Institute of Tropical Medicine, Nagasaki University
Abstract
The present study was done to establish an in vitro axenic culture of amastigote like forms of Leishmania (Leishmania) donovani (Dd-8 strain), the causative agent of Indian kala-azar. Transformation of promastigotes to amastigote like forms was induced by temperature shift from 26±1℃ to 34±1℃ at pH 7.0 in NNN medium. These forms were dividing as evidenced by flow cytometry. Scanning and transmission electron microscopic studies revealed a remarkable ultrastructural similarity of these in vitro cultured amastigotes with intracellular amastigotes. These forms have been successfully maintained for a period of more than one year, during which they have remained infective. On subjecting these forms to temperature of 26±1℃, they reverted back to the promastigote forms. Thus a simple NNN medium, free from foetal calf serum has been developed to generate large amounts of amastigote like forms which can be used for further biochemical, immunological and chemotherapeutic studies
