Rodent Models in Leprosy Research

In 1960, Charles Shepard published his work on the growth of Mycobacterium leprae (see Chapter 5.1) in the footpads of immunocompetent Carworth Farms white mice (1). Although M. leprae was first associated with leprosy by Armauer Hansen nearly 90 years earlier, Shepard’s passage of the bacilli in mouse footpads (MFP) was the first successful reproducible propagation of this organism. His was not, however, the first attempt. Since its discovery, numerous investigators have tried to grow M. leprae and reproduce leprosy in a variety of animal models, including common laboratory species such as rodents, rabbits, and monkeys and other mammals, birds, and even cold-blooded animals [reviewed in (2)]. Most of these attempts were unsuccessful, some because of a natural resistance of the host species to infection, but others likely due to the poor viability of the human biopsy-derived inoculum and a lack of knowledge of the meticulous growth requirements of leprosy bacilli. Shepard and others (3, 4, 5) went on to confirm the utility of the MFP model for growing M. leprae and, for the first time, the establishment and maintenance of isolates of M. leprae was accomplished. Moreover, drug testing, detection of drug resistance, experimental vaccine evaluation, and immunological studies became feasible.