Pleiotropic roles of uvrY on biofilm formation, motility and virulence in uropathogenic Escherichia coli CFT073

PLoS One. 2013;8(2):e55492. doi: 10.1371/journal.pone.0055492. Epub 2013 Feb 1.

Abstract

Urinary tract infections primarily caused by uropathogenic strains of Escherichia coli (E. coli) remain a significant public health problem in both developed and developing countries. An important virulence determinant in uropathogenesis is biofilm formation which requires expression of fimbriae, flagella, and other surface components such as lipopolysaccharides. In this study, we explored the regulation of uvrY and csrA genes in biofilm formation, motility and virulence determinants in uropathogenic E. coli. We found that mutation in uvrY suppressed biofilm formation on abiotic surfaces such as polyvinyl chloride, polystyrene and glass, and complementation of uvrY in the mutant restored the biofilm phenotype. We further evaluated the role of uvrY gene in expression of type 1 fimbriae, an important adhesin that facilitates adhesion to various abiotic surfaces. We found that phase variation of type 1 fimbriae between fimbriated and afimbriated mode was modulated by uvrY at its transcriptional level. Deletion mutant of uvrY lowered expression of fimbrial recombinase genes, such as fimB, fimE, and fimA, a gene encoding major fimbrial subunit. Furthermore, transcription of virulence specific genes such as papA, hlyB and galU was also reduced in the deletion mutant. Swarming motility and expression of flhD and flhC was also diminished in the mutant. Taken together, our findings unravel a possible mechanism in which uvrY facilitates biofilm formation, persistence and virulence of uropathogenic E. coli.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biofilms / growth & development*
  • Escherichia coli / pathogenicity
  • Escherichia coli / physiology*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Fimbriae, Bacterial / metabolism
  • Gene Expression Regulation, Bacterial / genetics*
  • Genetic Complementation Test
  • Genetic Pleiotropy / genetics
  • Genetic Pleiotropy / physiology*
  • Gentian Violet
  • Glass
  • Humans
  • Movement
  • Mutation / genetics
  • Oligonucleotides / genetics
  • Polystyrenes
  • Polyvinyl Chloride
  • RNA-Binding Proteins / metabolism
  • Real-Time Polymerase Chain Reaction
  • Repressor Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Urinary Tract Infections / microbiology*
  • Virulence

Substances

  • CsrA protein, E coli
  • Escherichia coli Proteins
  • Oligonucleotides
  • Polystyrenes
  • RNA-Binding Proteins
  • Repressor Proteins
  • Transcription Factors
  • UvrY protein, E coli
  • Polyvinyl Chloride
  • Gentian Violet