AtlasTM Salmonella detection method using transcription mediated amplification (TMA) to detect Salmonella enterica in a variety of foods and select surfaces

Abstract

The AtlasTM Salmonella detection assay was compared to the reference culture methods for 12 foods and three surfaces. Comparison of the Atlas method to the U.S. Food and Drug Administration Bacteriological Analytical Manual (FDA/BAM) and U.S. Department of Agriculture-Food Safety and Inspection Service/Microbiology Laboratory Guidebook (USDA-FSIS/MLG) reference methods required an unpaired approach. Each method had a total of 320 samples inoculated with an S. enterica strain. Each food and surface was inoculated with a different strain of S. enterica at two different levels/method. Meat and egg products were compared to the USDA-FSIS/MLG 4.05 method. All other foods were compared to the FDA/BAM-5 method. The Atlas method had 148 positives out of 320 total inoculated samples, compared to 119 positives for the reference methods. Overall, the probability of detection analysis of the results showed equivalent or better performance by the Atlas Salmonella detection method compared to the reference methods. The Atlas Salmonella detection assay detected all 100 inclusive organisms and none of the 30 exclusive organisms. The lot-to-lot and kit stability studies showed no statistical differences between lots or over the term of the shelflife. Instrument-to-instrument testing showed no statistical difference between instruments. Finally, the robustness study showed no difference when the sample volume added to the Atlas Salmonella detection assay varied by 10%, storage time was extended up to 5 days before analysis, or enrichment times were varied from 12 to 24 h.