Primary resistance to single and multiple drugs in leprosy--a mouse footpad study.

Skin biopsy homogenates obtained from three cases of lepromatous leprosy with no prior history of antileprosy treatment were tested in the mouse footpad for the sensitivity of Mycobacterium leprae to multiple drugs. One of the inocula was sensitive to all the three drugs tested using the highest concentration each of DDS 0.01 g%, RFP 0.03 g% and CLF 0.01 g%. The 2nd inocula showed growth in the presence of 0.01 g% DDS only. While the 3rd inocula (Pt. KU) tested resistant to all the three drugs in the first, i.e. man to mouse, as well as in the second passage, i.e. mouse to mouse.