Purpose: The PCR Listeria monocytogenes assay was evaluated according to the current AOAC validation guidelines. The evaluation consisted of the following studies: inclusivity/exclusivity, method comparison of 13 food matrices, lot-to-lot/stability and robustness. This poster presentation will focus on the food comparison portion of the AOAC validation study.
Methods: The alternative method was compared to the USDA/FSIS-MLG 8.09 Isolation and Identification of Listeria monocytogenes from Red Meat, Poultry and Egg Products, and Environmental Sponges (2013) for deli ham, deli roast beef, deli turkey and turkey hot dogs; to the FDA/BAM Chapter 10 Detection and Enumeration of Listeria monocytogenes in Foods (2011) for cooked shrimp, fresh spinach, mixed bagged salad, liquid whole egg and whey powder; and to the AOAC OMA 993.12 Listeria monocytogenes in Milk and Dairy Products for Mexican soft cheese and vanilla ice cream. All analytical outcomes were biochemically confirmed by both traditional reference method and by an alternative method, which included an additional streak to chromogenic Agar Listeria Ottavani and Agosti (ALOA) agar.
Results: In the method comparison study, the alternative method demonstrated no statistically significant differences between presumptive and confirmed results (dPODCP) or between candidate and reference method results (dPODC) for the food matrices tested.
Significance: These data demonstrate that the GENE-UP LMO assay is a suitable method for detecting Listeria monocytogenes in a variety foods. The method provides significant savings in terms of time and improved convenience when compared to reference methods.