食品中单核细胞增生性李斯特氏菌PCR快速检测

Rapid Detection of Listeria monocytogenes in Food by PCR

通过扩增hly基因建立检测单核细胞增生性李斯特氏菌(Lm)的PCR方法。该方法具有较强的特异性,35株经传统方法鉴定的菌株PCR结果均为阳性,而其他三种同属异种菌,包括英诺克李斯特氏菌、绵羊李斯特氏菌和威尔斯李斯特氏菌及非李斯特氏菌均未扩增出特异性的片段。PCR方法对Lm纯培养物的最低检测限为7.3CFU/μl,对模拟污染的生猪肉和蔬菜的检测低限为4CFU/g,牛奶为4CFU/ml。应用该方法对285份食品样品检测,17份样品Lm呈阳性,结果与常规的分离培养方法完全一致。该种方法具有敏感、特异、快速及准确的优点,可用于食品中Lm的快速检测。

A polymerase chain reaction （PCR） assay targeting the hly gene was developed to detect Listeria monocytogenes. The PCR product was detected in 35 L monocytogenes strains and not in other Listeria spp, including innocua, ivanovii and welshimer and also not in non-Listeria species, indicating that this method was highly specific for L. monocytogenes. The dotection limit of the PCR assay was 7.3 CFU/μl of pure cell culture. The PCR assay could detect 4 CFU of L. monocytogenes ha the contaminated pork and vegetable （1g） and milk （1ml）. From 285 samples, 17 samples were proved positive for L. monocytogenes by the PCR method, and the results were quite consisted with those detected by conventional biochemical testing. The PCR assay is highly sensitive, specific, rapid and accurate and can be used for rapid detection of L, monocytogenes in food.