Application and evaluation of multiple cross displacement amplification in detection of Listeria monocytogenes / 中国人兽共患病学报

ABSTRACT

Listeria monocytogenes is a significant food-borne pathogen that is capable of causing severe listeriosis in both humans and animals.Traditional techniques such as culture-based approaches have good specificity and sensitivity,while they are time-consuming and tend to be tedious.Hence,we presented a simple and rapid molecular technique using multiple cross displacement amplification (MCDA) targeting L.monocytogenes-specific gene lmo0733 for sensitive and specific detection of the pathogen.L.monocytogenes-MCDA assay used a set of ten primers spanning ten distinct regions of target sequence and was carried out at a constant temperature 61 ℃ to evaluate the specificity,sensitivity and feasibility.A total of three methods were used to confirm MCDA products,including color change of Loopamp Fluorescent Detection Reagent,real-time measurement of turbidity and agarose gel electrophoresis.The limit of detection (LoD) of the MCDA was 10 fg DNA,which was 25-fold and 250-fold more sensitive than that of the LAMP and CPA assay for detecting L.monocytogenes DNA,respectively.The detection ability of MCDA method was identical to the culture-biotechnical method for 153 rat intestinal feces samples,and was better than LAMP,CPA and conventional PCR.The results in this study indicated that the MCDA assay could be used as a rapid,sensitive and effective tool for the detection of L.monocytogenes in the food industry,medical institutions and field.