Emerg Infect Dis. 2018 Feb;24(2):275-283. doi: 10.3201/eid2402.171268.
After the introduction of pneumococcal conjugate vaccines, the incidence of pneumococcal infections due to meropenem-resistant serotype 15A-ST63 strains increased in Japan. By using whole-genome sequencing and comparing sequences with those of clones from the United Kingdom, the United States, and Canada, we clarified the traits of the serotype 15A-ST63 clone. Our analysis revealed that the meropenem-resistant serotype 15A-ST63 strains from Japan originated from meropenem-susceptible strains from Japan. Recombination site prediction analysis showed that the meropenem-resistant strain-specific recombination regions included the pbp1a and pbp2b regions. A detailed analysis of the composition of these genes indicated that resistance seems to be caused by pbp1a recombination. The pbp1a gene in meropenem-resistant isolates was identical to that in multidrug (including meropenem)-resistant serotype 19A-ST320 pneumococci, which have spread in the United States. The global spread of pneumococci of this lineage is noteworthy because serotype 15A is not included in the currently used 13-valent pneumococcal conjugate vaccine.
在肺炎球菌结合疫苗问世后，日本耐美罗培南血清型 15A-ST63 菌株引起的肺炎球菌感染发生率有所增加。通过使用全基因组测序并将序列与来自英国、美国和加拿大的克隆序列进行比较，我们阐明了血清型 15A-ST63 克隆的特征。我们的分析表明，日本的耐美罗培南血清型 15A-ST63 菌株源自日本的美罗培南敏感菌株。重组位点预测分析显示，耐美罗培南菌株特异性重组区域包括 pbp1a 和 pbp2b 区域。对这些基因组成的详细分析表明，耐药性似乎是由 pbp1a 重组引起的。耐美罗培南分离株中的 pbp1a 基因与已在美国传播的多药（包括美罗培南）耐药血清型 19A-ST320 肺炎球菌中的 pbp1a 基因相同。值得注意的是，这种谱系的肺炎球菌在全球传播，因为目前使用的 13 价肺炎球菌结合疫苗不包括血清型 15A。
