Shin Jeong-Ih, Cho Sung-Yeon, Chu Jiyon, Park Chulmin, Lee Minho, Song Joon Young, Jung Seung-Hyun, Lee Dong-Gun
Department of Medical Sciences, Graduate School of The Catholic University of Korea, Seoul, Republic of Korea.
Catholic Research Institute for Human Genome Polymorphism, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Microb Genom. 2025 Jul;11(7). doi: 10.1099/mgen.0.001433.
, a clinically significant pathogen, causes invasive diseases in children and older adults. Pneumococcal conjugate vaccines (PCVs) have substantially reduced the incidence of vaccine serotype (VT) pneumococcal diseases. However, serotype replacement, characterized by the emergence of non-vaccine serotypes (NVTs), presents a persistent challenge to disease prevention. To address this, we analysed 236 pneumococcal isolates collected in South Korea between 1997 and 2023, spanning both pre- and post-PCV13 periods. Whole-genome sequencing was performed to assess serotypes, antimicrobial resistance, virulence factors and global pneumococcal sequence clusters (GPSCs). Capsular switching events and the relationships among pneumococcal lineages, serotypes and disease invasiveness were also evaluated. Among the 37 identified serotypes, NVTs such as 23A, 15B/15C and 10A were dominant post-PCV13. Serotype 10A, associated with invasive pneumococcal diseases (IPDs), belonged to GPSC634-ST11189 and showed elevated minimum inhibitory concentrations for -lactams. Capsular switching events were observed between VTs and NVTs, highlighting the adaptability of pneumococcal populations. Antimicrobial non-susceptibility was highest for azithromycin (82.7%), followed by tetracycline (76.5%) and co-trimoxazole (70.4%), with higher rates observed in the post-PCV13 period. Notably, amoxicillin (=0.049) and meropenem (=0.002) showed significant non-susceptibility in the post-PCV13 period. Virulence factors and were associated with IPDs, while pilus islet PI-1-related genes were more frequent in non-invasive cases. These findings underscore the importance of genomic surveillance to monitor pneumococcal population dynamics and inform public health strategies. The inclusion of serotype 10A in the recently approved PCV20 offers promise for further reducing the global burden of IPDs, including in South Korea.
作为一种具有临床意义的病原体，可导致儿童和老年人发生侵袭性疾病。肺炎球菌结合疫苗（PCV）已大幅降低了疫苗血清型（VT）肺炎球菌疾病的发病率。然而，以非疫苗血清型（NVT）出现为特征的血清型替换，对疾病预防构成了持续挑战。为应对这一问题，我们分析了1997年至2023年在韩国收集的236株肺炎球菌分离株，涵盖了PCV13接种前后两个时期。进行全基因组测序以评估血清型、抗菌药物耐药性、毒力因子和全球肺炎球菌序列簇（GPSC）。还评估了荚膜转换事件以及肺炎球菌谱系、血清型和疾病侵袭性之间的关系。在鉴定出的37种血清型中，23A、15B/15C和10A等NVT在PCV13接种后占主导地位。与侵袭性肺炎球菌疾病（IPD）相关的血清型10A属于GPSC634-ST11189，对β-内酰胺类药物的最低抑菌浓度升高。在VT和NVT之间观察到荚膜转换事件，突出了肺炎球菌群体的适应性。阿奇霉素的抗菌药物不敏感性最高（82.7%），其次是四环素（76.5%）和复方新诺明（70.4%），在PCV13接种后时期的发生率更高。值得注意的是，阿莫西林（P = 0.049）和美罗培南（P = 0.002）在PCV13接种后时期显示出显著的不敏感性。毒力因子和与IPD相关，而菌毛岛PI-1相关基因在非侵袭性病例中更为常见。这些发现强调了基因组监测对于监测肺炎球菌群体动态和为公共卫生策略提供信息的重要性。最近批准的PCV20中包含血清型10A有望进一步降低包括韩国在内的全球IPD负担。
