食品中单核细胞增生李斯特菌株的分离及聚合酶链式反应鉴定

目的 建立单核细胞增生李斯特菌的聚合酶链式反应(PCR)检测方法,了解市售食品中单核细胞增生李斯特菌的污染情况.方法 采集成都市市售生畜肉、生禽肉、熟肉制品、水产品、生食蔬菜以及其他熟食等食品样品共135份,采用李氏增菌肉汤(LB1,LB2)进行初增菌,应用选择性分离培养基PALCAM和在TSA-YE平板上进行分离,利用单增李斯特显色平板进行鉴定；根据李斯特菌的特异性基因iap基因设计引物,采用PCR方法检测所有分离的李斯特菌株；根据单增李斯特菌的特异性基因hly基因和prfA基因设计引物检测单核细胞增生李斯特菌株.结果 135份样品中共检出李斯特菌17株,检出率为12.6％；其中单核细胞增生李斯特菌4株,检出率为3.0％.结论 本研究建立的PCR方法具有特异性,本市市售食品不同程度受到李斯特菌的污染.

Isolation of Listeria strains from food and identification of Listeria monocytogenes with polymerase chain reaction

Objective To develop a specific PCR detection method for L.monocytogenes and to investigate the contamination of L.monocytogenes in different foods in Chengdu city.Methods A total of 135 random samples from sorts of meat,fish,dairy,vegetable and other ready-to-eat food were collected from free markets and supermarkets.The samples were followed an enrichment period with LB1 and LB2 broth,then separated and identified by using PALCAM medium,TSA-YE agar and CHROMagarTM Listeria.The virulence gene iap was used ...