Project Summary

Comparison of analysis for Escherichia coli O157:H7 of samples from commercial beef processing plants

Principle Investigator(s):
Mildred Rivera-Betancourt and Mohammad Koohmaraie
U.S. Department of Agriculture, Agricultural Research Service
Completion Date:
May 2003



Contamination of carcass surfaces by food-borne pathogens is a major public health problem. Foodborne illness and death have been linked to ground beef, and many meat recalls and outbreaks have occurred because of Escherichia coli O157:H7. Sources of this pathogen on carcasses during slaughter are multiple and may be classified as those associated with the animal, processing practices, slaughter plant facilities, and employees. A healthy animal may harbor pathogenic bacteria on its hide, hair, and hooves as well as in its intestinal tract. Generally, the muscle surfaces of the carcasses are sterile, and contamination occurs as a result of transfer of hide removal and dressing defects occurring during the slaughtering process. Even though the Food Safety and Inspection Service (FSIS) has issued a “zero tolerance” policy that included drastic measures to control this pathogen during slaughter, possible points within the plant facilities of carcass cross-contamination have not been well established. The slaughter plants in the United States have developed Hazard Analysis-Critical Control Point (HACCP) plans to decrease the risk of foodborne illness by intervening at stages of processing that pose a plausible risk of carcass contamination. These plans require adequate microbiological data to be able to assess the effectiveness of control programs for foodborne pathogens. There is little historical data on the prevalence of E. coli O157:H7 within the environment of the slaughtering plants in the United States at different time points of beef processing.   

The stated objectives for this work were: To compare prevalence of E. coli O157:H7 in different commercial beef processing plants.

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