Molecular characterization of quinolone resistance mechanisms and extended-spectrum β-lactamase production in Escherichia coli isolated from dogs

Comp Immunol Microbiol Infect Dis. 2015 Aug:41:43-8. doi: 10.1016/j.cimid.2015.04.004. Epub 2015 May 12.

Abstract

The increasing prevalence of antimicrobial resistances is now a worldwide problem. Investigating the mechanisms by which pets harboring resistant strains may receive and/or transfer resistance determinants is essential to better understanding how owners and pets can interact safely. Here, we characterized the genetic determinants conferring resistance to β-lactams and quinolones in 38 multidrug-resistant Escherichia coli isolated from fecal samples of dogs, through PCR and sequencing. The most frequent genotype included the β-lactamase groups TEM (n=5), and both TEM+CTX-M-1 (n=5). Within the CTX-M group, we identified the genes CTX-M-32, CTX-M-1, CTX-M-15, CTX-M-55/79, CTX-M-14 and CTX-M-2/44. Thirty isolates resistant to ciprofloxacin presented two mutations in the gyrA gene and one or two mutations in the parC gene. A mutation in gyrA (reported here for the first time), due to a transversion and transition (TCG→GTG) originating a substitution of a serine by a valine in position 83 was also detected. The plasmid-encoded quinolone resistance gene, qnrs1, was detected in three isolates. Dogs can be a reservoir of genetic determinants conferring antimicrobial resistance and thus may play an important role in the spread of antimicrobial resistance to humans and other co-habitant animals.

Keywords: Antimicrobial resistance; Dogs; Escherichia coli; Quinolones; β-Lactamases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Ciprofloxacin / pharmacology
  • DNA Topoisomerase IV / genetics
  • Dogs
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Electrophoresis, Gel, Pulsed-Field
  • Escherichia coli / drug effects*
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / genetics
  • Escherichia coli Infections / transmission
  • Escherichia coli Infections / veterinary*
  • Feces / microbiology*
  • Genotype
  • Microbial Sensitivity Tests
  • Mutation
  • Phylogeny
  • Quinolones
  • beta-Lactamases / biosynthesis
  • beta-Lactamases / genetics*

Substances

  • Anti-Bacterial Agents
  • Quinolones
  • Ciprofloxacin
  • beta-lactamase CTX-2
  • beta-lactamase TEM-3
  • beta-Lactamases
  • DNA Topoisomerase IV