Adhesion of Staphylococcus aureus to surface-bound platelets: role of fibrinogen/fibrin and platelet integrins.
Platelets adhering to artificial or biologic surfaces have been implicated in the pathogenesis of catheter infections or endocarditis; however, the ligands involved in Staphylococcus aureus interaction with adherent platelets remain incompletely understood. Radiolabeled S. aureus Cowan I were incubated with purified platelets adherent to polymethylmethacrylate (PMMA) coverslips and washed, and adhesion was determined. Platelets promoted adhesion of S. aureus approximately 30-fold compared with adhesion to albumin-PMMA. In the presence of both plasma (1% vol/vol) and platelets, adhesion was extensively promoted, with 30% (of inoculated) S. aureus adherent (150-fold increase). Platelet pretreatment with anti-GPIIb/IIIa monoclonal antibodies or inhibitors of platelet activation decreased plasma-enhanced adhesion, suggesting a role of platelet activation in S. aureus adhesion. Plasma-enhanced adhesion was sensitive to thrombin antagonists, proteinase inhibitors, heparin, or antifibrinogen antibodies, indicating that fibrinogen/fibrin is necessary for bridging between adherent platelets and S. aureus. In conclusion, S. aureus adhesion to immobilized platelets may play a role in the pathogenesis of invasive bloodstream infections or endocarditis.
Herrmann
M
M
Department of Medical Microbiology and Immunology, University of Wisconsin, Madison 53706.
Lai
Q J
QJ
Albrecht
R M
RM
Mosher
D F
DF
Proctor
R A
RA
D001422:Bacterial Adhesion; D001792:Blood Platelets / Q000378:metabolism / Q000382:microbiology* / Q000648:ultrastructure; D001798:Blood Proteins / Q000502:physiology*; D005337:Fibrin / Q000502:physiology; D005340:Fibrinogen / Q000502:physiology; D006801:Humans; D016023:Integrins / Q000502:physiology*; D008024:Ligands; D008768:Methylmethacrylates / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D013211:Staphylococcus aureus / Q000378:metabolism* / Q000648:ultrastructure
D001798:Blood Proteins; D016023:Integrins; D008024:Ligands; D008768:Methylmethacrylates; D005337:Fibrin; D005340:Fibrinogen