Department of Bacteriology, National Institute of Infectious Diseases, Tokyo, Japan.
Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan.
J Med Microbiol. 2022 Mar;71(3). doi: 10.1099/jmm.0.001504.
Only approximately 40 cases of invasive meningococcal diseases are reported annually in Japan, and the dominant strains are serogroup Y meningococci (MenY) followed by serogroup B meningococci (MenB). Within the last 10 years, strains belonging to clonal complex (cc)2057 have become dominant among Japanese MenB and have not been identified in countries other than Japan. The uniqueness of cc2057 strains was considered to be epidemiologically of importance, and some genetic features could be hidden in the genome of cc2057 meningococci. We investigated 22 cc2057 MenB and one cc2057 MenY using whole genome sequencing (WGS) and also predicted the potential coverage of 4CMenB and bivalent rLP2086 vaccines . cc2057 strains were phylogenetically assigned to two clades. Three hypothetical genes homologous to those in and sequences related to a new CRISPR Cas9 system were found only in the genome of cc2057 strains. Moreover, one cc2057 MenY strain was presumed to be capsular-switched at the capsule synthesis () locus. The potential coverage of 4CMenB and rLP2086 for cc2057 MenB strains was estimated to be very low. To the best of our knowledge, this is the first study to provide genetic insights from epidemiologically unique cc2057 strains isolated only in Japan, an island country.
在日本，每年报告的侵袭性脑膜炎球菌病病例约为 40 例，优势菌株为血清群 Y 脑膜炎球菌（MenY），其次是血清群 B 脑膜炎球菌（MenB）。在过去的 10 年中，属于克隆复合体（cc）2057 的菌株已成为日本 MenB 的优势菌株，并且在日本以外的国家尚未发现。cc2057 菌株的独特性被认为在流行病学上很重要，一些遗传特征可能隐藏在 cc2057 脑膜炎球菌的基因组中。我们使用全基因组测序（WGS）对 22 株 cc2057 MenB 和 1 株 cc2057 MenY 进行了研究，并预测了 4CMenB 和双价 rLP2086 疫苗的潜在覆盖范围。cc2057 菌株在系统发育上被分为两个分支。在 cc2057 菌株的基因组中发现了三个与和序列相关的、与新的 CRISPR Cas9 系统同源的假定基因。此外，一种 cc2057 MenY 菌株被推测在荚膜合成（）基因座发生了荚膜转换。cc2057 MenB 菌株对 4CMenB 和 rLP2086 的潜在覆盖率估计非常低。据我们所知，这是首次对仅在日本这个岛国分离的具有流行病学独特性的 cc2057 菌株进行遗传分析的研究。
