Those establishments further process the product by either cooking it or repackaging the meat. Mickelson says there is no danger if the meat is cooked properly. E. coli is a bacterium that ordinarily lives harmlessly in the stomachs of cattle. Contamination occurs when cattle are confined to feed lots to be fattened for slaughter. The animals spread the germ by defecating and drooling into shared water troughs.
Mistakes sometimes happen.
That gets into the air on tiny water droplets, and then it falls back onto the carcass, and that's one way of contamination. The other way is during evisceration, when contents of the gut can spill out. Beef-processing plants try to prevent contamination as much as possible, Slade says. Some of them have air-handling systems to remove dust and water droplets. And some of the plants have intervention strategies to treat the carcass.