Validation of the 3M™ Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) for the Detection of Shiga Toxin Gene (stx1 and/or stx2) and Intimin Gene (eae): AOAC Performance Tested MethodSM 071902.

ABSTRACT

BACKGROUND: The 3M™ Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) method is based on gene amplification by the use of real-time loop-mediated isothermal amplification when used with the 3M Molecular Detection System for the rapid and specific detection of Shiga toxin gene (stx1 and/or stx2) and intimin gene (eae) from Shiga toxin-producing enterohemorrhagic Escherichia coli (STEC) in enriched foods. OBJECTIVE: The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) method was evaluated as a Level 2 method modification to add new matrixes to the certified claim: 25 g fresh raw ground beef (approximately 75% lean), 375 g fresh raw ground pork (approximately 70% lean), 375 g fresh raw poultry parts, and 25 g sprouts. METHODS: Matrix studies were conducted to assess the method's performance compared to the U. S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook, 5C.00 for meat and poultry, and to the U. S. Food and Drug Administration Bacteriological Analytical Manual, Ch. 4A for sprouts, using an unpaired study design. RESULTS: The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) method demonstrated no significant differences between presumptive and confirmed results or between candidate and reference method results for any of the matrixes tested. CONCLUSION AND HIGHLIGHTS The data collected in these studies demonstrate that the 3M Molecular Detection Assay 2 - STEC Gene Screen (stx and eae) is a reliable method for the rapid and specific detection of STEC in fresh raw ground beef (approximately 75% lean), fresh raw ground pork (approximately 70% lean), fresh raw poultry parts, and sprouts.