Biofilm formation of Escherichia coli title as a trigger of catheter-associated urinary tract infections

Abstract

The widespread use in urological practice of biological and artificial materials, on the surface of which bacterial biofilms form, increases the risk of pathogen persistence in the human body. Nowaday, there is an acute problem of catheter-associated urinary tract infections (САUTI), which are most commonly caused by uropathogenic Escherichia coli (UPEC) strains, either in monoculture and as part of polymicrobial associations with fecal microbiota. Bacterial adhesion and colonization of the catheter surface are determined, the one hand, by the nature of the polymeric material, and, on the other hand, by a set of fimbrial and afimbrial adhesins, as well as outer membrane proteins of pathogens. Attachment of bacteria to cells in human biotopes is also mediated by various adhesins and is important in the pathogenesis of CAUTI. Optimal conditions for horizontal gene transfer (HGT), of numerous virulence- associated and antibiotic resistance factors through conjugation and mobilization are created in adhered microbial communities. At the same time, conjugative transfer can introduce additional dynamics into biofilm formation due to increased expression of sex pili needed for plasmid transfer. As part of the implementation of scientific projects, the genetic profiles of adhesins of uropathogenic strains of E. coli were studied, their relationship with adhesion was assessed, considering the type of surface material, and the effect of some antibacterial drugs on the colonization of the surface of urethral catheters was determined. In addition, the frequency of F-plasmid transmission in plankton and biofilm was studied depending on the biological properties of recipient strains: the phylogenetic group, biofilm-forming ability, lysogeny, bacteriocin production, and bacteriocin sensitivity. The data obtained will contribute to a better understanding of the mechanisms of intraspecific interaction of E. coli in biofilms, which will allow us to identify the features and patterns of UPEC persistence in CAUTI.