Global population structure and phase variation of serotype 12F Streptococcus pneumoniae following the introduction of pneumococcal conjugate vaccine

作者：Thi N M Huynh, Alannah C. King, Jason Chen Qixiang, Kathryn Mulvihill, Hayley Demetriou, Kate C. Mellor, Rebecca A. Gladstone, Gemma G. R. Murray, Oliver Lorenz, Harry C. H. Hung, Teodora Mateeva, Sonu Shrestha, Sarah Kelly, A J Pollard, Shrijana Shrestha, John A. Lees, Samuel Horsfield, Feroze Ganaie, Sam Manna, Catherine Satzke, Lesley McGee, Chris Lok To Sham, David Goldblatt, Stephen D Bentley, Stephanie W Lo · 发表于：bioRxiv (Cold Spring Harbor Laboratory) · 年份：2026 · DOI：10.64898/2026.04.03.714713 · 被引用次数：1 · 研究领域：Pneumonia and Respiratory Infections、Tuberculosis Research and Epidemiology、Respiratory viral infections research

Abstract Background After the global deployment of pneumococcal conjugate vaccines (PCVs), serotype 12F has become the predominant serotype responsible for invasive pneumococcal disease (IPD) worldwide. As PCVs that include serotype 12F are gradually introduced, we aim to characterise the global population structure and genetic diversity of the 12F capsule locus using whole-genome sequencing. Capsule variants with vaccine evasion potential were further investigated by functional experiments. Methods A global collection of pneumococcal serotype 12F genomes (n=806) from 37 countries across six continents were included in this study. To characterise the serotype 12F population, Global Pneumococcal Sequence Cluster (GPSC), in silico serotype, and antimicrobial resistance profile were inferred from whole-genome data for each isolate. The capsule biosynthesis ( cps ) locus was analysed for gene content variations that could alter polysaccharide capsule production or structure, thereby influencing recognition by vaccine-induced antibodies. These isolates were further investigated by assessing their capsule production using immunofluorescence assays and its susceptibility to vaccine-elicited antibody killing by opsonophagocytosis assays. Findings The global increase in serotype 12F was driven by both distinct pneumococcal lineages across different continents, and a globally-disseminated and multidrug-resistant lineage GPSC26. We identified six capsule variants in nine isolates that h...