Glad you brought it up, actually. Leprosy and tuberculosis are caused by the same genus, a bacillus named
Mycobacterium, the former
Mycobacterium leprae and the latter (big surprise)
Mycobacterium tuberculosis. It is exceedingly interesting that both of these are present in the same population. The organisms are difficult to treat with antibiotics because they have a lipid (fatty) coating that prevents them from absorbing the antibiotics. Some of the ones that do work are the sulfones, which is pretty wicked stuff. Beats dying, I guess, but only barely.
I stayed up nights studying this stuff a long time ago and I'm gonna get something out of it, dang it! ;-)