Implantable medical devices such as cannulae, catheters, and stents are indispensable in the management of critically and chronically ill patients for the administration of electrolytes, drugs, parenteral nutrients, and blood components, or the drainage of secretions and pus. Articial heart valves, prosthetics, ceramics, metals, and bone cements are now common implants or implant materials. All of these implants save human lives and enhance quality of life. At the same time, they are the leading cause for millions of primary nosocomial bloodstream infections with substantial morbidity and mortality (Bisno and Waldnagel, 1994). A property common to all these biomaterials is the ease by which they are colonized by pathogenic and nonpathogenic microorganisms, often requiring immediate removal.