Fibronectin and fibrinogen contribute to the enhanced binding of Staphylococcus aureus to atopic skin

J Allergy Clin Immunol. 2001 Aug;108(2):269-74. doi: 10.1067/mai.2001.117455.


Background: Staphylococcus aureus colonizes the skin lesions of more than 90% of patients with atopic dermatitis (AD). The mechanism for increased S aureus colonization in AD is unknown. However, the initial event in colonization requires adherence of S aureus to the skin.

Objective: The purpose of this study was to examine the roles of various bacterial adhesins on S aureus binding to AD skin.

Methods: In an attempt to delineate the mechanism behind this adherence process, an in vitro bacterial binding assay was developed to quantitate the adherence of various S aureus strains to AD, psoriatic, and normal skin sections. S aureus strains used in this study were obtained either from cultures of AD skin lesions or from genetically manipulated strains of S aureus that lacked specific microbial surface components recognizing adhesive matrix molecules (MSCRAMMs)--namely, fibronectin-binding protein (Fnbp), fibrinogen-binding protein (Clf), collagen-binding protein (Cna), and their parent strains. In addition, S aureus strains from patients with AD were pretreated with fibronectin or fibrinogen to block MSCRAMM receptors and interfere with binding.

Results: Under all experimental conditions, binding of S aureus was localized primarily to the stratum corneum. Immunocytochemical staining of AD skin sections showed a redistribution of fibronectin to the cornified layer, an observation not seen in normal skin. S aureus binding to uninvolved AD skin was significantly greater than the binding to uninvolved psoriatic skin (P <.0001) and normal skin (P <.0005). The Fnbp-negative S aureus showed a significant reduction in binding to the AD skin (P <.0001) but not to the psoriatic and normal skin. In the AD skin, a significant reduction in the binding of S aureus was also observed in the Clf-negative strain (P <.0001) but not in the Cna-negative S aureus. Preincubation of S aureus with either fibronectin or fibrinogen also inhibited bacterial binding to AD skin (P <.0001).

Conclusion: These data suggest that fibronectin and fibrinogen--but not collagen--play a major role in the enhanced binding of S aureus to the skin of patients with AD.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Adhesion / physiology*
  • Cell Adhesion Molecules
  • Dermatitis, Atopic / complications*
  • Extracellular Matrix Proteins
  • Fibrinogen / metabolism*
  • Fibronectins / metabolism*
  • Humans
  • Psoriasis / complications
  • Staphylococcal Skin Infections / etiology*
  • Staphylococcus aureus / genetics


  • Cell Adhesion Molecules
  • Extracellular Matrix Proteins
  • Fibronectins
  • Fibrinogen