Emergence of clinical isolates of and from Japan harbouring an acquired gene encoding a carbapenemase VIM-2.

and , belonging to the phylogenetic group, are occasionally isolated from clinical samples, partly because they are often misidentified as in clinical laboratories. There are five reports describing carbapenem-resistant clinical isolates of these species. Carbapenem-resistant strains of and were isolated from stool samples. These isolates were sequenced using Illumina MiSeq and reidentified using average nucleotide identity (ANI) based on comparisons of their whole-genome sequences using the OrthoANI algorithm. The clonal relatedness of the isolates was assessed by pulse-field gel electrophoresis (PFGE). The size of plasmids conveying was examined by Southern blotting. A total of six carbapenem-resistant clinical isolates of (two isolates) and (four isolates) were obtained from stool samples from five patients in a Japanese hospital. All isolates harboured . The two isolates of had a different pattern in the PFGE analysis, with both having a 23 kb plasmid. Of the four isolates of with similar patterns in the PFGE analysis, three had 320 kb plasmids and one had a 240 kb plasmid. The genetic environments of the 320/240 kb and 23 kb plasmids differed. The results strongly indicated that carbapenem-resistant and producing metallo-β-lactamase are emerging in Japan. This is the first report of carbapenem-resistant and in Japan.