Staphylococcus epidermidis Esp inhibits Staphylococcus aureus biofilm formation and nasal colonization

Nature. 2010 May 20;465(7296):346-9. doi: 10.1038/nature09074.


Commensal bacteria are known to inhibit pathogen colonization; however, complex host-microbe and microbe-microbe interactions have made it difficult to gain a detailed understanding of the mechanisms involved in the inhibition of colonization. Here we show that the serine protease Esp secreted by a subset of Staphylococcus epidermidis, a commensal bacterium, inhibits biofilm formation and nasal colonization by Staphylococcus aureus, a human pathogen. Epidemiological studies have demonstrated that the presence of Esp-secreting S. epidermidis in the nasal cavities of human volunteers correlates with the absence of S. aureus. Purified Esp inhibits biofilm formation and destroys pre-existing S. aureus biofilms. Furthermore, Esp enhances the susceptibility of S. aureus in biofilms to immune system components. In vivo studies have shown that Esp-secreting S. epidermidis eliminates S. aureus nasal colonization. These findings indicate that Esp hinders S. aureus colonization in vivo through a novel mechanism of bacterial interference, which could lead to the development of novel therapeutics to prevent S. aureus colonization and infection.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / isolation & purification
  • Bacterial Proteins / metabolism*
  • Bacterial Proteins / pharmacology
  • Biofilms / growth & development*
  • Female
  • Humans
  • Male
  • Nose / microbiology*
  • Odds Ratio
  • Serine Proteases / chemistry
  • Serine Proteases / deficiency
  • Serine Proteases / isolation & purification
  • Serine Proteases / metabolism*
  • Staphylococcal Infections / microbiology
  • Staphylococcal Infections / prevention & control
  • Staphylococcal Infections / therapy
  • Staphylococcus aureus / growth & development*
  • Staphylococcus aureus / immunology
  • Staphylococcus epidermidis / enzymology*
  • Staphylococcus epidermidis / genetics
  • Staphylococcus epidermidis / physiology*
  • Superinfection / immunology
  • Superinfection / microbiology
  • Superinfection / prevention & control
  • Superinfection / therapy
  • Young Adult
  • beta-Defensins / immunology
  • beta-Defensins / pharmacology


  • Bacterial Proteins
  • DEFB4A protein, human
  • beta-Defensins
  • Serine Proteases