Inhibition of bacterial adhesion by antibacterial surface pretreatment of vascular prostheses

Polytetrafluoroethylene grafts were pretreated with oxacillin, with the cationic detergent benzalkonium, or with both substances, either at room temperature or at 90 degrees C. Inhibition zones ranging from 6.4 to 15.2 mm formed around all grafts incubated on Staphylococcus aureus-streaked agar plates except control disks and those treated with oxacillin. Treated grafts were exposed in vitro to S. aureus in high concentration, followed by distilled water lavage. The graft surface was then stained with ruthenium red to stain polysaccharides and studied by scanning and transmission electron microscopy. Colonization of the graft surface by adhesive bacteria was demonstrated in all cases, although it was less prevalent on grafts pretreated with benzalkonium bound at 90 degrees C.