Abstract:
Listeria monocytogenes and Staphylococcus aureus are food-borne pathogene widerly distributed in dairy products, especially in ready-to-eat foods. Due to undercooked and storage of ready-to-eat foods in cold temperature is optimal for growth of L. monocytogenes. Moreover, S. aureus is commonly found on the skin of healthy people therefore it can contaminate in food products during preparation and processing. In this study, specific primers for Coagulase (coa) gene from S. aureus and PrfA gene from L. monocytogenes were designed and used for detection of those bacteria by a multiplex PCR. The multiplex PCR can detect at least 1 ngand 0.15 ng of S. aureus and L. monocytogenes DNA, respectively. Investigation of the artificially contaminated foods, the multiplex PCX was possible to detect S. aureus 10 5 celsl per 5 g (2 x 10 4 cells/g) of food and detect L. monocytogenes less than 1 cellper 5 g (< cell/g) of food. No amplification DNA of Related food pathogens in PCR reaction, indicate specificity of the primers. The multiplex PCX was then used as a tool to detect contaminated foods in local makets in Chonburi province. Fifty-eight samples of several types of ready-to-eat foods were analyzed and the results showed that none of them were contaminated with L. monocytogenes and S. aureus. However, it needs further Investigation for the surveillance in the future This multiples PCR can be used for L. monocytogenes and S. aureus detection incontaminated ready-to-eat foods as a rapid, high sensitive and specific assay. This multiplex PCR assay can be further developed, and could be benefit for public health and surveillance of disease outbreaks.