奶牛乳房炎金黄色葡萄球菌脉冲场凝胶电泳分型研究

Genotyping of Staphylococcus aureus isolated from bovine mastitis using pulsed-field gel electrophoresis

为探讨新疆北疆奶牛乳房炎致病菌的流行规律,本研究采用SmaⅠ酶切,脉冲场凝胶电泳(PFGE)分型的方法对43株分离自新疆6个规模奶牛场隐性乳房炎奶样的金黄色葡萄球菌进行了分子分型比较研究。结果表明,所有菌株都能被PFGE法分型,43株金黄色葡萄球菌可分为A、B、C、D和E5个基因型。A型株(22株,51.2%)有13个亚型,相似度在81.8%～96.8%之间,在5个奶牛场均分离到,是主要的流行株;B型(25.6%)、C型(14.0%)、D型(7.0%)各型别内菌株间的相似度为100%,E型仅有1株。不同地区主要流行株有差别:乌鲁木齐主要流行A型菌株,昌吉以A型和B型菌株为主,而奎屯主要流行C型和B型。有2个奶牛场流行株只有1个基因型,也有2种基因型(3个牛场)或3种基因型(1个牛场)同时存在,但以1种为优势株。这些结果提示,不同地区主要流行株有差别,多数奶牛场以1种流行株感染为主,不同牛场可能流行相同的菌株,在较大地域范围内某些流行株具有侵染优势。

Genetic relationships of 43 Staphylococcus aureus isolates from Xinjiang were analyzed by pulsed-field gel electrophoresis with Sma I digested bactera DNA. Five distinct types designated as pulsed-field types A-D were identified. Type A （51.2 %） was the most dominant type observed in multiple herds. Different predominant type was observed in different region. Four herds had two or three types with one predominant type. These data suggested that some strains of Staphylococcus aureus may have the advantage of infection.