Sequence data from ST801-related outbreak isolates from Norway (n = 17), Finland (n = 11) and Northern Ireland (n = 2) were combined with invasive pneumococcal disease surveillance from the respective countries, and ST801-related genomes from an international collection (n = 41 of > 40,000), totalling 106 genomes. Raw data were mapped and recombination excluded before phylogenetic dating.
Outbreak isolates were relatively diverse, with up to 100 SNPs (single nucleotide polymorphisms) and a common ancestor estimated around the year 2000. However, 19 Norwegian and Finnish isolates were nearly indistinguishable (0-2 SNPs) with the common ancestor dated around 2017.
The total diversity of ST801 within the outbreaks could not be explained by recent transmission alone, suggesting that harsh environmental and associated living conditions reported in the shipyards may facilitate invasion of colonising pneumococci. However, near identical strains in the Norwegian and Finnish outbreaks does suggest that transmission between international shipyards also contributed to those outbreaks. This indicates the need for improved preventative measures in this working population including pneumococcal vaccination.
来自挪威的ST801相关爆发分离株的序列数据(n=17),芬兰(n=11)和北爱尔兰(n=2)结合了来自各自国家的侵袭性肺炎球菌疾病监测,和来自国际集合的ST801相关基因组(n=41,共>40,000),共有106个基因组。在系统发育测年之前,绘制了原始数据并排除了重组。
疫情分离株相对不同,具有多达100个SNP(单核苷酸多态性)和大约2000年估计的共同祖先。然而,19个挪威和芬兰的分离株几乎无法区分(0-2个SNP),其共同祖先可追溯到2017年左右。
疫情中ST801的总多样性不能仅仅用最近的传播来解释,这表明造船厂报告的恶劣环境和相关生活条件可能会促进定殖肺炎球菌的入侵。然而,挪威和芬兰爆发的几乎相同的菌株确实表明,国际造船厂之间的传播也导致了这些爆发。这表明在该工作人群中需要改进的预防措施,包括肺炎球菌疫苗接种。