Purpose: To conduct a matrix extension validation for the Atlas Salmonella SG2 Detection Assay for the detection of Salmonella enterica spp. in 12 additional food matrices.
Methods: After enriching for 10 to 24 h for tomatoes, cookie dough and chicken carcass rinses, 16 to 24 h for string cheese, soy flour and pasteurized dried egg powder and 24 to 28 h for peanut butter, raw almonds, milk chocolate, cocoa powder, whey powder and non-fat dried milk, an aliquot of the enrichment is transferred and processed by a fully automated platform for bacterial lysis, template specific sample extraction, amplification, and probe detection. A total of 12 foods were compared to the FSIS MLG 4.07 or the FDA BAM-5 reference method in an internal study and three foods in an external study.
Results: The internal matrix studies demonstrated the Atlas method was equivalent to the FSIS MLG 4.07 and FDA BAM-5 reference methods for raw tomatoes, chicken carcass rinse, string cheese, pasteurized dried whole egg, soy flour, cocoa powder, milk chocolate, non-organic creamy peanut butter, raw almonds, non-fat dried milk, cookies dough and whey powder. The independent laboratory study demonstrated similar results to the internal study for pasteurized dried whole egg, non-organic creamy peanut butter and milk chocolate.
Significance: The Atlas method detected Salmonella enterica spp. in a wide variety of food and offers the benefits of high sensitivity and high specificity for the detection of Salmonella enterica while reducing the overall time to results compared to the US reference methods.