University of Iceland, Faculty of Medicine, Reykjavík, Iceland.
Landspitali University Hospital, Department of Clinical Microbiology, Reykjavík, Iceland.
J Clin Microbiol. 2018 Nov 27;56(12). doi: 10.1128/JCM.01046-18. Print 2018 Dec.
Vaccination with pneumococcal conjugate vaccines (PCVs) disrupts the pneumococcal population. Our aim was to determine the impact of the 10-valent PCV on the serotypes, genetic lineages, and antimicrobial susceptibility of pneumococci isolated from children in Iceland. Pneumococci were collected between 2009 and 2017 from the nasopharynges of healthy children attending 15 day care centers and from the middle ears (MEs) of children with acute otitis media from the greater Reykjavik capital area. Isolates were serotyped and tested for antimicrobial susceptibility. Whole-genome sequencing (WGS) was performed on alternate isolates from 2009 to 2014, and serotypes and multilocus sequence types (STs) were extracted from the WGS data. Two study periods were defined: 2009 to 2011 (PreVac) and 2012 to 2017 (PostVac). The overall nasopharyngeal carriage rate was similar between the two periods (67.3% PreVac and 61.5% PostVac, = 0.090). Vaccine-type (VT) pneumococci decreased and nonvaccine-type (NVT) pneumococci (serotypes 6C, 15A, 15B/C, 21, 22F, 23A, 23B, 35F, and 35B) significantly increased in different age strata post-PCV introduction. The total number of pneumococci recovered from ME samples significantly decreased as did the proportion that were VTs, although NVT pneumococci (6C, 15B/C, 23A, and 23B) increased significantly. Most serotype 6C pneumococci were multidrug resistant (MDR). Serotype 19F was the predominant serotype associated with MEs, and it significantly decreased post-PCV introduction: these isolates were predominantly MDR and of the Taiwan-14 PMEN lineage. Overall, the nasopharyngeal carriage rate remained constant and the number of ME-associated pneumococci decreased significantly post-PCV introduction; however, there was a concomitant and statistically significant shift from VTs to NVTs in both collections of pneumococci.
接种肺炎球菌结合疫苗（PCV）会破坏肺炎球菌群体。我们的目的是确定 10 价 PCV 对冰岛儿童鼻咽部和急性中耳炎中耳（ME）分离的肺炎球菌血清型、遗传谱系和抗菌药物敏感性的影响。2009 年至 2017 年间，从大雷克雅未克首都地区 15 个日托中心健康儿童的鼻咽部和急性中耳炎儿童的 ME 中采集了肺炎球菌。对分离株进行血清分型和抗菌药物敏感性检测。对 2009 年至 2014 年的交替分离株进行全基因组测序（WGS），并从 WGS 数据中提取血清型和多位点序列类型（ST）。定义了两个研究期：2009 年至 2011 年（PreVac）和 2012 年至 2017 年（PostVac）。两个时期鼻咽部携带率相似（PreVac 为 67.3%，PostVac 为 61.5%，= 0.090）。疫苗型（VT）肺炎球菌减少，非疫苗型（NVT）肺炎球菌（血清型 6C、15A、15B/C、21、22F、23A、23B、35F 和 35B）在 PCV 引入后不同年龄层显著增加。从 ME 样本中回收的肺炎球菌总数以及 VT 比例均显著减少，尽管 NVT 肺炎球菌（6C、15B/C、23A 和 23B）显著增加。大多数血清型 6C 肺炎球菌为多药耐药（MDR）。血清型 19F 是与 ME 相关的主要血清型，PCV 引入后显著减少：这些分离株主要为 MDR，且属于台湾 14 型 PMEN 谱系。总体而言，鼻咽部携带率保持不变，PCV 引入后 ME 相关肺炎球菌数量显著减少；然而，在这两个肺炎球菌分离株中，VT 向 NVT 的转变同时发生且具有统计学意义。
