Jan Kochanowski University, Institute of Medical Sciences, Kielce, Poland; Department of Microbiology, Tumor and Cell Biology, Karolinska University Hospital & Karolinska Institutet, Stockholm, Sweden.
Department of Microbiology, Tumor and Cell Biology, Karolinska University Hospital & Karolinska Institutet, Stockholm, Sweden.
Microb Pathog. 2019 Jan;126:287-291. doi: 10.1016/j.micpath.2018.11.020. Epub 2018 Nov 14.
Reactive oxygen intermediates, such as hydrogen peroxide, are toxic molecules produced by immune cells in response to bacterial invasion into the host. Bacteria try to protect themselves against the immune system through specific properties such as biofilm formation. This phenomenon occurs also during urinary tract infections. Cellulose is an important factor of Escherichia coli biofilm and contributes to building a protective shield around bacterial cells upon the host immune response. In this study, we aimed to analyze the effect of hydrogen peroxide on the production of this biofilm component. To achieve this goal, 25 clinical E. coli strains isolated from patients with urinary tract infections were used. These bacterial strains were characterized based on their growth characteristics, their ability to form biofilm and their capacity to produce cellulose upon exposure to sub-lethal concentrations of hydrogen peroxide growth, and the biofilm formation of these strains was analyzed. Our results revealed that the analyzed uropathogenic E. coli strains slightly, but significantly, reduced growth and biofilm production upon hydrogen peroxide treatment. However, when separating these strains regarding their ability to produce cellulose, we found that general biofilm production was reduced but cellulose expression was induced upon peroxide treatment. This finding contributes to a better understanding of how bacterial biofilm formation is triggered and provides interesting insights into how uropathogenic E. coli protect themselves in an inhospitable environment.
活性氧中间体，如过氧化氢，是免疫细胞在细菌入侵宿主时产生的有毒分子。细菌通过生物膜形成等特定特性来试图保护自己免受免疫系统的侵害。这种现象也发生在尿路感染中。纤维素是大肠杆菌生物膜的重要因素，有助于在宿主免疫反应时为细菌细胞形成保护屏障。在这项研究中，我们旨在分析过氧化氢对这种生物膜成分产生的影响。为了实现这一目标，使用了 25 株从尿路感染患者中分离出来的临床大肠杆菌菌株。根据这些细菌菌株的生长特性、形成生物膜的能力以及在亚致死浓度过氧化氢生长条件下产生纤维素的能力对其进行了表征，并分析了这些菌株的生物膜形成情况。我们的结果表明，经过氧化氢处理后，分析的尿路致病性大肠杆菌菌株的生长和生物膜形成略有但显著减少。然而，当根据其产生纤维素的能力对这些菌株进行分离时，我们发现总生物膜形成减少，但纤维素表达在过氧化物处理时被诱导。这一发现有助于更好地理解细菌生物膜形成是如何被触发的，并为了解尿路致病性大肠杆菌在恶劣环境中如何保护自己提供了有趣的见解。
