First report of New Delhi metallo--lactamase-1-producing Acinetobacter soli in Japan

New Delhi metallo-beta-lactamase (NDM)-producing gram-negative rods, including Acinetobacter species, are a global problem but have rarely been isolated in Japan. To our knowledge, this is the first study to isolate an NDM-1-producing Acinetobacter soli strain, KUH106, in Japan. We analyzed this strain using next-generation sequencing to examine the plasmid carrying NDM-1. This plasmid, named pKUH106_NDM1, is 41,135 bp in length and contains genetic contexts with the structure ISAba14-aph(3')-VI-ISAba125-bla(NDM-1)ble-(MBL). Comparative analysis of the plasmid revealed that it resembled the plasmids of Acinetobacter detected in various countries, such as the A. soli isolate from Taiwan and the Acinetobacter baumannii isolate from a healthcare facility in Osaka Prefecture, Japan. These results suggest that bla(NDM-1) may spread via this plasmid in Acinetobacter species. This phenomenon needs to be confirmed through the genetic analysis of A. baumannii and other carbapenem-resistant Acinetobacter species. In particular, bla(NDM-1) and other resistance genes must be investigated, and the spread of these genes in the community must be cautioned.