Purpose: In this study, the Reveal test was evaluated for rapid detection of SE in raw shell eggs, poultry feed and chicken carcass rinse.
Methods: A low level of SE was inoculated into pooled raw shell eggs and a paired analysis was conducted utilizing a common primary enrichment method prescribed in the FDA/BAM procedure. Chicken carcass rinse and poultry feed samples spiked with SE were tested with the Reveal test and the USDA-FSIS/MLG or FDA/BAM reference methods, respectively. The novel secondary enrichment methodology incorporates modified semisolid Rappaport-Vassiliadis broth (MSRV) and the direct application of the Reveal device. For each matrix, 20 replicate test portions were inoculated to produce fractional positive levels, along with 5 high level and 5 uninoculated samples. Statistical analysis was conducted on the Reveal test and reference method data using probability of detection (POD) models.
Results: Method comparison data for fractional positive samples, at a 95% confidence interval, produced a dPOD of 0 (-0.14, +0.14) for raw shell egg samples, a dPOD of 0 (-0.26, +0.26) for chicken rinse samples and a dPOD of 0.3 (0, 0.54) for poultry feed samples. There was no statistically significant difference between performance of Reveal and reference methods. The Reveal test demonstrated inclusivity of 98% for target strains (49/50) and exclusivity of 100% for non-target strains (40/40) tested.
Significance: The study results demonstrate the utility of Reveal 2.0 for Group D1 Salmonella, as a rapid test for detection of SE in raw shell eggs, poultry feed and chicken carcass rinse.