Purpose: During the validation study conducted by the ADRIA Développement (Quimper FRANCE), a sensitivity study was performed comparing this alternative method to the ISO 6579 Reference method for the detection of Salmonella spp. in seven categories of food samples.
Methods: Two protocols have been developed for same day, next day detection, and larger sample size. For next day detection, 333 samples of 25g (including ready-to-eat/ready-to-reheat, meat products, milk and dairy products, vegetables, fruits and seafood, specific ingredients and food) were tested by both methods. For same day detection and larger sample size, 65 raw meat samples of 25g and 63 raw meat samples of 375g were tested. This new method consists of a single enrichment in BPW incubated 8 to 24h (depending on food) at 41.5°C. DNA is extracted using mechanical lysis in a dedicated lysis tube: 20µL are introduced through a cap that does not require any tube or cap handling. Amplification, based on dual probe detection, is performed directly with freeze dried PCR reagents. The call is positive when it combines an amplification curve and a melting peak allowing a strong specificity of the test.
Results: Methods were evaluated following the new ISO 16140-2 guidelines. The GENE-UP® Salmonella method showed similar results to the ISO 6579 Reference method for Salmonella spp. detection.
Significance: The GENE-UP® Salmonella method enabled reliable and rapid detection of Salmonella spp. in a variety of food using an 8 to 24h enrichment (depending of food category and size) and providing a user-friendly workflow.