Department of Medical Microbiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, 727 McDermot Avenue, Winnipeg, Manitoba R3E 3P5, Canada
Department of Medical Microbiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, 727 McDermot Avenue, Winnipeg, Manitoba R3E 3P5, Canada Clinical Microbiology-Health Sciences Centre, Diagnostic Services Manitoba, MS673-820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9, Canada.
J Antimicrob Chemother. 2015 Jul;70(7):1960-4. doi: 10.1093/jac/dkv061. Epub 2015 Mar 11.
Serotype replacement in Streptococcus pneumoniae following the implementation of a new vaccine has been associated with the emergence of non-vaccine serotypes as prominent causes of invasive pneumococcal disease (IPD). The aim of this study was to characterize specific non-PCV-13 serotypes 15A, 22F, 33F and 35B from IPD, isolated in Canada post-PCV-13 introduction in 2010.
Of 3802 IPD isolates collected from across Canada in 2011-13, 18.4% were found to be serotypes 15A, 22F, 33F and 35B. These 699 isolates were subjected to antimicrobial susceptibility testing, PFGE, MLST, molecular detection of pneumococcal pili and comparison with Pneumococcal Molecular Epidemiology Network (PMEN) clones.
This study demonstrated clonal spread of specific STs, including MDR ST63 and its Sweden(15A)-25-related variants, the increasingly common ST433 and a variant of piliated, penicillin-non-susceptible ST558, related to PMEN clone Utah(35B)-24 (ST377). New STs of serotype 33F were identified. Several potential capsular switching events were identified within these serotypes.
Non-PCV-13 serotype 22F is increasing in Canada through the rapid clonal expansion of ST433. Numerous new STs associated with serotype 33F indicate the potential divergence of the serotype. Serotypes 15A and 35B in Canada are related to international clones of S. pneumoniae.
在接种新型疫苗后，肺炎链球菌血清型转变与非疫苗血清型的出现有关，这些血清型已成为侵袭性肺炎球菌病（IPD）的主要病因。本研究旨在对加拿大在 2010 年引入 PCV-13 后分离出的 IPD 中，6 种非 PCV-13 血清型 15A、22F、33F 和 35B 的特定血清型进行特征描述。
在 2011 年至 2013 年期间，从加拿大各地采集了 3802 株 IPD 分离株，其中 18.4%为血清型 15A、22F、33F 和 35B。对这 699 株分离株进行了抗菌药物敏感性试验、PFGE、MLST、肺炎球菌菌毛分子检测，并与肺炎球菌分子流行病学网络（PMEN）克隆进行了比较。
本研究表明，特定 ST 的克隆传播，包括多药耐药 ST63 及其与瑞典（15A）-25 相关的变体、越来越常见的 ST433 以及与 PMEN 克隆犹他（35B）-24（ST377）相关的、具菌毛、耐青霉素非敏感的 ST558 变体。鉴定出血清型 33F 的新 ST。在这些血清型中还发现了几个潜在的荚膜转换事件。
加拿大非 PCV-13 血清型 22F 正通过 ST433 的快速克隆扩张而增加。与血清型 33F 相关的多个新 ST 表明该血清型可能出现了分化。加拿大的血清型 15A 和 35B 与国际肺炎链球菌克隆有关。
