Development of Antimicrobial-resistant Bacteria in Feedlot Cattle

The use of antimicrobials in feedlot cattle, as in all food animal species, has come under increased scrutiny because of concerns about the potential transfer of resistant zoonotic pathogens to people and also transfer of resistant genetic determinants to human pathogens. A pathogen of concern related to resistance in cattle is Salmonella spp. Transfer of Escherichia coli O157:H7 through the food chain, while a valid zoonotic disease concern, is not related to an issue of resistance. The American Association of Bovine Practitioners publishes Prudent Drug Usage Guidelines, which provides guidelines for antimicrobial usage in cattle feedlot operations.