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Updated: Jun 15, 2025

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria
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Published on: September 16, 2013

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Lipid lysination by MprF contributes to hemolytic pigment retention in group B Streptococcus

Elise Caliot1, Arnaud Firon1, Audrey Solgadi2

  • 1Institut Pasteur, Université Paris Cité, CNRS UMR6047, Biology of Gram-positive Pathogens Unit, F-75015 Paris, France.

Research in Microbiology
|August 28, 2024
PubMed

Insights

Group B Streptococcus virulence is linked to a toxin. The MprF enzyme modifies lipids, affecting toxin activity and bacterial resistance to antibiotics and pH.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Group B Streptococcus (GBS) causes neonatal sepsis and meningitis.
  • A key GBS virulence factor is a pigmented beta-haemolytic/cyto-lysin (β-h/c) toxin.
  • The toxin possesses an ornithine rhamnolipid structure.

Purpose of the Study:

  • To investigate the role of the MprF enzyme in GBS virulence.
  • To understand how MprF affects the β-h/c toxin and bacterial membrane properties.

Main Methods:

  • Analysis of GBS strains lacking the MprF enzyme.
  • Assessment of pigmentation and hemolytic activity.
  • Investigation of lipid lysination and membrane property alterations.

Main Results:

  • Absence of MprF altered GBS pigmentation and hemolytic activity.
  • MprF-dependent lipid lysination retains the toxin in the GBS membrane.
  • Cationic lipidation by MprF enhances resistance to daptomycin and acidic pH.

Conclusions:

  • The MprF enzyme is crucial for modulating GBS virulence.
  • Cationic lipids play a significant role in cell envelope homeostasis.
  • MprF activity impacts both toxin function and bacterial stress resistance.
Keywords:
Beta-haemolytic/cytolysin (β-h/c) toxinCationic lipidsGBSMprFRhamnolipid pigmentStreptococcus agalactiae

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