A new rapid real-time PCR method for detection of listeria monocytogenes targeting the hlyA gene

In this study, primer sets of L. monocytogenes virulence gene hlyA were designed for the L. monocytogenes- specific PCR assay. To evaluate the performance of these primer sets, the detection sensitivity and specificity were examined and the most suitable primer set was selected. Subsequently, it was subjected to compare the performance for detection of L. monocytogenes with commercially available kits (TaKaRa detection kit and ABI detection kit) on DNA level. Results of real-time PCR showed that the efficiency of this new primer set was 101.6% while TaKaRa and ABI detection kit were 101.1% and 107.4%, respectively. The detection sensitivity of all three methods was equivalent to less than 1 copy per reaction using purified genomic DNA as template. Detection specificity were 100% when testing L. monocytogenes isolates, and for other Listeria isolates were 15.4%, 76.9% and 100% by the method using hlyA L. monocytogenes detection primer set 7, TaKaRa and ABI detection kit, respectively. In summary, this new PCR detection method is relatively sensitive and more specific to L. monocytogenes under certain conditions, could serve as a rapid detection method and has the potential for detection of L. monocytogenes from contaminated food.