Liu Chun-Lin, Zhao Chun-Jiang, Liu Yu-Dong, Wang Hui
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
Zhonghua Yi Xue Za Zhi. 2010 Jun 8;90(22):1565-70.
To investigate the serotype distribution, antimicrobial resistance patterns and molecular epidemiology of Streptococcus pneumoniae (S. pneumoniae) isolated from invasive pneumococcal diseases in order to provide rationales for antibiotics application and immunity control of S. pneumoniae.
A total of 148 isolates of invasive S. pneumoniae were collected from blood, cerebrospinal fluid and other sterile body fluids from 15 regions between January 2005 and August 2008 nationwide. Agar dilution method was used to determine the minimal inhibitory concentrations (MICs) of penicillin and other antibiotics against these isolates. Simplified chessboard system and capsule swelling reaction were used for serotyping of S. pneumoniae. Multilocus sequence typing (MLST) was used to determine the genetic relationship of 53 strains of serogroup-19.
Twenty serotypes/serogroups were identified in 148 strains. The prevalent serotypes (70.9%) were 19A, 19F, 3, 23F, 5, 6, 14 and 9 respectively. Serotypes 19A (22.3%, 33/148) and 19F (16.9%, 25/148) were the most frequent type observed. And serotypes 3 (7.4%, 11/148) and 23F (6.8%, 10/148) were less prevalent. Of all 36 strains isolated from infants under 2 years old, 33.3% (12/36) were covered by 7-valent pneumococcal conjugate vaccine (PCV7). The resistant rates to amoxicillin/clavulanic acid, erythromycin and other antibiotics in PCV7-related pneumococcal strains were significantly higher than those in PCV7-unrelated group (P < 0.05). Fifty-three strains of serogroup-19 were genotyped by MLST and 9 sequence types (STs) identified. ST320 (52.8%, 28/53) and ST271 (22.6%, 12/53) were the most frequent STs.
The major serotypes of invasive S. pneumoniae are 19A, 19F, 3 and 23F. Antimicrobial-resistant S. pneumoniae has become a serious issue of public health.
研究从侵袭性肺炎球菌疾病中分离出的肺炎链球菌（S. pneumoniae）的血清型分布、抗菌耐药模式及分子流行病学，为肺炎链球菌的抗生素应用及免疫控制提供依据。
2005年1月至2008年8月期间，从全国15个地区的血液、脑脊液及其他无菌体液中收集了148株侵袭性肺炎链球菌分离株。采用琼脂稀释法测定青霉素及其他抗生素对这些分离株的最低抑菌浓度（MICs）。采用简化棋盘系统和荚膜肿胀反应对肺炎链球菌进行血清分型。采用多位点序列分型（MLST）确定53株19血清群菌株的亲缘关系。
在148株菌株中鉴定出20种血清型/血清群。流行血清型（70.9%）分别为19A、19F、3、23F、5、6、14和9型。19A血清型（22.3%，33/148）和19F血清型（16.9%，25/148）是最常见的血清型。3血清型（7.4%，11/148）和23F血清型（6.8%，10/148）的流行率较低。在所有从2岁以下婴儿分离出的36株菌株中，7价肺炎球菌结合疫苗（PCV7）覆盖了33.3%（12/36）。PCV7相关肺炎球菌菌株对阿莫西林/克拉维酸、红霉素及其他抗生素的耐药率显著高于PCV7不相关组（P < 0.05）。对53株19血清群菌株进行MLST基因分型，鉴定出9种序列型（STs）。ST320（52.8%，28/53）和ST271（22.6%，12/53）是最常见的STs。
侵袭性肺炎链球菌的主要血清型为19A、19F、3和23F。耐抗菌药物的肺炎链球菌已成为一个严重的公共卫生问题。
