Antimicrobial resistance risk factors and characterisation of faecal E. coli isolated from healthy Labrador retrievers in the United Kingdom.
Antimicrobial resistant bacteria are increasingly detected from canine samples but few studies have examined commensal isolates in healthy community dogs. We aimed to characterise faecal Escherichia coli from 73 healthy non-veterinarian-visiting and non-antimicrobial treated Labrador retrievers, recruited from dog shows in the North West United Kingdom between November 2010 and June 2011. Each enrolled dog provided one faecal sample for our study. E. coli were isolated from 72/73 (99%) faecal samples. Disc diffusion susceptibility tests were determined for a range of antimicrobials, including phenotypic extended-spectrum beta-lactamase (ESBL) and AmpC-production. PCR assay detected phylogenetic groups and resistance genes (blaCTX-M, blaSHV, blaTEM, blaOXA, blaCIT, qnr), and conjugation experiments were performed to investigate potential transfer of mobile genetic elements. Multivariable logistic regression examined potential risk factors from owner-questionnaires for the presence of antimicrobial resistant faecal E. coli. Antimicrobial resistant, multi-drug resistant (≥3 antimicrobial classes; MDR) and AmpC-producing E. coli were detected in 63%, 30% and 16% of samples, respectively. ESBL-producing E. coli was detected from only one sample and conjugation experiments found that blaCTX-M and blaCIT were transferred from commensal E. coli to a recipient strain. Most isolates were phylogenetic groups B1 and A. Group B2 isolates were associated with lower prevalence of resistance to at least one antimicrobial (P<0.001) and MDR (P<0.001). Significant at P<0.003, was the consumption of raw meat for clavulanate-amoxicillin (OR: 9.57; 95% CI: 2.0-45.7) and third generation cephalosporin resistance (3GCR) (OR: 10.9; 95% CI: 2.2-54.0). AMR E. coli were surprisingly prevalent in this group of non-antimicrobial treated and non-veterinarian-visiting dogs and consumption of raw meat was a significant risk factor for antimicrobial resistance. These findings are of concern due to the increasing popularity of raw-meat canine diets, and the potential for opportunistic infection, zoonotic transmission and transmission of antimicrobial resistant determinants from commensal isolates to potential pathogenic bacteria.
Department of Infection Biology, The University of Liverpool, Leahurst Campus, Neston CH64 7TE, United Kingdom; Department of Epidemiology and Population Health, The University of Liverpool, Leahurst Campus, Neston CH64 7TE, United Kingdom. Electronic address: v.schmidt@liv.ac.uk.
Vanessa M
VM
Schmidt
Department of Epidemiology and Population Health, The University of Liverpool, Leahurst Campus, Neston CH64 7TE, United Kingdom.
Gina L
GL
Pinchbeck
University of Edinburgh, The Royal (Dick) School of Veterinary Studies, Easter Bush Campus, Midlothian CH64 7TE, United Kingdom.
Tim
T
Nuttall
Department of Infection Biology, The University of Liverpool, Leahurst Campus, Neston CH64 7TE, United Kingdom; School of Veterinary Science, The University of Liverpool, Leahurst Campus, CH64 7TE, United Kingdom.
Neil
N
McEwan
School of Veterinary Science, The University of Liverpool, Leahurst Campus, CH64 7TE, United Kingdom.
Susan
S
Dawson
Department of Epidemiology and Population Health, The University of Liverpool, Leahurst Campus, Neston CH64 7TE, United Kingdom.
Nicola J
NJ
Williams
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004283:Dog Diseases / Q000453:epidemiology* / Q000382:microbiology; D004285:Dogs; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D005260:Female; D008297:Male; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D012307:Risk Factors; D013045:Species Specificity; D006113:United Kingdom / Q000453:epidemiology
D000900:Anti-Bacterial Agents
AmpC; Dogs; E. coli; ESBL; Multi-drug resistance; Phylogenetic group