Simultaneous Detection of Four Main Foodborne Pathogens in Ready-to-Eat Food by Using a Simple and Rapid Multiplex PCR (mPCR) Assay

Abstract

[EN] The increasing consumption of organic or ready-to-eat food may cause serious foodborne outbreaks. Microbiological culture for detection of food-borne pathogens is time-consuming, expensive and laborious. Thus, alternative methods such as PCR are usually employed for outbreaks investigation. In this work we aimed to develop a rapid and simple protocol for the simultaneous detection of E. coli, L. monocytogenes, S. aureus and S. enterica, by the combination of an enrichment step in a single culture broth and a multiplex PCR (mPCR) assay. The effectiveness of several enrichment media was assessed by culture and PCR. Buffered Peptone Water was selected as the optimum one. Then, mPCR conditions were optimized and applied both, to pure co-cultures and artificially inoculated food samples (organic lettuce and minced meat). In culture medium inoculated at 100 CFU/mL, mPCR was able to detect the four microorganisms. When performed on artificially food samples, the mPCR was able to detect E. coli, S. enterica and L. monocytogenes. In conclusion, Buffered Peptone Water broth can effectively support the simultaneous growth of E. coli, S. aureus, L. monocytogenes and S. enterica and could be, thus, used prior to a mPCR detection assay in ready-to-eat food, therefore considerably reducing time, efforts and costs of analyzes.