中文摘要：

目的寻找金黄色葡萄球菌基因组进化相关的关键基因。方法利用含有2457个金黄色葡萄球菌基因的比较基因组芯片对23株不同时间、不同地点分离的ST239-spat037和ST239-spat030的甲氧西林耐药的金黄色葡萄球菌（methieillin-resistant S.aureus，MRSA）进行比较基因组分析，鉴定差异区段，并利用PCR验证差异基因。结果通过对北京地区MRSA早期克隆（ST239-spat037，1994-1998年）和晚期克隆（ST239-spa t030，2000-2006年）的比较基因组分析，发现4个基因簇仅存在于晚期克隆，主要定位于3个已知的基因组岛（vSa4，前噬菌体ФSal和ФSa3）。不同地区的ST239-spa t030MRSA的比较基因组分析发现：在不同地区的菌株中有8个基因存在差异。结论北京地区MRSA从t037进化到t030的过程中获得3个基因组岛（vSa4、前噬菌体ФSal和ФSa3），从而增强了ST239-spat030MRSA的毒力和适应性，对其取代ST239-spa t037MRSA发挥关键作用。

英文摘要：

Objective To identify critical genes in evolution of Staphylococcus aureus （S. au- reus）. Methods A total of 2457 genes from two whole genomes of S. aureus strains were amplified for fab- ricating whole genome microarray, which was employed for comparative genome hybridization （CGH） analy- sis of 23 strains of divergent MRSA clones, including ST239-spa t037 and ST239-spa t030. Representatives of differential genes were confirmed by PCR. Results Four gene clusters were identified to be associated with evolution of major epidemic MRSA clones. The four gene clusters were specific to ST239-spa t030, and belonged to three known genomic islands （vSa4, prophage ФPSal and ФSa3 ）. Eight genes were variable ex- pressed in ST239-spa t030 MRSA from different coutries. Conclusion The acquisition of genomic islands vSa4, prophage ФSal and ФPSa3 enhanced the virulence and resistance of ST239-spa t030 MRSA, and con- tributed to its rapid replacement of ST239-spa t037 MRSA in China.