Let’s review some biological facts about Escherichia coli (E. coli). There are thousands of species in this group, and many of them inhabit our lower intestines at all times. In fact, they can be very helpful by synthesizing vitamin K for us. Strains of E. coli also inhabit the lower intestines of all warm blooded animals, including cattle. E. coli bacteria arrive in our bodies within 40 hours of birth through food, water or handling, and stay there the rest of our lives.
Escherichia coli O157:H7 is a relatively new strain of E. coli. It can produce any one of several food-borne illnesses, and was first identified in 1982. Cattle, swine and deer can all carry this strain of E. coli without harm because they lack a specific receptor. The problem with this strain is that it secrets shiga-like toxins. At some time in the past, E. coli populations acquired the ability to produce these toxins when large numbers of the bacteria came into prolonged contact with Shigella, a very virulent bacterium that causes severe gastrointestinal disease only in humans and other primates. The cross between these two bacteria likely happened when cattle began to be confined to feed lots, deep in manure, and fed parts of other animals. It is possible to test animals to see if they are infected. There is also a vaccine for cattle developed by a Canadian company, Bioniche, that can eliminate almost all of the bacteria in cattle. Why is this not being used?
Yes, you can eliminate E. coli 0157:H7 in your beef with proper handling and cooking. But why is it the consumer’s responsibility to fix a problem that was created by poor animal husbandry in the name of profit and efficiency? It can be eliminated in one generation. Who will pay to do this before more Canadians get sick or die?
PENNY POWERS, PH.D., RN
Professor, School of Nursing
Thompson Rivers University