Reveal 8-hour test system for detection of Escherichia coli O157 : H7 in raw ground beef, raw beef cubes, and iceberg lettuce rinse: Collaborative study

Five different food types were analyzed by the Reveal for E, coil 0157:H7 8 -Hour Test System (Reveal 8) and either the U,S, Food and Drug Administrati on's Bacteriological Analytical Manual(BAM) culture method or the U,S, Depa rtment of Agriculture Food Safety Inspection Service (FSIS) culture method for the presence of E. coil 0157:H7, A total of 27 laboratories representin g academia and private industry in the United States and Canada participate d. Food types were inoculated with E, coli 0157:H7 at 2 different levels: a high level where predominantly positive results were expected, and a low l evel where fractional recovery was anticipated. During this study, 1110 sam ples and controls were analyzed by both the Reveal 8 and by BAM or FSIS by each of the collaborators (2220 samples in total). For each set of samples, 740 were artificially inoculated with E, coli 0157:H7, and 370 were uninoc ulated controls. The Reveal 8 detected 528 presumptive positives of which 4 87 were confirmed positive by the BAM culture method. In comparison, BAM an d FSIS detected 489 of the 740 artificially contaminated samples as positiv e. In an additional in-house study performed only on chilled and frozen raw ground beef, 240 artificially inoculated samples were analyzed by both the Reveal 8 and by FSIS, The Reveal 8 detected and confirmed 104 samples as p ositive compared to 79 confirmed positive by FSIS.