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Focal targeting by human β-defensin 2 disrupts localized virulence factor assembly sites in Enterococcus faecalis

Kumaravel Kandaswamy1, Tze Horng Liew, Charles Y Wang

  • 1Interdisciplinary Graduate School and School of Biological Sciences, Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551.

Proceedings of the National Academy of Sciences of the United States of America
|November 6, 2013
PubMed

Insights

Antimicrobial peptides target bacterial secretion sites, disrupting virulence factor assembly. Modifying bacterial lipids enhances resistance, suggesting a new strategy against Gram-positive pathogens.

Area of Science:

  • Microbiology
  • Cell Biology
  • Biochemistry

Background:

  • Virulence factor secretion is crucial for Gram-positive bacterial pathogenesis.
  • Secretion occurs at specific cellular foci, making them potential antimicrobial targets.

Purpose of the Study:

  • To investigate the localization of SecA and Sortase A in Enterococcus faecalis.
  • To determine the effect of antimicrobial peptides on these secretion foci.
  • To explore mechanisms of antimicrobial peptide resistance.

Main Methods:

  • Microscopy to observe protein localization during the cell cycle.
  • Treatment with cationic human β-defensins and multiple peptide resistance factor.
  • Assessment of bacterial resistance and susceptibility to antimicrobial peptides.

Main Results:

  • SecA and Sortase A localize to discrete septal domains in E. faecalis.
  • Cationic antimicrobial peptides disrupt these secretion foci.
  • Lipid modification confers resistance to antimicrobial peptides and reduces susceptibility to focal targeting.

Conclusions:

  • Antimicrobial peptide efficacy is linked to their ability to disrupt bacterial virulence factor assembly sites.
  • Targeting these focal sites represents a promising strategy for developing new antimicrobials.
  • Understanding lipid-mediated resistance mechanisms is key to overcoming antimicrobial peptide resistance.
Keywords:
MprFfocal localizationimmunofluorescencemicroscopy

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