2010-2011年中国10个主要城市金黄色葡萄球菌分子流行病学研究

Molecular epidemiology of Staphylococcus aureus in 10 main cities of China from 2010 to 2011

目的了解我国10个主要城市金黄色葡萄球菌近两年耐药情况及其分子流行病学。方法共收集2010到2011全国10个城市12所教学综合医院的507株非重复金黄色葡萄球菌，所有菌株进行20种药物敏感性检测及其spa分子分型分析。结果甲氧西林耐药的金黄色葡萄球菌（MRSA）的流行率是52．9％（268／507），多重耐药率高达97．4％（261／268），而甲氧西林敏感金黄色葡萄球菌（MSSA）的多重耐药率是26．8％（64／239），主要见于spa—t796（23．4％，15／64）。MRSA中共有34种spa分型，主要是MRSAspa-t030、spa—t037、spa．t002、spa-t570、spa．t437、spa．t311。MSSA中共有58种spa分型，常见spa分型为spa—t701、spa—t189、spa—ff96、spa—t091、spa—t571。spa分型具有独特的地理分布差异，其中北京、西安、武汉、天津、重庆主要是spa-t030，而广州以spa加37为主，上海主要是spa加37和spa-t002，杭州和沈阳分别以spa—B11和spa-t570为主。值得注意的是，万古霉素MIC≥1mg／L主要见于spa-t037、spa-t570、spa-if01（P〈0．05），spa—t030同利福平耐药相关（P〈0．001），而同其他克隆相比，spa-t437主要表现为低水平苯唑西林耐药（P〈0．001）。结论spa分型具有独特的地理分布差异，主要spa分型与特殊耐药表型相关，提示临床用药要注：意这些特殊表型。

Objective To investigate the molecular epidemiology of Staphylococcus aureus through analyzing the antibiotic resistance and genotypes of the isolates collected from 10 main cities of China from 2010 to 2011. Methods A total of 507 consecutive and non-duplicate S. aureus isolates were collected from 12 hospitals of 10 cities in China. Antibiotic susceptibility test for 20 antibiotics and spa typing were carried out on all isolates. Results The prevalence of methicillin-resistant S. aureus （MRSA） was 52.9% （268/507）. 97.4% （261/268） of those isolates were multidrug resistance. Among all methicillin-sensitive S. aureus （MSSA） isolates, multidrug resistant rate was 26.8% （64/239）, in which spa-t796 phenotype accounted for 23.4% （15/64）. Thirty-four spa types were identified among MRSA, of which the major clones were spa-t030, spa-t037, spa-t002, spa-t570, spa-t437 and spa-t311. Fifty-eight spa types were de- tected among MSSA, of which spa-t701, spa-t189, spa-t796, spa-t091 and spa-t571 were the major strains. The geographical distribution of these strains varied significantly. The strains with spa-t030 phenotype was more commonly distributed in Beijing, Xi＇an, Wuhan, Tianjin and Chongqing. The spa-037 and spa-tO02 were the dominant strains in Shanghai, while spa-t037, spa-t311 and spa-t570 were prevalent strains in Guangzhou, Hangzhou and Shenyang respectively. Notably, the strains with vancomycin MIC greater than or equal to 1 mg/L were largely detected in spa-t037, spa-t570 and spa-t701 （P〈O. 05）. However, rifampicin resistance was overwhelmingly associated with spa-t030 （P〈0. 001 ）. The oxacillin MICa were relatively low in the strains of spa-t437 as compared with other clones （P〈0. 001 ）. Contusion The spa types possessed a feature of distinctive geographical distribution. The major spa types were associated with specific antimicro- bial resistance, suggesting more attention should be paid to the phenotypes of bacterial strains for the treatment purpose in clinic.