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Virulent clones of Klebsiella pneumoniae: identification and evolutionary scenario based on genomic and phenotypic

Sylvain Brisse1, Cindy Fevre, Virginie Passet

  • 1Institut Pasteur, Genotyping of Pathogens and Public Health, Paris, France. sylvain.brisse@pasteur.fr

Plos One
|March 26, 2009
PubMed

Insights

This study identified distinct virulent clones of Klebsiella pneumoniae associated with specific infections, revealing evolutionary pathways from commensalism to pathogenicity. Understanding these clones aids in controlling Klebsiella pneumoniae infections.

Area of Science:

  • Microbiology
  • Evolutionary Biology
  • Infectious Diseases

Background:

  • Klebsiella pneumoniae is both an environmental commensal and a significant nosocomial pathogen.
  • Virulent clones are critical for understanding pathogenicity evolution and infection control.

Purpose of the Study:

  • To identify and define virulent clones of Klebsiella pneumoniae.
  • To understand the evolutionary links between clones, virulence, and genomic features.

Main Methods:

  • Multilocus sequence typing of 235 K. pneumoniae isolates.
  • Analysis of virulence gene content, biochemical and capsular profiling.
  • Mouse virulence assays and phylogenetic analysis.

Main Results:

  • Phylogenetic analysis defined distinct clones associated with specific clinical sources and features.
  • Two K1 clones (CC23(K1), CC82(K1)) linked to pyogenic liver abscess and respiratory infections.
  • Ozena and rhinoscleroma strains formed monomorphic clones, suggesting derivation from K. pneumoniae.

Conclusions:

  • Klebsiella pneumoniae subsp. ozaenae and subsp. rhinoscleromatis are identified as virulent clones.
  • Horizontal gene transfer of the capsular operon explains variable capsular types within clones.
  • Specialization to pathogenic lifestyles observed in some clones, while others show recent invasive potential.

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