The Prevalence of Escherichia coli O157-H7 and Indicator Organisms on the Surface of Intact Beef Sub-Primals Prior to Further Processing

Findings: Sub-primal cuts (spc) were sampled during Winter (January through February, 2004) and Summer (August through October, 2004). During each collection period, six representative sub-primal cuts (chuck tenders, 0.64 cm trimmed strips, bottom round flat, rough trimmed brisket, cap-on top rounds and cap-off insides) were sampled. A total of 600 samples in Winter (i.e., 100 samples per sub-primal) and 599 samples in Summer (i.e., 100 chuck tenders, 100 0.64 cm trimmed strips, 100 bottom round flats, 100 cap-off insides, 97 rough trimmed briskets and 102 cap-on top rounds) were collected from five plants in the Midwest, Southern Midwest, Northern Midwest and Southeast, and swabbed using the sponge swab method. All sponges were analyzed for E. coli O157:H7. In addition, 400 sub-primal cuts from four plants were analyzed for aerobic plate counts, total coliforms and generic E. coli during each collection period. E. coli O157:H7 was not detected on any of the 1199 sub-primal samples, and thus, incidence of E. coli O157:H7 was <0.083%. Seasonal differences between aerobic plate counts and total coliforms for each of the same cuts were 1.0 log colony forming units per subprimal cut (CFU/spc) or less. Generic E. coli was not detected in 82, 52, 69 and 82% of the chuck tenders, 0.64 cm trimmed strips, bottom round flats, and cap-off insides, respectively.