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

Abstract

The wide spread of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae is great threat to public health in China. Plasmids are among the major factors mediating blaKPC gene dissemination. A total of 156 carbapenem-resistant Enterobacteriaceae (CRE) isolates were identified in a tertiary hospital in China. Six KPC-producing isolates, namely, E. coli (n = 2), E. asburiae (n = 1), C. freundii (n = 1), C. portucalensis (n = 1), and C. koseri (n = 1), tested positive for the pCKPC18-1-like untypeable plasmid, which was described recently in C. freundii. All 6 plasmids could be easily transferred into E. coli by chemical transformation or conjugation and were confirmed by sequencing to harbor blaKPC−2. 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 repA, DnaJ, StpA, and yafB, which were characteristic of the untypeable plasmid, and had similar blaKPC−2 genetic contexts of the Tn3-Tn4401 chimera. Nucleotide comparison revealed high sequence identity of the 2 plasmids with previously reported blaKPC−2-carrying untypeable plasmids. In particular, the pCP40 plasmid from C. portucalensis and the pHS062105-3 plasmid from K. pneumoniae differed by only 20 single-nucleotide polymorphisms (SNPs). To the best of our knowledge, this is the first report of a blaKPC-harboring untypeable plasmid spread into E. coli, E. asburiae, and C. koseri strains in China.

Characterization of Antimicrobial Resistance in Serratia spp. and Citrobacter spp. Isolates from Companion Animals in Japan: Nosocomial Dissemination of Extended-Spectrum Cephalosporin-Resistant Citrobacter freundii

“…portucalensis ( n = 6), and C. europaeus ( n = 2) (Figure 1). To the best of our knowledge, this is the first report on the isolation of C. portucalensis and C. europaeus strains from animals, although these species have been rarely reported in humans [26,27]. These findings imply the prevalence of several Citrobacter species in companion animals, in addition to C. freundii .…”

Comparative Analysis of bla KPC Expression in Tn 4401 Transposons and the Tn 3 -Tn 4401 Chimera

“…However, except for TZP and ATM, the IPM, MEM, FEP, and CAZ MICs for CTB were higher than that for Tn4401B but lower than that for Tn4401A. In addition, previous studies have shown that the ertapenem and FEP MICs for the E. coli transformants bearing wild-type plasmids with the Tn3-Tn4401 chimera were the same as those for the corresponding strains trans- formed with plasmids containing Tn4401a but were much higher than those for the transformants containing Tn4401b or Tn4401h (12,20). Further evaluation revealed that the bla KPC mRNA expression of Tn4401A was 3-fold (P Ͻ 0.01) higher than that of Tn4401B, which is consistent with the results of a previous study (17).…”

“…Bacterial species were initially identified with the VITEK2 Compact system (bioMérieux Vitek, USA) and further confirmed by the automated mass spectrometry microbial identification system (matrix-assisted laser desorption ionization-time of flight [MALDI-TOF]; Bruker, USA). Genetic environments of the bla KPC gene were initially detected by PCR with specific primers described in our previous study (20) and further confirmed by Sanger sequencing. DNA fragments containing the promoter region and bla KPC gene (complement sequence corresponding to positions 19105 to 21715 of pKP048 [16]) were amplified and cloned into pET28X (a modified pET28a vector with T7 promoter deletion [ Fig.…”

<p>Molecular Mechanisms and Epidemiology of Carbapenem-Resistant <em>Escherichia coli</em> Isolated from Chinese Patients During 2002–2017</p>

“…has been confirmed in Shandong, Zhejiang, Taiwan, and other provinces. [33][34][35] KPC-2 was the most important in K. pneumoniae, whereas NDM-1 was the most important in E. coli. Notably, in previous studies in China, a few strains of E. coli with KPC-2 were detected.…”