Rhodococcus Erythropolis Septic Arthritis.

A woman in her 50s presented with a 4-day history of left knee pain, erythema, swelling as well as malaise and rigours 1 month after undergoing a left knee meniscectomy. She was diagnosed with left native knee septic arthritis and underwent arthroscopic irrigation and debridement of the knee; cultures from synovial tissue grew Rhodococcus erythropolis. Rhodococcus spp are soil-dwelling and livestock-dwelling bacteria which occasionally cause disease in immunocompromised hosts. Infection in immunocompetent hosts is rare, and septic arthritis secondary to Rhodococcus erythropolis has not been reported previously.