Colonisation dynamics and virulence of two clonal groups of multidrug-resistant Escherichia coli isolated from dogs

Hanna E. Sidjabat, James C. Chin, Toni Chapman, Kent Wu, Glen C. Ulett, Cheryl Y. Ong, Mark A. Schembri, James R. Johnson, Darren J. Trott*

*Corresponding author for this work

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The study established the virulence potential of multidrug-resistant Escherichia coli (MDREC) isolates from nosocomial infections in hospitalised dogs. The isolates were resistant to fluoroquinolones, belonged to two distinct clonal groups (CG1 and CG2) and contained a plasmid-mediated AmpC (CMY-7) beta-lactamase. CG1 isolates (n = 14) possessed two of 36 assayed extraintestinal virulence genes (iutA and traT) and belonged to phylogenetic group A, whereas CG2 isolates (n = 19) contained four such genes (iutA, ibeA, fimH and kpsMT K5) and belonged to group D. In a mouse gastrointestinal tract colonisation model, colonisation by index CG1 strain Cl was transient, in contrast to the index CG2 strain C2b, which persisted up to 40 days post-inoculation. In a mouse subcutaneous challenge model, both strains were less virulent than archetypal group 132 extraintestinal pathogenic E. coli (ExPEC) strain CFT073; strain C1 caused no systemic signs and strain C2b was lethal to only one of six mice. In a mouse urinary tract infection model, strain C2b colonised the mouse bladder over 2 logs higher compared to strain C1. Whilst both groups of canine MDREC appear less virulent than a reference human ExPEC strain, CG2 strains have greater capacity for colonisation and virulence. (c) 2008 Published by Elsevier Masson SAS.

Original languageEnglish
Pages (from-to)100-107
Number of pages8
JournalMicrobes and Infection
Volume11
Issue number1
DOIs
Publication statusPublished - Jan 2009
Externally publishedYes

Keywords

  • Virulence
  • Phylogeny
  • Multidrug-resistant E. coli
  • URINARY-TRACT-INFECTION
  • EXTRAINTESTINAL INFECTION
  • GROUP-A
  • STRAINS
  • PHYLOGENY
  • QUINOLONE
  • GENOTYPE
  • GENES
  • FLUOROQUINOLONE
  • IDENTIFICATION

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