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Updated: Jul 14, 2025

Interactions with and Membrane Permeabilization of Brain Mitochondria by Amyloid Fibrils
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Interactions with and Membrane Permeabilization of Brain Mitochondria by Amyloid Fibrils

Published on: September 28, 2019

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Staphylococcus aureus delta toxin modulates both extracellular membrane vesicle biogenesis and amyloid formation

Xiaogang Wang1, Divakara Ssm Uppu1, Seth W Dickey2,3

  • 1Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School , Boston, Massachusetts, USA.

Mbio
|October 5, 2023
PubMed
Abstract

Insights

Staphylococcus aureus produces membrane vesicles (MVs) critical for biogenesis. The δ-toxin protein forms amyloid fibrils within these MVs during planktonic growth, but not in vivo.

Area of Science:

  • Microbiology
  • Bacterial Pathogenesis
  • Protein Biochemistry

Background:

  • Extracellular membrane vesicles (MVs) from Staphylococcus aureus contain diverse biomolecules, protected from external degradation.
  • The phenol soluble modulin family member, δ-toxin, plays a crucial role in MV biogenesis.
  • Amyloid fibrils are found associated with MVs from virulent S. aureus strains.

Purpose of the Study:

  • To investigate the role of δ-toxin in Staphylococcus aureus MV biogenesis and amyloid formation.
  • To determine if amyloid fibrils are present in vivo during S. aureus infection.

Main Methods:

  • Culturing Staphylococcus aureus in planktonic conditions.
  • Co-purification of MVs and associated amyloid fibrils.
  • Mass spectrometry analysis to identify fibril components.
  • In vivo studies using a murine infection model.

Main Results:

  • δ-toxin is essential for MV biogenesis in S. aureus.
  • Amyloid fibrils composed of δ-toxin were identified in MVs from planktonic cultures.
  • Amyloid fibrils were not detected in MVs produced during in vivo murine infection.

Conclusions:

  • δ-toxin is a key factor in Staphylococcus aureus MV biogenesis and amyloid fibril formation.
  • Amyloid fibril formation by S. aureus appears to be a condition-specific phenomenon, occurring in vitro but not in vivo.
Keywords:
Staphylococcus aureusamyloid fibrilsdelta-toxinextracellular membrane vesiclesphenol-soluble modulins

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