Fluoroquinolone-Resistant Avian PathogenicIsolated from Asymptomatic Broiler Chickens in a Slaughterhouse in Northern Thailand.

Abstract

: Avian pathogenic(APEC) are significant bacterial pathogens that cause economic losses in the poultry industry and can pose a potential foodborne zoonotic risk. Herein, we examined APEC distribution and antimicrobial resistance inisolated from slaughtered broiler chickens in northern Thailand.: PCR was used to classify APEC as either virulent or avirulent on 108 storedstrains, as well as to perform Clermont phylotyping. Antimicrobial susceptibility to ciprofloxacin, cefotaxime, ceftazidime, imipenem, and colistin was examined.: Of the 108strains, 101 (93.5%) isolates were APEC, and the remaining isolates were non-APEC. Among the APEC isolates, 58.4% were classified as virulent APEC; these isolates showed a statistically significant association with phylogroups F and C and (= 54, 56.8%) more frequently exhibited a ciprofloxacin-resistant phenotype than avirulent APEC (= 35, 36.8%). Among the ten APEC virulence genes,,,,,, andwere significantly associated with virulent APEC.: This study reveals a high prevalence of virulent APEC with fluoroquinolone resistance in slaughtered broiler chickens. Almost all virulent APEC strains belong to phylogroups F and C. The prediction of virulent APEC using,,,,, andmay be useful.