[Characterization of experimental infection with Mycobacterium lepraemurium in 2 strains of mice]

A model of experimental leprosy in two strains of mice, namely CBA/J and CBi, has been developed based on: 1) the histological examination of a granuloma in the hind foot pad 200 days after inoculation of 0.30 microliter of Mycobacterium lepraemurium (6 x 10(8) MLm/ml); 2) the assessment of T lymphocytes in the granuloma identified by the alpha-naphthyl acetate method for esterase, and c) dissemination of the infection. The histological findings in the low resistance CBA/J strain included positive acid fast bacilli vacuolated cells, without lymphocytic infiltration, scarce number of T lymphocytes and a generalized and important dissemination, similarly to the one observed in human lepromatous leprosy. The histological findings in the hind foot pad granuloma of 30-40 per cent of the medium to high resistance CBi strain, consisted of vacuolated cells and lymphocytic infiltration, a large number of T cells and a scarce dissemination, similar to the human borderline leprosy. Both strains present a different susceptibility to a unique challenge with the mycobacterium which could be useful to disentangle the immunogenetic components involved, by means of appropriate selection and crosses. Furthermore, it could be of interest to perform immunoprotection assays in CBi mice, which might have some bearing on the development of a vaccine in human leprosy.