摘要
为研究牛源耐甲氧西林金黄色葡萄球菌(MRSA)的产生和可能的流行趋势,使用EBURST对多位点测序分型(MLST)数据库中的牛源金黄色葡萄球菌、牛源MRSA和医源MRSA进行比较分析。结果显示,国外的牛源mecA+MRSA为CC97(ST1623和ST1624)、CC5(ST5)、CC59(ST87)、CC509(ST89)及单独的序列型(ST1622和STST1625);牛源金黄色葡萄球菌中25.25%和12.54%的分别属于CC97和CC705,但仍有一半以上的菌株分布在众多、较小的克隆复合群中。同时,本实验室对我国5株SCCmecⅣ型和1株未分型MRSA、28株非mecA基因介导的MRSA和11株甲氧西林敏感(MSSA)菌株的MLST分型分析显示,我国mecA+MRSA分布在CC97、5、6和CC9 4个克隆复合群(CCs)中,6株MSSA属于CC97,新发现的28株mecA-MRSA菌株的序列型(STs)为ST121、120、398、97、2154、25、20和938。对以上数据的分析表明,目前,MLST数据库中所有牛源mecA+MRSA可能均由MSSA获得SCCmec而产生,且相对于特定的医源MRSA(mecA+)菌株的快速扩散而导致在某一区域形成大规模流行的现状,牛源MR-SA可能仍在形成流行的早期,已形成的MRSA尚未大范围扩散,但有可能沿着医源MRSA的流行模式发展;并且遗传多样性使金黄色葡萄球菌表面抗原异质化,导致金黄色葡萄球菌性奶牛乳腺炎疫苗的研制较为困难。
To understand the formation and epidemic of bovine methicillin-resistant Staphylococcus au- reus（MRSA） ,the multilocus sequence typing（MLST） data of bovine S. aureus,bovine MRSA and human MRSA strains was analyzed by the EBURS software. The result showed mecA＋ MRSA strains isolated from other countries were in CC97（ST1623,ST1624）,CC5（ST5）,CC59（ST87）,CC509（ST89） and singletons（ST1622and STST1625）. And the EBURST analysis also showed that more than half of bovine S. aureus strains belonged to smaller and different CCs. Additionally,the MLST profiles of forty-five strains isolated in China by our laboratory showed 6 mecA＋ MRSA strains distributed in 97,5,6 and 9 clone complexes（CCs） ,6 MSSA strains were in CC97 also,and 28 mecA- MRSA strains were found in Xinjiang and the sequence type（ST） were ST121,120,398,97,2154,25,20 and 938. The conclusion is that the generation of bovine MRSA which reported in MLST database depends on migration of SCCmec to MSSA which belongs to different CCs. However,the bovine MRSA was still at early stage of pandemic and the strains did not spread widely regarding to human MRSA strains which now are regional epidemic caused by rapid diffusion, but the epidemic model of human MRSA would be repeated by bovine MRSA. Additionally, genetic diversity of bovine S. aureus was indicated by the EBURST analysis, suggesting that the surface antigens are heterogeneous,which makes it difficult to develop a vaccine against bovine mastitis caused by S. aureus.
出处
《中国兽医科学》
CAS
CSCD
北大核心
2013年第4期331-338,共8页
Chinese Veterinary Science
基金
新疆维吾尔自治区自然科学基金项目(2010211B32)
公益性行业(农业)科研专项(201103008)
