Purpose: This study evaluated the performance of the system for the detection of Salmonella in a variety of raw and processed seafood products from Thailand as compared to the standard ISO 6579-1:2007 method.
Methods: Products (n = 200) were purchased, as manufacturer-sealed packaging or individually weighed/sliced from retail counters, markets, and street vendors. Products included 43 raw seafood products, 66 processed (ready-to-cook) seafood products (e.g., dried assorted fish), and 91 RTE products (e.g., mixed fish wonton). Each sample tested (approx. 100 g) was homogenized and screened for Salmonella following two methods; the system and ISO 6579-1:2007.
Results: The system showed comparable detection results to those obtained from the ISO method. Overall, 112/200 samples were positive for Salmonella (56%). Twelve samples tested positive by the system only. These samples encompassed a variety of different food matrices; six were products with high microbial loads. The sensitivity of the system was 100% (95% CI: 95.4-100%), specificity was 88.0% (95% CI: 81.6-94.4%), accuracy was 94.0%, and the positive predictive value was 89.3% (95% CI: 83.6-95.0%).
Significance: Rapid detection and monitoring of Salmonella in seafood products can improve seafood safety and quality in domestic and international markets. The 3M Petrifilm SALX System is a new all-in-one detection method that can facilitate high-throughput sample screening for Salmonella to obtain faster and reliable results.