Mycobacterium marinum tenosynovitis in a Long Island fisherman

The purpose of this report is to alert physicians to the occurrence of a seldom appreciated infection in man caused by Mycobacterium marinum, an atypical mycobacterium found in several species of fish living in Long Island Sound. Lesions caused by M. marinum are useful of three types: 1) a self-limited verrucous lesion; 2) an ulcerative skin lesion which may or may not lead to granuloma formation in the subcutaneous tissue; and 3) a deep-seated or a disseminated variety involving lymphatics, tenosynovium, joint space, bursa, or bone. Antibiotics of the tetracycline class (tetracycline and minocycline hydrochloride) are effective in treatment of M. marinum infections. M. marinum is resistant to isoniazid and para-aminosalicylic acid with variable resistance to streptomycin. In a review of literature, it is clear that M. marinum resistance to these drugs is highly variable, while the organism appears to be sensitive to ethambutol, rifampin, cycloserine, and ethionamide as noted by several authors. Combination therapy antituberculous drugs should consist of at least ethambutol (10 to 25 mg. per kilogram per day) and rifampin (7 mg per kilogram per day) for a period of time lasting from six weeks to several months. Cycloserine and ethionamide should be considered as additional or alternative agents.