Biofilm最新文献

{"title":"RpoN mediates biofilm formation by directly controlling vps gene cluster and c-di-GMP synthetic metabolism in V. alginolyticus","authors":"Na Zhang ,&nbsp;Yanhua Zeng ,&nbsp;Jiachengzi Ye ,&nbsp;Chuancao Lin ,&nbsp;Xiaoxiao Gong ,&nbsp;Hao Long ,&nbsp;Haimin Chen ,&nbsp;Zhenyu Xie","doi":"10.1016/j.bioflm.2024.100242","DOIUrl":"10.1016/j.bioflm.2024.100242","url":null,"abstract":"<div><div><em>Vibrio alginolyticus</em> is a prevalent pathogen in both humans and marine species, exhibiting high adaptability to various adverse environmental conditions. Our previous studies have shown that Δ<em>rpoN</em> formed three enhanced biofilm types, including spectacular surface-attached biofilm (SB), scattered pellicle biofilm (PB), and colony rugosity. However, the precise mechanism through which <em>rpoN</em> regulates biofilm formation has remained unclear. Based on the critical role of Vibrio exopolysaccharide (VPS) in biofilm formation, several genes related to the production and regulation of VPS were characterized in <em>V. alginolyticus</em>. Our findings from mutant strains indicated that VPS has complete control over the formation of rugose colony morphology and PB, while it only partially contributes to SB formation. Among the four transcriptional regulators of the <em>vps</em> gene cluster, <em>vpsR</em> and VA3545 act as promoters, whereas VA3546 and VA2703 function as repressors. Through transcriptome analysis and c-di-GMP concentration determination, VA0356 and VA3580 which encoded diguanylate cyclase were found to mediate the Δ<em>rpoN</em> biofilm formation. As a central regulator, <em>rpoN</em> governed biofilm formation through two regulatory pathways. Firstly, it directly bound to the upstream region of VA4206 to regulate the expression of the <em>vps</em> gene cluster (VA4206-VA4196). Secondly, it directly and indirectly modulated c-di-GMP synthesis gene VA3580 and VA0356, respectively, thereby affecting c-di-GMP concentration and subsequently influencing the expression of <em>vps</em> transcription activators <em>vpsR</em> and VA3545. Under conditions promoting SB formation, Δ<em>rpoN</em> was unable to thrive below the liquid level due to significantly reduced activities of three catalytic enzymes (ACK, ADH, and ALDH) involved in pyruvate metabolism, but tended to reproduce in air-liquid interface, a high oxygen niche compared to the liquid phase. In conclusion, both exopolysaccharide synthesis and oxygen-related metabolism contributed to Δ<em>rpoN</em> biofilm formation. The role of RpoN-mediated hypoxic metabolism and biofilm formation were crucial for comprehending the colonization and pathogenicity of <em>V. alginolyticus</em> in hosts, providing a novel target for treating <em>V. alginolyticus</em> in aquatic environments and hosts.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100242"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11722192/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142973488","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":"Decoding interactions between biofilms and DNA nanoparticles","authors":"Alexandra Sousa ,&nbsp;Rutuparna Kulkarni ,&nbsp;Mona Johannessen ,&nbsp;Thorsten Wohland ,&nbsp;Nataša Škalko-Basnet ,&nbsp;Sybil Obuobi","doi":"10.1016/j.bioflm.2025.100260","DOIUrl":"10.1016/j.bioflm.2025.100260","url":null,"abstract":"<div><div>Biofilms present a great challenge in antimicrobial therapy due to their inherent tolerance to conventional antibiotics, promoting the need for advanced drug delivery strategies that improve therapy. While various nanoparticles (NPs) have been reported for this purpose, DNA-based NPs remain a largely unexploited resource against biofilm-associated infections. To fill this gap and to lay the groundwork for their potential therapeutic exploitation, we investigated the diffusion, penetration, and retention behaviors of three DNA-based nanocarriers —plain or modified—within <em>P. aeruginosa</em> biofilms. Watson-Crick base pairing or hydrophobic interactions mediated the formation of the plain NPs whilst electrostatic interaction enabled optimization of coated NPs via microfluidic mixing. We assessed the interactions of the nanocarriers with biofilm structures via Single Plane Illumination Microscopy – Fluorescence Correlation Spectroscopy (SPIM-FCS) and Confocal Laser Scanning Microscopy (CLSM). We demonstrate the impact of microfluidic parameters on the physicochemical properties of the modified DNA NPs and their subsequent distinct behaviors in the biofilm. Our results show that single stranded DNA micelles (ssDNA micelle) and tetrahedral DNA nanostructures (TDN) had similar diffusion and penetration profiles, whereas chitosan-coated TDN (TDN-Chit) showed reduced diffusion and increased biofilm retention. This is attributable to the relatively larger size and positive surface charge of the TDN-Chit NPs. The study shows first and foremost that DNA can be used as building block in drug delivery for antibiofilm therapeutics. Moreover, the overall behavioral findings are pivotal for the strategic selection of therapeutic agents to be encapsulated within these structures, possibly affecting the treatment efficacy. This research not only highlights the underexplored potential of DNA-based NPs in antibiofilm therapy but also advocates for further studies using different optimization strategies to refine these nanocarrier systems for targeted treatments in biofilm-related infections.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100260"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387471","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":"Nanowire arrays with programmable geometries as a highly effective anti-biofilm surface","authors":"Marina A. George ,&nbsp;David McGiffin ,&nbsp;Anton Y. Peleg ,&nbsp;Roey Elnathan ,&nbsp;David M. Kaye ,&nbsp;Yue Qu ,&nbsp;Nicolas H. Voelcker","doi":"10.1016/j.bioflm.2025.100275","DOIUrl":"10.1016/j.bioflm.2025.100275","url":null,"abstract":"<div><div>Biofilm-related microbial infections are the Achilles’ heel of many implantable medical devices. Surface patterning with nanostructures in the form of vertically aligned silicon (Si) nanowires (VA-SiNWs) holds promise to prevent these often “incurable” infections. In this study, we fabricated arrays of highly ordered SiNWs varying in three geometric parameters, including height, pitch size, and tip diameter (sharpness). Anti-infective efficacies of fabricated SiNW arrays were assessed against representative laboratory reference bacterial strains, <em>Staphylococcus aureus</em> ATCC 25923 and <em>Escherichia coli</em> ATCC 25922, using a modified microwell biofilm assay representing microorganism-implant interactions at a liquid-solid interface. To further understand the role of individual geometric parameters to the SiNW-induced bacterial killing, SiNW arrays with stepwise changes in individual geometric parameters were compared. The force that NWs applied on bacterial cells was mathematically calculated. Our results suggested that NWs with specific geometries were able to kill adherent bacterial cells and prevent further biofilm formation on biomaterial surfaces. Tip diameter and pitch size appeared to be key factors of nanowires predetermining their anti-infectiveness. Mechanistic investigation found that tip diameter and pitch size co-determined the pressure that NWs put on the cell envelope. The most effective anti-infective NWs fabricated in our study (50 nm in tip diameter and 400 nm in pitch size for <em>S. aureus</em> and 50 nm in tip diameter and 800 nm in pitch size for <em>E. coli</em>) put pressures of approximately 2.79 Pa and 8.86 Pa to the cell envelop of <em>S. aureus</em> and <em>E. coli</em>, respectively, and induced cell lyses. In addition, these NWs retained their activities against clinical isolates of <em>S. aureus</em> and <em>E. coli</em> from patients with confirmed device-related infections and showed little toxicity against human fibroblast cells and red blood cells.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100275"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725917","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":"Assessing the impact of UV-C exposure on pre-existing cultured marine diatom biofilms","authors":"Kailey N. Richard ,&nbsp;Andrew Palmer ,&nbsp;Geoffrey Swain ,&nbsp;Kelli Z. Hunsucker","doi":"10.1016/j.bioflm.2025.100285","DOIUrl":"10.1016/j.bioflm.2025.100285","url":null,"abstract":"<div><div>Ultraviolet-C (UV–C) has been considered as a potential tool in the maintenance and prevention of marine biofouling. However, it is unclear how irradiation disturbs biofouling, specifically biofilms, or the duration and frequency needed to reduce or eliminate their growth. The marine diatom, <em>Navicula incerta</em>, was used in a two-part lab study to determine the minimum time between UV-C duty cycling (also known as interval testing) that would result in the reduction and prevention of marine biofilms. The first study assessed the diatom's metabolic activity, morphology, behavior, and recovery to understand the influence of UV-C on the biofilm. Cell viability, biofilm matrixes, and chlorophyll <em>a</em> were significantly reduced immediately following UV-C exposure, yet when exposure was ceased biofilms began to recover. Based on these results, the second study investigated the duty cycle duration required to limit the growth of the cultured biofilm. Duty cycle testing was able to initially deplete cell viability and chlorophyll <em>a</em>; however, in between exposures, recovery was evident. These findings indicate that shorter (10 min; 1.86 J/cm²) doses of UV-C exposures must be applied more frequently than more prolonged doses (60 min; 11.16 J/cm²) to keep biofilm formation minimal. The duty cycles established here also provide a guideline of efficacy for future studies that can be applied to biofilms in both laboratory and the field.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100285"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144124341","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":"Surfactin accelerates Bacillus subtilis pellicle biofilm development","authors":"Rune Overlund Stannius ,&nbsp;Sarah Fusco ,&nbsp;Michael S. Cowled ,&nbsp;Ákos T. Kovács","doi":"10.1016/j.bioflm.2024.100249","DOIUrl":"10.1016/j.bioflm.2024.100249","url":null,"abstract":"<div><div>Surfactin is a biosurfactant produced by many <em>B. subtilis</em> strains with a wide variety of functions from lowering surface tension to allowing motility of bacterial swarms, acting as a signaling molecule, and even exhibiting antimicrobial activities. However, the impact of surfactin during biofilm formation has been debated with variable findings between studies depending on the experimental conditions.</div><div>B. subtilis is known to form biofilms at the solid-air, the solid-medium, and the liquid-air interfaces, the latter of which is known as a pellicle biofilm. Pellicle formation is a complex process requiring coordinated movement to the liquid-air interface and subsequent cooperative production of biofilm matrix components to allow robust pellicle biofilm formation. This makes pellicle formation a promising model system for assaying factors in biofilm formation and regulation.</div><div>Here, we assayed the influence of surfactin and additional metabolites on the timing of pellicle biofilm formation. Using time-lapse imaging, we assayed pellicle formation timing in 12 <em>B. subtilis</em> isolates and found that one, MB9_B4, was significantly delayed in pellicle formation by approximately 10 h. MB9_B4 was previously noted to lack robust surfactin production. Indeed, deletion of surfactin synthesis in the other isolates delayed pellicle formation. Further, pellicle delay was rescued by addition of exogeneous surfactin. Testing reporters of biofilm-related gene expression revealed that induction of pellicle formation was caused by a combination of increased gene expression of one of the biofilm components and promotion of growth.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100249"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11754971/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143030291","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":"Decoding the impact of interspecies interactions on biofilm matrix components","authors":"Cristina I. Amador ,&nbsp;Henriette L. Røder ,&nbsp;Jakob Herschend ,&nbsp;Thomas R. Neu ,&nbsp;Mette Burmølle","doi":"10.1016/j.bioflm.2025.100271","DOIUrl":"10.1016/j.bioflm.2025.100271","url":null,"abstract":"<div><div>Multispecies biofilms are complex communities where extracellular polymeric substances (EPS) shape structure, adaptability, and functionality. However, characterizing the components of EPS, particularly glycans and proteins, remains a challenge due to the diverse bacterial species present and their interactions within the matrix. This study examined how interactions between different species affect EPS component composition and spatial organization. We analyzed a consortium of four bacterial soil isolates that have previously demonstrated various intrinsic properties in biofilm communities: <em>Microbacterium oxydans</em>, <em>Paenibacillus amylolyticus</em>, <em>Stenotrophomonas rhizophila</em>, and <em>Xanthomonas retroflexus</em>. We used fluorescence lectin binding analysis to identify specific glycan components and <em>meta</em>-proteomics to characterize matrix proteins in mono- and multispecies biofilms. Our results revealed diverse glycan structures and composition, including fucose and different amino sugar-containing polymers, with substantial differences between monospecies and multispecies biofilms. In isolation, <em>M. oxydans</em> produced galactose/N-Acetylgalactosamine network-like structures and influenced the matrix composition in multispecies biofilms. Proteomic analysis revealed presence of flagellin proteins in <em>X. retroflexus</em> and <em>P. amylolyticus</em>, particularly in multispecies biofilms. Additionally, surface-layer proteins and a unique peroxidase were identified in <em>P. amylolyticus</em> multispecies biofilms, indicating enhanced oxidative stress resistance and structural stability under these conditions. This study highlights the crucial role of interspecies interactions in shaping the biofilm matrix, as well as the production of glycans and proteins, thereby enhancing our understanding of biofilm complexity.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100271"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696943","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":"Co-culture biofilm patterns among different Pseudomonas aeruginosa clones from cystic fibrosis patients","authors":"Irene Cadenas-Jiménez ,&nbsp;Morten Levin Rybtke ,&nbsp;Doaa Higazy ,&nbsp;Sara Martí-Martí ,&nbsp;Tim Tolker-Nielsen ,&nbsp;Oana Ciofu ,&nbsp;Niels Høiby","doi":"10.1016/j.bioflm.2025.100257","DOIUrl":"10.1016/j.bioflm.2025.100257","url":null,"abstract":"<div><h3>Background</h3><div><em>Pseudomonas aeruginosa</em> chronic lung infection is the leading cause of death in the cystic fibrosis (CF) population. The high genome versatility of this microorganism allows it to adapt to the hostile CF lung where the same clone can persist for decades. Paranasal sinuses serve as a reservoir for bacterial adaptation before lung infection. Our study investigates biofilm compatibility among identical and different <em>P. aeruginosa</em> genotypes from sinus and lungs of CF patients. Strains were further characterized by whole genome sequencing and motility assays were performed.</div></div><div><h3>Methodology</h3><div>Motility, gentamicin susceptibility and growth rates were assessed in four strains coming from three CF patients. The strains were subjected to whole genome sequencing with the Illumina MiSeq platform.</div><div>Conjugation assays using the mini Tn7 transposon were performed in order to tag bacteria with the fluorescent proteins YFP (yellow) and CFP (cyan). Biofilm experiments were carried out in a flow cell system and images were acquired using a confocal laser microscope (CLSM) on days 3 and 5. Four experiments were performed: Experiment 1 with two clonal isolates from sinus and lungs from patient P01 (CF430-142, CF430-11621); experiments 2 (CF430-11621 + 75885-B) and 3 (CF430-11621 + 80271-B) with two lung isolates belonging to two different clones from different patients (P02, P03) and experiment 4 with one lung strain (CF430-11621) and <em>P. aeruginosa</em> PAO1 reference strain.</div></div><div><h3>Results</h3><div><em>P. aeruginosa</em> clonal isolates coming from paranasal sinuses and lungs from the same patient were able to form mixed biofilm. When different clones were employed no mixed biofilms were observed. Similar results were observed when combining the lung strain and the reference strain PAO1. Biofilms of both strains were observed in the flow-cell channels but no mixed biofilms of them were observed, with the exception of strain 75887-B which did not appear to form any biofilm when mixed with strain CF430-11621. All strains performed swarming while strains CF430-142 and 75887B lacked twitching motility. An aminoacidic change in SadB was observed in the strain 75887B.</div></div><div><h3>Conclusion</h3><div>Mixed biofilms were only observed when identical clones from the same patient were cultured together. Our experiments indicate that twitching motility does not significantly affect biofilm formation or architecture in our isolates.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100257"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101122","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":"Cellulophaga algicola alginate lyase and Pseudomonas aeruginosa Psl glycoside hydrolase inhibit biofilm formation by Pseudomonas aeruginosa CF2843 on three-dimensional aggregates of lung epithelial cells","authors":"Neetu ,&nbsp;Shilpee Pal ,&nbsp;Srikrishna Subramanian ,&nbsp;T.N.C. Ramya","doi":"10.1016/j.bioflm.2025.100265","DOIUrl":"10.1016/j.bioflm.2025.100265","url":null,"abstract":"<div><div><em>Pseudomonas aeruginosa</em> is an opportunistic pathogen that produces a biofilm containing the polysaccharides, alginate, Psl, and Pel, and causes chronic lung infection in cystic fibrosis patients. Others and we have previously explored the use of alginate lyases in inhibiting <em>P. aeruginosa</em> biofilm formation on plastic and lung epithelial cell monolayers. We now employ a more physiologically representative model system, i.e., three-dimensional aggregates of A549 lung epithelial cells cultured under conditions of microgravity in a rotary cell culture system to mimic the natural lung environment, and a previously isolated clinical strain, <em>Pseudomonas aeruginosa</em> CF2843 that we engineered by transposon-mediated integration to express Green Fluorescent Protein and for which we also report the complete genome sequence. Immunostaining and lectin binding studies indicated that the three-dimensional cell aggregates harbored sialylated and fucosylated epitopes as well as Muc1, Muc5Ac, and β-catenin on their surfaces, suggestive of mucin secretion and the presence of tight junctions, hallmark features of lung epithelial tissue. Using this validated model system with confocal microscopy and viable bacterial counts as readouts, we demonstrated that <em>Cellulophaga algicola</em> alginate lyase and <em>Pseudomonas aeruginosa</em> Psl glycoside hydrolase, but not <em>Pseudomonas aeruginosa</em> Pel glycoside hydrolase, inhibit biofilm formation by <em>Pseudomonas aeruginosa</em> on three-dimensional lung epithelial cell aggregates.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100265"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143478545","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":"Drosera rotundifolia L. as E. coli biofilm inhibitor: Insights into the mechanism of action using proteomics/metabolomics and toxicity studies","authors":"Sandy Gerschler ,&nbsp;Sandra Maaß ,&nbsp;Philip Gerth ,&nbsp;Lukas Schulig ,&nbsp;Toni Wildgrube ,&nbsp;Jan Rockstroh ,&nbsp;Martina Wurster ,&nbsp;Karen Methling ,&nbsp;Dörte Becher ,&nbsp;Michael Lalk ,&nbsp;Christian Schulze ,&nbsp;Sebastian Guenther ,&nbsp;Nadin Schultze","doi":"10.1016/j.bioflm.2025.100268","DOIUrl":"10.1016/j.bioflm.2025.100268","url":null,"abstract":"<div><div>The successful sustainable cultivation of the well-known medicinal plant sundew on rewetted peatlands not only leads to the preservation of natural populations, but also provides a basis for the sustainable pharmaceutical use of the plant. The bioactive compounds of sundew, flavonoids and naphthoquinones, show biofilm-inhibiting properties against multidrug-resistant, ESBL-producing <em>E. coli</em> strains and open up new therapeutic possibilities.</div><div>This study investigates the molecular mechanisms of these compounds in biofilm inhibition through proteomic analyses. Specific fractions of flavonoids and naphthoquinones, as well as individual substances like 7-methyljuglone and 2″-<em>O</em>-galloylhyperoside, are analyzed. Results show that naphthoquinones appear to act via central regulatory proteins such as OmpR and alter the stress response while flavonoids likely affect biofilm formation by creating an iron-poor environment through iron complexation and additionally influence polyamine balance, reducing intracellular spermidine levels. Further investigations including assays for iron complexation and analysis of polyamines confirmed the proteomic data. Safety evaluations through cytotoxicity tests in 3D cell cultures and the <em>Galleria mellonella in vivo</em> model confirm the safety of the extracts used. These findings highlight sundew as a promising candidate for new phytopharmaceuticals.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100268"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143563489","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":"Efficacy of nitric oxide donors and EDTA against Pseudomonas aeruginosa biofilms: Implications for antimicrobial therapy in chronic wounds","authors":"Aaron Crowther ,&nbsp;Gareth LuTheryn ,&nbsp;Ramón Garcia-Maset ,&nbsp;Maryam Parhizkar ,&nbsp;J. Mark Sutton ,&nbsp;Charlotte Hind ,&nbsp;Dario Carugo","doi":"10.1016/j.bioflm.2025.100280","DOIUrl":"10.1016/j.bioflm.2025.100280","url":null,"abstract":"<div><div>Opportunistic pathogen <em>Pseudomonas aeruginosa</em> plays a crucial role in chronic wound biofilms, increasing infection's morbidity and mortality. In recent years, the signalling molecule nitric oxide (NO) and chelating agent tetrasodium EDTA (T-EDTA) have been applied therapeutically owing to their multifactorial effects including bacterial killing, biofilm dispersal, and wound healing. However, previous studies assessing NO's antibiofilm efficacy have not considered the variable pH and temperature of the wound environment. Here, pH-dependent NO donors <em>N</em>-diazeniumdiolates (NONOates), PAPA NONOate (PA-NO) and Spermine NONOate (SP–NO), and T-EDTA were applied in wound-relevant pH environments (pH 5.5–8.5) and temperatures (32 °C and 37 °C) to <em>P. aeruginosa</em> PAO1 biofilms grown for either 24 or 48 h. At 32 °C and pH 7.5, 250 μM PA-NO reduced 24-h biofilm biomass by 35 %. At 37 °C, 250 μM PA-NO and 4 % w/v T-EDTA caused 21 % and 57 % biomass reduction in 24-h biofilms, respectively. In 48-h biofilms, NONOates did not induce significant biomass reduction, while T-EDTA maintained its efficacy with a 64 % reduction. A subsequent experiment investigated the impact of NONOates and T-EDTA as pre-treatments before exposure to ciprofloxacin. Unexpectedly, NONOate pre-treatment decreased ciprofloxacin's effectiveness, resulting in approximately 1-log increase in viable planktonic and biofilm-residing cells compared to ciprofloxacin alone. It was hypothesized that this protective effect might stem from NO-induced decreased cellular respiration, which inhibits reactive oxygen species (ROS)-mediated bactericidal mechanisms. These findings highlight both the potential and complexities of developing effective antimicrobial strategies for chronic wound infections, emphasizing the need for further research to optimize treatment approaches.</div></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"9 ","pages":"Article 100280"},"PeriodicalIF":5.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877455","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}