Purpose: The project aim was to evaluate the 3M Molecular Detection Assay (MDA) Salmonella for screening water samples and to compare the results obtained to the Australian standard method.
Methods: Water samples analyzed in this study were “as-received” from clients; some of the samples were artificially inoculated with Salmonella to provide positive results. An aliquot of each sample was vacuum filtered and enriched in Buffered Peptone Water for 18-24 h and then tested by two methods: (a) 3M MDA Salmonella as per the manufacturer’s instructions; and (b) Australian Standard cultural method via subculturing into MKTTn and RVS, further selective enrichment incubation for 24 h and 48 h and plating of the selective enrichments onto two different selective agars.
Results: Of the 222 samples tested for Salmonella, 49 were positive by the 3M MDA and Australian standard method while 173 were negative by both methods. This shows 100% agreement between the two methods under the test conditions used.
Significance: The 3M MDA Salmonella provides a presumptive result for the presence of Salmonella in water, within 24 hours, allowing for more timely reporting of results without compromising accuracy.