Mycobacterium tuberculosis belongs to the myobacteria complex, just like Mycobacterium bovis und Mycobacterium africanum.Closely related to the tuberculosis bacterium are Mycobacterium leprae (pathogen of lepra) and Mycobacterium ulcerans (pathogen of Buruli-Ulkus).A common property of myobacteria is the specific wax-like construction of the cell wall, which contains a characteristic structure element called mycolic acid. Because of this cell wall, myobacteria have a strong resistance against outside influences.