Trypanosoma cruzi: Colony formation and clonal growth in agar

Trypanosoma cruzi exhibited colonial growth when incorporated into 0.5–0.6% agar. Colonies were established from a single organism and clones readily derived. The plating efficiencies were variable depending on the original inoculum but were consistently over 50% when 10 4 to 10 5 parasites were added. The use of this technique for evaluation of an antitrypanosomal agent, nifurtimox, was demonstrated, making possible large-scale testing of potential antitrypanosomal agents and assessment of microbicidal and microbio-static drug levels.