Abstract
Leishmania parasites cause a wide range of human diseases from localized self-healing cutaneous lesions to fatal visceral disease. These parasites are characterized by having a non-motile form, amastigotes, within the macrophage of the mammalian host and a motile form, promastigotes, in the sand fly. Transformation of promastigotes has been attracting considerable attention in studying the parasite-host interaction. It is the purpose of this article to review the transformation of promastigotes to amastigotes and the growth of the later form in a cell free medium, i.e. axenically. Also, results of original work on axenic amastigotes of Leishmania donovani are shown. The effect of temperature, pH, and gas requirements on the transformation and further growth of Leishmania donovani axenic amastigotes are discussed.