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Meningitis-associated pneumococcal serotype 8, ST 53, strain is hypervirulent in a rat model and has non-haemolytic

Annelies Müller1,2, Cebile Lekhuleni3,4, Sabrina Hupp5

  • 1Institute for Infectious Diseases, Faculty of Medicine, University of Bern, Bern, Switzerland.

Frontiers in Cellular and Infection Microbiology
|January 23, 2023
PubMed
Abstract

Insights

Serotype 8 Streptococcus pneumoniae caused severe meningitis and brain injury in rats. Liposomes reduced inflammation, showing potential as an adjuvant therapy against hypervirulent pneumococcal strains.

Area of Science:

  • Microbiology
  • Immunology
  • Neuroscience

Background:

  • Streptococcus pneumoniae causes invasive pneumococcal disease (IPD), a serious infection including meningitis.
  • Pneumococcal serotypes and pneumolysin toxin influence disease severity.
  • Serotype 8 strains are increasingly prevalent in IPD globally.

Purpose of the Study:

  • To compare the virulence of a prevalent serotype 8 Streptococcus pneumoniae isolate with serotype 14 and 15B isolates in a rat meningitis model.
  • To investigate the potential of liposomes as an adjuvant therapy against hypervirulent pneumococcal strains.

Main Methods:

  • A rat model of meningitis was used to compare the virulence of serotype 8, 14, and 15B Streptococcus pneumoniae isolates.
  • Cytokine responses were measured in vivo and in vitro using primary mouse glial cells.
  • The effect of pneumolysin-sequestering liposomes on neuroinflammation was assessed.

Main Results:

  • The serotype 8 isolate was hypervirulent, causing high mortality and brain injury in rats.
  • Serotype 8 induced a stronger inflammatory cytokine response compared to serotypes 14 and 15B.
  • Pneumolysin-sequestering liposomes reduced neuroinflammation in vitro.

Conclusions:

  • Serotype 8 Streptococcus pneumoniae isolates are hypervirulent and associated with severe meningitis and brain injury.
  • Liposomes show promise as an adjuvant therapy for invasive pneumococcal disease, even against strains with non-haemolytic pneumolysin.
Keywords:
Streptococcus pneumoniaehyperviruent serotype 8liposomesmeningitispneumolysinserotype 8

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