Cultivation of procyclic trypomastigotes of Trypanosoma congolense in a semi-defined medium with direct adaptation from bloodstream forms.

Bloodstream forms of Trypanosoma congolense added to the semi-defined medium 109-c (Minimum Essential Medium with Earle's salts, 60 mM HEPES, haemin, and heat-inactivated FBS) and incubated at 28 degrees C transformed into procyclic trypomastigotes. Established cultures of the procyclic forms yielded up to 4.5 X 10(7) parasites/ml. The cultivated populations consisted only of trypomastigotes and were not infective for mice. The amino acids consumed to the greatest extent were glutamine, proline, and threonine. Changes in glucose, pyruvate, and lactate concentrations during growth were determined. The procyclic organisms possessed a well-developed mitochondrion.