Evaluation of the 3M™ Molecular Detection Assay (MDA) 2 - Cronobacter for the Detection of Cronobacter species in Select Foods and Environmental Surfaces: Collaborative Study, First Action 2018.01.

The 3M™ Molecular Detection Assay (MDA) 2 - Cronobacter combines the use of loop-mediated isothermal amplification to rapidly amplify nucleic acid sequences while using bioluminescence to detect the amplification. Using a paired study design, the MDA 2 - Cronobacter was compared with ISO 22964:2017 for the detection of Cronobacter species in powdered infant formula containing probiotics. Technicians from 11 laboratories from the United States, Mexico, and Croatia participated. Collaborators received test portions with three levels of contamination. Statistical analysis was conducted according to the probability of detection (POD) statistical model. Results obtained for the low-inoculum level test portions produced a difference in POD values obtained from combining all valid collaborator POD data values with 95% confidence intervals of -0.01, -0.12, and 0.10, indicating that the difference between methods was not statistically significant at the 0.05 probability level.

Evaluation of 3M Molecular Detection Assay (MDA) 2-Listeria for the Detection of Listeria Species in Select Foods and Environmental Surfaces: Collaborative Study, First Action 2016.07.

3M Molecular Detection Assay (MDA) 2-Listeria uses loop-mediated isothermal amplification and bioluminescence detection to rapidly detect Listeria species in a broad range of food types and environmental surfaces. Using an unpaired study design, MDA 2-Listeria was compared with the U.S. Department of Agriculture, Food Safety and Inspection Service's Microbiology Laboratory Guidebook Chapter 8.09 "Isolation and identification of Listeria monocytogenes from red meat, poultry and egg products, and environmental samples" reference method for the detection of Listeria in deli turkey and raw chicken breast fillet. Technicians from 13 laboratories located within the continental United States and Canada participated in the collaborative study. Each matrix was evaluated at three levels of contamination: uninoculated control (0 CFU/test portion), low inoculum (0.2-2 CFU/test portion), and high inoculum (2-5 CFU/test portion). Statistical analysis was conducted according to the probability of detection (POD) statistical model. Results obtained for the low-inoculum-level test portions produced a difference between two laboratory POD values (dLPOD) with 95% confidence intervals of 0.04 (-0.08, 0.17) for deli turkey, indicating the difference between the methods was not statistically significant at the P = 0.05. For raw chicken breast fillet, a dLPOD value with 95% confidence interval of 0.16 (0.04, 0.28) indicated a statistically significant difference between the two methods, with an observed higher proportion of positive results by the candidate method than the reference method.

Evaluation of the 3M™ Molecular Detection Assay (MDA) 2 - Listeria monocytogenes for the Detection of Listeria monocytogenes in a Variety of Foods and Select Environmental Surfaces: Collaborative Study, First Action 2016.08.

The 3M™ Molecular Detection Assay (MDA) 2 - Listeria monocytogenes uses loop-mediated isothermal amplification of unique DNA target sequences combined with bioluminescence to rapidly detect Listeria monocytogenes in a broad range of food types and on environmental surfaces. Using an unpaired study design, technicians from 13 laboratories located in the United States and Canada compared the 3M MDA 2 - Listeria monocytogenes to the U.S. Department of Agriculture Food Safety Inspection Service Microbiology Laboratory Guidebook Chapter 8.09 "Isolation and Identification of Listeria monocytogenes from Red Meat, Poultry, and Egg Products, and Environmental Samples" reference method for the detection of L. monocytogenes in deli turkey and raw chicken breast fillet. Each matrix was evaluated at three levels of contamination: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2-2 CFU/test portion), and a high inoculum level (2-5 CFU/test portion). Statistical analysis was conducted according to the probability of detection (POD) statistical model. Results obtained for the low inoculum level test portions produced a difference in the collaborating laboratory POD (dLPOD) value of 0.04 with a 95% confidence interval of (-0.08, 0.17) for deli turkey, indicating that the difference between methods was not statistically significant at the 0.05 probability level. For raw chicken breast fillet, a dLPOD value of 0.16 with a 95% confidence interval of (0.04, 0.28) indicated a statistically significant difference, with an observed higher proportion of positive results by the candidate method compared to the reference method.

Evaluation of the 3M™ Molecular Detection Assay (MDA) 2 - Salmonella for the Detection of Salmonella spp. in Select Foods and Environmental Surfaces: Collaborative Study, First Action 2016.01.

The 3M™ Molecular Detection Assay (MDA) 2 - Salmonella uses real-time isothermal technology for the rapid and accurate detection of Salmonella spp. from enriched select food, feed, and food-process environmental samples. The 3M MDA 2 - Salmonella was evaluated in a multilaboratory collaborative study using an unpaired study design. The 3M MDA 2 - Salmonella was compared to the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 5 reference method for the detection of Salmonella in creamy peanut butter, and to the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook Chapter 4.08 reference method "Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg and Catfish Products and Carcass and Environmental Samples" for the detection of Salmonella in raw ground beef (73% lean). Technicians from 16 laboratories located within the continental United States participated. Each matrix was evaluated at three levels of contamination: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2-2 CFU/test portion), and a high inoculum level (2-5 CFU/test portion). Statistical analysis was conducted according to the probability of detection (POD) statistical model. Results obtained for the low inoculum level test portions produced difference in collaborator POD values of 0.03 (95% confidence interval, -0.10 to 0.16) for raw ground beef and 0.06 (95% confidence interval, -0.06 to 0.18) for creamy peanut butter, indicating no statistically significant difference between the candidate and reference methods.

Evaluation of 3M™ Molecular Detection Assay (MDA) Listeria monocytogenes for the Detection of Listeria monocytogenes in Selected Foods and Environmental Surfaces: Collaborative Study, First Action 2014.07.

The 3M™ Molecular Detection Assay (MDA) Listeria monocytogenes combines isothermal amplification and bioluminescence to detect Listeria monocytogenes with high specificity and efficiency in select foods and environmental samples. The 3M MDA Listeria monocytogenes method was evaluated using an unpaired study design in a multilaboratory collaborative study to the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook 8.09 (2011) Isolation and Identification of Listeria monocytogenes from Red Meat, Poultry, and Egg Products and Environmental Samples for deli turkey, and the AOAC Official Method of Analysis(SM) 993.12 Listeria monocytogenes in Milk and Dairy Products for full-fat (4% milk fat) cottage cheese following the current AOAC guidelines. A total of 16 laboratories located in the continental United States and Canada participated in this collaborative study. For deli turkey, 125 g test portions were evaluated using heat-stressed cells by each method. For full-fat cottage cheese, 25 g test portions were evaluated using nonheat-stressed cells. Each matrix had three inoculation levels: an uninoculated control level (0 CFU/test portion), and two levels artificially contaminated with L. monocytogenes, a low inoculum level (0.2-2 CFU/test portion) and a high inoculum level (2-5 CFU/test portion). In total, 1584 unpaired replicate samples were analyzed. Statistical analysis was conducted according to the probability of detection (POD) model. Results obtained for the low inoculum level full-fat cottage cheese test portions produced a difference in cross-laboratory POD (dLPOD) value of -0.08 with a 95% confidence interval (CI) of (-0.20, 0.05). For the low-level deli turkey test portions, a dLPOD value of -0.02 with a 95% CI of (-0.14, 0.11) was obtained.

Evaluation of 3M™ Molecular Detection Assay (MDA) Listeria for the Detection of Listeria species in Selected Foods and Environmental Surfaces: Collaborative Study, First Action 2014.06.

The 3M™ Molecular Detection Assay (MDA) Listeria is used with the 3M Molecular Detection System for the detection of Listeria species in food, food-related, and environmental samples after enrichment. The assay utilizes loop-mediated isothermal amplification to rapidly amplify Listeria target DNA with high specificity and sensitivity, combined with bioluminescence to detect the amplification. The 3M MDA Listeria method was evaluated using an unpaired study design in a multilaboratory collaborative study and compared to the AOAC Official Method of AnalysisSM (OMA) 993.12 Listeria monocytogenes in Milk and Dairy Products reference method for the detection of Listeria species in full-fat (4% milk fat) cottage cheese (25 g test portions). A total of 15 laboratories located in the continental United States and Canada participated. Each matrix had three inoculation levels: an uninoculated control level (0 CFU/test portion), and two levels artificially contaminated with Listeria monocytogenes, a low inoculum level (0.2-2 CFU/test portion) and a high inoculum level (2-5 CFU/test portion) using nonheat-stressed cells. In total, 792 unpaired replicate portions were analyzed. Statistical analysis was conducted according to the probability of detection (POD) model. Results obtained for the low inoculum level test portions produced a difference in cross-laboratory POD value of -0.07 with a 95% confidence interval of (-0.19, 0.06). No statistically significant differences were observed in the number of positive samples detected by the 3M MDA Listeria method versus the AOAC OMA method.