Infections from biomaterials and implants: a race for the surface.

Microorganisms in nature and disease are dependent on substratum attachment for optimal growth and development. Similarly, implanted biomaterials tend to potentiate bacteria on their surfaces so that normally friendly special or opportunistic organisms become virulent pathogens. Virulence is also enhanced because both bacteria and biomaterials interfere with host defense mechanisms. Infections centered on biomaterials are most difficult to eliminate and usually require removal of the device. The consequences of device failure are catastrophic and costly. It is the specific nature of the biomaterial surface, which is indirectly a reflection of bulk features, that causes and directs the changes in bacterial behavior which result in virulence. Features of organisms and materials and interactions responsible for these phenomena are reviewed.