TY - JOUR A1 - Schiebel, Juliane A1 - Boehm, Alexander A1 - Nitschke, Joerg A1 - Burdukiewicz, Michal A1 - Weinreich, Joerg A1 - Ali, Aamir A1 - Roggenbuck, Dirk A1 - Roediger, Stefan A1 - Schierack, Peter T1 - Genotypic and Phenotypic Characteristics Associated with Biofilm Formation by Human Clinical Escherichia coli Isolates of Different Pathotypes JF - Applied and environmental microbiology N2 - Bacterial biofilm formation is a widespread phenomenon and a complex process requiring a set of genes facilitating the initial adhesion, maturation, and production of the extracellular polymeric matrix and subsequent dispersal of bacteria. Most studies on Escherichia coli biofilm formation have investigated nonpathogenic E. coli K-12 strains. Due to the extensive focus on laboratory strains in most studies, there is poor information regarding biofilm formation by pathogenic E. coli isolates. In this study, we genotypically and phenotypically characterized 187 human clinical E. coli isolates representing various pathotypes (e.g., uropathogenic, enteropathogenic, and enteroaggregative E. coli). We investigated the presence of biofilm-associated genes ("genotype") and phenotypically analyzed the isolates for motility and curli and cellulose production ("phenotype"). We developed a new screening method to examine the in vitro biofilm formation ability. In summary, we found a high prevalence of biofilm-associated genes. However, we could not detect a biofilm-associated gene or specific phenotype correlating with the biofilm formation ability. In contrast, we did identify an association of increased biofilm formation with a specific E. coli pathotype. Enteroaggregative E. coli (EAEC) was found to exhibit the highest capacity for biofilm formation. Using our image-based technology for the screening of biofilm formation, we demonstrated the characteristic biofilm formation pattern of EAEC, consisting of thick bacterial aggregates. In summary, our results highlight the fact that biofilm-promoting factors shown to be critical for biofilm formation in nonpathogenic strains do not reflect their impact in clinical isolates and that the ability of biofilm formation is a defined characteristic of EAEC. IMPORTANCE Bacterial biofilms are ubiquitous and consist of sessile bacterial cells surrounded by a self-produced extracellular polymeric matrix. They cause chronic and device-related infections due to their high resistance to antibiotics and the host immune system. In nonpathogenic Escherichia coli, cell surface components playing a pivotal role in biofilm formation are well known. In contrast, there is poor information for their role in biofilm formation of pathogenic isolates. Our study provides insights into the correlation of biofilm-associated genes or specific phenotypes with the biofilm formation ability of commensal and pathogenic E. coli. Additionally, we describe a newly developed method enabling qualitative biofilm analysis by automated image analysis, which is beneficial for high-throughput screenings. Our results help to establish a better understanding of E. coli biofilm formation. KW - biofilm formation KW - Escherichia coli KW - pathotypes KW - VideoScan Y1 - 2017 U6 - https://doi.org/10.1128/AEM.01660-17 SN - 0099-2240 SN - 1098-5336 VL - 83 PB - American Society for Microbiology CY - Washington ER - TY - JOUR A1 - Awan, Asad Bashir A1 - Schiebel, Juliane A1 - Boehm, Alexander A1 - Nitschke, Joerg A1 - Sarwar, Yasra A1 - Schierack, Peter A1 - Ali, Aamir T1 - Association of biofilm formation and cytotoxic potential with multidrug resistance in clinical isolates of pseudomonas aeruginosa JF - EXCLI Journal N2 - Multidrug resistant (MDR) Pseudomonas aeruginosa having strong biofilm potential and virulence factors are a serious threat for hospitalized patients having compromised immunity In this study, 34 P. aeruginosa isolates of human origin (17 MDR and 17 non-MDR clinical isolates) were checked for biofilm formation potential in enriched and minimal media. The biofilms were detected using crystal violet method and a modified software package of the automated VideoScan screening method. Cytotoxic potential of the isolates was also investigated on HepG2, LoVo and T24 cell lines using automated VideoScan technology. Pulse field gel electrophoresis revealed 10 PFGE types in MDR and 8 in non-MDR isolates. Although all isolates showed biofilm formation potential, strong biofilm formation was found more in enriched media than in minimal media. Eight MDR isolates showed strong biofilm potential in both enriched and minimal media by both detection methods. Strong direct correlation between crystal violet and VideoScan methods was observed in identifying strong biofilm forming isolates. High cytotoxic effect was observed by 4 isolates in all cell lines used while 6 other isolates showed high cytotoxic effect on T24 cell line only. Strong association of multidrug resistance was found with biofilm formation as strong biofilms were observed significantly higher in MDR isolates (p-value < 0.05) than non-MDR isolates. No significant association of cytotoxic potential with multidrug resistance or biofilm formation was found (p-value > 0.05). The MDR isolates showing significant cytotoxic effects and strong biofilm formation impose a serious threat for hospitalized patients with weak immune system. KW - Pseudomonas aeruginosa KW - multidrug resistance KW - biofilm KW - cytotoxicity KW - VideoScan technology Y1 - 2019 U6 - https://doi.org/10.17179/excli2018-1948 SN - 1611-2156 VL - 18 SP - 79 EP - 90 PB - Leibniz Research Centre for Working Environment and Human Factors CY - Dortmund ER - TY - JOUR A1 - Nawaz, Shiza A1 - Khan, Muhammad Moman A1 - Noack, Jonas A1 - Awan, Asad Bashir A1 - Schiebel, Juliane A1 - Roggenbuck, Dirk A1 - Schierack, Peter A1 - Sarwar, Yasra A1 - Ali, Aamir T1 - Rapid detection of biofilm formation by zoonotic serovars of Salmonella enterica and avian pathogenic E. coli isolates from poultry JF - Pakistan veterinary journal N2 - Biofilms are complex, sessile microbial communities that are problematic in clinical settings due to their association with survival and pathogenicity of bacteria. The biofilm formation supporting conditions for zoonotic serovars of Salmonella and avian pathogenic E. coli (APEC) from poultry have not been well studied yet. Clinical isolates of zoonotic Salmonella and APEC from poultry were evaluated for biofilm formation in four media at 37 degrees C and 40 degrees C after incubation of 48 and 72 hrs. The biofilms formed in 96 well plates were visualized and quantified with a new module of Aklides system using fluorescence microscope coupled with automated VideoScan Technology. After 72 hrs, brain heart infusion at 40 degrees C and Rappaport-Vassiliadis Soya broth at 37 degrees C were found most suitable for APEC and Salmonella biofilm formations respectively. The new information will be useful for further biofilm associated studies particularly for evaluation of antibiofilm compounds and contribute in infection control. (C) 2020 PVJ. All rights reserved KW - APEC KW - biofilm formation KW - Salmonella KW - video scan technology Y1 - 2020 U6 - https://doi.org/10.29261/pakvetj/2020.066 SN - 0253-8318 SN - 2074-7764 VL - 40 IS - 4 SP - 527 EP - 530 PB - University of Agriculture, Faculty of Veterinary Science CY - Faisalabad ER -