Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China.
Department of Laboratory, Liuzhou Maternity and Child Healthcare Hospital, Liuzhou, China.
Vaccine. 2018 Jan 29;36(5):599-605. doi: 10.1016/j.vaccine.2017.12.063. Epub 2017 Dec 27.
Streptococcus pneumoniae (S. pneumoniae) is an important pathogen in causing global morbidity and mortality among children. This study aimed to determine phenotypic and molecular characteristics of S. pneumoniae causing infections in children under five years in China.
A hospital-based retrospective study was conducted. All 537 S. pneumoniae isolates were tested for antimicrobial susceptibility by E-test method, molecular characteristics including resistance genes, virulence genes and serotypes by multiplex polymerase chain reaction (PCR) method, and sequence types (STs) by sequencing seven housekeeping genes. Minimum spanning tree and correspondence analysis were used to reveal the potential relationship between serotypes and STs.
Most of S. pneumoniae isolates were resistant to erythromycin (93.9%) and tetracycline (86.4%), with the predominant resistance genes being erm(B) (92.6%) and tet(M) (95.5%). The prevalent serotypes were 19F, 6B, 19A, 23F and 14, the coverage rate of PCV13 was high in 85.8%, and the predominant STs were ST271, ST320, ST3173, ST81 and ST876. A significant correlation existed between STs and serotypes, with ST271/19F and ST320/19A as the most prevalent clones. Notably, ST271/19F and ST320/19A isolates were associated with resistance to specific antibiotics and carrying of mef(A/E), rlrA and sipA genes.
Our findings suggest the introduction of PCV13 vaccine to Chinese children, and underscore the value of monitoring multiple characteristics to detect new epidemiologic trends and provide implications for the formulation of multivalent pneumococcal vaccines.
肺炎链球菌（Streptococcus pneumoniae，S. pneumoniae）是导致全球 5 岁以下儿童发病和死亡的重要病原体。本研究旨在确定中国 5 岁以下儿童感染 S. pneumoniae 的表型和分子特征。
本研究采用医院为基础的回顾性研究。采用 E 试验法检测 537 株 S. pneumoniae 分离株的抗菌药物敏感性，采用多重聚合酶链反应（PCR）法检测耐药基因、毒力基因和血清型，采用测序 7 个管家基因的方法检测序列型（ST）。最小生成树和对应分析用于揭示血清型和 ST 之间的潜在关系。
大多数 S. pneumoniae 分离株对红霉素（93.9%）和四环素（86.4%）耐药，主要耐药基因是 erm（B）（92.6%）和 tet（M）（95.5%）。主要血清型为 19F、6B、19A、23F 和 14，PCV13 的覆盖率高达 85.8%，主要 ST 型为 ST271、ST320、ST3173、ST81 和 ST876。ST 与血清型之间存在显著相关性，ST271/19F 和 ST320/19A 是最常见的克隆。值得注意的是，ST271/19F 和 ST320/19A 分离株与特定抗生素耐药和携带 mef（A/E）、rlrA 和 sipA 基因有关。
本研究结果表明，PCV13 疫苗在中国儿童中的应用，强调了监测多种特征以检测新的流行病学趋势的价值，并为制定多价肺炎球菌疫苗提供了依据。
