Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.
Pediatric Infectious Disease Unit, Soroka University Medical Center, Beer Sheva, Israel.
Clin Infect Dis. 2021 Dec 6;73(11):e3768-e3777. doi: 10.1093/cid/ciaa1720.
Invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae serotype 2 (Sp2) is infrequent. Large-scale outbreaks were not been reported following pneumococcal conjugate vaccine (PCV) implementation. We describe a Sp2 IPD outbreak in Israel, in the PCV13 era, with focus on Sp2 population structure and evolutionary dynamics.
The data were derived from a population-based, nationwide active surveillance of IPD since 2009. PCV7/PCV13 vaccines were introduced in July 2009 and November 2010, respectively. Sp2 isolates were tested for antimicrobial susceptibility, multilocus sequence typing, and whole-genome sequencing (WGS) analysis.
Overall, 170 Sp2 IPD cases were identified during 2009-2019; Sp2 increased in 2015 and caused 6% of IPD during 2015-2019, a 7-fold increase compared with 2009-2014. The outbreak was caused by a previously unreported molecular type (ST-13578), initially observed in Israel in 2014. This clone caused 88% of Sp2 during 2015-2019. ST-13578 is a single-locus variant of ST-1504, previously reported globally including in Israel. WGS analysis confirmed clonality among the ST-13578 population. Single-nucleotide polymorphism-dense regions support a hypothesis that the ST-13578 outbreak clone evolved from ST-1504 by recombination. All tested strains were penicillin-susceptible (minimum inhibitory concentration <0.06 μg/mL). The ST-13578 clone was identified almost exclusively (99%) in the Jewish population and was mainly distributed in 3 of 7 Israeli districts. The outbreak is still ongoing, although it began declining in 2017.
To the best of our knowledge, this is the first widespread Sp2 outbreak since PCV13 introduction worldwide, caused by the emerging ST-13578 clone.
由肺炎链球菌血清型 2（Sp2）引起的侵袭性肺炎球菌病（IPD）并不常见。在实施肺炎球菌结合疫苗（PCV）后，并未报告大规模爆发。我们描述了以色列在 PCV13 时代 Sp2 IPD 爆发的情况，重点关注 Sp2 人群结构和进化动态。
该数据源自 2009 年以来基于人群的全国性 IPD 主动监测。PCV7/PCV13 疫苗分别于 2009 年 7 月和 2010 年 11 月推出。对 Sp2 分离株进行了抗生素敏感性、多位点序列分型和全基因组测序（WGS）分析。
总体而言，在 2009-2019 年间发现了 170 例 Sp2 IPD 病例；Sp2 在 2015 年增加，并导致 2015-2019 年期间 6%的 IPD，与 2009-2014 年相比增加了 7 倍。此次爆发是由一种以前未报告的分子型（ST-13578）引起的，该型于 2014 年首次在以色列发现。该克隆在 2015-2019 年期间导致 88%的 Sp2。ST-13578 是先前在全球（包括以色列）报道的 ST-1504 的单一位点变异。WGS 分析证实了 ST-13578 人群中的克隆性。单核苷酸多态性密集区支持了一个假设，即 ST-13578 爆发克隆是由 ST-1504 通过重组进化而来的。所有测试菌株对青霉素均敏感（最小抑菌浓度<0.06μg/ml）。ST-13578 克隆几乎仅在犹太人群中被鉴定（99%），主要分布在以色列 7 个区中的 3 个区。尽管该爆发始于 2017 年开始下降，但仍在继续。
据我们所知，这是全球范围内自 PCV13 推出以来首次广泛发生的 Sp2 爆发，由新兴的 ST-13578 克隆引起。
