The rapidly increasing prevalence of Klebsiella pneumoniae carbapenemase 2 (KPC-2)-producing bacteria has become a serious challenge to public health. Currently, the bla _KPC- ₂ gene is mainly disseminated through plasmids of different sizes and replicon types. However, the plasmids carrying the bla _KPC- ₂ gene have not been fully characterized. In this study, we report the complete genome sequences of two novel bla _KPC- ₂-harboring incompatibility group U (IncU) plasmids, pEC2341-KPC and pEC2547-KPC, from international high-risk clones of Escherichia coli isolated from Zhejiang, China. Two KPC-2-producing E. coli isolates (EC2341 and EC2547) were collected from clinical samples. Whole-genome sequencing (WGS) analysis indicated that EC2341 and EC2547 belonged to the ST410 and ST131 clones, respectively. S1-nuclease pulsed-field gel electrophoresis (S1-PFGE), Southern blot and conjugation experiments confirmed the presence of the bla _KPC- ₂ gene on the pEC2341-KPC plasmid and that this was a conjugative plasmid, while the bla _KPC- ₂ gene on the pEC2547-KPC plasmid was a non-conjugative plasmid. In addition, plasmid analysis further revealed that the two bla _KPC- ₂-harboring plasmids have a close evolutionary relationship. To the best of our knowledge, this is the first report of E. coli strains carrying the bla _KPC- ₂ gene on IncU plasmids. The emergence of the IncU-type bla _KPC- ₂-positive plasmid highlights further dissemination of bla _KPC- ₂ in Enterobacteriaceae. Therefore, effective measures should be taken immediately to prevent the spread of these bla _KPC- ₂ _-positive plasmids.

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