Developmental cycles of Trypanosoma (Schizotrypanum) cruzi (Chagas, 1909) in mouse peritoneal macrophages in vitro

Abstract

Mouse peritoneal macrophage cells suspended in a TC 199 calf serum medium and cultured in Leighton tubes, were infected with Trypanosoma (Schizotrypanum) cruzi culture forms in order to study the development of this parasite in vitro. Three cycles of development were thought to occur: 1. Epimastigotes or trypomastigotes were taken up by macrophages and transformed into amastigotes. These multiplied by binary fission and ruptured the infected cell after 4‐5 days. Released amastigotes were taken up by uninfected macrophages and the cycle was repeated. 2. A small proportion of intracellular amastigotes developed into ‘ovoid forms’ which transformed progressively into promastigotes, epimastigotes and trypomastigotes. 3. Some amastigotes became ‘round forms’ from which sphaeromastigotes developed. These transformed directly into trypomastigotes without the formation of epimastigotes.