Fatal pulmonary infection due to Mycobacterium fortuitum.

Environmental (atypical, opportunist, other) mycobacteria were first isolated nearly a century ago. The classification of these "other than Mycobacterium tuberculosis" organisms was initially chaotic until Runyon proposed a scheme of four groups in 1959. Mycobacterium fortuitum is a member of group IV: Rapid growers. These ubiquitous terrestrial and aquatic forms contaminate water supplies, reagents, and clinical samples. They may colonise the respiratory systems of patients whose local defence mechanisms have been impaired or those with congenital and acquired immune defects. They can also cause disease in immunocompetent individuals. There have been fewer than 20 published cases of pulmonary infection caused by M fortuitum. A further case is reported of fatal pulmonary infection in an elderly patient with long standing chronic obstructive airways disease (COAD). He had left upper zone shadowing on chest radiography and lung abscesses at post mortem examination yielded only M fortuitum.