不同地区致奶牛乳房炎金葡菌毒力因子的分布

金黄色葡萄球菌(Staphylococcus aureus,SA)是引起奶牛乳房炎的重要病原,该致病菌主要通过毒力因子刺激乳腺组织引起炎症反应。为研究金黄色葡萄球菌重要毒力因子分布的地域性差异,本试验从上海以及云南的3个奶牛场采集奶样和环境污水,利用PCR技术对70株分离菌株和2株标准菌株进行检测。结果显示,在上海地区分离的18株金黄色葡萄球菌中,有7种毒力基因nuc(94.4%)、FnBPA(77.8%)、Hla(88.9%)、Hlb(94.4%)、ClfA(88.9%)、spa(61.1%)和coa(94.4%)的检出率超过50%;在云南分离到的19株金黄色葡萄球菌中,有8种毒力基因nuc(84.2%)、FnBPA(78.9%)、Hla(100%)、Hlb(78.9%)、ClfA(52.6%)、spa(78.9%)、set1 (57.9%)和coa(84.2%)的检出率超过50%,这说明该8种毒力因子可能是致奶牛乳房炎金黄色葡萄球菌中主要的毒力因子。

Distribution of virulence factor of Staphylococcus aureusisolated from dairy cow with mastitis in different regions

Staphylococcus aureus (SA) is the main pathogen that could cause dairy cow mastitis.Through its virulence factors,SA can give rise to inflammatory reaction due largely to stimulation of mammary tissues.In order to investigate the regional difference of crucial virulence factors of S.aureus rooted in Shanghai and Yunnan,we collected milk and sewage samples from three dairy farms.Polymerase chain reaction (PCR) was used to detect 2 standard strains and 70 strains isolated from two regions.The detection rates of 7 kinds of virulence factors,including nuc (94.4%),FnBPA (77.8%),Hla (88.9%),Hlb (94.4%),ClfA (88.9%),spa (61.1%) and coa (94.4%),are higher than 50% in18 S.aureus strains isolated from Shanghai.By contrast,the detection rates of 8 kinds of virulence factors,including nuc (84.2%),FnBPA (78.9%),Hla (100%),Hlb (78.9%),ClfA (52.6%),spa (78.9%),set1 (57.9%) and coa (84.2%),are higher than 50% in 19 S.aureus strains isolated from Yunnan.The results demonstrate that these 8 virulence factors are probably the dominating virulence factors in dairy cow mastitis.