AOAC-RI ERP Book Micro Jan 19 2017

1) Raw Ground Beef (73% lean) (325 gram test portion) (c) Summary of Validated Performance Claims The 3M MDA 2 - E. coli O157 is considered equivalent to the USDA/FSIS- MLG 5.09 reference method [1] for the detection of E. coli O157 in raw ground beef (73% lean). Definitions (a) Probability of Detection Probability of Detection (POD) is the proportion of positive analytical outcomes for a qualitative method for a given matrix at a given analyte level or concentration. POD is concentration dependent. There are several POD measures that can be calculated, e.g., POD R (reference method POD), POD C (confirmed candidate method POD), POD CP (candidate method presumptive result POD), POD CC (candidate method confirmation result POD) and dPOD, the difference between any two POD values. General Information Most E. coli bacteria are harmless; however, some produce a toxin (Shiga toxin) that can cause serious illness, including bloody diarrhea, hemolytic anemia, renal failure, and sometimes death. For example, a recent outbreak occurred on February 25, 2016, by a company called Jack & the Green Sprouts, Inc. recalled all alfalfa and alfalfa onion sprout products due to nine people infected with the outbreak strain of Shiga toxin- producing Escherichia coli O157 [2]. Like generic E. coli , toxin-producing Shiga- toxigenic Escherichia coli (STEC) are Gram-negative, rod-shaped bacteria, but are characterized by the production of Shiga toxins ( stx 1, stx 2, and eae ). Depending on the reference cited, there are approximately 200 to 400 STEC serotypes, many of which have not been implicated in human illness; however, a subset of STEC called Enterohemorrhagic Escherichia coli (EHEC) includes only those that cause serious illness. Serotype O157:H7 is the prototypic EHEC strain [3]. Principle of the Method 3M™ Molecular Detection Assay 2 - E. coli O157 is used with the 3M™ Molecular Detection System for the rapid and specific detection of E. coli O157 in enriched food samples. The 3M Molecular Detection Assay uses a loop-mediated isothermal amplification to rapidly amplify nucleic acid sequences with high specificity and sensitivity, combined with bioluminescence to detect the amplification. Presumptive positive results are reported in real-time while negative results are displayed after the assay is completed. Presumptive positive results should be confirmed using the appropriate reference method.

Page 2 of 17