Abstract: Listeria monocytogenes is a kind of food-borne pathogenic bacterium strain grown at low temperature and can cause zoonosis. The method is based on real time reverse-transcription-PCR (RT-PCR) amplification of mRNA to detect viable Listeria monocytogenes by specific hlyA gene. This method can overcome the false-positive caused by amplification of nonviable Listeria monocytogenes in the detection process. Both sensitivity and specification of this method were studied, and the artificially contaminated milk by Listeria monocytogenes was assayed. The results showed that the specific primers and probe do not cross-react with other food-borne pathogens. The sensitivity of detection Listeria monocytogenes is 3×102 CFU/ml after being cultivated 1 h and 30 CFU/ml after 3 h. The sensitivity of detection of artificially contaminated milk is 17 CFU/ml after being cultivated 6 h. So this method can satisfy the demandion of diagnosis and detection of Listeria monocytogenes.

Key words:  , real time RT-PCR； Listeria monocytogenes； hlyA； artificially contaminated milk； viable bacterium；