Comparative evaluation of the VIDASReg.Listeria monocytogenes Xpress (LMX) for the detection of Listeria monocytogenes in a variety of foods.

摘要

The VIDASReg.Listeria monocytogenes Xpress (LMX) test is an enzyme-linked fluorescent immunoassay designed for use with the automated VIDAS or mini-VIDAS instruments for the specific detection of L. monocytogenes using a 26 h proprietary enrichment broth. The VIDAS LMX method was validated according to harmonized AOAC Research Institute (RI) and Official Methods of Analysis guidelines in both the AOAC Performance Tested MethodSM (PTM) and GovVal programs. In the PTM comparison studies, the VIDAS LMX method was compared to the US Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook, the US Food and Drug Administration Bacteriological Analytical Manual, and AOAC Official Methods. The comparative food studies consisted of 2 main parts: internal testing and AOAC independent laboratory testing, which included 7 food matrixes (deli ham, processed cheese, vanilla ice cream, cooked shrimp, smoked white fish, frozen spinach and peanut butter). As part of the AOAC RI GovVal program, the VIDAS LMX method was compared to the Health Canada MFHPB-30 method for the detection of L. monocytogenes in 5 ready-to-eat (RTE) meats (hot dogs, deli turkey, deli ham, fermented sausage and liver pate). 20 replicates of each inoculation level and 5 uninoculated controls were evaluated in each study. The LMX method also included the use of chromogenic media, chromIDTM Ottaviani Agosti agar and chromIDTML. mono. agar, for confirmation of LMX presumptive results. In both the PTM and GovVal evaluations, there were no significant differences in the Chi-square values for the LMX method when compared to reference methods. The additional parameters tested in the PTM evaluation (inclusivity, exclusivity, ruggedness, stability, and lot-to-lot) satisfied the AOAC RI performance requirements. In both the PTM and GovVal validation studies, the VIDAS LMX method demonstrated reliability as a rapid qualitative method for next-day detection of L. monocytogenes in a variety of foods, including RTE meats.