Mycobacterium is a genus of Actinobacteria, given its own family, the Mycobacteriaceae. Over 190 species are recognized in this genus. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis (Mycobacterium tuberculosis) and leprosy (Mycobacterium leprae) in humans.
The genus Mycobacterium encompasses a number of medically important species that exact an alarming toll in human morbidity and mortality. Mycobacteria are members of the order Actinomycetales, and the only genus in the family Mycobacteriaceae. Currently, the genus Mycobacterium has more than 100 recognized or proposed species, including numerous pathogens and saprophytic organisms of warm-blooded animals. The distinguishing characteristics of this genus include acid-fastness and the presence of mycolic acids. Mycobacterium is a genus of Actinobacteria, given its own family, the Mycobacteriaceae. Over 190 species are recognized in this genus. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis (Mycobacterium tuberculosis) and leprosy (Mycobacterium leprae) in humans. The Greek prefix myco- means "fungus," alluding to the way mycobacteria have been observed to grow in a mold-like fashion on the surface of cultures. It is acid fast and cannot be stained by the Gram stain procedure.