Background Clostridioides difficile ribotype (RT) 019/sequence type (ST) 67 strains belong to a hypervirulent lineage closely related to RT027/ST1; however, limited data are available for hypervirulent clade 2 lineages in Japan. Herein, we report the draft genome of a C. difficile strain B18-123 belonging to clade 2, RT019/ST67 for the first time in Japan. Results The pathogenicity locus carried by B18-123 (19.6 kb) showed higher homology (97.29% nucleotide identity) with strain R20291 (RT027/ST1) than the reference strain 630 (RT012/ST54), and B18-123 harbored 8-nucleotide substitutions in tcdC. However, it did not contain an 18-base pair (bp) deletion or a single-bp deletion at position 117 in tcdC, which was identified in the previous strain R20291. A cytotoxicity assay revealed similar cytotoxicity levels between strains B18-123 and ATCC BAA-1870 (RT027/ST1). The B18-123 strain was found to be susceptible to metronidazole and vancomycin. Conclusion Our findings contribute to the further understanding of the characteristics of hypervirulent clade 2 including RT019/ST67 lineages.

中文翻译：

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来自日本的高毒性进化枝 2，核糖型 019/序列 67 型艰难梭菌菌株。

背景艰难梭菌核糖型（RT）019/序列型（ST）67株属于与RT027/ST1密切相关的高毒性谱系；然而，日本的高毒性进化枝 2 谱系的数据有限。在此，我们首次在日本报告属于进化枝 2、RT019/ST67 的艰难梭菌菌株 B18-123 的基因组草图。结果 B18-123 (19.6 kb) 携带的致病性位点与菌株 R20291 (RT027/ST1) 比参考菌株 630 (RT012/ST54) 具有更高的同源性 (97.29% 核苷酸同一性)，并且 B18-123 具有 8 个核苷酸取代在 tcdC 中。然而，它在 tcdC 中的第 117 位不包含 18 个碱基对 (bp) 缺失或单 bp 缺失，这在之前的菌株 R20291 中被鉴定。细胞毒性测定显示菌株 B18-123 和 ATCC BAA-1870 (RT027/ST1) 之间的细胞毒性水平相似。发现 B18-123 菌株对甲硝唑和万古霉素敏感。结论 我们的研究结果有助于进一步了解包括 RT019/ST67 谱系在内的高毒性进化枝 2 的特征。