Soft-tissue infection due to Mycobacterium smegmatis: report of two cases.

Mycobacterium smegmatis is an uncommon pathogen in humans. Fourteen cases of skin or soft-tissue infection due to M. smegmatis have been previously reported. We report two cases of posttraumatic M. smegmatis infection of the lower extremity. M. smegmatis infection produces chronic cellulitis with fistula formation that is most commonly a result of direct traumatic inoculation of contaminated material. Extensive surgical debridement followed by skin grafting has been necessary for cure in the majority of cases.