Tropical fish aquariums. A source of Mycobacterium marinum infections resembling sporotrichosis.

Tropical fish aquariums are a possible, though uncommon, source for Mycobacterium marinum skin infections, which may assume the morphological pattern of sporotrichosis. We have observed three of six patients with this condition during the past two years. Shortly before onset, each patient experienced a minor abrasion on the hand, after which he cleaned an aquarium where many of the fish had recently died. Smear cultures of material obtained from the lesions revealed atypical acid-fast organisms, and in each case M marinum was identified. A smear culture from the fish tank of one patient showed M marinum , and acid-fast organisms were observed in the material we obtained from the tubing of the tank of another patient.