Extended spectrum β lactamase-producing Enterobacteriaceae shedding by race horses in Ontario, Canada (original) (raw)

Background We aimed to investigate the prevalence, molecular epidemiology and prevalence factors for Extended Spectrum β-Lactamase-producing Enterobacteriaceae (ESBL-E) shedding by race horses. A cross-sectional study was performed involving fecal samples collected from 169 Thoroughbred horses that were housed at a large racing facility in Ontario, Canada. Samples were enriched, plated on selective plates, sub-cultured to obtain pure cultures and ESBL production was confirmed. Bacterial species were identified and antibiotic susceptibility profiles were assessed. E. coli sequence types (ST) and ESBL genes were determined using multilocus sequence type (MLST) and sequencing. Whole genome sequencing was performed to isolates harboring CTX-M-1 gene. Medical records were reviewed and associations were investigated. Results Adult horses ( n = 169), originating from 16 different barns, were sampled. ESBL-E shedding rate was 12% ( n = 21/169, 95% CI 8–18%); 22 ESBL-E isolates were molecu...