Purpose: The purpose of this study was to conduct an NF Validation by AFNOR Certification extension study to validate use of the SureTect™ Listeria monocytogenes PCR Assay on the Applied Biosystems™ 7500 Fast PCR Instrument with Applied Biosystems™ RapidFinder™ Express version 2.0 Software (the alternative method) using meat products, milk and dairy products, seafood and fishery products, vegetables, plus environmental samples.
Methods: A method comparison study and relative limit of detection (RLOD) study was conducted. For the alternative method, all samples underwent an enrichment step followed by direct lysis. Following direct lysis, PCR was run and results were automatically interpreted by the software. The reference method was conducted according to EN ISO 11290-1/A1:2004.
Results: A total of 393 food and environmental samples (78 meat products, 78 milk and dairy products, 65 seafood and fishery products, 75 vegetables, plus 97 environmental samples) were tested using the alternative and EN ISO 11290-1/A1:2004 reference methods. For the RLOD study, five different L. monocytogenes isolates were spiked into representative matrices and tested as per the alternative method protocol and the EN ISO 11290-1/A1: 2004 reference method. The alternative method demonstrated equivalent performance for all human food and environment samples analyzed as per the EN ISO 11290-1/A1:2004 reference method. The alternative method showed an RLOD (0.2-1.0 CFU/25 g) similar to that of the EN ISO 11290-1/A1:2004 reference method (0.3-0.9 CFU/25 g).
Significance: The alternative method proved to be a suitable substitute to the EN ISO 11290-1/A1:2004 reference method for L. monocytogenes detection.