为建立生鲜牛奶中牛分支杆菌的PCR检测方法，选择牛分支杆菌pncA的基因序列中一段大小为423 bp的片段作为靶序列，设计并合成一对引物，对所建立的PCR方法进行了特异性、敏感性和重复性试验。结果表明，建立的PC R方法在牛分支杆菌污染模型乳中成功扩增出了423 bp的特异性目的条带，而分别添加有沙门菌、大肠埃希菌、无乳链球菌、金黄色葡萄球菌、嗜肺巴氏杆菌、铜绿假单胞菌及枯草杆菌的乳样中均未扩增出任何条带。牛分支杆菌的DN A最低检测限为12．18 pg/μL ，牛分支杆菌污染牛奶模型的敏感性为3 cfu/mL。建立的方法可用于牛奶中牛分支杆菌的检测。%The present work aimed to establish a PCR method for detecting Mycobacterium bovis in raw milk .The pncA gene of Mycobacterium bovis was taken as the target sequence to design primers .A specif-ic 423 bp fragment of pncA gene was amplified from Mycobacterium bovis and subjected to PCR analysis . The further tests were carried out to evaluate specificity ,sensibility and repeatability .A 423 bp specific objective band was propagated from milk contaminated with Mycobacterium bovis ,and nothing fragment was propagated in negative groups ,including Salmonella ,E .coli ,Streptococcus agalactiae ,Staphylococ-cusaureus ,Bacillus subtilis ,Pseudomonas aeruginosa ,Pasteurella pneumotropica .The lowest test limit of DNA in Mycobacterium bovis was 12 .18 pg/μL in this study ,and the sensibility of detection was found to be 3 cfu/mL in raw milk artificially contaminated with Mycobacterium bovis .These results indicated the established PCR method could be used for detecting M ycobacterium bov is in raw milk .
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