Hypervirulent clade 2, ribotype 019/sequence type 67 Clostridioides difficile strain from Japan

Abstract

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.