The suite of food safety tests, the BAX System STEC Suite, was developed in collaboration with the Agricultural Research Service of the US Department of Agriculture (USDA ARS) and is closely aligned with the testing approach used by the Food Safety and Inspection Service (USDA FSIS).
The screening assay detects a combination of virulence genes-called stx and eae-to quickly clear negative samples in the production line. Two multiplex panel assays can determine which of the top six non-O157 STEC serogroups-O26, O45, O103, O111, O121, O145-are present in positive samples. The USDA recently declared these pathogenic serogroups as adulterants in non-intact beef, and FSIS will begin enforcing a zero tolerance policy in March 2012.