Tracking microevolution events among ST11 carbapenemase-producing hypervirulent Klebsiella pneumoniae outbreak strains

Emerg Microbes Infect. 2018 Aug 12;7(1):146. doi: 10.1038/s41426-018-0146-6.

Abstract

The recent convergence of genetic elements encoding phenotypic carbapenem-resistance and hypervirulence within a single Klebsiella pneumoniae host strain represents a major public concern. To obtain a better understanding of the genetic characteristic of this emerging 'superbug', the complete genomes of 3 isolates of ST11 carbapenemase-producing hypervirulent K. pneumoniae were generated using the Oxford nanopore MinION platform. Comparative whole-genome analysis identified 13 SNPs and 3 major regions of indels in the chromosomes of the clonally disseminated isolates. ISKpn18-mediated disruption in the mgrB gene, which was associated with colistin resistance, was identified in two later strains, leading to the emergence of hypervirulent K. pneumoniae that was simultaneously colistin- and carbapenem-resistant. Five plasmids were recovered from each isolate, including a 178 Kb IncHI1B/FIB-type rmpA2-bearing virulence plasmid, a 177.5 Kb IncFII/R self-transferable blaKPC-2-bearing MDR plasmid, a 99.7 Kb Incl1 plasmid and two ColRNAI-type plasmids of sizes of 11.9 and 5.6 Kb, respectively. The presence of homologous regions between the non-conjugative virulence plasmid and conjugative blaKPC-2-bearing MDR plasmid suggests that transmission of the virulence plasmid from ST23 K. pneumoniae to ST11 CRKP may be mediated by the co-integrated transfer of these two plasmids. Emergence of colistin-resistant and carbapenemase-producing hypervirulent K. pneumoniae strains further emphasizes the urgency for the establishment of a coordinated global program to eradicate hypervirulent and/or pan-drug-resistant strains of K. pneumoniae from clinical settings and the community.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Colistin / pharmacology
  • Disease Outbreaks
  • Evolution, Molecular*
  • Genome, Bacterial
  • Humans
  • Klebsiella Infections / epidemiology
  • Klebsiella Infections / microbiology*
  • Klebsiella pneumoniae / enzymology*
  • Klebsiella pneumoniae / genetics
  • Klebsiella pneumoniae / isolation & purification
  • Klebsiella pneumoniae / pathogenicity
  • Multilocus Sequence Typing
  • Plasmids / genetics
  • Plasmids / metabolism
  • Virulence
  • beta-Lactamases / genetics
  • beta-Lactamases / metabolism*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • beta-Lactamases
  • carbapenemase
  • Colistin