InstantLabs® E. coli O157 Food Safety Kit

The InstantLabs® E. coli O157 Food Safety Kit was validated against the International Organization for Standardization reference method 16654 for the detection of Escherichia coli O157. The matrixes, raw ground beef, raw beef trim, Romaine lettuce, pasteurized apple juice, and raw ground chicken, were inoculated with appropriate CFU/test portion of E. coli O157 to generate fractional positives (5-15) in 20 inoculated samples. The matrixes were co-inoculated with Salmonella at 2-5 times the level of E. coli O157 to demonstrate the potential for using the same enrichment culture for the detection of multiple organisms. Samples were enriched in prewarmed FASTGRO SE broth at 42±1°C for 10-20 h. All samples were confirmed using the ISO reference method, regardless of initial screen result. The InstantLabs test method performed as well as or better than the reference method for the detection of E. coli O157 in all tested samples. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 E. coli O157 serovars and 30 non-E. coli O157 species examined. Finally, the method was shown to be robust when variations were applied to enrichment time, volume for DNA extraction, and heat block time.