Type 1 fimbriae contribute to catheter-associated urinary tract infections caused by Escherichia coli

J Bacteriol. 2014 Mar;196(5):931-9. doi: 10.1128/JB.00985-13. Epub 2013 Dec 13.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adhesins, Escherichia coli / genetics
  • Adhesins, Escherichia coli / metabolism
  • Biofilms / growth & development
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Escherichia coli / physiology*
  • Escherichia coli Infections / etiology
  • Escherichia coli Infections / microbiology*
  • Fimbriae Proteins / genetics
  • Fimbriae Proteins / metabolism*
  • Flagella / genetics
  • Flagella / metabolism
  • Flagella / physiology
  • Gene Expression Regulation, Bacterial / physiology
  • Humans
  • Mutation
  • Urinary Catheters / adverse effects*
  • Urinary Tract Infections / etiology
  • Urinary Tract Infections / microbiology*


  • Adhesins, Escherichia coli
  • antigen 43, E coli
  • Fimbriae Proteins