Clinical and phenotypic differences between classic and hypervirulent Klebsiella pneumonia: an emerging and under-recognized pathogenic variant

  • D. K. Pomakova
  • C-B. Hsiao
  • J. M. Beanan
  • R. Olson
  • U. MacDonald
  • Y. Keynan
  • T. A. Russo
Article

DOI: 10.1007/s10096-011-1396-6

Cite this article as:
Pomakova, D.K., Hsiao, CB., Beanan, J.M. et al. Eur J Clin Microbiol Infect Dis (2012) 31: 981. doi:10.1007/s10096-011-1396-6

Abstract

The purpose of this study was to increase awareness, gain insight into acquisition, and assess the virulence of the hypervirulent (hypermucoviscous) clinical variant (hvKP) that is entrenched in the Pacific Rim but emerging in Western countries. A case of community-acquired liver abscess with metastatic spread to the spleen is described. Comparative in vitro and in vivo virulence studies on this isolate (hvKP1) and four randomly chosen blood isolates of “classic” K. pneumonia strains (cKP1-4) were performed. Cases of hvKP infection are occurring in Western countries and are under-recognized. A hypermucoviscous phenotype is a surrogate laboratory marker for this variant. The propensity of hvKP strains for metastatic spread in non-compromised hosts is both a defining and unusual trait. The mode of acquisition in the described case was unclear but potential means are discussed. hvKP1 was more resistant to complement and neutrophil-mediated bactericidal activity and was more virulent in a rat subcutaneous abscess model than cKP1-4. Recognition of the hypermucoviscous phenotype, defined by a positive “string-test”, will alert the microbiologist or clinician that the infecting strain may be a hvKP, which is hypervirulent compared to cKP. This will improve our understanding of the epidemiology and clinical spectrum of infection, which may be more extensive than appreciated.

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • D. K. Pomakova
    • 1
    • 2
  • C-B. Hsiao
    • 3
    • 4
  • J. M. Beanan
    • 2
    • 5
  • R. Olson
    • 2
    • 5
  • U. MacDonald
    • 2
    • 5
  • Y. Keynan
    • 6
  • T. A. Russo
    • 1
    • 2
    • 4
    • 5
    • 7
  1. 1.Veterans Administration Western New York Healthcare SystemBuffaloUSA
  2. 2.Department of MedicineUniversity at Buffalo-State University of New YorkBuffaloUSA
  3. 3.Erie County Medical CenterErieUSA
  4. 4.Department of Microbiology and ImmunologyUniversity at Buffalo-State University of New YorkBuffaloUSA
  5. 5.The Witebsky Center for Microbial PathogenesisUniversity at Buffalo-State University of New YorkBuffaloUSA
  6. 6.Department of Medical MicrobiologyUniversity of ManitobaWinnipegCanada
  7. 7.Department of Medicine, Division of Infectious DiseasesUniversity at Buffalo-State University of New YorkBuffaloUSA

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