Contribution of Staphylococcus aureus Coagulases and Clumping Factor A to Abscess Formation in a Rabbit Model of Skin and Soft Tissue Infection

PLoS One. 2016 Jun 23;11(6):e0158293. doi: 10.1371/journal.pone.0158293. eCollection 2016.

Abstract

Staphylococcus aureus produces numerous factors that facilitate survival in the human host. S. aureus coagulase (Coa) and von Willebrand factor-binding protein (vWbp) are known to clot plasma through activation of prothrombin and conversion of fibrinogen to fibrin. In addition, S. aureus clumping factor A (ClfA) binds fibrinogen and contributes to platelet aggregation via a fibrinogen- or complement-dependent mechanism. Here, we evaluated the contribution of Coa, vWbp and ClfA to S. aureus pathogenesis in a rabbit model of skin and soft tissue infection. Compared to skin abscesses caused by the Newman wild-type strain, those caused by isogenic coa, vwb, or clfA deletion strains, or a strain deficient in coa and vwb, were significantly smaller following subcutaneous inoculation in rabbits. Unexpectedly, we found that fibrin deposition and abscess capsule formation appear to be independent of S. aureus coagulase activity in the rabbit infection model. Similarities notwithstanding, S. aureus strains deficient in coa and vwb elicited reduced levels of several proinflammatory molecules in human blood in vitro. Although a specific mechanism remains to be determined, we conclude that S. aureus Coa, vWbp and ClfA contribute to abscess formation in rabbits.

MeSH terms

  • Abscess / microbiology*
  • Abscess / pathology
  • Animals
  • Bacterial Proteins / metabolism
  • Coagulase / metabolism*
  • Cytokines / metabolism
  • Disease Models, Animal
  • Inflammation Mediators / metabolism
  • Rabbits
  • Soft Tissue Infections / microbiology*
  • Soft Tissue Infections / pathology
  • Staphylococcal Skin Infections / microbiology*
  • Staphylococcal Skin Infections / pathology
  • Staphylococcus aureus / metabolism*
  • Staphylococcus aureus / pathogenicity*

Substances

  • Bacterial Proteins
  • ClfA protein, Staphylococcus aureus
  • Coagulase
  • Cytokines
  • Inflammation Mediators