G (2002) Platelet-binding domains in 2 fibrinogen-binding proteins of Staphylococcus aureus identified by phage display

The adherence of microorganisms to platelets previously immobilized on the subendocar-dium in nonbacterial thrombotic endocarditis is considered an important pathogenic step in Staphylococcus aureus endocarditis. To identify and characterize bacterial factors involved in the adherence to platelets, a phage display library of S. aureus was generated by use of the phagemid pG8H6. The library was affinity panned against purified immobilized platelets. After a second panning against platelets, a significant increase in the number of eluted phag-emid particles was observed; 27 % of 88 randomly isolated clones expressed overlapping de-duced amino acid sequences with high similarity to the C-terminal domain of the S. aureus coagulase. In addition, 22 % of the clones expressed the N-terminal domain of the fibrinogen-binding protein Efb. The surface-associated fraction of the C-terminal domain of coagulase or the N-terminal domain of Efb may be involved in bacterial adherence to immobilized platelets, and fibrinogen may act as a bridging molecule in that interaction. Staphylococcus aureus is an important cause of acute infective endocarditis. The pathogenesis of infective endocarditis is a complex process involving initial endocardial damage that re