Towards a Better Understanding of the Life Cycle of Trypanosoma copemani.

Trypanosoma copemani has been found infecting several threatened/endangered marsupial species within Australia and is thought to be a key player in the rapid decline of the woylie (Bettongia penicillata). To better understand the biology and life cycle of this parasite, the growth requirements, and kinetics of infection of two newly described genotypes, T. copemani G1 and G2, were investigated and compared with the T. cruzi strain-10R26 in vitro. Both G1 and G2 were able to infect all four cell lines tested. The number of infected cells where at least one intracellular amastigote of T. copemani G1 and G2 was seen was below 7% and 15% respectively in most cell lines. However, in VERO cells the rate of infection for T. copemani G2 was 70%-approximately seven and two times higher than for G1 and T. cruzi respectively. Despite the higher infection rate, the number of intracellular forms of T. copemani G2 was lower compared with T. cruzi, and intracellular replicating forms were not observed. The capability of T. copemani G2 to infect cells may have important consequences for pathogenicity and suggests it might employ similar strategies to complete its life cycle in the vertebrate host to those seen in T. cruzi.