Problem
A 23-year-old i.v. drug abuser is brought to the ER from the homeless shelter because of fever, chills, a productive cough, and the presence of blood in his sputum. He has no pain in any of his joints and no pain on urination. You initially thought it might be influenza. However, when you listened to his chest, you heard the presence of an appreciable heart murmur. An echocardiogram showed that he had growths on his tricuspid valve, indicative of endocarditis. Blood and urine samples were drawn and sent to the lab for culture. The lab obtained yellow b-hemolytic colonies on sheep blood agar plates, but only from the blood cultures. The causative organism was found to be Gram-positive, catalase-positive, and coagulase-positive. It was found to contain a b-lactamase activity, so it was resistant to two drugs commonly used to treat this infection. Luckily, i.v. administration of a third drug was successful in relieving his symptoms, so it was NOT necessary to use the "drug of last resort."
How should his illness be treated?