Case of Mycobacterium marinum infection with unusual patterns of susceptibility to commonly used antibiotics.

Mycobacterium marinum, found commonly in salt water and freshwater, is the causative agent of disease in many species of fish and occasionally in humans. MICs to most antimicrobial agents are relatively low. Susceptibility testing is not routinely performed, and single-drug therapy is used for the treatment of most infections. Here, we report an infection caused by a drug-resistant M. marinum strain in an otherwise healthy patient.