[Rhodococcus erythropolis infection in HIV-associated immunodeficiency]

We report the first case in the literature of human infection with Rhodococcus erythropolis in an HIV-positive patient. A 24-year-old bisexual flight attendant had severe HIV-associated immunodeficiency with a CD4 cell count of 0.02 G/l. He complained of multiple subcutaneous nodules at different sites on the extremities. Biopsy of one node at his left knee revealed granulomatous inflammation filled with acid-fast rods. These bacteria were identified as Rhodococcus erythropolis. The disseminated infection was restricted to the skin and showed a slow response to long-term therapy with amoxicillin/clavulanic acid. No relapse has been observed more than 6 months after discontinuation of antibiotic therapy. The etiology of a concomitant polyarthritis remains unknown; a relationship with the rhodococcus infection is possible as the arthritis responded well to the antibiotic therapy and did not reactivate after discontinuation of antibiotics. Due to the difficult isolation technic, this pathogen may be overlooked in routine diagnostic procedures. The implications in clinical practice are discussed.