Molecular Survey of the Dissemination of Two bla KPC -Harboring IncFIA Plasmids in New Jersey and New York Hospitals

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae strains have spread worldwide and become a major threat in health care facilities. Transmission of bla KPC , the plasmid-borne KPC gene, can be mediated by clonal spread and horizontal transfer. Here, we report the complete nucleotide sequences of two novel bla KPC-3 -harboring IncFIA plasmids, pBK30661 and pBK30683. pBK30661 is 74 kb in length, with a mosaic plasmid structure; it exhibits homologies to several other plasmids but lacks the plasmid transfer operon ( tra ) and the origin of transfer ( oriT ) that are required for plasmid transfer. pBK30683 is a conjugative plasmid with a cointegrated plasmid structure, comprising a 72-kb element that highly resembles pBK30661 (>99.9% nucleotide identities) and an extra 68-kb element that harbors tra and oriT . A PCR scheme was designed to detect the distribution of bla KPC -harboring IncFIA (pBK30661-like and pBK30683-like) plasmids in a collection of clinical Enterobacteriaceae isolates from 10 hospitals in New Jersey and New York. KPC-harboring IncFIA plasmids were found in 20% of 491 K. pneumoniae isolates, and all carried bla KPC-3 . pBK30661-like plasmids were identified mainly in the epidemic sequence type 258 (ST258) K. pneumoniae clone, while pBK30683-like plasmids were widely distributed in ST258 and other K. pneumoniae sequence types and among non- K. pneumoniae Enterobacteriaceae species. This suggests that both clonal spread and horizontal plasmid transfer contributed to the dissemination of bla KPC -harboring IncFIA plasmids in our area. Further studies are needed to understand the distribution of this plasmid group in other health care regions and to decipher the origins of pBK30661-like and pBK30683-like plasmids.