北京地区上呼吸道感染儿童青霉素不敏感肺炎链球菌的血清型分布研究

The serotype distribution of penicillin-nonsusceptible streptococcus pneumoniae isolated from children with upper respiratory tract infection in Beijing

目的了解青霉素不敏感肺炎链球菌(PNSP)的耐药性和血清型分布。方法以2000～2004年门诊上呼吸道感染的0～5岁患儿鼻咽部分离的肺炎链球菌为研究菌株,采用E-test法检测青霉素最低抑菌浓度,简易棋盘式分型系统进行血清分型。结果检出PNSP菌株129株,其中中介102株,耐药27株;2000～2004年各年耐药株占PNSP比率分别为19.0%、8.0%、17.6%、30.0%和26.1%;常见血清型共有124株(96.1%),为19群、23群、不能分型、6群和14型;7价结合疫苗覆盖率从2000年到2004年分别为57.1%、76.0%、88.2%、75.0%和82.6%。结论北京儿童中分离的PNSP的青霉素耐药性有所增强;7价结合疫苗覆盖率升高,有利于应用疫苗来预防PNSP的携带、感染及耐药性的进一步播散。

Objectives To investigate the serotype epidemiology of penicillin-nonsusceptible streptococcus pneumoniae （PNSP） in children with upper respiratory tract infection in Beijing. Methods The PNSP strains were isolated from children aged 0 ～ 5 years with upper respiratory tract infection from 2000～ 2004. E-test was used to determine the penicillin susceptibility. The serotype was determined by simplified checkerboard system. Results One hundred and twenty-nine PNSP strains were collected, 102 strains of which were intermediate type （79.1%） while 27 were resistant type （20.9%） . The prevalence of resistant strains in PNSP in each year were 19.0%, 8.0%, 17.6%, 30.0% and 26.1% from year 2000 ～ 2004. Seven serotypes were identified, which covered 104 strains （80.6%）. The other 25 strains cannot be typed. One hundred and twenty-four strains were classified as the serotype 19, 23, nontypable, 6 and 14. The number of strains with serotype 19, 6 and 14 increased while serotype 23 decreased from 2000 ～ 2004. The covering rates of the heptavalent conjugate vaccine were 57.1%, 76%, 88.2%, 75.0%, and 82.6% in the each year from 2000 ～2004. Conclusions The penicillin resistance of PNSP isolated from children in Beijing has increased from 2000 to 2004. The elevated covering rate of the heptavalent conjugate vaccine prompts us to control the carriage, infection and transmission of PNSP.