temperature downshifts induce biofilm formation in Pseudomonas aeruginosa through the SiaABCD signal and functional module.

The Journal of biological chemistry pii:S0021-9258(25)02938-2 [Epub ahead of print].

Pseudomonas aeruginosa is a highly adaptable Gram-negative pathogen known for its remarkable ability of forming biofilms. Understanding the environmental cues and regulatory mechanisms that drive biofilm formation is essential for developing effective control strategies. In this study, we screened 57 clinical and environmental P. aeruginosa isolates and discovered that a universal environmental cue, temperature downshift from host-associated 37°C to room temperature (21°C), significantly promotes biofilm formation in 63% of strains. Using the ATCC 27853 strain as a model, we demonstrate that this enhancement results from increased production of the Psl exopolysaccharides at lower temperature. LC-MS/MS analysis revealed elevated levels of the secondary messenger c-di-GMP, a key regulator of the motile-to-sessile transition, at room temperature. Through screening a mutant library targeting 18 c-di-GMP metabolic enzymes, we identified the diguanylate cyclase SiaD within the SiaABCD signaling and functional module as a principal driver of c-di-GMP elevation and biofilm promotion. Further investigation showed that the entire SiaABCD module, especially the signal-sensing domain of SiaA, mediates the temperature-dependent response. Integrating lipidomics with genetics and physiological assays, we show that a temperature downshift triggers rapid membrane perturbations that activate the SiaABCD signaling module, thereby increasing Psl production to strengthen surface adhesion and drive robust biofilm formation. These findings establish temperature downshift as a previously unrecognized physiological cue that promotes biofilm formation in P. aeruginosa, and define an adaptive regulatory pathway linking specific environmental stresses of membrane perturbation to dedicated c-di-GMP signaling module, paving the way for new strategies to disrupt biofilm-associated infections and transmission.

RevDate: 2025-12-24

Wang Y, Ye S, Deng Y, et al (2025)

Zinc deficiency reverses biofilm azole resistance in Candida albicans.

International journal of antimicrobial agents pii:S0924-8579(25)00250-X [Epub ahead of print].

Biofilm formation is one of the causes of azole resistance in Candida albicans. Although zinc is an essential trace element involved in biofilm regulation, its specific mechanistic role remains unclear. Here, we systematically evaluated the effects and mechanisms of zinc deficiency on biofilm formation and drug resistance. Intracellular zinc deficiency was induced using the zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and a CSR1 knockout strain, as confirmed using zinquin fluorescence. Biofilm formation and susceptibility were assessed using standardized microdilution techniques, including sessile minimum inhibitory concentration (sMIC) determinations via the XTT reduction assay, while drug interactions were assessed using a checkerboard assay. Efflux pump activity was measured using a Rhodamine 6G assay, and transcriptomic analysis was performed to elucidate underlying mechanisms. Pathogenicity was validated using a Galleria mellonella infection model. The results show that zinc deficiency inhibited biofilm development at all stages. Low-concentration TPEN (5µM) reduced the sMIC of fluconazole by more than 16-fold and ultimately reversed its azole resistance. This effect was mechanistically associated with the downregulation of key biofilm-related transcription factors and multidrug efflux pumps, as revealed by transcriptomic analysis, which also indicated that zinc deficiency triggered ribosomal remodeling and activated glucose metabolism. Survival analysis in the G. mellonella infection model confirmed that zinc deficiency reduced the overall pathogenicity of C. albicans biofilms. These results validate zinc homeostasis as a novel therapeutic strategy against drug-resistant and recurrent fungal infections, especially those involving biofilms.

RevDate: 2025-12-24

Lee JR, Lee JK, Meirambek S, et al (2025)

Structure-driven enhancement of anti-biofilm and anti-inflammatory activities of chimeric antimicrobial peptides against Pseudomonas aeruginosa.

Biochemical and biophysical research communications, 797:153180 pii:S0006-291X(25)01896-0 [Epub ahead of print].

The emergence of antibiotic resistance, biofilm-associated persistence, and dysregulated inflammatory responses presents a major challenge in the treatment of bacterial infections. Here, we investigated a chimeric antimicrobial peptide, HnMc, and its structurally modified analogues (HnMc-W, HnMc-WP1, and HnMc-WP2) to evaluate their antibacterial, anti-biofilm, and anti-inflammatory activities against Pseudomonas aeruginosa. While all peptides effectively inhibited planktonic bacterial growth, HnMc-WP1 and HnMc-WP2 showed pronounced suppression of biofilm formation and significant reduction of established biofilms. Notably, these peptides exhibited minimal cytotoxicity toward mammalian cells and strongly attenuated lipopolysaccharide-induced inflammatory responses through enhanced LPS-binding capacity. These findings demonstrate that structure-driven modification of chimeric antimicrobial peptides enables simultaneous regulation of bacterial persistence and host inflammatory responses, providing a rational strategy for multifunctional peptide design.

RevDate: 2025-12-24
CmpDate: 2025-12-24

Karched M, S Alkandari (2025)

Differential Proteomic Analysis of Extracellular Vesicles Produced by Granulicatella adiacens in Biofilm vs. Planktonic Lifestyle.

Dentistry journal, 13(12): pii:dj13120557.

Background: Gram-positive bacteria, once considered incapable of producing extracellular vesicles (EVs) due to their thick peptidoglycan layer, are now known to secrete EVs that transport virulence factors and modulate host immunity. These EVs contribute to bacterial pathogenicity by facilitating biofilm formation, immune evasion, and inflammation. Granulicatella adiacens, an oral commensal associated with infective endocarditis, represents a clinically relevant model to study EV-mediated virulence. Objectives: This study's aim was to investigate whether the proteomic composition and immunomodulatory activity of G. adiacens EVs differ between biofilm and planktonic lifestyles, thereby contributing to distinct pathogenic behaviours. Methods: EVs isolated from G. adiacens CCUG 27809 cultures were characterized using nano LC-ESI-MS/MS, followed by comprehensive bioinformatic and cytokine assays. Results: Quantitative proteomic profiling identified 1017 proteins, revealing distinct signatures between biofilm- and planktonic-derived EVs. Principal component analysis showed clear segregation between the two states, with biofilm EVs enriched in proteins linked to stress adaptation, adhesion, and structural integrity, while planktonic EVs exhibited growth- and metabolism-related proteins. A total of 114 virulence-associated proteins were identified, including several novel candidates. Functionally, EVs from both conditions significantly induced pro-inflammatory cytokines IL-8 and IL-1β in a dose-dependent manner (p < 0.05), whereas IL-17 remained unchanged. Conclusions:G. adiacens EVs exhibit lifestyle-dependent proteomic and immunomodulatory differences, underscoring their role in host-pathogen interactions and endocardial infection. These findings provide a foundation for future mechanistic and in vivo studies exploring EV-mediated virulence and potential therapeutic modulation.

RevDate: 2025-12-24

Meliefste HM, Mudde SE, Ammerman NC, et al (2025)

Towards enhanced translational value: preclinical drug activity testing against actively multiplying, nutrient-starved and pellicle biofilm-embedded Mycobacterium abscessus.

The Journal of antimicrobial chemotherapy pii:8404116 [Epub ahead of print].

BACKGROUND AND OBJECTIVES: Mycobacterium abscessus can cause severe infections in at-risk patients. Treatment efficacy for M. abscessus infections remains low, and better treatment options are needed. Factors hampering antibiotic potency may include the ability of M. abscessus to form biofilms and to endure in nutrient-deprived environments. These factors are underrepresented in current preclinical drug activity assays. Diversifying preclinical models by incorporating characteristics of these harsh environments may be important to better predict drug efficacy in patients. We aimed to develop a novel tool for studying drug activity against biofilm-embedded M. abscessus. In addition, drug activity was assessed against actively multiplying and nutrient-starved M. abscessus.

METHODS: An in-house 3D-printed platform-disc-based biofilm model was developed to study M. abscessus pellicle biofilms. In vitro activity of 16× the MICs of amikacin, bedaquiline, clofazimine, imipenem, rifabutin and tigecycline was assessed using time-kill kinetics assays.

RESULTS: The platform-disc-based model established reliable and reproducible quantification of M. abscessus biofilms. Drug activity against biofilm-embedded and nutrient-starved M. abscessus seemed less pronounced than against actively multiplying mycobacteria. For biofilm-embedded M. abscessus, drug activity was dependent on the developmental stage of the biofilm.

CONCLUSIONS: The varying levels of drug activity observed across the different M. abscessus populations highlight their distinct physiological relevance. As such, the platform-disc-based biofilm model could serve as a valuable asset in preclinical drug activity assays for M. abscessus.

RevDate: 2025-12-24
CmpDate: 2025-12-24

Kini S, Shetty KH, Ballal NV, et al (2025)

Evaluation of antimicrobial and antibiofilm efficacy of different antimicrobial peptides on multispecies biofilm of endodontic pathogens.

Journal of conservative dentistry and endodontics, 28(12):1215-1221.

BACKGROUND: Assessing and evaluating the function and activity of different types of antimicrobial peptides (AMPs) in suppressing multispecies endodontic pathogens is necessary.

AIM: The study was conducted to assess the antimicrobial and antibiofilm efficiency of gramicidin S, D-cateslytin (D-Ctl), GH-12, and DJK-5 AMPs on multispecies biofilm formed by endodontic pathogens.

METHODOLOGY: Multispecies biofilm comprising Enterococcus faecalis, Actinomyces naeslundii, Lactobacillus salivarius, and Streptococcus mutans were formed on 80 hydroxyapatite disk samples. Sixteen samples were allocated for each peptide in the experimental group (n = 16) and eight samples each for the control group, 2% sodium hypochlorite (positive control) and normal saline (negative control). The total number of colony forming units (CFUs) and biofilm intensity to fluorochrome in each study group were measured using the culture method and dual stain fluorescence microscopy method. The differences across groups were compared using Tukey's multiple comparisons test and one-way analysis of variance (α =0.05).

RESULTS: DJK-5 (CFU = 110/ml), gramicidin (CFU = 110/ml), and D-Ctl (CFU = 60/ml) peptides showed statistically significant correlation with respect to CFUs and similar antibiofilm activity (P < 0.01), whereas GH-12 (CFU = 90/ml) peptide revealed differences that were not statistically significant (P > 0.05).

CONCLUSION: DJK-5, gramicidin S, and D-Ctl peptides demonstrated remarkable efficacy against multispecies oral biofilms of S. mutans, L. salivarius, A. naeslundii, and E. faecalis. Saline showed least antimicrobial and antibiofilm activity. Sodium hypochlorite (NaOCl) showed strongest difference when compared to peptides or saline, validating it as a potent control. Hence, these peptides can be employed as potential antibiofilm agents in endodontic treatment procedures for better outcomes.

RevDate: 2025-12-24

Reyes-Pavón D, Jiménez M, Rodríguez-Campos A, et al (2025)

Impact of glycomacropeptide on growth, adhesion, and biofilm formation of the probiotic Lacticaseibacillus rhamnosus GG.

Natural product research [Epub ahead of print].

Glycomacropeptide (GMP) is a milk-derived bioactive peptide with demonstrated prebiotic properties. It is composed of a 64-amino acid framework and different carbohydrate molecules, which may serve as carbon sources for beneficial bacteria. Lacticaseibacillus rhamnosus GG (LGG) is a widely used probiotic strain that promotes intestinal barrier function, prevents pathogen colonisation and exerts anti-inflammatory and immunomodulatory activities. In this study, we explored the effect of GMP supplementation to LGG cultures on growth, adhesion and biofilm-forming properties of the bacterium. Prebiotic GMP promoted LGG growth and acidifying activities, mainly under anaerobiosis, without modifying the binding-mucus ability. GMP supplementation also increased LGG-biofilm biomass 3.8- and 3.4-fold under aerobic and anaerobic conditions. Besides, GMP treatment increased LGG-biofilm volume 4.7-fold, thickness by 39% and roughness by 110%. Thus, incorporating GMP into food or nutraceutical formulations might represent a viable strategy to enhance the probiotic efficacy of LGG strain, potentially improving its performance in functional products.

RevDate: 2025-12-24

Karim MA, KianvashRad N, Cabo M, et al (2025)

Cell Adhesion and Biofilm Development via Force-Sensitive Mechanisms: A Perspective.

ACS biomaterials science & engineering [Epub ahead of print].

Microorganisms live in environments where mechanical forces, such as fluid shear, surface tension, or pressure, shape their adhesion, biofilm formation, and maturation strategies. Microbes employ force-sensitive molecular switches embedded in surface appendages like flagella, pili, and adhesins like ALS1p or FLO11p to interpret mechanical cues. These mechanical cues trigger chemosensation or generate conformational changes in mechanosensors, thereby activating downstream signaling cascades and modulating gene expression. Ultimately, these mechanical stimuli affect microbial adhesion to surfaces, biofilm resilience, and architecture, often enhancing pathogenicity and virulence. Yet, the mechanobiological basis of these events remains underexplored. In this perspective, we discuss how bacterial and fungal systems use mechanosensation to navigate complex surfaces, underscore the challenges in monitoring real-time molecular responses to force, and explore emerging tools to reveal force-driven molecular dynamics. We highlight insights for synthetic microbiologists, materials scientists, and biomedical engineers into microbial mechanosensation and its translational potential, guiding the development of next-generation antimicrobial strategies to prevent and disrupt persistent biofilms in clinical and industrial settings.

RevDate: 2025-12-23

Gholami Aghamahali R, Pahlavanian M, HR Goli (2025)

Prevalence of quorum-sensing genes (lasI, lasR, RhlI and rhlR) in biofilm-producing Pseudomonas aeruginosa clinical isolates in Northern Iran.

BMC infectious diseases pii:10.1186/s12879-025-12406-z [Epub ahead of print].

RevDate: 2025-12-23

Zhang Z, Hu W, Xu T, et al (2025)

Performance of combined membrane-aerated biofilm reactor denitrifying phosphorus removal-anammox process for nutrient removal from low carbon/nitrogen ratio wastewater.

Bioresource technology pii:S0960-8524(25)01825-5 [Epub ahead of print].

This study developed a membrane-aerated biofilm reactor denitrifying phosphorus removal-anammox (MABRDPR-anammox) process to address carbon limitations in low carbon/nitrogen (C/N) ratio wastewater treatment. At a C/N ratio of 2, the system achieved high removal efficiencies: 95.6 ± 2.3 % for ammonia nitrogen (NH4[+]-N), 91.7 ± 3.9 % for total nitrogen (TN), and 75.0 ± 6.9 % for total phosphorus (TP). Compared to the conventional anaerobic-anoxic-oxic process, energy consumption decreased by 41.5 %, while NH4[+]-N, TN, and TP removal increased by 20 %, 30 %, and 13 %, respectively. Microbial analysis revealed that biofilm primarily drove nitrification, whereas activated sludge dominated denitrification (denitrifying bacteria abundance: 6.83 %) and phosphorus removal (denitrifying polyphosphate-accumulating organisms' abundance: 12.87 %). Functional gene profiling confirmed distinct distributions of nitrification (amoA/B/C) and denitrification (narG/H) genes between biofilm and sludge. Thus, the MABRDPR-anammox system offers an efficient, energy-saving, and practical solution for low C/N wastewater treatment.

RevDate: 2025-12-23

Krantz RT, Nguyen JB, Renyer KM, et al (2025)

Adsorption of the antimicrobial triclosan to microplastics impacts biofilm and planktonic microbial communities in freshwater.

The Science of the total environment, 1012:181179 pii:S0048-9697(25)02819-0 [Epub ahead of print].

Microplastics (MPs) are ubiquitous contaminants in freshwater ecosystems that could be hotspots for the interaction of antimicrobial compounds and surface-attached microbial biofilm communities. MPs and antimicrobials are both common in wastewater and urban freshwaters and MPs can adsorb contaminants like antimicrobials to their surface. Within aquatic habitats, MPs also support colonization by microbial biofilms. Therefore, we hypothesized that the adsorption of antimicrobials to MP surfaces would affect microbial communities colonizing MPs, altering their diversity, composition, and antimicrobial resistance. Using a microcosm approach, we assessed the potential for MP fibers to adsorb the common antimicrobial compound triclosan and alter bacterial and algal communities in MP-associated biofilms and in the surrounding water. We exposed acrylic, nylon, and polyester MP fibers to triclosan and measured its adsorption to each, finding that polyester adsorbed the most triclosan (3674 μg g[-1]) and nylon the least (217 μg g[-1]). Microcosms containing triclosan-exposed or control fibers of each polymer type were incubated in the lab with water from the Chicago River for 30 days. Analysis of MP-attached and planktonic bacterial and algal communities via high-throughput amplicon sequencing determined that exposure to triclosan significantly changed the taxonomic composition of these communities. These results suggest that widespread MP and triclosan contamination could potentially alter bacterial and algal communities in freshwater habitats. We also used quantitative polymerase chain reaction (qPCR) to measure the abundance of the class 1 integrase gene intI1 as a proxy for the impact of triclosan on resistance, finding no significant difference in intI1 abundance according to triclosan exposure.

RevDate: 2025-12-23
CmpDate: 2025-12-23

Strompfová V, Štempelová L, Bujňáková D, et al (2025)

Characterization of Staphylococci colonizing healthy equine skin: antibiotic resistance, virulence factors, and biofilm formation.

Veterinary research communications, 50(2):83.

In order to develop non-antibiotic therapies to treat dermatological diseases it is urgent to spread knowledge on composition and properties of skin bacteria in healthy animals. Since horses are popular companions of humans, it is necessary to know what risk skin bacteria pose to humans. Therefore the aim of this work was to analyse species composition of staphylococci isolated from skin swabs of 50 healthy horses using MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight) spectrometry and to characterize their virulence properties. Swabs were collected from five body areas (neck, dorsal back, abdomen, pastern and muzzle). Among 19 different staphylococcal species identified, the most common species were Staphylococcus succinus, S. xylosus, S. vitulinus and S. warneri. The most frequent antimicrobial resistance in staphylococcal isolates was observed for penicillin G (48%). The blaZ gene was detected in 90% of penicillin resistant isolates while mecA and mecC genes were not observed. Only low level resistance was noted for erythromycin (12%), tetracycline (6%), linezolid (4%) and oxacillin (4%). No multidrug-resistant strain was found, the MAR (multiple antibiotic resistant) index in average was 0.048 ± 0.039. Biofilm production was observed in 90.1% of isolates whereas 62% of them showed strong production. Gelatinase, DNase, protease and lipase activity was found in 50.4%, 41.3%, 22.3% and 46.3% of isolates, respectively. The results of enzyme activities testing using API ZYM kits (BioMérieux) revealed common production of acid and alkaline phosphatase, esterase, esterase lipase and napthtol-AS-BI-phosphohydrolase. The caution when interacting with horses is important especially in the case of injury since their staphylococci showed many virulent characteristics however they were not multi-resistant.

RevDate: 2025-12-23

Mohamed MF, Abdelmegeed SM, Abdelsattar AS, et al (2025)

Dronedarone synergizes with colistin against planktonic and biofilm forms of multidrug-resistant Gram-negative pathogens.

Microbiology spectrum [Epub ahead of print].

Infections caused by multidrug-resistant Gram-negative pathogens (MDR-GNP) are associated with high mortality, prolonged hospital stays, and increased healthcare costs. The treatment of these infections is complicated by the scarcity of new antibiotics and rising resistance to existing drugs. Colistin is often considered a last-resort therapy for MDR-GNP, but its clinical use is limited by significant nephrotoxicity and neurotoxicity. These challenges highlight the need for alternative strategies to enhance the effectiveness of current antibiotics. One promising approach is the use of combination therapy, which can potentiate antimicrobial activity while mitigating toxicity. We screened ~3,400 FDA-approved compounds and identified dronedarone, an antiarrhythmic with a well-established safety profile, as a potent enhancer of colistin activity against several MDR-GNP, including Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli. The colistin/dronedarone (COL/DRO) combination restored colistin efficacy in vitro and significantly reduced bacterial burden in a Caenorhabditis elegans in vivo model. Mechanistic studies revealed that colistin disrupts the outer membrane, facilitating dronedarone entry, which then permeabilizes and depolarizes the inner membrane, leading to cell death. This synergistic mechanism likely explains the potent activity observed. Additionally, the COL/DRO combination completely eradicated preformed biofilms of all tested pathogens. These findings suggest that dronedarone may be effectively repurposed to enhance colistin therapy, offering a promising strategy to combat life-threatening infections caused by MDR-GNP.IMPORTANCEAntibiotic resistance in dangerous Gram-negative bacteria is a growing global health crisis, leaving doctors with very few treatment options. Colistin is often the last available antibiotic for these infections, but its effectiveness is limited by serious side effects including nephrotoxicity and neurotoxicity. Our study shows that dronedarone, a heart medication already approved for human use, can make colistin much more effective against highly resistant bacteria. By working together, these two drugs kill bacteria that neither drug can eliminate alone, including those that form hard-to-treat biofilms. The combination also proved effective in an in vivo infection model, showing promise beyond the laboratory. Because dronedarone has a known safety record in people, this approach could be developed more quickly than entirely new antibiotics. These findings highlight a practical strategy to repurpose existing medicines to strengthen current antibiotics and fight life-threatening, drug-resistant infections.

RevDate: 2025-12-23
CmpDate: 2025-12-23

Noorian P, Hamann K, Hoque MM, et al (2025)

A model, mixed-species urinary catheter biofilm derived from spinal cord injury patients.

Biofilm, 10:100332.

Complex multispecies biofilms consistently colonise urinary catheters, causing persistent asymptomatic bacteriuria and frequent symptomatic episodes in long-term catheterized individuals. Simple single-species models often fail to capture the complexities of mixed-species interactions and lab-based organisms may not reflect the genomic diversity found in real-world infections. Additionally, growth under flow conditions promotes robust, complex-biofilm structures. Therefore, to reflect the dynamics of in vivo infections, biofilm samples from clinical indwelling catheters of spinal cord injury (SCI) participants colonised by 5-10 species were used to establish polymicrobial macro-fluidic models, in catheters. This resulted in final models of 2-4 species biofilms. Metagenomic techniques using short-read Illumina and long-read Oxford Nanopore sequencing was used to assess the taxonomic composition, in vivo to in vitro biofilms diversity shifts, single nucleotide polymorphism (SNP) analysis and complete metagenome-assembled genomes (MAGs). In silico analysis revealed a high number of varied antibiotic resistance genes, virulence factors and biofilm associated factors present in these biofilms. Antibiotic resistance testing using our models highlighted the drastic differences between planktonic bacteria, single-species and multispecies biofilms. While single-species biofilms show considerably increased tolerance to antibiotics compared to their planktonic counterparts, this resistance is even greater in multispecies biofilms. Under flow conditions, all species in the multispecies biofilm showed increased resistance, unlike static conditions where only most did. Models developed and characterised in this study are expected to facilitate testing of effective strategies to prevent and treat catheter-associated infections by enabling more accurate analysis of biofilm inhibition, disruption and microbial interactions.

RevDate: 2025-12-23
CmpDate: 2025-12-23

Santos-Díaz G, Rodríguez-Rivas Á, A Cuetos (2025)

Relevance of the computational models of bacterial interactions in the simulation of biofilm growth.

Physical review. E, 112(5-1):054411.

This study explores the application of elongated particle interaction models, traditionally used in liquid crystal phase research, in the context of early bacterial biofilm development. Through computer simulations using an agent-based model, we have investigated the possibilities and limitations of modeling biofilm formation and growth using different models for interaction between bacteria, such as the Hertz model, soft repulsive spherocylindrical model, and attractive Kihara model. Our approach focuses on understanding how mechanical forces due to the interaction between cells, in addition to growth and diffusive parameters, influence the formation of complex bacterial communities. By comparing such force models, we evaluate their impact on the structural properties of bacterial microcolonies. The results indicate that, although the specific force model has some effect on biofilm properties, the intensity of the interaction between bacteria is the most important determinant. This study highlights the importance of properly selecting interaction strength in simulations to obtain realistic representations of biofilm growth and suggests which adapted models of rod-shaped bacterial systems may offer a valid approach to study the dynamics of complex biofilms.

RevDate: 2025-12-22

Zhang X, Dong Z, Zhang S, et al (2025)

Microplastic biofilm as hotspots of antibiotic resistance genes and potential pathogens.

NPJ biofilms and microbiomes pii:10.1038/s41522-025-00890-9 [Epub ahead of print].

Microplastic biofilms, known as the "plastisphere", harbor diverse microbial communities and serve as reservoirs for antibiotic resistance genes (ARGs). This review discussed the mechanisms driving bacterial community alteration on microplastics and delineated the pathways through which ARGs transfer within microplastic biofilms. We expected to provide a comprehensive understanding of the ecological and human health impacts associated with microplastic biofilms and ARGs, thereby informing strategies to mitigate plastic pollution and its risks.

RevDate: 2025-12-22

Mohanasundaram M, Kandaswamy K, P B H, et al (2025)

Anti-biofilm potential of Matricaria chamomilla against tetra species representative gut commensals.

Folia microbiologica [Epub ahead of print].

RevDate: 2025-12-22

Mahoudeau L, Crétin P, Joublin-Delavat A, et al (2025)

The interplay between the marine diazotroph Vibrio diazotrophicus and its prophage shapes both biofilm structure and nitrogen release.

Applied and environmental microbiology [Epub ahead of print].

UNLABELLED: Marine environments are frequently oligotrophic, characterized by low amount of bioassimilable nitrogen sources. At the global scale, the microbial fixation of N2, or diazotrophy, represents the primary source of fixed nitrogen in pelagic marine ecosystems, playing a key role in supporting primary production and driving the export of organic matter to the deep ocean. However, given the high energetic cost of N2 fixation, the active release of fixed nitrogen by diazotrophs appears counterintuitive, suggesting the existence of alternative passive release pathways that remain understudied to date. Here, we show that the marine non-cyanobacterial diazotroph Vibrio diazotrophicus is endowed with a prophage belonging to the Myoviridae family, whose expression is induced under anoxic and biofilm-forming conditions. We demonstrate that this prophage can spontaneously excise from the genome of its host and that it forms intact and infective phage particles. Moreover, phage-mediated host cell lysis leads to increased biofilm production compared with a prophage-free derivative mutant and to increased release of dissolved organic carbon and ammonium. Altogether, the results suggest that viruses may play a previously unrecognized role in oceanic ecosystem dynamics by structuring microhabitats suitable for diazotrophy and by contributing to the recycling of (in)organic matter.

IMPORTANCE: Diazotrophs are key players in ocean functioning by providing fixed nitrogen to ecosystems and fueling primary production. However, from a physiological point of view, the active release of nitrogenous compounds by diazotrophs is paradoxical, since they would invest in an energy-intensive process and supply nutrient to non-sibling cells, with the risk of being outcompeted. Therefore, alternative ways leading to the release of fixed nitrogen must exist. Here, we show that the marine non-cyanobacterial diazotroph Vibrio diazotrophicus possesses one prophage, whose activation leads to cell death, increased biofilm production, and the release of dissolved organic compounds and ammonium. Taken together, our results provide evidence that marine phage-diazotroph interplay leads to the creation of microhabitats suitable for diazotrophy, such as biofilm, and to nutrient cycling, and contributes to better understanding of the role of viruses in marine ecosystems.

RevDate: 2025-12-22
CmpDate: 2025-12-22

Yang M, Wang S, Qu Q, et al (2025)

ClpB affects biofilm formation in methicillin-resistant Staphylococcus aureus.

Frontiers in microbiology, 16:1723924.

INTRODUCTION: This study aims to explore the effects of the molecular chaperone ClpB on the biofilm formation and pathogenicity of methicillin-resistant Staphylococcus aureus (MRSA).

METHODS: The biological membrane formation was evaluated by constructing a clpB knockout strain (ΔclpB) and a complemented strain (CΔclpB) of USA300 MRSA, followed by crystal violet staining, scanning electron microscopy, confocal laser scanning microscopy, and quantitative analysis of extracellular matrix components. A mouse skin infection model was subsequently employed to assess wound healing, histopathological changes, and the expression levels of inflammatory factors.

RESULTS: The results showed that compared with the wild strain (WT), the biomass of ΔclpB biofilm was significantly reduced (p < 0.0001), the structure was damaged and the production of extracellular matrix (eDNA, polysaccharides, proteins) decreased. CΔclpB then returned to the WT level. In the in vivo experiments, the ΔclpB infection group had faster wound healing, reduced tissue damage, and decreased expressions of TNF-α and IL-6 at both protein and mRNA levels.

CONCLUSION: ClpB promotes the formation of MRSA biofilms by regulating extracellular matrix synthesis and host inflammatory responses and is a potential target for anti-biofilm therapy.

RevDate: 2025-12-22
CmpDate: 2025-12-22

Zhao J, Zhang J, Yu H, et al (2025)

Short-cut nitrogen removal from high-strength ammonia wastewater in a sequencing batch biofilm reactor: roles of NO and its production mechanism.

Frontiers in microbiology, 16:1653308.

Nitric oxide (NO) is a key intermediate in the biological nitrogen removal process. However, its role and production mechanism is still not fully understood. In this study, a sequencing batch biofilm reactor (SBBR) was used to study the short-cut nitrogen removal from high-strength ammonia wastewater and NO production mechanism. The ammonia concentration in SBBR was 1,000 mg-N/L, with a carbon-nitrogen ratio of 5, the simultaneous partial nitrification and denitrification efficiency reached 66.42%, while the average total inorganic nitrogen removal efficiency was 83.37 ± 6.93%. Microbial community analysis showed the vital role of functional bacteria such as Thauera, Stappia, and Nitrosomonas in the short-cut nitrogen removal process. The accumulation of NO occurred mainly under aerobic conditions, with the highest NO concentration of 0.19 mg-N/L. NO accumulation was mainly attributed to the incomplete oxidation of hydroxylamine, nitrifier denitrification and heterotrophic denitrification. Synergistic inhibition of nitrite-oxidizing bacteria by NO with free ammonia and free nitrous acid contributed to rapid establishment of partial nitrification and long-term stability of the process. The present study provides novel insights into the underlying mechanisms mediating the inhibition of nitrite-oxidizing bacteria.

RevDate: 2025-12-22

Zavala-Hernández AN, Salto-Reyes C, Bravo-Patiño A, et al (2025)

IL-1β, TNF-α, and IL-10 reduce cell viability and differentially alter biofilm structure and gene expression levels in Staphylococcus aureus USA 300.

Frontiers in immunology, 16:1665397.

RevDate: 2025-12-22
CmpDate: 2025-12-22

Kumar M, Soni R, Maniyar RS, et al (2025)

Characterization of Extracellular Polymeric Substances from Biofilm-Forming Marine Bacteria from the Arabian Sea, India.

Indian journal of microbiology, 65(4):1906-1918.

UNLABELLED: Extracellular polymeric substances (EPS) are complex, hydrated matrices produced by biofilm-forming bacteria to anchor themselves to surfaces and resist antibiotic treatment. EPS plays a critical role in the formation, maintenance and virulence of biofilms, leading to persistent infections and posing significant challenges in healthcare. Characterizing bacterial EPS is essential to understand their biochemical composition and functional properties, which is critical for optimizing their applications in biotechnology, medicine, and environmental management. Therefore, the present study aimed to isolate and screen the bacteria from Arabian Sea for their ability to produce EPS from biofilm surfaces. Additionally, the detailed characterization of the EPS was also carried out. These bacteria were identified using 16S rRNA gene sequence analysis and revealed that all the EPS-producing bacterial isolates belong to different bacterial genera (Oceanimonas, Psychrobacter and Vibrio). The bacteria were cultured on Zobell marine broth media and EPS were isolated using the propanol precipitation method. The EPS weight varied among the bacterial isolates and ranged from 0.81 g L[-1] to 2.21 g L[-1]. The EPS produced by the bacterial strains have shown antimicrobial as well as free radicals (2,2-diphenyl-1-picrylhydrazyl; DPPH) and 2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity. The antimicrobial and free radical scavenging properties of EPS have promising biotechnological applications in developing new antibiotics, enhancing food preservation, creating protective coatings, and improving wound healing therapies. The Fourier-transform infrared spectroscopy (FTIR) revealed the presence of aliphatic methyl, halide groups, saccharides and primary amines. Gas chromatography equipped with mass spectroscopy (GC-MS) confirmed the presence of monosaccharides such as glucose, galactose, arabinose and mannose. The EPS were further characterized using X-Ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The study highlights the importance of EPS in biofilm formation, antibiotic resistance and persistent infections, emphasizing the importance of isolating and characterizing of EPS for its potential biotechnological applications, including antimicrobial and free radical scavenging activities.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12088-024-01351-1.

RevDate: 2025-12-22
CmpDate: 2025-12-22

Wojnowska M, Wajima T, Yelland T, et al (2025)

Structural basis for collagen recognition by the Streptococcus pyogenes M3 protein and its involvement in biofilm.

eLife, 14: pii:105539.

The M protein is an essential virulence factor of Streptococcus pyogenes, or group A streptococcus (GAS), one of the most common and dangerous human pathogens. Molecular and functional characterization of M protein variants and their interactions with host components is crucial for understanding streptococcal pathogenesis and vaccine development. The M3 protein is produced by the prevalent emm3 GAS serotype, which is frequently associated with severe invasive diseases. Here, we structurally and biochemically characterize the interaction of M3 with human collagens. High-resolution structures of the N-terminal M3 domain in the free state as well as bound to a collagen peptide derived from the Collagen Ligands Collection reveal a novel T-shaped protein fold that presents binding sites complementing the characteristic topology of collagen triple helices. The structure of the M3/collagen peptide complex explains how emm3 GAS and related streptococci, such as Streptococcus dysgalactiae subsp. equisimilis, can target collagens to enable colonization of various tissues. In line with this, we demonstrate that the M3/collagen interaction promotes enhanced biofilm formation of emm3 GAS in an emm type-specific manner, which can be inhibited with the recombinant N-terminal M3 domain. Further, emm3 GAS are shown to colocalize with collagen in tissue biopsies from patients with necrotizing soft tissue infections, where GAS biofilms are common. This observation is reproduced in infected organotypic skin models. Together, these data provide detailed molecular insights into an important streptococcal virulence mechanism with implications for the understanding of invasive infections, strategies for treating biofilm and M-protein-based vaccine design.

RevDate: 2025-12-21

Geiken A, Gutman AS, Röder N, et al (2025)

A new method for continuous in vivo pH measurement in saliva and oral biofilm - a comparative pilot study.

Clinical oral investigations, 30(1):23.

RevDate: 2025-12-21

Du M, Wang Z, Yin D, et al (2025)

Nano Ag-AlOOH modified Cured-in-Place-Pipe (CIPP) composites for controlling sewer biofilm:performance and mechanism of extracellular polymeric substances reduction and antimicrobial activity.

Environmental research pii:S0013-9351(25)02845-2 [Epub ahead of print].

The sewer biofilms are recognized as a major reason for odor, pipe corrosion and flow restriction. Ultraviolet-cured-in-place pipe (UV-CIPP) has been a widely used trenchless repair technique in recent years because of their cost-effective and small jobsite footprint. This study compared the physicochemical properties, microbial community structures, and related functional genes of biofilms formed on CIPP, reinforced concrete (RCP) and ductile iron pipes (DIP). The total extracellular polymeric substances (EPS) contents of CIPP, RCP and DIP were 186.5, 286.3 and 214.9 mg/g VSS. Biofilms on RCP exhibited weaker motility and stress responses, whereas those on DIP displayed enhanced adhesion and EPS production. The formation of high ORP microenvironments on CIPP surfaces was not favorable for biofilm growth. The smooth surface of CIPP hindered microbial colonization and caused stressed microorganisms to allocate energy to growth and reproduction rather than EPS synthesis. Furthermore, a new strategy was proposed for effective biofilm inhibition by adding boehmite loaded with Ag nanoparticles (Ag-AlOOH) to the UV-CIPP resin layer. Ag-AlOOH/CIPP reduced biofilm thickness, EPS, protein, and polysaccharide contents of CIPP by 72.1%, 69.4%, 68.7%, and 73.5%, respectively. The polyhydroxy structure of AlOOH enhanced the hydrophilicity of the CIPP surface and reduced microbial colonization. Ag[0]/Ag[+] decreased the nitrogen and energy metabolism, limited Gram-positive bacterial abundance, and viable cell counts. This study showed that effects of CIPP materials on biofilm characteristics and microbial functions, and developed an efficient biofilm control strategy by incorporating Ag-AlOOH into UV-CIPP.

RevDate: 2025-12-21

Pulido-Sánchez M, Montero-Beltrán E, López-Sánchez A, et al (2025)

HsbA represses stationary phase biofilm formation in Pseudomonas putida.

Microbiological research, 305:128428 pii:S0944-5013(25)00387-8 [Epub ahead of print].

Pseudomonas putida biofilm growth is associated to nutrient-sufficient conditions and biofilm dispersal is induced by nutrient starvation, signaled by the stringent response-associated nucleotide alarmone (p)ppGpp. We have used transcriptomic analysis to show that (p)ppGpp regulates the hsbAR-hptB gene cluster, encoding components of a phosphorelay pathway and an anti-σ factor antagonist, and cfcR, encoding a response regulator with diguanylate cyclase (DGC) activity. Transcription of hsbAR-hptB and cfcR is RpoS-dependent and induced by stationary phase and the stringent response. A ∆hsbA mutant resumed biofilm formation after dispersal in late stationary phase and displayed increased pellicle formation at the medium-air interphase and Congo Red adsorption. All these phenotypes were traced down to increased c-di-GMP levels in stationary phase, dependent on the activity of CfcR and its cognate sensor kinase, CfcA. HsbA was reversibly phosphorylated by the combined action of HptB and HsbR. HsbA phosphorylation conditioned its interaction with CfcR and CfcA and the subcellular distribution of the three proteins. In spite of this, HsbA retained its ability to prevent biofilm formation regardless of its phosphorylation state. Our results support a model in which HsbA forms a complex with CfcR to inhibit its DGC activity regardless of its phosphorylation state. Upon HsbA dephosphorylation, this complex is recruited to the cell membrane by CfcA to strengthen the inhibitory effect. While this pathway contributes to biofilm dispersal by denying de novo c-di-GMP synthesis during nutrient starvation, it may also enable quick restoration of the biofilm phenotype to colonize new sites or during biofilm maturation.

RevDate: 2025-12-21

Fan X, Li B, Xu X, et al (2025)

Deciphering the regulatory role of the pfs gene on biofilm formation in Lactobacillus plantarum R: Insights from transcriptome and metabolome.

Bioresource technology, 443:133833 pii:S0960-8524(25)01800-0 [Epub ahead of print].

Lactobacillus plantarum is a widely recognized probiotic that forms biofilms to enhance environmental tolerance and probiotic properties, but the mechanisms regulating its biofilm formation remain unclear. This study successfully used CRISPR-Cas9 to delete the pfs gene in the high biofilm-producing strain L. plantarum R, and first investigated its role by integrated transcriptomic and metabolomic analyses. The pfs gene participates in the activated methyl cycle and AI-2 synthesis, which is involved in quorum sensing and biofilm formation. Deletion of pfs increased biofilm biomass by 91% and markedly enhanced matrix accumulation, including exopolysaccharides, extracellular proteins and extracellular DNA (eDNA). Transcriptomic analysis revealed significant perturbation of cysteine and methionine metabolism and altered expression of key genes involved in exopolysaccharide synthesis. Metabolomic profiling identified 223 differentially expressed metabolites, primarily associated with carbon flux and EPS precursor pathways. In summary, pfs deletion enhances biofilm formation via metabolic reprogramming rather than classical AI-2 dependent QS pathways. This study provides new insights into the pfs gene-mediated regulation of biofilm formation in L. plantarum and establishes a foundation for future strategies to manipulate biofilm formation in industrial applications.

RevDate: 2025-12-20

Wen Y, Li Y, Liu T, et al (2025)

Nucleoside-Based Hydrogel Platform Synergizes with Photothermal Effects for Enhanced Biofilm Eradication Against Periodontitis.

Advanced science (Weinheim, Baden-Wurttemberg, Germany) [Epub ahead of print].

Periodontitis is a chronic inflammatory disease primarily driven by pathogenic biofilms, and affects more than 90% of the global population. The increasing prevalence of bacterial resistance, coupled with the protective nature of resilient biofilms, makes it challenging to achieve satisfactory therapeutic outcomes. In this study, an organic small molecule-based photothermal reagent (FNP) with excellent photothermal property is designed by rational tailor of donor-acceptor combinations, and a supramolecular nucleoside hydrogel (ZBAg) is developed via silver ion-stabilized base pairing and dynamic boronate ester bonds. The ZBAg hydrogel exhibits a unique coordination mechanism distinct from the traditional intermolecular i-motif coordination mode. The ZBAg@FNP hydrogel is prepared by encapsulating FNP within ZBAg hydrogel, which demonstrates excellent biocompatibility and achieves controlled Ag[+] release triggered by localized hyperthermia. The ZBAg@FNP hydrogel can damage biofilm structure through photothermal therapy and then improves the penetration of Ag[+] into the biofilms, resulting in synergistic eradication of the biofilms of oral pathogenic bacteria (Porphyromonas gingivalis and Streptococcus mutans). ZBAg@FNP hydrogel treatment significantly reduces the levels of proinflammatory cytokines, increases the levels of anti-inflammatory cytokines, and reduces alveolar resorption in periodontitis of rats. This study provides a new strategy for treating periodontitis, and offers insights into the design of antibiofilm materials.

RevDate: 2025-12-19

Arazi P, Skurnik M, Mohsenipour Z, et al (2025)

Genomic and functional characterization of a novel lytic phage vB-AbaM-fThrA with anti-biofilm activity against CR-MDR Acinetobacter baumannii.

BMC microbiology pii:10.1186/s12866-025-04525-z [Epub ahead of print].

BACKGROUND: Multidrug-resistant Acinetobacter baumannii causes increasingly fat5al infections in humans. Phage therapy is considered as a promising approach to treat the infections.

METHODS: Here we present the isolation and characterization of a new lytic A. baumannii specific phage vB-AbaM-fThrA (fThrA for short) originating from hospital wastewater.

RESULTS: Phage fThrA has a myovirus morphology with a relatively broad host range. The phage forms large and transparent plaques with a halo and showed high lysis power in in-vitro laboratory studies. Based on the genome sequence analysis phage fThrA is a new member of the Obolenskvirus genus with about 75.6% genomic similarity to its closest relative. The phage, tolerated well pH range from 4 to 10, and heating at 50 °C, but not 80 °C. At pH 2 ca. 50% of the phage survived for 1 h, an indication that the phage would be suitable for oral administration and phage therapy of the digestive tract. Phage fThrA was highly active against formation of biofilm and in destruction of the formed biofilm, an asset when used as a supplement to antibiotics in severe infections. Also, in genomic studies, no genes related to pathogenicity and lysogenicity were observed in the whole phage sequence.

CONCLUSIONS: These features make phage fThrA as a promising candidate for phage therapy in-vivo.

RevDate: 2025-12-19

Fadely EC, Gehin G, Bone SE, et al (2025)

Enhanced Manganese Oxidation at the Biofilm-Fluid Interface Drives Pore-Scale Patterns in Mineral Precipitation.

Environmental science & technology [Epub ahead of print].

Microbial oxidation of manganese (Mn) from aqueous Mn(II) to solid-phase Mn(III, IV) minerals catalyzes Mn(II) removal in natural and engineered porous systems. However, little is known about the spatiotemporal evolution of Mn biomineralization in confined spaces that experience simultaneous Mn(II) delivery and Mn oxide precipitation. Here, we combine time-lapse microscopy, image analysis, and mass spectrometry to quantify the extent and rate of Mn biomineralization by Pseudomonas putida GB-1 in an optically transparent two-dimensional porous medium. We found that Mn(II) oxidation initially occurred within biofilms but shifted over time toward the edges of biofilms in contact with pore fluid. Minerals precipitated outside of the initial biofilm footprint likely due to surface-mediated oxidation of Mn(II) by nascent biogenic Mn oxides, reinforcing a gradient in mineral accumulation from the Mn(II) source near the reactor inlet to the outlet. The rate of mineral precipitation outside the biofilm footprint surpassed the rate of mineral accumulation inside biofilms within 6 h and accounted for two-thirds of the total Mn oxide mass in the pore space at the end of the experiment. This work advances a mechanistic understanding of coupled biotic and abiotic Mn oxidation in porous environments while providing a novel platform to quantify microbe-mineral-fluid interactions.

RevDate: 2025-12-19

Wang A, Wang W, Huang W, et al (2025)

A dual cross-linked pillar[5]arene/porphyrin-based supramolecular polysaccharide hydrogel for promoted wound healing by combating multidrug-resistant bacteria and biofilm eradication.

International journal of biological macromolecules pii:S0141-8130(25)10318-8 [Epub ahead of print].

Inappropriate use of antibiotics has emerged a large number of "multidrug-resistant bacteria" during the past decades, leading to a formidable challenge to global health. Photodynamic therapy exhibits effective antibacterial effects by the generation of abundant reactive oxygen species (ROS). However, the planar conjugated structure of most photosensitizers results in their close π-π stacking and the low ROS yield. Herein, we reported a dual cross-linked Pillar[5]arene/porphyrin-based supramolecular hydrogel for combating multidrug resistant bacteria and biofilm eradication. The supramolecular hydrogel consists of hyaluronic acid, naphthalene-functionalized positive charged porphyrin, and aldehyde-functionalized Pillar[5] arene via dual cross-linking by Schiff base bonding and host-guest interaction. Notably, the steric hindrance of Pillar[5]arene/porphyrin host-guest complexes effectively inhibits the π-π stacking of porphyrins and thereby enhances ROS generation. In vitro and in vivo antibacterial and biofilm disruption studies confirmed the outstanding antibacterial, biofilm eradication, and multidrug-resistant bacteria infected wound healing of the supramolecular hydrogel. The dynamic chemical bonding and host-guest interaction dual cross-linked hydrogel provides a promising strategy for addressing drug-resistant bacterial infections and promoting wound healing.

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In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

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This is a must read book for anyone with an interest in invasion biology. The full title of the book lays out the author's premise — The New Wild: Why Invasive Species Will Be Nature's Salvation. Not only is species movement not bad for ecosystems, it is the way that ecosystems respond to perturbation — it is the way ecosystems heal. Even if you are one of those who is absolutely convinced that invasive species are actually "a blight, pollution, an epidemic, or a cancer on nature", you should read this book to clarify your own thinking. True scientific understanding never comes from just interacting with those with whom you already agree. R. Robbins

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The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin and even a collection of poetry — Chicago Poems by Carl Sandburg.

Timelines

ESP now offers a large collection of user-selected side-by-side timelines (e.g., all science vs. all other categories, or arts and culture vs. world history), designed to provide a comparative context for appreciating world events.

Biographies

Biographical information about many key scientists (e.g., Walter Sutton).

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 28 JUL 2024 )