Complete genome sequencing and comparative plasmid analysis of KPC-2-producing Klebsiella pneumoniae isolated from hospital sewage water in Japan.

Objectives: The Klebsiella pneumoniae carbapenemase (bla) gene is one of the most widespread carbapenemase genes in the world. However, there are few reports on KPC-producing bacteria in Japan. The aim of this study was therefore to investigate KPC-producing K. pneumoniae in Japan.

Methods: A KPC-2-producingK. pneumoniae strain (KAM260) was isolated from hospital sewage water in Japan in 2018. The complete genome was determined by whole-genome sequencing. Subsequent comparative sequence analysis of the bla-carrying plasmid was performed.

Results: Klebsiella pneumoniae KAM260, belonging to sequence type 3026 (ST3026), harboured the bla gene in 114.6-kbp plasmid pKAM260_2 with IncFIB(pQIL) and IncFII(K) replicons. pKAM260_2 was highly identical to pKpQIL-like plasmids, which carry bla genes and have spread worldwide. pKAM260_2 had functional conjugation-associated genes and was transferable to Escherichia coli.

Conclusion: pKAM260_2, the self-transmissible plasmid carrying thebla gene, was detected from hospital sewage water in Japan and was characterised as a pKpQIL-like plasmid. This plasmid needs to be monitored in Japan in the future owing to its high diffusivity.