Mycobacterium fortuitum
M. fortuitum is responsible for up to 15% of RGM cases in the United States but is a relatively uncommon cause of lung disease except in patients with disorders associated with chronic aspiration.Among 26 patients in the Republic of Korea with two or more positive cultures for M. fortuitum, only one was treated and none of the 25 untreated patients showed progression during a median follow up of 12.5 months.185 The clinical and radiographic presentation of patients with pulmonary disease is similar to that of other RGM. Application of contemporary diagnostic guidelines must be used with caution and even with some skepticism when evaluating patients with M. fortuitum respiratory isolates. Skin, soft tissue, and bone infections are more common than pulmonary disease. Both sporadic and clustered outbreaks of furunculosis due to M. fortuitum (and other RGM) have been reported after exposure to contaminated water during pedicures