Biofilm最新文献

{"title":"Effects of the vfm quorum-sensing system on the phenotypic features and virulence of Dickeya zeae WH1","authors":"Xiaojuan Tan,&nbsp;Ting Yang,&nbsp;Minglong Wu,&nbsp;Liping Luo,&nbsp;Ruyi Zheng,&nbsp;Qianqian Liu,&nbsp;Guoping Zhu,&nbsp;Yang Sun","doi":"10.1016/j.bioflm.2025.100295","DOIUrl":"10.1016/j.bioflm.2025.100295","url":null,"abstract":"<div><div>mailto:Soft rot caused by <em>Dickeya zeae</em> is an important bacterial disease affecting rice and other plants around the world. Several studies found that the specific virulence factor-modulating quorum sensing (<em>vfm</em>-QS) system is present in bacteria. <em>vfmI</em> is the key member encoding a two-component system sensor histidine kinase. Therefore, to determine the effects of <em>vfm</em>-QS on phenotypic features and virulence, the system was inactivated through the construction of a <em>vfmI</em> mutant in the <em>D. zeae</em> WH1 strain. The results of the phenotypic features and pathogenicity assays revealed that the deletion of <em>vfmI</em> abolished motility and reduced biofilm-forming capacity. Moreover, the mutation had a limited role in regulating the activity of plant cell wall-degrading enzymes (PCWDEs) and decreased the maceration of potato tubers in the tested dicotyledonous plants. Importantly, the <em>vfmI</em> mutant became avirulent to the rice plants, although the gene mutation slightly increased rice seed germination. These features are considerably different from those that have been shown for other <em>Dickeya</em> strains. Finally, our findings indicated that the <em>vfm</em> system controls the motility of WH1 by regulating flagellar biosynthesis and biofilm formation, which is achieved by regulating the intracellular c-di-GMP level. Taken together, these findings highlight the complexity and plasticity of QS regulatory circuits in the <em>D. zeae</em> strain.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"10 ","pages":"Article 100295"},"PeriodicalIF":5.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antimicrobial efficacy of on-label vs. hand-mixed irrigation solutions against S. aureus biofilms","authors":"Robert Falconer ,&nbsp;Tyler Smith ,&nbsp;David Rothberg ,&nbsp;Jeremy Gililland ,&nbsp;Nicholas Ashton ,&nbsp;Dustin Williams","doi":"10.1016/j.bioflm.2025.100304","DOIUrl":"10.1016/j.bioflm.2025.100304","url":null,"abstract":"<div><div>Wound irrigation is routinely performed as part of the DAIR procedure and for hardware infections, yet the most effective irrigation solution for reducing bacterial bioburden is unknown. Clinicians can choose on-label, commercially available irrigation solutions or hand-mix preparations off-label on the operating back table. Current methods for evaluating antiseptic efficacy often do not represent the clinical scenario. Here, we present a proof-of-concept <em>ex vivo</em> setup to evaluate whether on-label, commercially available irrigation solutions were superior at reducing bacterial biofilm burden compared to off-label, hand-mixed irrigation solutions. <em>Staphylococcus aureus</em> ATCC 49525 (Xen36) biofilms were grown on Grade 5 titanium simulated fracture fixation plates and secured to sections of autoclaved bovine femur with cortical bone screws. Fourteen irrigation solutions (three commercial, eleven hand-mixed) and one untreated control group were evaluated by irrigating the biofilm-ridden plates and quantifying the remaining bioburden using a 10-fold dilution series to determine the log₁₀ reduction. None of the fourteen treatments reduced bioburden statistically significantly compared to the untreated control, where no irrigation was performed. Additionally, no treatment achieved the FDA benchmark of a 4 log₁₀ reduction for antibacterial activity. An off-label, hand-mixed 0.472 % w/v chlorhexidine gluconate solution reduced the greatest bioburden overall, with a 1.43 ± 0.20 log₁₀ reduction. On-label irrigation products did not reduce bioburden more than off-label, hand-mixed solutions clinicians often prepare in the operating room. Musculoskeletal infections remain a significant clinical challenge and contribute to increasing healthcare costs. The antimicrobial efficacy of irrigation products should be assessed using clinically relevant models.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"10 ","pages":"Article 100304"},"PeriodicalIF":5.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative and chemical adaptation of exopolymeric substances formed by a river microbial consortium during exposure to the antibiotic trimethoprim","authors":"Thibault Duteil,&nbsp;Andras Gorzsás,&nbsp;Madeleine Ramstedt","doi":"10.1016/j.bioflm.2025.100334","DOIUrl":"10.1016/j.bioflm.2025.100334","url":null,"abstract":"<div><div>In natural environments, most microorganisms reside attached to a surface growing as a biofilm, which is a universal microbial strategy for their survival. As a result, several studies have focused on the role of the biofilm matrix (made of extracellular polymeric substances (EPS)) in tolerance to antimicrobials. However, few studies have focused directly on the characterization of EPS as a response to antibiotic stress. In this study, we analyzed the impact of trimethoprim (TMP) on the production and characteristics of EPS from four natural biofilm-producing river bacterial strains. Extraction and characterization of EPS were carried out at three concentrations of TMP. EPS properties were monitored using colorimetric tests, infrared spectroscopy and sugar composition analysis. For all strains, EPS quantity and chemistry changed starting at 0.1 mM TMP. The combined results suggest that environmental bacterial strains adapt their EPS production and chemical composition in response to antibiotic exposure. Bacteria may benefit from the change in EPS chemistry since it limits the penetration of TMP into the biofilm and thus protects the cells from the action of the antibiotic. Three main mechanisms are proposed: an increase in the proportion of (i) proteins and reactive functional groups, (ii) mannose and (iii) fatty acids. This study shows that EPS represents a key factor in antibiotic tolerance of bacteria via multiple mechanisms. Thus, this study broadens the discussion concerning antibiotic-resistance as it presents additional processes that may work in tune with genetically acquired resistance to enhance bacterial tolerance to antibiotics.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"10 ","pages":"Article 100334"},"PeriodicalIF":4.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-resolved dual transcriptomics of Pseudomonas aeruginosa biofilm formation in cystic fibrosis","authors":"Núria Crua Asensio ,&nbsp;Javier Macho Rendón ,&nbsp;Juan José González López ,&nbsp;Sílvia Gartner Tizzano ,&nbsp;Maria Teresa Martín Gómez ,&nbsp;Marc Torrent Burgas","doi":"10.1016/j.bioflm.2025.100301","DOIUrl":"10.1016/j.bioflm.2025.100301","url":null,"abstract":"<div><div><em>Pseudomonas aeruginosa</em> biofilms cause severe infections in the airways of patients suffering from cystic fibrosis (CF) that are difficult to eradicate, even with intensive antibiotic therapy. The main goal of this study was to define the dual transcriptional response associated with the formation of <em>P. aeruginosa</em> biofilms in a polarized lung epithelium monolayer. We analyzed the dual response of healthy and CF epithelium after infection with <em>P. aeruginosa</em> isolates from acute and chronic infections. Our results show that strains of <em>P. aeruginosa</em> isolated from chronic infections specifically increase the expression of secretion systems of type I, III and VI to hijack the host response. Conversely, strains associated with acute illness use ABC transporters to counteract the antimicrobial response. In return, a distinctive expression pattern in the CF epithelium, including a high degree of cytokine secretion and keratinization, is largely observed in acute infections. Our results show that both host and pathogen genomic backgrounds contribute to the outcome of infection and specific transcriptional signatures could be used in the diagnosis, particularly in CF patients.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"10 ","pages":"Article 100301"},"PeriodicalIF":5.9,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144614544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Legionella pneumophila response to shifts in biofilm structure mediated by hydrodynamics","authors":"Ana Rosa Silva ,&nbsp;C. William Keevil ,&nbsp;Ana Pereira","doi":"10.1016/j.bioflm.2025.100258","DOIUrl":"10.1016/j.bioflm.2025.100258","url":null,"abstract":"<div><div>Preventing legionellosis in water systems demands effective hydrodynamic management and biofilm mitigation. This study investigates the complex relationship between hydrodynamics (80 RPM and stagnation), biofilm mesoscale structure and <em>Legionella pneumophila</em> colonization, by addressing three key questions: (1) How do low flow <em>vs</em> stagnation conditions affect biofilm response to <em>L. pneumophila</em> colonization?, (2) How do biofilm structural variations mediate <em>L. pneumophila</em> migration across the biofilm?, and (3) Can specific hydrodynamic conditions trigger <em>L. pneumophila</em> entrance in a viable but nonculturable (VBNC) state? It was found that <em>Pseudomonas fluorescens</em> biofilms exhibit different responses to <em>L. pneumophila</em> based on the prevailing hydrodynamic conditions. While biofilm thickness and porosity decreased under shear (80 RPM), thickness tends to significantly increase when pre-established 80 RPM-grown biofilms are set to stagnation upon <em>L. pneumophila</em> spiking. Imposing stagnation after the spiking also seemed to accelerate <em>Legionella</em> migration towards the bottom of the biofilm. Water structures in the biofilm seem to be key to <em>Legionella</em> migration across the biofilm. Finally, shear conditions favoured the transition of <em>L. pneumophila</em> to VBNC states (∼94 %), despite the high viable cell counts (∼8 log₁₀ CFU/cm²) found throughout the experiments. This research highlights the increased risk posed by biofilms and stagnation, emphasizing the importance of understanding the mechanisms that govern <em>Legionella</em> behaviour in diverse biofilm environments. These insights are crucial for developing more effective monitoring and prevention strategies in water systems.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100258"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of SMF-1 and cbl pili in Stenotrophomonas maltophilia biofilm formation","authors":"Radhika Bhaumik ,&nbsp;Alli Beard ,&nbsp;Oliver Harrigan ,&nbsp;Layla Ramos-Hegazy ,&nbsp;Seema Mattoo ,&nbsp;Gregory G. Anderson","doi":"10.1016/j.bioflm.2025.100253","DOIUrl":"10.1016/j.bioflm.2025.100253","url":null,"abstract":"<div><div><em>Stenotrophomonas maltophilia</em> is an emerging multidrug-resistant, Gram-negative opportunistic pathogen. It causes many healthcare-associated infections such as sepsis, endocarditis, meningitis, and catheter-related urinary tract infections. It also affects individuals with cystic fibrosis, exacerbating their lung condition. <em>S. maltophilia</em> often causes pathogenesis through the formation of biofilms. However, the molecular mechanisms <em>S. maltophilia</em> uses to carry out these pathogenic steps are unclear. The SMF-1 chaperone/usher pilus has been thought to mediate <em>S. maltophilia</em> attachment. To confirm this role, we created an isogenic deletion of the <em>smf-1</em> pilin gene and observed a defect in biofilm compared to wild type. We also discovered an additional chaperone/usher pilus gene cluster: <em>cbl</em>. Mutation of <em>cbl</em> also affects biofilm levels. Intriguingly, through transmission electron microscopy studies, we found suggestive evidence that the mutation of one pilus (<em>e.g. smf</em>) is not phenotypically compensated by another (<em>e.g. cbl</em>). Additionally, infection of <em>Galleria mellonella</em> larvae revealed increased virulence of an <em>smf-1</em> deletion mutant and an <em>smf-1 cbl</em> double deletion mutant. Together, these studies show that pili have an important role in switching between acute and chronic infections in conducting <em>S. maltophilia</em> virulence. Understanding their activity may help identify therapeutic targets for this pathogen.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100253"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corticosteroids modulate biofilm formation and virulence of Pseudomonas aeruginosa","authors":"Elena Jordana-Lluch ,&nbsp;María Escobar-Salom ,&nbsp;Gabriel Torrens ,&nbsp;Isabel María Barceló ,&nbsp;Miguel Ángel Estévez ,&nbsp;Alex González-Alsina ,&nbsp;Amanda Iglesias ,&nbsp;Pere Joan Pont-Antona ,&nbsp;María D. Macià ,&nbsp;Sebastián Albertí ,&nbsp;Paul Williams ,&nbsp;Borja G. Cosío ,&nbsp;Carlos Juan ,&nbsp;Antonio Oliver","doi":"10.1016/j.bioflm.2025.100289","DOIUrl":"10.1016/j.bioflm.2025.100289","url":null,"abstract":"<div><div>Corticosteroids are anti-inflammatory drugs commonly administered to patients with chronic obstructive pulmonary disease (COPD), cystic fibrosis and similar lung pathologies, in which persistent infections with <em>Pseudomonas aeruginosa</em> are frequent. However, their therapeutic value is debatable because of their adverse impact on host immunity. The aim of this work was to determine the impact of budesonide and fluticasone propionate on <em>P. aeruginosa</em> biology. We found that these corticosteroids attenuated its intrinsic pro-inflammatory properties (reduction of IL-8 release compared to controls ca. 15 % (budesonide) and 50 % (fluticasone propionate)) and cellular invasiveness (25 % and 40 % respectively). Corticosteroids enhanced <em>P. aeruginosa</em> biofilm formation in a time/dose-dependent manner (around 1.6-fold for the highest concentration, with this increase occurring more readily in sputum media)) and stimulated the release of extracellular DNA (2-fold increase), a key component of the biofilm matrix. Regarding the mechanisms involved, our results suggest that corticosteroids diffuse through <em>P. aeruginosa</em>'s membrane influencing its fluidity and triggering cell envelope stress signalling pathways, as shown by an initial increase in <em>muc</em>A (σ²² regulon) expression, outer membrane vesicle release and accumulation of cyclic diguanylate (c-di-GMP). Changes in the levels of this intracellular signalling molecule, responsible for the switch from planktonic to biofilm lifestyle, may explain some of the phenotypes observed. In conclusion, our data, first obtained with type strains and proved to be reproducible when using COPD clinical isolates, suggest that corticosteroids could mediate a faster acquisition of the phenotypic characteristics associated with <em>P. aeruginosa</em> long-term adaptation to the chronic lung niche without undergoing mutation.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100289"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144231619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A biofilm-targeting lipo-peptoid to treat Pseudomonas aeruginosa and Staphylococcus aureus co-infections","authors":"Samuel J.T. Wardell ,&nbsp;Deborah B.Y. Yung ,&nbsp;Josefine E. Nielsen ,&nbsp;Rajesh Lamichhane ,&nbsp;Kristian Sørensen ,&nbsp;Natalia Molchanova ,&nbsp;Claudine Herlan ,&nbsp;Jennifer S. Lin ,&nbsp;Stefan Bräse ,&nbsp;Lyn M. Wise ,&nbsp;Annelise E. Barron ,&nbsp;Daniel Pletzer","doi":"10.1016/j.bioflm.2025.100272","DOIUrl":"10.1016/j.bioflm.2025.100272","url":null,"abstract":"<div><div>Antibiotic-resistant bacterial infections are a significant clinical challenge, especially when involving multiple species. Antimicrobial peptides and their synthetic analogues, peptoids, which target bacterial cell membranes as well as intracellular components, offer potential solutions. We evaluated the biological activities of novel peptoids TM11-TM20, which include an additional charged <em>N</em>Lys residue, against multidrug-resistant <em>Pseudomonas aeruginosa</em> and <em>Staphylococcus aureus</em>, both <em>in vitro</em> and <em>in vivo</em>. Building on insights from previously reported compounds TM1-TM10, the lipo-peptoid TM18, which forms self-assembled ellipsoidal micelles, demonstrated potent antimicrobial, anti-biofilm, and anti-abscess activity. Transcriptome sequencing (RNA-seq) revealed that TM18 disrupted gene expression pathways linked to antibiotic resistance and tolerance, and biofilm formation in both pathogens. Under dual-species conditions, TM18 induced overlapping but attenuated transcriptional changes, suggesting a priming effect that enhances bacterial tolerance. In a murine skin infection model, TM18 significantly reduced dermonecrosis and bacterial burden in mono-species infections. When combined with the antibiotic meropenem, they synergistically nearly cleared co-infections. Our findings highlight that TM18 has potential as a novel therapeutic for combating antibiotic-resistant pathogens and associated biofilm-driven tolerance.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100272"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcriptional signatures associated with the survival of Escherichia coli biofilm during treatment with plasma-activated water","authors":"Heema Kumari Nilesh Vyas ,&nbsp;M. Mozammel Hoque ,&nbsp;Binbin Xia ,&nbsp;David Alam ,&nbsp;Patrick J. Cullen ,&nbsp;Scott A. Rice ,&nbsp;Anne Mai-Prochnow","doi":"10.1016/j.bioflm.2025.100266","DOIUrl":"10.1016/j.bioflm.2025.100266","url":null,"abstract":"<div><div>Biofilm formation on surfaces, tools and equipment can damage their quality and lead to high repair or replacement costs. Plasma-activated water (PAW), a new technology, has shown promise in killing biofilm and non-biofilm bacteria due to reactive oxygen and nitrogen species (RONS), particularly superoxide. However, the exact genetic mechanisms behind PAW’s effectiveness against biofilms remain unclear. Here, we examined the stress responses of <em>Escherichia coli</em> biofilms exposed to sub-lethal PAW treatment using bulk RNA sequencing and transcriptomics. We compared gene expression in PAW-treated <em>E. coli</em> biofilms with and without superoxide removal, achieved by adding the scavenger Tiron. Biofilms treated with PAW exhibited a 40 % variation in gene expression compared to those treated with PAW-Tiron and controls. Specifically, PAW treatment resulted in 478 upregulated genes (&gt;1.5 log₂FC) and 186 downregulated genes (&lt;−1.5 log₂FC) compared to the control. Pathway and biological process enrichment analysis revealed significant upregulation of genes involved in sulfur metabolism, ATP-binding transporter, amino acid metabolism, hypochlorite response systems and oxidative phosphorylation in PAW-treated biofilms compared to control. Biofilm viability and intracellular RONS accumulation were tested for <em>E. coli</em> mutants lacking key genes from these pathways. Knockout mutants of thioredoxin (<em>trxC</em>), thiosulfate-binding proteins (<em>cysP</em>), and NADH dehydrogenase subunit (<em>nuoM</em>) showed significantly reduced biofilm viability after PAW treatment. Notably, <em>ΔtrxC</em> biofilms had the highest intracellular ROS accumulation, as revealed by 2′,7′–dichlorofluorescin diacetate staining after PAW treatment. This confirms the importance of these genes in managing oxidative stress caused by PAW and highlights the significance of superoxide in PAW's bactericidal effects. Overall, our findings shed light on the specific genes and pathways that help <em>E. coli</em> biofilms survive and respond to PAW treatment, offering a new understanding of plasma technology and its anti-biofilm mechanisms.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100266"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strain-dependent emergence of aminoglycoside resistance in Escherichia coli biofilms","authors":"Raphaël Charron ,&nbsp;Pierre Lemée ,&nbsp;Antoine Huguet ,&nbsp;Ornella Minlong ,&nbsp;Marine Boulanger ,&nbsp;Paméla Houée ,&nbsp;Christophe Soumet ,&nbsp;Romain Briandet ,&nbsp;Arnaud Bridier","doi":"10.1016/j.bioflm.2025.100273","DOIUrl":"10.1016/j.bioflm.2025.100273","url":null,"abstract":"<div><div>In most Earth environments, bacteria predominantly exist within surface-associated communities known as biofilms, where they are embedded in an extracellular matrix. These collective structures play a critical role in bacterial physiology and significantly shape their evolutionary trajectories, contributing to the development of antimicrobial resistance and enhancing bacterial resilience to treatments, with profound implications for public health. This study assessed the impact of the biofilm lifestyle on the emergence of resistance to gentamicin, an aminoglycoside antibiotic, in one laboratory reference strain and seven <em>Escherichia coli</em> isolates from food-processing environments. Throughout a one-month evolution experiment, we observed that certain strains showed a markedly higher emergence of gentamicin-resistant variants in biofilms than in planktonic states, with the emergence of stable variants being closely linked to biofilm maturation. Genomic and phenotypic analyses of gentamicin-resistant (GenR) variants uncovered varied adaptive strategies among the strains. GenR variants from two food-processing isolates (Ec709 and Ec478) displayed point mutations in genes associated with central carbon metabolism (<em>aceE</em>, <em>ygfZ</em>, …) and cell respiration (<em>atpG</em>, <em>cydA</em>, …), while retaining relative growth and colonization capacities. Conversely, GenR variants from the reference strain (Ec1655) adapted preferentially through large genomic deletions, including consistent loss of the peptide transporter gene <em>sbmA,</em> significantly altering cellular fitness. These findings highlight the complexity of adaptive evolution in biofilms and underscore the importance of investigating diverse strains to grasp the full spectrum of adaptation in natural bacterial populations.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100273"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}