Medical management of pneumonia caused by Rhodococcus equi in a renal transplant recipient.

Rhodococcus equi is an animal pathogen that occasionally causes opportunistic infections in immunocompromised patients. The most common clinical picture is one of necrotizing pneumonia with a tendency toward cavitation and the formation of abscesses. We report a case of pneumonia caused by R equi in a renal transplant patient. An excellent response was shown to antibiotic treatment. Symptoms regressed, and the progressive disappearance of the lesion was confirmed on follow-up computed tomography scans. Surgical intervention or other invasive procedures were not required. To our knowledge, 14 cases of infection by R equi in solid-organ transplant patients have been described to date. Nine were recipients of a renal allograft. Surgery was required in many of these patients, and all the renal transplant recipients required the use of invasive therapeutic techniques, such as pleural drainage. This is the first case of a renal transplant recipient in whom radiologic presentation was as a solid nodule without ensuing cavitation that resolved exclusively with antibiotic treatment.