Prevalence and characterization of uropathogenic Escherichia coli harboring plasmid-mediated quinolone resistance in a Tunisian university hospital

Diagn Microbiol Infect Dis. 2014 Jun;79(2):247-51. doi: 10.1016/j.diagmicrobio.2014.03.011. Epub 2014 Mar 18.


The prevalence of plasmid-mediated quinolone resistance (PMQR) determinants was investigated in a Tunisian collection of 300 uropathogenic Escherichia coli. PMQR genes were detected in 68 isolates (22.7%) as follows: aac(6')-Ib-cr (n=66), qnrB1 (n=3), qnrA6 (n=1), and qnrS1 (n=1). Three isolates carried the 2 determinants aac(6')-Ib-cr and qnrB1. aac(6')-Ib-cr was usually carried on IncF-type plasmids (n=47/60) and frequently associated with blaCTX-M-15 (n=60). Substitutions in gyrA and parC genes were detected in 57.5% of strains. A major cluster including 29 isolates was individualized, 28 of them belonged to the virulent ST131 clone. In our hospital, the high prevalence of PMQR in E. coli isolates was due to horizontal transfer but also to the spread of ST131 clone.

Keywords: Escherichia coli; Phylogenetic groups; Plasmid-mediated quinolone resistance; ST131 clone; Uropathogenic strains; Virulence factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / pharmacology*
  • Child
  • Child, Preschool
  • Cluster Analysis
  • Drug Resistance, Bacterial*
  • Escherichia coli Infections / epidemiology*
  • Escherichia coli Infections / microbiology
  • Female
  • Genes, Bacterial
  • Hospitals, University
  • Humans
  • Infant
  • Male
  • Middle Aged
  • Molecular Epidemiology
  • Molecular Typing
  • Plasmids / analysis
  • Prevalence
  • Quinolones / pharmacology*
  • Tunisia / epidemiology
  • Uropathogenic Escherichia coli / classification
  • Uropathogenic Escherichia coli / drug effects*
  • Uropathogenic Escherichia coli / genetics
  • Uropathogenic Escherichia coli / isolation & purification
  • Virulence Factors / genetics
  • Young Adult


  • Anti-Bacterial Agents
  • Quinolones
  • Virulence Factors