Interaction of Leishmania Donovani and Hamster Peritoneal Macrophages: A Phase-Contrast Microscopical Study*

Abstract The interaction of promastigotes of Leishmania donovani and macrophages from the peritoneal exudates of hamsters was investigated with viable cell-culture preparations observed by phase-contrast microscopy. Observation of the sequences of events during the early stages of promastigote engulfment by macrophages and of the subsequent intracellular changes occurring in parasite morphology suggested that several events may influence the fate of the parasite. In one instance the parasite was apparently degraded. In another instance the parasite appeared to transform into the amastigote form.