Predicting the presence of non-O157 Shiga toxin-producing Escherichia coli in ground beef by using molecular tests for Shiga toxins, intimin, and O serogroups.

When 3,972 ground beef enrichments with 6 confirmed to contain a non-O157 Shiga toxin-producing intimin-positive Escherichia coli isolate were tested for Shiga toxin, intimin, and O group (O26, O45, O103, O111, O121, and O145) genes, 183 potential positives and only 2 of the 6 confirmed positives were identified.