Chronic knee monoarthritis caused by Mycobacterium chelonae.

Extrapulmonary tuberculosis occurs in 20% of all patients with tuberculosis and tubercular arthritis occurs in 10% of those with extrapulmonary tuberculosis. Arthritis caused by Mycobacterium tuberculosis is not uncommon in India. However, arthritis caused by Mycobacterium chelonae has not been reported to the best of our knowledge. We report a patient with arthritis caused by Mycobacterium chelonae in whom the diagnosis was confirmed by smear and culture of acid-fast bacilli. Polymerase chain reaction of the synovial fluid using IS6110 was negative.