COLLAGEN-BINDING OF STAPHYLOCOCCUS-AUREUS IS A VIRULENCE FACTOR IN EXPERIMENTAL ENDOCARDITIS

The role of Staphylococcus aureus collagen binding in the development of experimental endocarditis was studied. Two isogenic strains of S. a ureus, 1 carrying an insertional inactivation of the gene encoding col lagen-binding protein, were compared in a rat model of catheter-induce d infective endocarditis (IE). Separate groups of rats with traumatize d aortic valves were intravenously challenged with 1 of the strains. I n rats sacrificed 24 h after inoculation, the collagen-binding strain significantly outnumbered the mutant strain (P < .001); however, 1 h a fter challenge, there was no difference in numbers of the 2 strains. T he results were substantiated, using a 1:1 mixture of the parent strai n and the mutant as an inoculate. Our findings suggest that collagen b inding of S. aureus is important in the sustenance of experimental IE and plays a limited role during the initial attachment of the microorg anism to traumatized aortic valves.