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Comparison of Klebsiella pneumoniae virulence in mammalian and non-mammalian animal models

Abstract number: R2254

Vilches S., Jimenez N., Reyes M., Merino S., Salo M., Tomas J.

K. pneumoniae is an important cause of nosocomial infections occurring at almost all body sites, but with highest incidence in the urinary and the respiratory tracts.

The main populations at risk are neonates and predisposed and immunocompromised hosts. K. pneumoniae typically has both smooth LPS (O antigen) and capsule (K antigen) on its cell surface, and both contribute to the pathogenicity of this species. The aim of this study was to compare using different K. pneumoniae well defined mutants lacking only the capsule, the O-antigen LPS, several parts of the LPS core (outer and inner) with or without capsule, several mammalian and non mammalian animal models.

In K. pneumoniae, the O-antigen LPS is critical for serum resistance, changes in surface hydrophobicity, adhesion to UEC cells and urinary tract infection and colonisation in rats. The capsule is essential in the K. pneumoniae experimental model of pneumonia, while the colonisation of the urinary tract by K. pneumoniae requires a complete LPS with O-antigen. The K. pneumoniae virulence tested as LD50 in mice inoculated intraperitoneally seems to be dependent on the capsule and the complete LPS (probably full core LPS and O-antigen molecules). The two non mammalian experimental models used, unicellular Dictyostelium ameobae and the insect Drosophila melanogaster, renders similar results to the ones obtained in the experimental model of pneumonia about the important role of the capsule.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Barcelona, Spain
Presentation type:
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