Biochemical characteristic of biofilm of uropathogenic Escherichia coli Dr + strains

Abstract

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.

Pathogenesis of Human Diffusely Adhering Escherichia coli Expressing Afa/Dr Adhesins (Afa/Dr DAEC): Current Insights and Future Challenges

“…Recombinant DraE Ϫ /DraD ϩ or AfaE Ϫ /D ϩ -III E. coli failed to adhere to differentiated primary bladder cells (188) and CHO-hDAF-␣ 5 ␤ 1 cells (189), respectively. In contrast, Zalewska-Piatek et al (190) have reported that in HeLa cells, DraE Ϫ /DraD ϩ E. coli displays a low level of adhesion, ϳ3-fold lower that of DraE ϩ /DraD ϩ E. coli. In contrast to the chloramphenicol-sensitive adhesion of DraE, the DraD-induced binding is chloramphenicol insensitive (190).…”

“…In contrast, Zalewska-Piatek et al (190) have reported that in HeLa cells, DraE Ϫ /DraD ϩ E. coli displays a low level of adhesion, ϳ3-fold lower that of DraE ϩ /DraD ϩ E. coli. In contrast to the chloramphenicol-sensitive adhesion of DraE, the DraD-induced binding is chloramphenicol insensitive (190).…”

“…Zalewska-Piatek et al (233) were the first to observe that that Dr-positive E. coli formed biofilms. This phenomenon means that Dr-positive E. coli strains form live filamentous bacteria, depending on their nutritional environment (190,233). It has been observed that adhering Dr-positive E. coli forms filamentous forms at the cell surface of CHO-hDAF-␣5␤1 (189) or CHO-hDAF (234) cells.…”

“…Bacterial biofilm formed by UPEC after aggregation of three-dimensional structured cells connected by self-produced exopolysaccharide matrix plays a major role in persistent and chronic UTIs (199). Exopolysaccharide production, which plays a pivotal role in biofilm completion, has been found in UTIassociated E. coli strains expressing Dr (190,233) or Afa-VIII (231) adhesins. Interestingly, exopolysaccharide production is controlled by the vpeBC gene (231), which is present in the vpe locus of afa-8-positive E. coli (43).…”

Identification of antigen Ag43 in uropathogenic Escherichia coli Dr+ strains and defining its role in the pathogenesis of urinary tract infections

“…DraD protein can be expressed in two forms: fimbriae associated and fimbria non-associated (Zalewska et al, 2005;Zalewska-Piątek et al, 2008). These main virulence determinants of E. coli Dr + strains are responsible for adhesion to the receptors of host tissues or adhesion to abiotic surfaces, which is the first step of biofilm formation by the bacteria (Zalewska-Piątek et al, 2008, 2009, 2013. The ability of the E. coli Dr + strain to adhere to a diverse range of surfaces is important for colonization, survival and persistence of the bacteria within the urinary tract.…”