It is concerning to me that the USDA is being blamed for inaction on antibiotic resistant strains of Salmonella. It is not the responsibility of the USDA to regulate on-farm practices, such as antibiotic use. The USDA (specifically the FSIS) is in charge of meat, poultry, and egg inspection in the abattoir. They have no on-farm authority and tend to focus on issues of real risk. Antibiotic approvals as well as use practices are under the jurisdiction of the FDA. Steps are being taken by the FDA to ensure judicious on-farm antibiotic use. Guidance 209 calls for the elimination of using antibiotics for growth promotion. Currently, only 13% of antibiotics are used for this purpose. This guidance will likely decrease this number to zero.
Most antibiotics used in animal medicine are not critically important in human medicine. About 30% of antibiotics used in food-producing animals are ionophores. There is no human equivalent to ionophores, so their usage does not pose a threat to human antibiotic resistance. Penicillin is a critical drug commonly used in human medicine but not commonly used in food animal medicine. Conversely, tetracycline is rarely used in human medicine, but is commonly used in animal medicine. The CSPI cites that 30 million pounds of antimicrobials are used annually in food animal medicine. While this figure may seem alarming, one needs to keep in mind the relative amount of body weight as well as the number of animals versus humans (a 1,200 pound steer is going to need a larger dose of antibiotics versus a 150 pound human).
As I have said, “it is a long way from the farm to harm.” This is because a chain of events (causal pathway) must occur in order for the adverse outcome to occur. The antibiotic resistant bacteria need to leave the farm, survive harvesting, survive to retail, and then survive preparation. The person then needs to get sick, get treated with an antibiotic, and then have treatment failure. Even if bacteria are present in the meat, thorough cooking will kill both resistant and susceptible bacteria. Thanks to the USDA’s efforts and the plans in place in our abattoirs, the risk to humans from on-farm antibiotic use is generally negligible.