title: Type 1 fimbriae contribute to catheter-associated urinary tract infections caused by Escherichia coli.
abstract: Biofilm formation on catheters is thought to contribute to persistence of catheter-associated urinary tract infections (CAUTI), which represent the most frequent nosocomial infections. Knowledge of genetic factors for catheter colonization is limited, since their role has not been assessed using physicochemical conditions prevailing in a catheterized human bladder. The current study aimed to combine data from a dynamic catheterized bladder model in vitro with in vivo expression analysis for understanding molecular factors relevant for CAUTI caused by Escherichia coli. By application of the in vitro model that mirrors the physicochemical environment during human infection, we found that an E. coli K-12 mutant defective in type 1 fimbriae, but not isogenic mutants lacking flagella or antigen 43, was outcompeted by the wild-type strain during prolonged catheter colonization. The importance of type 1 fimbriae for catheter colonization was verified using a fimA mutant of uropathogenic E. coli strain CFT073 with human and artificial urine. Orientation of the invertible element (IE) controlling type 1 fimbrial expression in bacterial populations harvested from the colonized catheterized bladder in vitro suggested that the vast majority of catheter-colonizing cells (up to 88%) express type 1 fimbriae. Analysis of IE orientation in E. coli populations harvested from patient catheters revealed that a median level of ∼73% of cells from nine samples have switched on type 1 fimbrial expression. This study supports the utility of the dynamic catheterized bladder model for analyzing catheter colonization factors and highlights a role for type 1 fimbriae during CAUTI.
authors: University of Applied Sciences, Biomedical Science, Graz, Austria.
authors: Andreas
authors: A
authors: Reisner
authors: Mario
authors: M
authors: Maierl
authors: Michael
authors: M
authors: Jörger
authors: Robert
authors: R
authors: Krause
authors: Daniela
authors: D
authors: Berger
authors: Andrea
authors: A
authors: Haid
authors: Dijana
authors: D
authors: Tesic
authors: Ellen L
authors: EL
authors: Zechner
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004927:Escherichia coli Infections / Q000209:etiology / Q000382:microbiology*; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D005407:Flagella / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D006801:Humans; D009154:Mutation; D062885:Urinary Catheters / Q000009:adverse effects*; D014552:Urinary Tract Infections / Q000209:etiology / Q000382:microbiology*
chemical_list: D018830:Adhesins, Escherichia coli; C118376:antigen 43, E coli; D036781:Fimbriae Proteins