Extended spectrum β lactamase-producing Enterobacteriaceae shedding by race horses in Ontario, Canada.
Authors: Shnaiderman-Torban Anat, Navon-Venezia Shiri, Paitan Yossi, Archer Holly, Abu Ahmad Wiessam, Bonder Darryl, Hanael Erez, Nissan Israel, Zizelski Valenci Gal, Weese Scott J, Steinman Amir
Journal: BMC veterinary research
Summary
# ESBL-Producing Enterobacteriaceae in Racing Horses: A Canadian Cross-Sectional Study Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) represent a significant antimicrobial resistance threat in human healthcare, but their prevalence and epidemiology in equine populations remain poorly characterised. Researchers collected faecal samples from 169 Thoroughbreds at a single large Ontario racing facility, enriching samples on selective media and performing molecular characterisation via multilocus sequence typing (MLST) and whole genome sequencing to identify ESBL genes and bacterial species. The study identified concerning rates of ESBL-E shedding among the cohort, with *E. coli* being the predominant organism and CTX-M-1 the most commonly detected resistance gene, alongside evidence of multiple sequence types indicating diverse strains circulating within the facility. Clinical significance lies in the zoonotic potential of these multidrug-resistant organisms and their implications for infection control protocols at racing yards and veterinary facilities—farriers, vets and yard staff represent potential transmission vectors to other horses and human contacts, making screening and biosecurity measures increasingly relevant to equine practitioners managing racehorses or horses from high-density facilities.
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Practical Takeaways
- •Racehorses may be reservoirs for antibiotic-resistant bacteria; biosecurity and hygiene protocols are important to minimize transmission risk on racing facilities
- •Understanding which horses shed ESBL-producing bacteria can inform targeted antimicrobial stewardship and treatment decisions
- •Identification of specific bacterial strains and resistance genes helps predict treatment failures and guides appropriate antibiotic selection when infection occurs
Key Findings
- •Cross-sectional study of 169 Thoroughbred racehorses identified prevalence and molecular epidemiology of ESBL-producing Enterobacteriaceae shedding
- •E. coli sequence types and ESBL genes (including CTX-M-1) were characterized using MLST and whole genome sequencing
- •Antibiotic susceptibility profiles were assessed to determine resistance patterns in isolated bacterial species
- •Medical records were analyzed to investigate associations between horse characteristics and ESBL-E shedding