Genomic Analysis of Emerging Florfenicol-Resistant Campylobacter coli Isolated from the Cecal Contents of Cattle in the United States

Campylobacter is a leading cause of foodborne diarrheal illness worldwide, with more than one million cases each year in the United States alone. The global emergence of antimicrobial resistance in this pathogen has become a growing public health concern. Florfenicol-resistant (FFNr )Campylobacter has been very rare in the United States. In this study, we employed whole-genome sequencing to characterize 16 multidrug-resistantCampylobacter coli isolates recovered from cattle in the United States. A gene [cfr (C)] was found to be responsible for resistance not only to florfenicol but also to several other antimicrobials, including linezolid, a critical drug for treating infections by Gram-positive bacteria in humans. The results showed thatcfr (C) is located in a conjugative pTet MDR/virulence plasmid. This report highlights the power of antimicrobial resistance surveillance to uncover the intricacies of transmissible coresistance and provides information that is needed for accurate risk assessment and mitigation strategies.