USDA researchers say they have found little difference in levels of antimicrobial resistant bacteria in ground beef samples from either cattle raised without antibiotics and in ground beef from conventionally raised cattle.
A total of 370 ground beef samples, about half from conventional and half from “raised without antibiotics” production systems, were collected over 13 months from three food service suppliers.
The researchers noted that U.S. ground beef with “raised without antibiotics” label claims is perceived as harboring fewer bacteria with antimicrobial resistance (AMR) than are found in conventional ground beef with no such label claim. However, USDA said it found the study results were consistent with prior research suggesting antimicrobial use in U.S. beef cattle has minimal impact on the antimicrobial resistance of bacteria found in these products.
In fact, analyses revealed that ground beef microbiomes differed more by supplier than by production system. The researchers said these results should spur a reevaluation of assumptions regarding the impact of antimicrobial use during U.S. beef production on the antimicrobial resistance in ground beef.