MLST Genotypes and Antibiotic Resistance ofCampylobacterspp. Isolated from Poultry in Grenada

Abstract

This study determined whether multilocus sequence types (MLST) ofCampylobacterfrom poultry in 2 farms in Grenada, West Indies, differed by farm, antimicrobial resistance and farm antibiotic use. Farm A used fluoroquinolones in the water and Farm B used tetracyclines. The E-test was used to determine resistance of isolates to seven antibiotics. PCR of theIpxAgene confirmed species and MLST was used to characterize 38 isolates. All isolates were eitherC. jejuniorC. coli. Farm antibiotic use directly correlated with antimicrobial resistance ofCampylobacterisolates. Almost 80% of the isolates from Farm A were fluoroquinolone resistant and 17.9% of the isolates from Farm B were fluoroquinolone resistant. AllCampylobacterisolates from Farm A were tetracycline sensitive, whereas 35.7% of isolates from Farm B were tetracycline resistant. Six previously recognized sequence types (STs) and 2 novel STs were identified. Previously recognized STs were those overwhelmingly reported from poultry and humans globally. Isolates with the same ST did not always have the same antibiotic resistance profile. There was little ST overlap between the farms suggesting that within-farm transmission ofCampylobactergenotypes may dominate. MLST typing was useful for trackingCampylobacterspp. among poultry units and can help elucidateCampylobacterhost-species population structure and its relevance to human health.