Complete Nucleotide Sequences ofblaKPC-4- andblaKPC-5-Harboring IncN and IncX Plasmids from Klebsiella pneumoniae Strains Isolated in New Jersey

Abstract

ABSTRACTKlebsiella pneumoniaecarbapenemase (KPC)-producingEnterobacteriaceaehave emerged as major nosocomial pathogens.blaKPC, commonly located on Tn4401, is found in Gram-negative bacterial strains, with the two most common variants,blaKPC-2andblaKPC-3, identified in plasmids with diverse genetic backgrounds. In this study, we examinedblaKPC-4- andblaKPC-5-bearing plasmids recovered from twoK. pneumoniaestrains, which were isolated from a single New Jersey hospital in 2005 and 2006, respectively. IncN plasmid pBK31551 is 84 kb in length and harborsblaKPC-4,blaTEM-1,qnrB2,aac(3)-Ib,aph(3′)-I,qacF,qacEΔ1,sul1, anddfrA14, which confer resistance to β-lactams, quinolones, aminoglycosides, quaternary ammonium compounds, and co-trimoxazole. The conserved regions within pBK31551 are similar to those of other IncN plasmids. Surprisingly, analysis of the Tn4401sequence revealed a large IS110- and Tn6901-carrying element (8.3 kb) inserted into theistAgene, encoding glyoxalase/bleomycin resistance, alcohol dehydrogenase, andS-formylglutathione hydrolase. Plasmid pBK31567 is 47 kb in length and harborsblaKPC-5,dfrA5,qacEΔ1, andsul1. pBK31567 belongs to a novel IncX subgroup (IncX5) and possesses a highly syntenic plasmid backbone like other IncX plasmids; however, sequence similarity at the nucleotide level is divergent. TheblaKPC-5gene is carried on a Tn4401element and differs from the genetic environment ofblaKPC-5described inPseudomonas aeruginosastrain P28 from Puerto Rico. This study underscores the genetic diversity of multidrug-resistant plasmids involved in the spread ofblaKPCgenes and highlights the mobility and plasticity of Tn4401. Comparative genomic analysis provides new insights into the evolution and dissemination of KPC plasmids belonging to different incompatibility groups.