Spread and pathogenecity of PVL-positive MRSA strains emerging in the community

从皮肤科门诊患者分离的MRSA菌株大多数携带IV型或V型SCCmec元素，这是社区获得性MRSA菌株的特征。PVL阳性分离株大致分为两类，一类是可能从其他国家（如美国、印度或台湾）输入的国际克隆，另一类是国内克隆。在ST59和ST772两个国际克隆中鉴定出2个新型PVL噬菌体，属于siphoviridae 3族。儿童血清抗pvl和抗金黄色葡萄球菌抗体滴度低于成人，提示这可能是儿童发生危及生命的感染的原因之一。

The majority of MRSA strains isolated from outpatients of dermatology carried types IV or V SCCmec elements, which are characteristic in community-acquired MRSA strains. PVL positive isolates were roughly classified into two, the international clones that might be imported from other countries, e. g., US, India, or Taiwan, and the domestic clones.Two novel PVL phages belonging to group 3 siphoviridae were identified in two international clones, ST59 and ST772. Titers of anti-PVL as well as anti-staphylococcus aureus antibodies in the sera of children were lower than those of adults, suggesting that it might be a reason that life-threatening infection was occurred among children.