Characterization of ESBL-producing Escherichia coli recovered from companion dogs in Tai'an, China

Introduction: Animals are considered to be reservoirs of extended-spectrum beta-lactamase (ESBL)-producing bacteria, but few epidemiological data on ESBL-producing Escherichia coli urinary tract isolates in pet dogs are available in China. Methodology: This study was conducted to describe the prevalence and characterization of ESBL producers among E. coli urinary tract isolates from pet dogs in Tai'an, China. Results: A total of 118 E. coli were obtained from urinary samples of 80 companion dogs suffering from acute or chronic cystitis, of which three isolates from different dogs were ESBL producers. One isolate from dog A was of phylogroup A/ST410/CTX-M-15/TEM-1; one from dog B was of phylogroup B1/ST533/CTX-M-15/TEM-1; one from dog C was of phylogroup D/ST648/CTX-M-15. All ESBL producers were resistant to ampicillin, cephalexin, cefalotin, cefpodoxime, ceftiofur, enrofloxacin, marbofloxacin, and trimethoprim/sulfamethoxazole, but were susceptible to imipenem and amoxicillin/clavulanic acid. E. coli of ST533 carrying bla(CTX-M-15) were first detected in pet dogs in China. Conclusions: Collectively, the findings could expand our knowledge about the prevalence and characterization of ESBL-producing E. coli urinary tract isolates in pet dogs in China.