Cultivation of Mycobacterium leprae in artificial culture medium

A novel procedure in the cultivation of M. leprae in combined Dubos-Lowenstein-Jenson medium after addition of thyroxine sodium is being reported. This has been found to be successful as the organisms, after multiplying vigorously in the thyroxine containing Dubos medium, have produced a visible colony on the surface of Lowenstein-Jensen medium during 8-16 wks of incubation at 37 degrees C. The enhanced growth of this recalcitrant organism is due to stimulating effect of thyroxine as well as supply of ready-made basic nutrients in the synthetic Dubos medium. Intradermal inoculation of the bacterial suspension from the subculture into the foot pad of cortisone treated mouse revealed an early appearance of specific histological lesion of leprosy with infiltration of nerve fibres by lepra cells. The methodology, described here for in-vitro cultivation, may open out a new era in the preparation of purified vaccine, the study of in-vitro drug sensitivity, and as such ensure rapid eradication of leprosy.