Quantification of staphylococcal-collagen binding interactions in whole blood by use of a confocal microscopy shear-adhesion assay.
In bloodborne staphylococcal infections, bacteria and platelets often combine, forming thrombi on the subendothelium, where collagen is exposed. In this process, the collagen serves as a potential binding surface for Staphylococcus aureus. However, the extent and importance of S. aureus-collagen binding interactions in the development of infected thrombi is uncertain. We quantified S. aureus adhesion to collagen in a whole-blood suspension under defined physiologically relevant fluid shear conditions. S. aureus-collagen binding interactions, mediated by both the S. aureus collagen adhesin (CNA) and protein A-von Willebrand factor (vWf), were evaluated using mutant strains and antibody-blocking techniques. The position of adherent bacteria (at the collagen surface or above the surface in the platelet aggregate) was measured using confocal laser microscopy. Results demonstrated significant CNA-collagen interactions and protein A-vWf-collagen binding interactions under physiological shear conditions. We conclude that collagen binding interactions are important in the development of infected thrombi.
Mascari
Lisa M
LM
Department of Chemical and Biochemical Engineering, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA.
Ross
Julia M
JM
D018829:Adhesins, Bacterial; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism*; D006801:Humans; D018613:Microscopy, Confocal / Q000379:methods*; D011485:Protein Binding; D013205:Staphylococcal Protein A / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000145:classification / Q000378:metabolism*; D014841:von Willebrand Factor / Q000378:metabolism*
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D013205:Staphylococcal Protein A; C048165:adhesin, Staphylococcus aureus; D014841:von Willebrand Factor; D003094:Collagen