Further Spread of a -Harboring Untypeable Plasmid in in China.

The wide spread of carbapenemase (KPC)-producing is great threat to public health in China. Plasmids are among the major factors mediating gene dissemination. A total of 156 carbapenem-resistant (CRE) isolates were identified in a tertiary hospital in China. Six KPC-producing isolates, namely, ( = 2), ( = 1), ( = 1), ( = 1), and ( = 1), tested positive for the pCKPC18-1-like untypeable plasmid, which was described recently in . All 6 plasmids could be easily transferred into by chemical transformation or conjugation and were confirmed by sequencing to harbor . Multilocus PCRs and EcoRI-RFLP revealed that the 6 untypeable plasmids belonged to 2 isoforms. High-throughput sequencing of representative plasmids (pCP40 and pEC86) led to the identification of 2 plasmids that shared the common backbone genes , and , which were characteristic of the untypeable plasmid, and had similar genetic contexts of the Tn-Tn chimera. Nucleotide comparison revealed high sequence identity of the 2 plasmids with previously reported -carrying untypeable plasmids. In particular, the pCP40 plasmid from and the pHS062105-3 plasmid from differed by only 20 single-nucleotide polymorphisms (SNPs). To the best of our knowledge, this is the first report of a -harboring untypeable plasmid spread into , and strains in China.