Rapid Detection of Listeria monocytogenes in Different Samples by Real Time Fluorescence Isothermal Amplification

Abstract:

In order to detect the Listeria monocytogenes in dairy products and clinical diarrhea rapidly，the outer primer F3 and B3，inter primer FIP and BIP were chosen as the loop-mediated isothermal amplification （LMAP） specific primers. Then a portable thermostat fluorescence detector was used as the detection platform，while the sensitivity and detection limit on genomic DNA were also determined with a standard strain of Lis. monocytegenes；Artificially contaminated 15 dairy products and 20 clinical diarrhea were served to measuring the applicability of this assay，and a Chinese national standard method （GB4789.30-2010） was used at the same time. The results showed that the sensitivity and detection limit respectively reached to 102 CFU/mL and 103 CFU/mL，while the probabilities of false positive were 0，0.03 and 0，the positive detection rate were 100%，99% and 92%. The results were essentially in agreement with the culture method of GB4789.30-2010，indicating that this real time fluorescence isothermal amplification assay is suitable for the rapid detection of Lis. monocytegenes in dairy products and clinical diarrhea.