ESCHERICHIA-COLI O1572-H7 VISUAL IMMUNOPRECIPITATE ASSAY - A COMPARATIVE VALIDATION-STUDY

A wide variety of food products, with emphasis on raw meat products, w ere analyzed simultaneously by 3 methods: the Escherichia coil O157:H7 (EHEC) visual immunoprecipitate assay (VIP), the Assurance EHEC enzym e immunoassay, and a modified Bacteriological Analytical Manual(BAM) c ulture method, This paper reports results of a comparative study of th e VIP and modified BAM methods, In this comparative study, 1050 sample s and controls gave false-negative rates of 1.0 and 0%, respectively, for the VIP and the modified BAM culture methods, The overall agreemen t between the 2 methods was 99.4%. Cultural confirmation of presumptiv e positive samples was problematic because competitive flora were pres ent in higher levels than EHEC in the enrichment broth after incubatio n and the target organism had nondescript characteristics on the prima ry selective agar, hemorrhagic coil agar, which necessitated picking o f additional colonies in many instances.