Evaluation of Enrichment Protocols for the 1-2Test™ for Salmonella Detection in Naturally Contaminated Foods & Feeds

The 1-2 test™ system was used to detect Salmonella in naturally contaminated foods and feeds. The results were compared with the official Canadian Wet Culture Method. In Phase I, the analytical procedure used for the 1-2 test™ was that suggested by the manufacturer. For both methods, 196 food and feed samples were analyzed. Thirty-four samples were found positive by the Wet Culture Method but only 26 were found positive by the 1-2 test™. In Phase II, the procedure for the 1-2 test™ was modified to include an enrichment stage using tetrathionate brilliant green broth. Of the 314 samples analyzed, 84 samples were found to be positive. There were 79 samples found positive by both methods. In the remaining positives, 3 tested positive only by the 1-2 test™, and 2 tested positive only by the Wet Culture Method. The majority of positive samples in Phase II were animal feeds. The selective enrichment modification to the 1-2 Test™ procedure has enhanced its reliability for Salmonella detection in foods and feeds. The manufacturer's current procedure specifies a selective enrichment step.