capitalized: a genus of nonmotile acid-fast aerobic bacteria of the family Mycobacteriaceae that are usually slender and difficult to stain and that include the causative agents of tuberculosis (M. tuberculosis) and leprosy (M. leprae) as well as numerous purely saprophytic forms
pluralmy·co·bac·te·ria\-ē-ə\: any bacterium of the genus Mycobacterium or a closely related genus
Any of the rod-shaped bacteria that make up the genus Mycobacterium. The two most important species cause tuberculosis and leprosy in humans; another species causes tuberculosis in both cattle and humans. Some mycobacteria live on decaying organic matter; others are parasites. Most are found in soil and water in a free-living form or in diseased tissue of animals. Various antibiotics have had some success against mycobacterium infections.