AOACRIMicroMethods-2017Awards

980 B ird et al .: J ournal of aoaC i nternational V ol . 99, n o . 4, 2016 FOOD BIOLOGICAL CONTAMINANTS

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 P atrick B ird , J onathan F lannery , e rin c rowley , J ames r. a gin , and d avid g oins Q Laboratories, Inc., 1400 Harrison Ave, Cincinnati, OH 45214 l isa m onteroso 3M Food Safety Department, 3M Center, Bldg 260-6B-01, St. Paul, MN 55144 Collaborators: C. Barnes; B. Bastin; J. Blumfield; T. Bonilla; R. Brooks; E. Budge; A. Calle; D. Campos; J. Casimir; N. Cuthbert; A. Deshields; Z. Geurin; C. Gies; A. Hankins; L. Hardrath; B. Kupski; M. Mendres; J. Miller; K. Naylor; J. Pickett; A. Repeck; J. Reynolds; B. Schindler; J. Schoeni; M. Tillottson; L. Thompson; H. Wright; C. Zook

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 Submitted for publication March 25, 2016. This method was approved by the Expert Review Panel for Microbiology Methods for Food and Environmental Surfaces as First Action. The Expert Review Panel for Microbiology Methods for Food and Environmental Surfaces invites method users to provide feedback on the First Action methods. Feedback from method users will help verify that the methods are fit-for-purpose and are critical for gaining global recognition and acceptance of the methods. Comments can be sent directly to the corresponding author or methodfeedback@aoac.org. Corresponding author’s e-mail: pbird@qlaboratories.com DOI: 10.5740/jaoacint.16-0085

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. S almonella is a nonspore-forming, rod-shaped, Gram-negative bacterium that can cause disease in humans (1). Most of the Salmonella serovars cause gastrointestinal illness, with annual estimates of over 1 million illnesses and 450 deaths in the United States (1). A few serovars, Salmonella Typhi and Salmonella Paratyphi A, B, and C, can cause typhoidal illness also known as enteric fever (2). In the past year, Salmonella has been identified as the source of over 20 food-related outbreaks in the United States (3, 4). The 3M™ Molecular Detection Assay (MDA) 2 – Salmonella method uses a combination of bioluminescence and isothermal amplification of nucleic acid sequences to rapidly detect Salmonella in select food matrixes and from environmental surfaces. The isothermal amplification is a molecular reaction conducted at a constant temperature, eliminating the need for temperature cycling and decreasing the time to results. The 3M MDA 2 – Salmonella method allows for the rapid and specific detection of Salmonella spp. in select matrixes after as little as 10 to 18 h of preenrichment using an International Organization for Standardization (ISO) formulation of buffered peptone water (BPW; 5). After enrichment, samples are evaluated using the 3MMDA2 – Salmonella on the 3MMolecular Detection System (MDS). Presumptive positive results are reported in real time, whereas negative results are displayed after completion of the assay in approximately 60 min. Before the collaborative study, the 3M MDA 2 – Salmonella method was validated according to AOAC INTERNATIONAL guidelines (6) in a harmonized AOAC Performance Tested Method SM (PTM) study. The objective of the PTM study was to demonstrate that the 3M MDA 2 – Salmonella method could detect Salmonella in select food matrixes and environmental surfaces as claimed by the manufacturer. For the 3M MDA 2 – Salmonella PTM evaluation, 18 matrixes were evaluated: raw ground beef (73% lean; 25 and 325 g), raw ground chicken (25 and 325 g), chicken carcass rinse, chicken carcass sponge,