 - Has implanted medical devices that pose a high risk for colonization andor cannot be easily removed e.g., prosthetic joints, artificial heart valves, pacemakers, orthopedic screws, metal plates, bone grafts, or other exogenous implants. NOTE: More common devices and prosthetics which include arterial and venous stents, dental and breast implants, and venous access devices e.g., Port-a-Cath or Mediport are permitted. Sponsor must be contacted prior to consenting any subject who has any other device andor implant. 