Validation of the Neogen® Molecular Detection Assay 2 - Salmonella Enteritidis/Salmonella Typhimurium Method for Specific Detection of Salmonella enterica Ser. Enteritidis and Salmonella enterica Ser. Typhimurium in Chicken Carcass Rinse and Raw Ground Chicken AOAC Performance Tested MethodSM 122302.

Background: The Neogen® Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium (MDA2-SE/ST) method is a rapid, nucleic acid amplification-based test for specific detection of Salmonella enterica ser. Enteritidis (SE) and Salmonella enterica ser. Typhimurium (ST), including the ST monophasic variant Salmonella enterica  1,4 , [5] , 12: i:-, in select poultry samples. Results for SE and ST are generated separately.

Objective: The objective of the study was to validate the MDA2-SE/ST method for detection of SE and ST in chicken carcass rinse and raw ground chicken (325 g) for Performance Tested Methods  SM (PTM) certification.

Methods: The study consisted of inclusivity/exclusivity testing and independent laboratory testing of chicken carcass rinse and raw ground chicken using inoculated matrixes. Data were analyzed using a paired probability of detection model to determine if differences in the number of positive results obtained with the MDA2-SE/ST and reference methods were significant.

Results: In inclusivity testing, all 50 SE strains produced positive results in the SE assay and negative results in the ST assay. All 53 ST strains (including the monophasic variant) produced positive results in the ST assay and negative results in the SE assay. All 35 exclusivity strains produced negative results in both assays. The exclusivity panel included multiple non-SE group D1  Salmonella serovars, multiple non-ST group B serovars, Salmonella spp. from other somatic groups, and other Enterobacteriaceae. In matrix testing, results for the MDA2-SE/ST and reference methods were in complete agreement for both matrixes.

Conclusions: Results of the validation study showed that the MDA2-SE/ST method is an accurate, specific method for detection of SE and ST in select poultry matrixes.

Highlights: The data were reviewed by the AOAC PTM Program and approval was granted for certification of the Molecular Detection Assay 2-Salmonella Enteritidis/Salmonella Typhimurium method as PTM 122302.