Purpose: The purpose of this study was to conduct a method comparison evaluation of the bioMérieux VIDAS® Listeria monocytogenes Xpress (LMX) to the Health Canada Compendium of Analytical Methods , Volume 2 MFHPB-30 Isolation of Listeria monocytogenes and other Listeria spp. from foods and environmental samples in order to obtain the “all foods” claim for detection of Listeria monocytogenes.
Methods: For the evaluation, test matrices included 16 food types from the following categories: Ready-to-Eat Meat and Poultry (n=4), Multi Ingredient Composite Ingredient Foods (n=3), Fish and Seafood Product (n=3), Fruit and Vegetable- Based Products (n=3), and Dairy Products (n=3). Each of these food types included either 25 gm and /or 125 gm test portions. Each food item was inoculated with L. monocytogenes such that n=20 were at fractional level (0.2-2 CFU/test portion), n=5 were at high level (2-5 CFU/test portion); n=5 were left uninoculated. All analytical outcomes were biochemically confirmed by both MFHPB-30 and by an alternative method using bioMérieux’s chromogenic Agar Listeria Ottavani and Agosti (ALOA) agar.
Results: No statistically significant differences were observed between presumptive and confirmed results (dPODCP) or between candidate and reference method results (dPODC) for the food matrices tested. Sensitivity, specificity, false negative, false positive, and test efficacy were found to be 100%, 100%, <1.0, <1.0, and 100%, respectively for fractional and high inoculated samples. No Listeria monocytogenes was recovered from the uninoculated samples.
Significance: These data demonstrate that the LMX assay is equivalent to the Health Canada MFHPB-30 reference method and is suitable for detecting Listeria monocytogenes in all foods.