AUTHOR=Huang Jiansheng , Ding Hui , Shi Yang , Zhao Yunan , Hu Xiaolei , Ren Jianmin , Huang Guiying , Wu Rongzhen , Zhao Zhigang 

TITLE=Further Spread of a blaKPC-Harboring Untypeable Plasmid in Enterobacteriaceae in China

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01938

DOI=10.3389/fmicb.2018.01938

ISSN=1664-302X

ABSTRACT=<p>The wide spread of <italic>Klebsiella pneumoniae</italic> carbapenemase (KPC)-producing <italic>Enterobacteriaceae</italic> is great threat to public health in China. Plasmids are among the major factors mediating <italic>bla</italic><sub>KPC</sub> gene dissemination. A total of 156 carbapenem-resistant <italic>Enterobacteriaceae</italic> (CRE) isolates were identified in a tertiary hospital in China. Six KPC-producing isolates, namely, <italic>E. coli</italic> (<italic>n</italic> = 2), <italic>E. asburiae</italic> (<italic>n</italic> = 1), <italic>C. freundii</italic> (<italic>n</italic> = 1), <italic>C. portucalensis</italic> (<italic>n</italic> = 1), and <italic>C. koseri</italic> (<italic>n</italic> = 1), tested positive for the pCKPC18-1-like untypeable plasmid, which was described recently in <italic>C. freundii</italic>. All 6 plasmids could be easily transferred into <italic>E. coli</italic> by chemical transformation or conjugation and were confirmed by sequencing to harbor <italic>bla</italic><sub>KPC−2</sub>. 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 <italic>repA, DnaJ, StpA</italic>, and <italic>yafB</italic>, which were characteristic of the untypeable plasmid, and had similar <italic>bla</italic><sub>KPC−2</sub> genetic contexts of the Tn<italic>3</italic>-Tn<italic>4401</italic> chimera. Nucleotide comparison revealed high sequence identity of the 2 plasmids with previously reported <italic>bla</italic><sub>KPC−2</sub>-carrying untypeable plasmids. In particular, the pCP40 plasmid from <italic>C. portucalensis</italic> and the pHS062105-3 plasmid from <italic>K. pneumoniae</italic> differed by only 20 single-nucleotide polymorphisms (SNPs). To the best of our knowledge, this is the first report of a <italic>bla</italic><sub>KPC</sub>-harboring untypeable plasmid spread into <italic>E. coli, E. asburiae</italic>, and <italic>C. koseri</italic> strains in China.</p>