Attempts to cultivate Mycobacterium leprae in fat tissue.

The behaviour of M. leprae in fat tissue was studied. Preadipocyte cells were infected with M. leprae and injected intradermally (I.D.) into nude mice. Adipose nodules obtained by in vivo differentiation of infected cells were maintained in vivo for 3 months and subsequently incubated in vitro for 3 months. Counts of bacilli showed no increase over this 6 months period. It is concluded that undifferentiated preadipocyte and mature fat cells are not permissive for M. leprae. The morphological changes observed following passage of M. leprae into adipose nodules might be related to the process of adipose cell differentiation.