Trypanosoma cruzi: isolation and characterization of two clones derived from neonatal mice.

The Tulahuen strain of Trypanosoma cruzi was cloned in 15 C3H/Anf neonatal mice. Ten of these 15 neonates became parasitemic before the 12th day and died before the 19th day after the inoculation of a single bloodstream trypomastigote. Two clones were selected and maintained, while the other isolates which did not grow in a liquid metacyclic stage culture (LMC) medium were eventually discarded. The kinetics of in vitro growth and transformation from epimastigote to metacyclic trypomastigote of these two clones were characterized in LMC medium at 27 degrees C. Infectivities for vertebrate cells in vitro were retained by these two clones during the period of cultivation. The tropism for brain, heart, lungs, esophagus, stomach, large intestine, liver, pancreas, spleen, lymph nodes, kidneys, bladder, and skeletal muscles was also examined in the mice. The communication describes the establishment and characterization of T. cruzi clones. The utilization of these cloned parasites should produce some advantages in generating reproducible data in investigations.