Biofilm最新文献

{"title":"Hyperbaric oxygen therapy counteracts Pseudomonas aeruginosa biofilm micro-compartment phenomenon in murine thermal wounds","authors":"Anne Sofie Laulund ,&nbsp;Franziska Angelika Schwartz ,&nbsp;Niels Høiby ,&nbsp;Kim Thomsen ,&nbsp;Claus Moser","doi":"10.1016/j.bioflm.2023.100159","DOIUrl":"https://doi.org/10.1016/j.bioflm.2023.100159","url":null,"abstract":"<div><h3>Background</h3><p>Biofilm antibiotic tolerance is partly explained by the behavior of a biofilm as an independent pharmacokinetic micro-compartment. Hyperbaric oxygen therapy has been shown to potentiate antibiotic effects in biofilms. The present study investigates the effect of hyperbaric oxygen therapy (HBOT) on the biofilm micro-pharmacokinetic/pharmacodynamic behavior of tobramycin in an animal biofilm model.</p></div><div><h3>Methods</h3><p>Full-thickness necroses were created mid-scapular on mice by means of a thermal lesion. After four days, three 16 h seaweed alginate biofilm beads containing <em>Pseudomonas aeruginosa</em> PAO1 were inserted under the necrosis, and three beads were inserted under the adjacent non-affected skin. The mice were randomized to three groups I) HBOT for 1.5 h at 2.8 atm and 0.8 mg tobramycin/mouse subcutaneously; II) Tobramycin as monotherapy, same dose; III) Saline control group. Half the number of mice from group 1 and 2 were sacrificed, and beads were recovered <em>in toto</em> after 3 h and the other half and the placebo mice were sacrificed and beads collected after 4.5 h.</p></div><div><h3>Results</h3><p>Lower CFUs were seen in the burned group receiving HBOT at 3 and 4.5 h compared to beads in the atmospheric environment (p = 0.043 and p = 0.0089). At 3 h, no CFU difference was observed in the non-burned skin (HBOT vs atmospheric). At 4.5 h, CFU in the non-burned skin had lower CFUs in the group receiving HBOT compared to the corresponding atmospheric group (p = 0.02). CFU was higher in the burned skin than in the non-burned skin at 3 h when HBOT was applied (p = 0.04), effect faded out at 4.5 h.</p><p>At both time points, the tobramycin content in the beads under burned skin were higher in the HBOT group than in the atmospheric groups (p = 0.031 and p = 0.0078). Only at 4.5 h a higher tobramycin content was seen in the beads under the HBOT-treated burned skin than the beads under the corresponding non-burned skin (p = 0.006).</p></div><div><h3>Conclusion</h3><p>HBOT, as an anti-biofilm adjuvant treatment of chronic wounds, counteracts biofilm pharmacokinetic micro-compartmentalization through increased available tobramycin and augmented bacterial killing.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100159"},"PeriodicalIF":6.8,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50171106","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":"Spectrum of activity of Salmonella anti-biofilm compounds: Evaluation of activity against biofilm-forming ESKAPE pathogens","authors":"Aliyah N. Bennett ,&nbsp;Katherine J. Woolard ,&nbsp;Amy Sorge ,&nbsp;Christian Melander ,&nbsp;John S. Gunn","doi":"10.1016/j.bioflm.2023.100158","DOIUrl":"https://doi.org/10.1016/j.bioflm.2023.100158","url":null,"abstract":"<div><p>The ESKAPE pathogens are a group of bacteria that are a leading cause of health-care associated infections and are known to be agents of chronic, biofilm-mediated infections. These chronic bacterial infections often respond poorly to antibiotics and in some cases may require surgical intervention in order to cure the infection. As biofilms are often the critical mediator of a chronic infection, it is essential to develop therapies that target bacteria within the biofilm state. Herein, we report the development of a rapid, 96-well plate-based assay that employs conditions specific for each species to optimize biofilm production and allow for easy identification of differences in biofilm mass after treatment with anti-biofilm candidates. We used these ESKAPE-specific biofilm assays to test our previously identified <em>Salmonella</em> anti-biofilm small molecule compounds, JG-1 and M4, for anti-biofilm activity. The results demonstrated that JG-1 and M4 have anti-biofilm activity against <em>Enterobacter</em> spp., <em>S. aureus, E. faecium, P. aeruginosa</em>, and <em>A. baumannii</em>. In addition, we identified that M4 has significant antimicrobial activity against <em>S. aureus</em> and <em>E. faecium</em> at concentrations &gt;10 μM (X μg/mL). These findings support the claim that JG-1 and M4 have broad-spectrum anti-biofilm activity, while M4 has antimicrobial activity against the Gram-positive members of the ESKAPE pathogens. Thus, these compounds have the potential to have a significant impact on treating multiple types of commonly encountered biofilm-mediated infections.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100158"},"PeriodicalIF":6.8,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50171104","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":"Multiscale spatial segregation analysis in digital images of biofilms","authors":"Iztok Dogsa,&nbsp;Ines Mandic-Mulec","doi":"10.1016/j.bioflm.2023.100157","DOIUrl":"10.1016/j.bioflm.2023.100157","url":null,"abstract":"<div><p>Quantifying the degree of spatial segregation of two bacterial strains in mixed biofilms is an important topic in microbiology. Spatial segregation is dependent on spatial scale as two strains may appear to be well mixed if observed from a distance, but a closer look can reveal strong separation. Typically, this information is encoded in a digital image that represents the binary system, e.g., a microscopy image of a two species biofilm. To decode spatial segregation information, we have developed quantitative measures for evaluating the degree of the spatial scale-dependent segregation of two bacterial strains in a digital image. The constructed algorithm is based on the new segregation measures and overcomes drawbacks of existing approaches for biofilm segregation analysis. The new approach is implemented in a freely available software and was successfully applied to biofilms of two strains and bacterial suspensions for detection of the different spatial scale-dependent segregation levels.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100157"},"PeriodicalIF":6.8,"publicationDate":"2023-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/50/16/main.PMC10542597.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41168231","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":"Sub-MIC streptomycin and tetracycline enhanced Staphylococcus aureus Guangzhou-SAU749 biofilm formation, an in-depth study on transcriptomics","authors":"Junyan Liu ,&nbsp;Tengyi Huang ,&nbsp;Zhenbo Xu ,&nbsp;Yuzhu Mao ,&nbsp;Thanapop Soteyome ,&nbsp;Gongliang Liu ,&nbsp;Chunyun Qu ,&nbsp;Lei Yuan ,&nbsp;Qin Ma ,&nbsp;Fang Zhou ,&nbsp;Gamini Seneviratne","doi":"10.1016/j.bioflm.2023.100156","DOIUrl":"https://doi.org/10.1016/j.bioflm.2023.100156","url":null,"abstract":"<div><p><em>Staphylococcus aureus</em> is a major human pathogen, a potential “Super-bug” and a typical biofilm forming bacteria. With usage of large amount of antibiotics, the residual antibiotics in clinical settings further complicate the colonization, pathogenesis and resistance of <em>S. aureus</em>. This study aimed at investigating the phenotypical and global gene expression changes on biofilm formation of a clinical <em>S. aureus</em> isolate treated under different types of antibiotics. Firstly, an isolate Guangzhou-SAU749 was selected from a large sale of previously identified <em>S. aureus</em> isolates, which exhibited weak biofilm formation in terms of biomass and viability. Secondly, 9 commonly prescribed antibiotics for <em>S. aureus</em> infections treatment, together with 10 concentrations ranging from 1/128 to 4 minimum inhibitory concentration (MIC) with 2-fold serial dilution, were used as different antibiotic stress conditions. Then, biofilm formation of <em>S. aureus</em> Guangzhou-SAU749 at different stages including 8 h, 16 h, 24 h, and 48 h, was tested by crystal violet and MTS assays. Thirdly, the whole genome of <em>S. aureus</em> Guangzhou-SAU749 was investigated by genome sequencing on PacBio platform. Fourthly, since enhancement of biofilm formation occurred when treated with 1/2 MIC tetracycline (TCY) and 1/4 MIC streptomycin (STR) since 5 h, the relevant biofilm samples were selected and subjected to RNA-seq and bioinformatics analysis. Last, expression of two component system (TCS) and biofilm associated genes in 4 h, 8 h, 16 h, 24 h, and 48 h sub-MIC TCY and STR treated biofilm samples were performed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Although most antibiotics lowered the biomass and cell viability of Guangzhou-SAU749 biofilm at concentrations higher than MIC, certain antibiotics including TCY and STR promoted biofilm formation at sub-MICs. Additionally, upon genome sequencing, RNA-seq and RT-qPCR on biofilm samples treated with sub-MIC of TCY and STR at key time points, genes <em>lytR</em>, <em>arlR</em>, <em>hssR</em>, <em>tagA</em>, <em>clfB</em>, <em>atlA</em> and <em>cidA</em> related to TCS and biofilm formation were identified to contribute to the enhanced biofilm formation, providing a theoretical basis for further controlling on <em>S. aureus</em> biofilm formation.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100156"},"PeriodicalIF":6.8,"publicationDate":"2023-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50171103","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":"Plasma activated water as a pre-treatment strategy in the context of biofilm-infected chronic wounds","authors":"Heema K.N. Vyas ,&nbsp;Binbin Xia ,&nbsp;David Alam ,&nbsp;Nicholas P. Gracie ,&nbsp;Joanna G. Rothwell ,&nbsp;Scott A. Rice ,&nbsp;Dee Carter ,&nbsp;Patrick J. Cullen ,&nbsp;Anne Mai-Prochnow","doi":"10.1016/j.bioflm.2023.100154","DOIUrl":"10.1016/j.bioflm.2023.100154","url":null,"abstract":"<div><p>Healing and treatment of chronic wounds are often complicated due to biofilm formation by pathogens. Here, the efficacy of plasma activated water (PAW) as a pre-treatment strategy has been investigated prior to the application of topical antiseptics polyhexamethylene biguanide, povidone iodine, and MediHoney, which are routinely used to treat chronic wounds. The efficacy of this treatment strategy was determined against biofilms of <em>Escherichia coli</em> formed on a plastic substratum and on a human keratinocyte monolayer substratum used as an <em>in vitro</em> biofilm-skin epithelial cell model. PAW pre-treatment greatly increased the killing efficacy of all the three antiseptics to eradicate the <em>E. coli</em> biofilms formed on the plastic and keratinocyte substrates. However, the efficacy of the combined PAW-antiseptic treatment and single treatments using PAW or antiseptic alone was lower for biofilms formed in the <em>in vitro</em> biofilm-skin epithelial cell model compared to the plastic substratum. Scavenging assays demonstrated that reactive species present within the PAW were largely responsible for its anti-biofilm activity. PAW treatment resulted in significant intracellular reactive oxygen and nitrogen species accumulation within the <em>E. coli</em> biofilms, while also rapidly acting on the microbial membrane leading to outer membrane permeabilisation and depolarisation. Together, these factors contribute to significant cell death, potentiating the antibacterial effect of the assessed antiseptics.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100154"},"PeriodicalIF":6.8,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/e2/2a/main.PMC10522953.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41174187","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":"Glycosyl hydrolase from Pseudomonas fluorescens inhibits the biofilm formation of Pseudomonads","authors":"Di Wang ,&nbsp;Syed Tatheer Alam Naqvi ,&nbsp;Fanglin Lei ,&nbsp;Zhenyu Zhang ,&nbsp;Haiying Yu ,&nbsp;Luyan Z. Ma","doi":"10.1016/j.bioflm.2023.100155","DOIUrl":"https://doi.org/10.1016/j.bioflm.2023.100155","url":null,"abstract":"<div><p>Biofilms are complex microbial communities embedded in extracellular matrix. Pathogens within the biofilm become more resistant to the antibiotics than planktonic counterparts. Novel strategies are required to encounter biofilms. Exopolysaccharides are one of the major components of biofilm matrix and play a vital role in biofilm architecture. In previous studies, a glycosyl hydrolase, PslG_PA, from <em>Pseudomonas aeruginosa</em> was found to be able to inhibit biofilm formation by disintegrating exopolysaccharide in biofilms. Here, we investigate the potential spectrum of PslG homologous protein with anti-biofilm activity. One glycosyl hydrolase from <em>Pseudomonas fluorescens</em>, PslG_PF, exhibits anti-biofilm activities and the key catalytic residues of PslG_PF are conserved with those of PslG_PA. PslG_PF at concentrations as low as 50 nM efficiently inhibits the biofilm formation of <em>P. aeruginosa</em> and disassemble its preformed biofilm. Furthermore, PslG_PF exhibits anti-biofilm activity on a series of <em>Pseudomonads</em>, including <em>P. fluorescens, Pseudomonas stutzeri</em> and <em>Pseudomonas syringae</em> pv. <em>phaseolicola</em>. PslG_PF stays active under various temperatures. Our findings suggest that <em>P. fluorescens</em> glycosyl hydrolase PslG_PF has potential to be a broad spectrum inhibitor on biofilm formation of a wide range of <em>Pseudomonads</em>.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100155"},"PeriodicalIF":6.8,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50171077","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":"NaCl-induced modulation of species distribution in a mixed P. aeruginosa / S. aureus /B. cepacia biofilm","authors":"Jeanne Trognon ,&nbsp;Maya Rima ,&nbsp;Barbora Lajoie ,&nbsp;Christine Roques ,&nbsp;Fatima El Garah","doi":"10.1016/j.bioflm.2023.100153","DOIUrl":"https://doi.org/10.1016/j.bioflm.2023.100153","url":null,"abstract":"<div><p><em>Pseudomonas aeruginosa</em>, <em>Staphylococcus aureus</em>, and <em>Burkholderia cepacia</em> are notorious pathogens known for their ability to form resilient biofilms, particularly within the lung environment of cystic fibrosis (CF) patients. The heightened concentration of NaCl, prevalent in the airway liquid of CF patients' lungs, has been identified as a factor that promotes the growth of osmotolerant bacteria like <em>S. aureus</em> and dampens host antibacterial defenses, thereby fostering favorable conditions for infections.</p><p>In this study, we aimed to investigate how increased NaCl concentrations impact the development of multi-species biofilms <em>in vitro</em>, using both laboratory strains and clinical isolates of <em>P. aeruginosa</em>, <em>S. aureus</em>, and B. cepacia co-cultures. Employing a low-nutrient culture medium that fosters biofilm growth of the selected species, we quantified biofilm formation through a combination of adherent CFU counts, qPCR analysis, and confocal microscopy observations.</p><p>Our findings reaffirmed the challenges faced by <em>S. aureus</em> in establishing growth within 1:1 mixed biofilms with <em>P. aeruginosa</em> when cultivated in a minimal medium. Intriguingly, at an elevated NaCl concentration of 145 mM, a symbiotic relationship emerged between <em>S. aureus</em> and <em>P. aeruginosa</em>, enabling their co-existence. Notably, this hyperosmotic environment also exerted an influence on the interplay of these two bacteria with <em>B. cepacia</em>. We demonstrated that elevated NaCl concentrations play a pivotal role in orchestrating the distribution of these three species within the biofilm matrix.</p><p>Furthermore, our study unveiled the beneficial impact of NaCl on the biofilm growth of clinically relevant mucoid <em>P. aeruginosa</em> strains, as well as two strains of methicillin-sensitive and methicillin-resistant <em>S. aureus</em>. This underscores the crucial role of the microenvironment during the colonization and infection processes. The results suggest that hyperosmotic conditions could hold the key to unlocking a deeper understanding of the genesis and behavior of CF multi-species biofilms.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100153"},"PeriodicalIF":6.8,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50171102","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":"Bacillus subtilis NDmed, a model strain for biofilm genetic studies","authors":"Yasmine Dergham ,&nbsp;Dominique Le Coq ,&nbsp;Arnaud Bridier ,&nbsp;Pilar Sanchez-Vizuete ,&nbsp;Hadi Jbara ,&nbsp;Julien Deschamps ,&nbsp;Kassem Hamze ,&nbsp;Ken-ichi Yoshida ,&nbsp;Marie-Françoise Noirot-Gros ,&nbsp;Romain Briandet","doi":"10.1016/j.bioflm.2023.100152","DOIUrl":"https://doi.org/10.1016/j.bioflm.2023.100152","url":null,"abstract":"<div><p>The <em>Bacillus subtilis</em> strain NDmed was isolated from an endoscope washer-disinfector in a medical environment. NDmed can form complex macrocolonies with highly wrinkled architectural structures on solid medium. In static liquid culture, it produces thick pellicles at the interface with air as well as remarkable highly protruding ‘‘beanstalk-like’’ submerged biofilm structures at the solid surface. Since these mucoid submerged structures are hyper-resistant to biocides, NDmed has the ability to protect pathogens embedded in mixed-species biofilms by sheltering them from the action of these agents. Additionally, this non-domesticated and highly biofilm forming strain has the propensity of being genetically manipulated. Due to all these properties, the NDmed strain becomes a valuable model for the study of <em>B</em>. <em>subtilis</em> biofilms. This review focuses on several studies performed with NDmed that have highlighted the sophisticated genetic dynamics at play during <em>B</em>. <em>subtilis</em> biofilm formation. Further studies in project using modern molecular tools of advanced technologies with this strain, will allow to deepen our knowledge on the emerging properties of multicellular bacterial life.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100152"},"PeriodicalIF":6.8,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50171101","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":"α,α-disubstituted β-amino amides eliminate Staphylococcus aureus biofilms by membrane disruption and biomass removal","authors":"Dominik Ausbacher ,&nbsp;Lindsey A. Miller ,&nbsp;Darla M. Goeres ,&nbsp;Philip S. Stewart ,&nbsp;Morten B. Strøm ,&nbsp;Adyary Fallarero","doi":"10.1016/j.bioflm.2023.100151","DOIUrl":"https://doi.org/10.1016/j.bioflm.2023.100151","url":null,"abstract":"<div><p>Bacterial biofilms account for up to 80% of all infections and complicate successful therapies due to their intrinsic tolerance to antibiotics. Biofilms also cause serious problems in the industrial sectors, for instance due to the deterioration of metals or microbial contamination of products. Efforts are put in finding novel strategies in both avoiding and fighting biofilms. Biofilm control is achieved by killing and/or removing biofilm or preventing transition to the biofilm lifestyle. Previous research reported on the anti-biofilm potency of α,α-disubstituted β-amino amides <strong>A1</strong>, <strong>A2</strong> and <strong>A3</strong>, which are small antimicrobial peptidomimetics with a molecular weight below 500 Da. In the current study it was investigated if these derivatives cause a fast disintegration of biofilm bacteria and removal of <em>Staphylococcus aureus</em> biofilms. One hour incubation of biofilms with all three derivatives resulted in reduced metabolic activity and membrane permeabilization in <em>S. aureus</em> (ATCC 25923) biofilms. Bactericidal properties of these derivatives were attributed to a direct effect on membranes of biofilm bacteria. The green fluorescence protein expressing <em>Staphylococcus aureus</em> strain AH2547 was cultivated in a CDC biofilm reactor and utilized for disinfectant efficacy testing of <strong>A3</strong>, following the single tube method (<em>American Society for Testing and Materials designation number E2871)</em>. <strong>A3</strong> at a concentration of 90 μM acted as fast as 100 μM chlorhexidine and was equally effective. Confocal laser scanning microscopy studies showed that chlorhexidine treatment lead to fluorescence fading indicating membrane permeabilization but did not cause biomass removal. In contrast, <strong>A3</strong> treatment caused a simultaneous biofilm fluorescence loss and biomass removal. These dual anti-biofilm properties make α,α-disubstituted β-amino amides promising scaffolds in finding new control strategies against recalcitrant biofilms.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100151"},"PeriodicalIF":6.8,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50171100","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":"Octanoic acid promotes clearance of antibiotic-tolerant cells and eradicates biofilms of Staphylococcus aureus isolated from recurrent bovine mastitis","authors":"Wen-Chun Lin ,&nbsp;Kai-Chen Hsu ,&nbsp;Ming-Feng You ,&nbsp;Kuo-Hua Lee ,&nbsp;Chau-Hwa Chi ,&nbsp;Jyh-Yih Chen","doi":"10.1016/j.bioflm.2023.100149","DOIUrl":"https://doi.org/10.1016/j.bioflm.2023.100149","url":null,"abstract":"<div><p>Antibiotic therapy is the primary treatment for bovine mastitis, but the drawbacks of this strategy include poor cure rate and economic losses from the need to discard milk with antibiotic residues. Unfortunately, few other treatment options are currently available for mastitis. Failure of antibiotic treatments is often attributed to formation of bacterial biofilms and abscesses in the mammary gland tissue, which lead to chronic infections that are difficult to eradicate and drive recurrent disease. A major mastitis-causing pathogen (MCP) associated with biofilms in bovine mastitis is <em>Staphylococcus aureus</em>. In this study, we demonstrate that octanoic acid has broad-spectrum microbicidal activity against MCPs and effectively inhibits <em>S. aureus</em> biofilm formation in milk (&gt;50% inhibition at 3.13 mM). Octanoic acid effectively clears biofilms (95% eradication at 1<em>X</em> minimum bactericidal concentration, MBC) and infrequently induces <em>S. aureus</em> small colony variants (SCVs) that may cause recurrent mastitis. Additionally, octanoic acid rapidly kills persistent biofilm cells and cells with antibiotic tolerance (within 4 h). In contrast, antibiotics treated at &gt;100<em>X</em> MBC cannot eradicate biofilms but do induce SCVs and antibiotic-tolerant cells. These effects may accelerate the transition from biofilm to chronic infection. Thus, octanoic acid exhibits bactericidal action against <em>S. aureus</em> biofilms, and it is less likely than antibiotic therapy to induce persistent cells and pathogen tolerance. Moreover, octanoic acid acts additively with antibiotics against <em>S. aureus</em>, and it attenuates tetracycline-induced virulence factor gene expression in <em>S. aureus</em> cells. According to these data, octanoic acid may prevent the pathological progression of bovine mastitis and offer a new strategy for treating the condition.</p></div>","PeriodicalId":55844,"journal":{"name":"Biofilm","volume":"6 ","pages":"Article 100149"},"PeriodicalIF":6.8,"publicationDate":"2023-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50171098","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}