E. coli is an abbreviation for the bacteria Escherichia coli. It was discovered in the human colon in 1885 by German bacteriologist Theodor Escherich. Although it was initially called Bacterium coli, the name was later changed to Escherichia coli for its discoverer. It's been in the news often as a food born bacteria, although the vast majority of E. coli strains are harmless. The strain that has aroused so much attention is E. coli 0157:H7. This strain was first identified at the U. S. Center for Disease Control in 1975, but it wasn't until 1982, that it was conclusively determined to be a cause of intestinal disease.

It is thought that the E. coli O157: H7 bacteria lives in the intestines of cattle, but it's also been found in the intestines of chickens, deer, sheep, and pigs. It doesn't make the animals that carry it sick, they are merely the reservoir for the bacteria. While the majority of food born illness outbreaks associated with E. coli O157: H7 have involved ground beef, they have also involved unpasteurized apple and orange juice, unpasteurized milk, alfalfa sprouts, and water. An outbreak can also be caused by person-to-person transmission in settings like daycare centers, hospitals, and nursing homes. Proper hygiene can limit the risk of this kind of transmission, at least with regard to adults and older children.

Meat typically becomes contaminated with E. coli O157: H7 during the slaughtering process, if the contents of the animal's intestine are allowed to come into contact with the carcass. If this happens the E. coli bacteria are eventually mixed into the meat as it's ground into hamburger. The number of organisms required to cause an infection is not known although it's suspected to be very small. In meat that has been contaminated, thorough cooking is required to kill the bacteria. Contaminated meat looks and smells normal.

At our slaughter facility seven hand operated steam vacuum stations sanitize the carcass at every step of the hide removal. Quick removal of any bacterial contamination stops the growth. After the hide is removed the carcass is run thru a lactic acid wash prior to the evisceration. As the animal is eviscerated the USDA inspects the offal to determine the wholesomeness. At the same time they are inspecting the carcass before it is split. After it is split it is given a minute inspection again by the USDA and any contamination is trimmed off. The sides then go through a steam pasteurization cabinet followed immediately by a lactic acid rinse. Then to the chill box. We take no chances with bacteria. After that the carcasses arrive at Meyer Foods, our state of the art processing facility in Lincoln, Nebraska.

E. coli 0157:H7 is characterized by the sudden onset of abdominal pain and severe cramps, followed within 24 hours by diarrhea. As it progresses, the diarrhea becomes watery and then may become bloody. Vomiting can also occur, but there is usually no fever. The incubation period is typically 3 to 9 days, although shorter and longer periods are not that unusual. An incubation period of less than 24 hours would be unusual, however. In most individuals it lasts about a week and results with no long-term problems. Antibiotics do not improve the illness, and some medical researchers believe that these medications can increase the risk of complications. There is no specific therapy other than paying close attention to hydration and nutrition. Most individuals recover within two weeks.

You can kill E. coli 0157:H7 in ground beef and hamburger by thoroughly cooking it. Because ground beef can turn brown before the bacteria are killed, you should use a meat thermometer to make sure that it's cooked well enough. Ground beef should be cooked until a thermometer inserted into the thickest part, reads at least 160º F. If you cook it without using a thermometer you can decrease your risk of illness by not eating ground beef patties that are still pink in the middle. If you are served an undercooked hamburger or other ground beef product in a restaurant, send it back for further cooking. You can avoid spreading the bacteria in your kitchen by keeping raw meat separate from ready-to-eat foods. Wash your hands, counters, and utensils with hot soapy water after they touch raw meat. Never place cooked hamburgers or ground beef on the unwashed plate that held raw patties. Be sure to wash meat thermometers in between tests of patties that require further cooking.

Additional Resources:

www.cdc.gov/ncidod/dbmd/diseaseinfo/escherichiacoli_g.htm
The Center for Disease Control, Division of Bacterial and Mycotic Diseases

www.mayohealth.org/home?id=DG00005
A Mayo Clinic Condition Centers article entitled "E. coli: Preventing a common type of food poisoning