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Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
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Impact of bacteremia on the pathogenesis of experimental pneumococcal meningitis

Christian T Brandt1, David Holm, Matthew Liptrot

  • 1National Center for Antimicrobials and Infection Control, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. ctb@ssi.dk

The Journal of Infectious Diseases
|January 5, 2008
PubMed
Abstract

Insights

Bacteremia significantly impacts pneumococcal meningitis outcomes. Reducing bacteremia improved symptoms and reduced brain swelling and blood-brain barrier damage in rats.

Area of Science:

  • Neuroscience
  • Infectious Diseases
  • Pathophysiology

Background:

  • Bacteremia is a critical factor influencing the prognosis of pneumococcal meningitis.
  • Understanding the impact of systemic infection on brain pathophysiology is essential.

Purpose of the Study:

  • To investigate the influence of bacteremia on the brain's pathophysiologic profile in experimental pneumococcal meningitis.
  • To assess the effects of attenuated and early-onset bacteremia on brain injury markers.

Main Methods:

  • Rats with Streptococcus pneumoniae meningitis were divided into three groups: attenuated bacteremia, early-onset bacteremia, and meningitis control.
  • Magnetic resonance imaging (MRI) was used to evaluate blood-brain barrier (BBB) breakdown, ventricle size, and brain edema.
  • Clinical disease scores and laboratory data were collected.

Main Results:

  • Attenuation of bacteremia significantly improved clinical symptoms and reduced ventricle expansion and BBB breakdown.
  • Early-onset bacteremia did not exacerbate ventricle enlargement or BBB leakage.
  • Both attenuated and early-onset bacteremia led to significantly increased brain edema.

Conclusions:

  • While focal brain lesions stem from local meningeal infection, systemic infection (bacteremia) significantly contributes to clinical presentation, BBB breakdown, and ventricle expansion.
  • Future research should differentiate the effects of systemic and local infectious processes on meningitis outcomes.

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