An Optimized EMA ‐ RAPD ‐ PCR for a Reliable Detection of Viable S almonella spp. in Chicken Products

This study aimed to develop the reliable technique called ethidium bromide monoazide‐random amplified polymorphic DNA ‐ PCR ( EMA ‐ RAPD ‐ PCR ) for detection of only viable S almonella cells due to PCR cannot distinguish DNA from viable and dead cells. In EMA ‐ RAPD ‐ PCR , EMA was used to intercalate the DNA obtained from 1.2 × 10 6 cells of viable and heat‐killed S almonella Typhimurium and S almonella Enteritidis. The optimized conditions of EMA treatment for an effective prevention of DNA amplification from dead cells by RAPD ‐ PCR were as follows: the minimum amount of 3 μg/mL EMA ; the suitable light exposure time of at least 5 min; and the optimum light exposure distance of 20 cm. To improve a reliability in specific detection of viable S almonella cells in food samples, use of an optimized 20‐h preenrichment in nutrient broth followed by EMA ‐ RAPD ‐ PCR could inhibit the DNA amplification of the dead cells in all artificially and naturally S almonella ‐contaminated chicken products tested. Practical Applications The developed E thidium B romide M onoazide‐ R andom A mplified P olymorphic DNA ‐Polymerase Chain Reaction ( EMA ‐ RAPD ‐ PCR ) involving 20‐h culturing in preenrichment medium is an efficient, reliable and economical procedure to detect only viable Salmonella spp . in food samples. This technique has demonstrated effectiveness in preventing the DNA amplification of dead S almonella cells. Moreover, the EMA ‐ RAPD ‐ PCR has the potential for use as a rapid, simple and reliable monitoring tool of S almonella spp. prevalence along the food production chain.