Resistance patterns, ESBL genes, and genetic relatedness of Escherichia coli from dogs and owners

Braz J Microbiol. 2016 Jan-Mar;47(1):150-8. doi: 10.1016/j.bjm.2015.11.005. Epub 2016 Jan 27.


Antimicrobial resistance in Escherichia coli isolated from pet dogs can be considered a potential threat of infection for the human population. Our objective was to characterize the resistance pattern, extended spectrum beta-lactamase production and genetic relatedness of multiresistant E. coli strains isolated from dogs (n=134), their owners (n=134), and humans who claim to have no contact with dogs (n=44, control), searching for sharing of strains. The strains were assessed for their genetic relatedness by phylogenetic grouping and pulsed-field gel electrophoresis. Multiresistant E. coli strains were isolated from 42 (31.3%) fecal samples from pairs of dogs and owners, totaling 84 isolates, and from 19 (43.1%) control group subjects. The strains showed high levels of resistance to ampicillin, streptomycin, tetracycline, trimethoprim and sulfamethoxazole regardless of host species or group of origin. The blaTEM, blaCTX-M, and blaSHV genes were detected in similar proportions in all groups. All isolates positive for bla genes were ESBL producers. The phylogenetic group A was the most prevalent, irrespective of the host species. None of the strains belonging to the B2 group contained bla genes. Similar resistance patterns were found for strains from dogs, owners and controls; furthermore, identical PFGE profiles were detected in four (9.5%) isolate pairs from dogs and owners, denoting the sharing of strains. Pet dogs were shown to be a potential household source of multiresistant E. coli strains.

Keywords: Antimicrobial resistance; Dogs; Escherichia coli; Genetic relatedness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Dogs
  • Drug Resistance, Bacterial*
  • Electrophoresis, Gel, Pulsed-Field
  • Escherichia coli / drug effects*
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli Infections / microbiology*
  • Escherichia coli Infections / veterinary*
  • Feces / microbiology
  • Genotype*
  • Humans
  • Molecular Typing
  • Pets
  • Phylogeny
  • beta-Lactamases / genetics*


  • Anti-Bacterial Agents
  • beta-Lactamases