On October 27, 2024, McDonald's USA said beef patties were not the source of E. coli contamination, according to Food Safety News.

McDonald's USA said that tests have confirmed that the beef patty in the burger is not the source of E. coli contamination, and McDonald's will resume sales of burger products previously removed from shelves due to involvement in E. coli contamination, but the resumed burgers will be free of the slices of raw onion that are currently believed to be the source of the contamination.

It is understood that the U.S. Food and Drug Administration (FDA) believes that raw onion slices from a single supplier could be the source of the E. coli contamination, and McDonald's has confirmed that Taylor Farms, a California-based produce company, is the supplier of the sliced onions in question, which came from a plant in Colorado Springs, Colo. Taylor Farms Taylor Farms has voluntarily recalled yellow onions sent to customers from its Colorado plant and is continuing to work with the U.S. Centers for Disease Control and Prevention (CDC) and the FDA on the investigation, the company said on 25 May.