Department of Microbiology, Gdańsk University of Technology, ul. G. Narutowicza 11/12, 80-233 Gdańsk, Poland.
Department of Microbiology, Gdańsk University of Technology, ul. G. Narutowicza 11/12, 80-233 Gdańsk, Poland.
Microbiol Res. 2013 Jul 19;168(6):367-378. doi: 10.1016/j.micres.2013.01.001. Epub 2013 Jan 30.
Urinary tract infections caused by Escherichia coli are very common health problem in the developed countries. The virulence of the uropathogenic E. coli Dr(+) IH11128 is determined by Dr fimbriae, which are homopolymeric structures composed of DraE subunits with the DraD protein capping the fiber. In this study, we have analyzed the structural and biochemical properties of biofilms developed by E. coli strains expressing Dr fimbriae with or without the DraD tip subunit and the surface-exposed DraD protein. We have also demonstrated that these E. coli strains form biofilms on an abiotic surface in a nutrient-dependent fashion. We present evidence that Dr fimbriae are necessary during the first stage of bacterial interaction with the abiotic surface. In addition, we reveal that the DraD alone is also sufficient for the initial surface attachment at an even higher level than Dr fimbriae and that chloramphenicol is able to reduce the normal attachment of the analyzed E. coli. The action of chloramphenicol also shows that protein synthesis is required for the early events of biofilm formation. Additionally, we have identified reduced exopolysaccharide coverage in E. coli that express only Dr fimbrial polyadhesins at the cell surface with or without the DraD capping subunit.
大肠埃希菌引起的尿路感染是发达国家非常常见的健康问题。尿路致病性大肠埃希菌 Dr(+) IH11128 的毒力由 Dr 菌毛决定，Dr 菌毛是由 DraE 亚基组成的同聚体结构，纤维顶端由 DraD 蛋白封闭。在这项研究中，我们分析了表达 Dr 菌毛的大肠埃希菌菌株在有无 DraD 顶端亚基和表面暴露的 DraD 蛋白的情况下形成的生物膜的结构和生化特性。我们还证明了这些大肠埃希菌菌株以营养依赖的方式在非生物表面形成生物膜。我们提供的证据表明，Dr 菌毛在细菌与非生物表面最初相互作用的阶段是必需的。此外，我们还揭示了 DraD 蛋白本身就足以在更高水平上实现初始表面附着，甚至超过 Dr 菌毛，并且氯霉素能够降低分析的大肠埃希菌的正常附着。氯霉素的作用还表明，蛋白质合成是生物膜形成早期事件所必需的。此外，我们还发现，仅在细胞表面表达 Dr 菌毛多聚粘附素的大肠埃希菌的胞外多糖覆盖减少，无论是否存在 DraD 盖帽亚基。
