Use of 3M Molecular Detection Assay for the Detection of Salmonella spp. from Dehydrated Products

Introduction: Salmonella is widely recognized as a foodborne pathogen. Salmonella has been linked to products with low water activity. Traditional methods used for the detection of Salmonella are labor intensive with typical time to result of 4-5 days. Fast and accurate pathogen detection in low water activity products is critical for effective food safety management.

Purpose: Use of 3M Molecular Detection Assay for the detection of Salmonella spp. from dehydrated products.

Methods: Three different dehydrated matrixes were evaluated (Tomato, carrots and chicken broth). Samples were inoculated with Salmonella, three inoculum levels were used: high level (50-100 CFU/sample), low (1-5 CFU/sample) and non-inoculated samples. Ten samples were analyzed for each inoculum level and matrix combination. Twenty-five-g samples of the dehydrate matrices were added to 225 ml of buffered peptone water and incubated for 37°C/24 h. Samples were evaluated using the 3M Molecular Detection Assay (MDA). All samples were confirmed by the traditional method.

Results: One hundred percent of the inoculated samples were positive for MDA and the traditional method. Statistical difference between the two methods was not found (P>0.05). Sensitivity was 100% for the three matrices analyzed with the MDA. Negative controls yielded negative results. False negative are not reported.

Significance: 3M MDA can detect Salmonella present in dehydrated products providing next day results that are equivalent to those obtained by the traditional methods. The dehydrated matrices were not inhibitory to bacterial growth.