It’s bad enough when pathogenic bacteria work their way into the animal food supply. Here’s a related problem that has recently attracted scientists’ attention: some of the pathogens may become resistant to the antimicrobials that are used to fight animal disease, and that might lead to more human resistance to the benefits of antibiotics. The use of antibiotics as growth promoters appears to create large reservoirs of resistance to antibiotics in animals. That resistance could be transferred to humans who consume the food from those animals.