2010-2011年中国肺炎链球菌耐药性和血清型研究

Antimicrobial resistance and serotype distribution of Streptococcus pneumoniae isolated from multicenters across China,2010--2011

目的了解我国肺炎链球菌的耐药性和血清型分布，为合理使用抗生素和免疫预防提供依据。方法收集2010-2011年我国10个城市13家医院临床分离的非重复性肺炎链球菌471株，采用琼脂稀释法测定15种抗生素的MIC值；采用简易棋盘式肺炎链球菌分型系统和荚膜肿胀实验进行血清型鉴定。结果全部菌株中对青霉素耐药（口服折点，MIC〉t2mg／L）的肺炎链球菌（PRSP）占50．1％（236／471）。对左氧氟沙星和莫西沙星的耐药率分别为1．5％（7／471）和0．6％（3／471）。对阿莫西彬克拉维酸、头孢克洛、头孢呋辛和头孢曲松4种β-内酰胺类药物的耐药率分别为27．4％（129／471）、60．3％（284／471）、58．8％（277／471）和18．5％（87／471）。对红霉素、克林霉素、四环素、磺胺甲嗯唑／甲氧苄啶和氯霉素的耐药率分别为93．2％（439／471）、88．7％（417／471）、89．6％（422／471）、62．8％（296／471）和22．1％（104／471）。471株肺炎链球菌中常见的血清型依次为19F（112，23．8％）、19A（63，13．4％）、3（48，10．2％）、14（43，9．1％）、23F（29，6．2％）、15（25，5．3％）及6A（23，4．9％）。19F与19A血清型中PRSP感染的发生率高达82．1％（100／122）和92．1％（58／63）。7价和13价结合疫苗对所有菌株的覆盖率分别为45．3％（213／471）和76．0％（358／471）。儿童中7价和13价结合疫苗的覆盖率为59．0％（72／122）和86．9％（106／122），成人中为42．3％（94／222）和73．4％（163／222）。结论肺炎链球菌对红霉素、克林霉素及四环素耐药严重。血清型19A和19F耐药严重。7价和13价结合疫苗在儿童中的覆盖率均高于成人。13价结合疫苗可覆盖大部分菌株，特别是PRSP。

Objective To investigate the trends of resistance of S. pneumoniae and to evaluate the potential coverage of pneumococcal conjugate vaccine. Methods The antibiotic susceptibility and serotype distribution of 471 pneumococcal strains isolated from pneumococcal diseases in 13 hospitals across China during 2010 to 2011 were studied. In vitro susceptibility to 15 antimicrobial agents was determined by agar dilution method. Serotyping of S. pneumoniae was performed by using latex and quelling reaction. Vaccine coverage by 7-, 10-, 13-and 23- valent conjugate vaccines was estimated by calculating the percentage of isolates that belonged to the serotypes included in the vaccines. Results Among all strains tested, 50. 1% （236/471） was resistant to penicillin （ Oral breakpoint, MIC 〉1 2 mg/L） . Overall, 27.4% （ 129/471 ） , 60. 3% （284/471）, 58.8% （277/471） and 18.5% （87/471） of S. pneumoniae were resistant to amoxicillin/elavulanate, cefaclor, eefuroxime and eeftriaxone, respectively. 1.5 % （7/471） of all stains were resistant to levofloxaein and 0. 6% （3/471） of all strains were resistant to moxifloxacin. The resistance rates to other antibiotic agents, such as erythromycin, clindamycin, tetracycline, trimethoprim/sulfamethoxazole, and chloramphenicol, were 93.2% （ 439/471 ）, 88.7% （417/471）, 89.6% （ 422/471 ）, 62. 8% （296/471） and 22. 1% （ 104/471 ）, respectively. The most prevalent serotype was 19F（ 112,23.8% ）, followed by 19A（63,13.4% ）, 3（48,10. 2% ）, 14（43,9. 1% ）, 23F（29,6.2% ）, 15（25,5.3% ）and 6A （23,4. 9% ）. The potential coverage by 7- and 13-valent pneumococcal conjugate vaccines was 45.3%（213/471） and 76% （358/471）, respectively. The potential coverage of PCV7 and PCV13 in children were 59.0% （72/122） and 86. 9% （106/122）, and the potential coverage of PCV7 and PCV13 in adult were 42. 3% （94/222） and 73.4% （163/222）. Conclusions The antibiotic resistance of S. pneumoniae was serious in China, especially to tetracycline, erythromycin and clindamycin. The majority of serotypes 19A and 19F was penicillin-resistant. The potential coverage of PCV7 and PCV13 in children was higher than those in adult. PCV13 could cover most of the isolates, especially for penicillin-resistant S. pneumoniae.