Mycobacterium marinum infection in Taiwan

Mycobacterium marinum often causes skin infections, tenosynovitis, arthritis, and osteomyelitis, and occasionally results in severe disseminated infections in immunocompromised patients. In this study, the clinical features of 14 cases of M. marinum infection were retrospectively analyzed. One patient had septic arthritis, the other 13 had skin infections and/or tenosynovitis. It usually took 2 months or longer for a definite diagnosis to be made in these patients. Three of the 14 patients were cured using clarithromycin alone or in combination with rifampin plus ethambutol. Most patients did not respond to conventional antituberculosis agents. Pulsed-field gel electrophoresis and infrequent-restriction-site polymerase chain reaction are efficient tools for the molecular typing of M. marinum. Both methods yielded a concordant result, and 4 of 12 isolates were genetically closely related to each other based on their banding patterns. This study indicates that these isolates were derived from the same clone. Because M. marinum infection is curable, early diagnosis is important. Poor healing of wounds after exposure to aquatic animals appears to be the most important clinical clue indicating the need for culture and inclusion of M. marinum infection in the differential diagnosis.