Rhodococcus equi infection in the patient with AIDS: literature review and report of an unusual case.

Rhodococcus equi is an aerobic, intracellular, gram-positive rod-coccus that is partially acid fast. The organism is primarily a pathogen in animals and has only rarely been seen in immunocompromised humans. Its most common manifestation is a slowly progressive pneumonia that may cavitate. Infections are thought to be acquired via respiratory exposure to animals or soil. R. equi infections are difficult to treat, usually requiring prolonged administration of parenteral antibiotics and often necessitating surgical drainage. A case of cavitary pneumonia and recurrent bacteremia with R. equi in a patient with AIDS is reported, and the current literature on R. equi infections in humans is reviewed.