Purpose: The purpose of this study was to conduct an NF Validation by AFNOR Certification extension study to validate use of the SureTect Salmonella species PCR Assay on the Applied Biosystems™ 7500 Fast PCR Instrument with Applied Biosystems™ RapidFinder™ Express version 2.0 Software (the alternative method) with meat products, milk and dairy products, powdered infant formula, raw beef meats, seafoods and 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 ISO 6579:2002.
Results: Three hundred ninety-one food and environmental samples (72 meat products, 62 milk and dairy products, 64 powdered infant formula, 61 raw beef meats, 63 seafood and vegetables, plus 69 environmental samples) were tested using the alternative and ISO 6579:2002 reference methods. For the RLOD study, five Salmonella spp. isolates were spiked into representative matrices and tested as per the alternative method protocol and ISO 6579:2002 reference method. The alternative method demonstrated equivalent performance for the food and environment samples analysed to the ISO 6579:2002 reference method. The alternative method showed a similar RLOD (0.4-1.5 CFU/25 g) to the ISO 6579:2002 reference method (0.4-1.3 CFU/25 g).
Significance: The alternative method proved to be a suitable substitute to the ISO 6579:2002 reference method for detection of salmonellae.