On Oct. 22, 2024, the Colorado Department of Agriculture laboratories received multiple lots of McDonald’s brand fresh and frozen beef patties collected from various Colorado McDonald’s locations associated with the ongoing E. Coli investigation. 

The CDA Microbiology Laboratory analyzed dozens of subsamples from all the lots, and all samples were found to be negative for E. coli. CDA has completed all beef testing and does not anticipate receiving further samples. 

The federal investigation has focused on ground beef patties and onions. At this time, CDA also has no information suggesting onions grown in Colorado are linked to this outbreak.

Source: Colorado Department of Agriculture