Role of Capsule in Klebsiella Pneumoniae Virulence: Lack of Correlation Between in Vitro and in Vivo Studies

FEMS Microbiol Lett. 2003 Jan 21;218(1):149-54. doi: 10.1111/j.1574-6968.2003.tb11511.x.


In vitro and in vivo models were used to investigate the role of capsule on the virulence of Klebsiella pneumoniae. We showed that capsule expression reduces dramatically the ability of the K. pneumoniae to bind to epithelial cells when compared to its non-capsulated variant. The presence/absence of capsule had no effect on the colonization of the gastrointestinal tract, while in the urinary tract we established that capsule is an important virulence factor. Our study demonstrates the caution needed when extrapolating from results of in vitro studies and emphasizes the necessity of in vivo models in studies of bacterial virulence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Outbred Strains
  • Bacterial Capsules / physiology*
  • Cell Line
  • Colony Count, Microbial
  • Enteritis / microbiology*
  • Epithelial Cells / microbiology
  • Female
  • Humans
  • In Vitro Techniques
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / microbiology*
  • Klebsiella Infections / microbiology*
  • Klebsiella pneumoniae / pathogenicity*
  • Mice
  • Virulence
  • Virulence Factors


  • Virulence Factors