E. coli: How can I tell if food is contaminated?

Answers from Katherine Zeratsky, R.D., L.D.

You can't tell whether a food is contaminated with E. coli by the way it looks, smells or tastes. Although most types of Escherichia coli (E. coli) bacteria are harmless, certain strains, such as E. coli O157:H7, can cause serious foodborne illness.

To protect yourself from E. coli and other foodborne illnesses, follow basic food safety guidelines:

  • Rinse raw produce thoroughly; scrub produce that has a firm surface.
  • Wash your hands, utensils and kitchen surfaces with hot, soapy water before and after preparing or eating food.
  • Keep raw foods, especially meats, separate from ready-to-eat foods.
  • Refrigerate or freeze perishable foods promptly.
  • Avoid unpasteurized juices, ciders and dairy products.
  • Don't drink untreated water from lakes or streams.
  • Cook foods thoroughly. Use a thermometer to verify the temperature.
    • Beef, pork, lamb and veal steaks, chops, and roasts should be cooked to a minimum internal temperature of 145 F (63 C) and allowed to rest for 3 minutes before serving.
    • Ground meats other than poultry should be cooked to at least 160 F (71 C).
    • Poultry should be cooked to 165 F (74 C).
    • Leftovers and casseroles should be cooked to 165 F (74 C).
Nov. 25, 2014 See more Expert Answers