Tuberculosis (TB) and leprosy are the two major human diseases caused by mycobacteria. Human tuberculosis is caused by M. tuberculosis and M.bovis, and leprosy is caused by M. leprae. Both organisms share one unique characteristics (acid fastness), but only the former can be cultured on artificial media. To this date, M. leprae can NOT be cultured on any artificial media!
Mycobacteria are uniquely capable of surviving within macrophages, and macrophages have to be activated in order to kill the intracellularly residing tubercle bacilli.
Tuberculosis and other mycobacterial infections (excluding leprosy) are becoming increasingly prevalent among compromised hosts, especially AIDS patients. In this lecture, M. tuberculosis and tuberculosis will be mainly discussed.