P1-142 Evaluation of a New Salmonella Detection Method for Seafood

Monday, July 29, 2013
Exhibit Hall (Charlotte Convention Center)
Kanokphan Srimanobhas, Fish Inspection and Quality Control Division, Bangkok, Thailand
Introduction: Thailand’s exports of fresh, chilled and frozen seafood products are approximately 570,000 metric tons, 50% more than a decade ago. The Fish Inspection and Quality Control Division (FIQD) of the Thailand Department of Fisheries (DOF) provides certification and inspection of pre-export seafood products and, to respond to the growing market needs, has prioritized the qualification of simpler and shorter methods for rapid Salmonella detection.

Purpose: To evaluate the performance of a new Salmonella detection method through comparison with a cultural method for local seafood matrices, including [1] Spiked Raw Shrimp; [2] Spiked Raw Cephalopod; [3] Spiked Processed Fish; [4] Raw Shrimp; [5] Raw Cephalopod; & [6] Raw Fish. 

Methods: The evaluation included pure-culture inclusivity and exclusivity testing. Food testing was performed using 141 samples comparing the performance of a molecular method and a reference cultural method. Sixty samples were spiked with a low level (1-10 CFU) of Salmonella: Raw shrimp (20 samples); Raw Cephalopod (20 samples); and Processed Fish (20 samples). Eighty-one samples were tested with natural contamination: Raw Shrimp (41 samples); Raw Cephalopod (20 samples); and Raw Fish (20 samples). After a shared enrichment, all samples were analyzed by two methods: (a) 3M Molecular Detection Assay Salmonella; and (b) ISO 6579. Presumptive positive molecular results were culturally and biochemically confirmed following ISO 6579 procedures.

Results: The molecular method yielded inclusivity and exclusivity rates of 100%. For the 141 samples tested, the molecular method showed 100% sensitivity, 100% specificity, 100% accuracy and no significant difference from the reference method using the chi-square statistic.  

Significance: For testing artificially and naturally contaminated seafood matrices from Thailand, the 3M Molecular Detection Assay Salmonella was found to be reliable and accurate, and to offer advantages to laboratories, including faster time to results.