儿童肺炎链球菌血清型分布及其对抗菌药物的耐药性

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolated from the children in Shanghai

目的了解上海交通大学附属儿童医院临床分离的肺炎链球菌血清型分布和对抗菌药物的耐药状况,为控制耐药菌株的播散和疫苗免疫预防的可行性提供参考依据。方法 2007年10月—2008年5月该院就诊患儿咽喉部分泌物中分离的肺炎链球菌株。采用荚膜肿胀试验进行血清型分析,E试验法检测菌株对8种抗菌药物的敏感性。结果临床共分离到338株肺炎链球菌,主要血清型依次为19F 138株(41.0%)、19A 67株(19.8%)、14型30株(8.9%)、23F 14株(4.1%)、6B 13株(3.8%)、6A 12株(3.6%)和15B 10株(3.0%)。在青霉素不敏感菌株(PNSP)和红霉素耐药株(ERSP)中多价疫苗(PCV7)的覆盖率分别为41.9%(26/62)和59.6%(198/332),PCV13的覆盖率分别为72.6%(45/62)和84.9%(282/332)。青霉素不敏感肺炎链球菌(PNSP)的血清型主要集中在19F、19A和未能分型株。除未能分型株之外,血清型的分布在2岁以下婴幼儿和2～5岁儿童之间没有显著差异。338株肺炎链球菌中,青霉素敏感株(PSSP)占81.7%(267/338),青霉素中介株(PISP)占10.9%(37/338),青霉素耐药株(PRSP)占7.4%(25/338)。19F和19A型的PNSP(PISP+PRSP)对阿莫西林-克拉维酸、头孢曲松的耐药率显著高于PSSP(P<0.01)。未能分型株的PNSP对阿莫西林-克拉维酸、头孢曲松以及头孢呋辛的耐药率显著高于PSSP(P<0.01)。结论该院临床分离的肺炎链球菌最常见血清型为19F、19A、14、23F、6B和6A,PCV13能覆盖多数PNSP和ERSP,应用该疫苗应能有效地预防儿童肺炎链球菌的感染和控制耐药菌株传播。

Objective To investigate the serotype distribution and antimicrobial resistance of S.pneumoniae isolated from the children in shanghai,and evaluate the significance of conjugated vaccine for preventing infection and controlling resistance.Methods A total of 338 S.pneumoniae strains were isolated from the children treated in Shanghai Children＇s Hospital during October 2007 and May 2008.Capsular typing was performed by Quellung reaction.Antimicrobial susceptibility was determined by E-test method.Results The common serotypes of these S.pneumoniae strains were 19F（138,41.0 %）,19A（67,19.8%）,14（30,8.9 %）,23F（14,4.1 %）,6B（13,3.8%）,6A（12,3.6%） and 15B（10,3.0%）.PCV7 vaccine was expected to cover 41.9%（26/62） of the penicillin non-susceptible S.pneumoniae（PNSP） and 59.6%（198/332） of macrolide resistant S.pneumoniae（ERSP） strains.PCV13 vaccine could cover 72.6%（45/62） of PNSP and 84.9%（282/332） of ERSP strains.Antibiotic susceptibility testing showed that 81.7%（267/338） of these S.pneumoniae strains were susceptible to penicillin（PSSP）,10.9%（37/338） intermediate（PISP）,and only 7.9%（25/338） resistant（PRSP）.As for 19F and 19A groups,PNSP strains were more resistant to amoxicillin-clavulanic acid and ceftriaxone than PSSP strains（P0.01）.In the nontypable group,PNSP strains were more resistant to amoxicillin-clavulanic acid,ceftriaxone and cefuroxime sodium than PSSP strains（P0.01）.Conclusions Serotypes 19F,19A,14,23F,6B and 6A were the common types of S.pneumoniae strains in Shanghai.PCV13 could cover most of the PNSP and ERSP strains,suggesting its preventive effect on pneumococcal infection and spread of antimicrobial resistance.