The Staphylococcus aureus epidermal cell differentiation inhibitor toxin promotes formation of infection foci in a mouse model of bacteremia

Infect Immun. 2010 Aug;78(8):3404-11. doi: 10.1128/IAI.00319-10. Epub 2010 May 17.

Abstract

Inactivation of the host GTPase RhoA by staphylococcal epidermal cell differentiation inhibitor (EDIN) exotoxins triggers the formation of large transcellular tunnels, named macroapertures, in endothelial cells. We used bioluminescent strains of Staphylococcus aureus to monitor the formation of infection foci during the first 24 h of hematogenous bacterial dissemination. Clinically derived EDIN-expressing S. aureus strains S25 and Xen36 produced many disseminated foci. EDIN had no detectable impact on infection foci in terms of histopathology or the intensity of emitted light. Moreover, EDIN did not modify the course of bacterial clearance from the bloodstream. In contrast, we show that EDIN expression promotes a 5-fold increase in the number of infection foci produced by Xen36. This virulence activity of EDIN requires RhoA ADP-ribosyltranferase activity. These results suggest that EDIN is a risk factor for S. aureus dissemination through the vasculature by virtue of its ability to promote the formation of infection foci in deep-seated tissues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacteremia / microbiology*
  • Bacteremia / pathology*
  • Bacterial Proteins / toxicity*
  • Female
  • Genes, Reporter
  • Histocytochemistry
  • Humans
  • Luminescent Measurements
  • Mice
  • Mice, Inbred BALB C
  • Microscopy
  • Staphylococcus aureus / isolation & purification
  • Staphylococcus aureus / pathogenicity*
  • Virulence Factors / toxicity*
  • Whole Body Imaging
  • rhoA GTP-Binding Protein / metabolism

Substances

  • Bacterial Proteins
  • Virulence Factors
  • epidermal cell differentiation inhibitor, Staphylococcus aureus
  • rhoA GTP-Binding Protein