E. coli O157

E. coli 0157 is a bacterium that is found normally in the feces of a small percentage of cattle. The prevalence of the bacterium varies among herds and in animals within herds. It is most commonly found in cattle in the summer months, suggesting that the environment may play a role in the transmission of the bacteria among cattle. To date, there have been no consistent management factors found to explain the occurrence of the bacteria in cattle.

E. coli 0157 is a type of bacteria that produces a toxin which does not cause disease in cattle, but it can cause severe disease in children, the elderly, and those whose immune system is compromised. Consuming contaminated undercooked or improperly refrigerated beef, raw milk, drinking water, fruit juices, and vegetables has infected humans. As well, humans have been infected from person to person spread in day care centres and in swimming pools. Ground beef may be a source because it consists predominantly of surface meat that may be contaminated by the bacteria through processing, storage, and handling.

Currently, there are no on-farm management practices known that will reduce the risk of the bacteria in cattle. Research continues on vaccines and probiotics (bacterial feed additives that competitively inhibit E. coli 0157). One source of the bacteria on carcasses is from a dirty hide. Therefore, producers are encouraged to use management procedures to reduce mud on hides, such as bedding, pen drainage and cleaning, and proper stocking densities. Since the bacteria are in the feces of cattle, producers are also encouraged to use good manure management practices, such as preventing manure run-off from entering watercourses.

Procedures that have been shown to reduce the risk of E. coli 0157 contamination of beef include processing methods such as hair removal, steam vacuum, carcass sterilization, carcass rinses, sanitation, and temperature controls. Proper refrigeration, handling, hygiene, and cooking are also effective controls.