Rapid PCR detection of enterohemorrhagic Escherichia coli (EHEC) in bovine food products and feces

Raw beef food products (raw ground beef and raw boneless beef) at 25 and 375 g samples and bovine fecal samples at 2 g were inoculated with 101, 103, 104, and 105 organisms of E. coli O157:H7 to test the sensitivity of this assay. Fourteen different foodborne bacteria (including E. coli O157:H7) and 19 various E. coli strains, obtained from the United States Department of Agriculture-Agricultural Research Service (USDA-ARS) were tested for specificity. E. coli O157:H7 was detected at the level of 101 organisms in both 25 and 375 g samples of raw ground and raw boneless beef products as well as 2 g samples of bovine feces after pre-enrichment and concentration. None of the 14 foodborne bacteria screened for cross-reactivity was detected. All USDA E. coli strains confirmed to contain the eae gene were detected.