关键词: 奶牛乳房炎, 金黄色葡萄球菌, MLVA, 分型

Abstract: Molecular typing of Staphylococcus aureus is valuable for presenting the strain spreading, detecting the strain geographical distribution and developing specific vaccine. We aimed at developing a MLVA method to type S. aureus isolates coming from Chinese herds，and then to perform a molecular epidemiological study. Another aim is to evaluate the discriminatory power of MLVA method by comparing with RS-PCR typing method. MLVA method (multiplex PCR system) was constructed to type 27 S. aureus isolated from different regions and herds. Meanwhile, all of the isolates were typed using RS-PCR method. Both of the methods can type all 27 isolates obtained from 17 herds located in eight regions. Nineteen distinct types were identified by MLVA method, all of which belong to individual herds. And the strains with the same source were typed identical other than those from two herds in Shanghai and Beijing. The discriminatory power of MLVA is 0.969. As for RS-PCR method, it can identify the isolates into 10 types, of which type Ⅰ, Ⅱ and Ⅴ were distributed in different regions. The discriminatory power of RS-PCR is 0.829. From the above results, we conclude that MLVA is a rapid and convenient method which shows good discriminatory power to type bovine S. aureus isolates. Meanwhile we infer that types of S. aureus are more likely to be restricted to a single herd, than found in multiple herds in China.

Key words: bovine mastitis, Staphylococcus aureus, molecular typing, MLVA