Interlaboratory study of a DNA Microarray for Salmonella Molecular Serotyping in comparison to the conventional serotyping method

• Principle : The Premi®Test Salmonella system uses a methodology called multiplex ligation detection reaction to generate a collection of circular DNA molecules that are subsequently PCR amplified by means of a single pair of amplimers (3). The PCR products are next sorted by hybridization to a low-density DNA microarray. Positive hybridization is detected using a biotin label incorporated in one of the PCR primer. A set of genetic markers has been selected with the purpose of yielding unique microarray hybridization profiles to identify and discriminate S. enterica serovars. The test allows single-tube processing, which simplifies the technical work associated with strain typing and can be applied directly after the enrichment and isolation steps of the Standard ISO method for Salmonella detection (Fig.1). Premitest Salmonella molecular serotyping ( Table 3) Molecular serotyping determination was analyzed on 24 out of the 26 tested strains and near 97% of the strains were correctly identified with the PTS (116 well identified on 120 analysis). Success rate per lab ranging from 92% to 100% in comparison to the expected results.