The Validation of the MEMP Salmonella Assay: AOAC Performance Tested MethodSM 042002

The Molecular Environmental Monitoring Program (MEMP) Salmonella Assay is a quick and reliable method for detecting Salmonella species in environmental samples. The assay incorporates a real-time PCR approach to identifying Salmonella cells expressed from the swab sample. The assay does not require an enrichment step, leading to much faster time to a negative result.

This report details the method validation study to validate the MEMP using environmental surface swabs for stainless steel, plastic, rubber, ceramic tile, and sealed concrete.

Matrix studies, inclusivity/exclusivity, product consistency and stability, and robustness testing were conducted to assess the method's performance. In the matrix studies, this method was compared to the US Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) Chapter 5 for environmental surface sponges and swabs.

Inclusivity/exclusivity testing showed that this assay was able to detect all 100 Salmonella strains tested while excluding the 30 non-Salmonella species. There were no statistically significant differences found between the candidate and reference methods. Small variations in critical test parameters (volume of extraction reagent and volume of extracted DNA sample) did not adversely affect the assay's performance, and stability testing indicated consistent results for at least one year.

The data presented in this report show that the candidate method performed as well as the reference method; therefore, it can be used in place of the reference method for detecting Salmonella species.

The MEMP Salmonella Assay is the first and only AOAC Performance Tested MethodSM approved for detecting Salmonella on surfaces without enrichment.