Figure 1. Evolutionary relationships among mismatch-repair class 2 gene (MSH2) and the thiol-disulfide oxido-reductase Tc52 gene (Tc52) from 50 and 51 Trypanosoma cruzi isolates, respectively.

Three phylogenetic trees were created by neighbor-joining (NJ), minimum evolution (ME), and maximum parsimony (MP) methods from the alignment of each gene target and a consensus tree was interpreted. Numbers at the branches are bootstrap values >50% (500 replicates) for the same nodes of the NJ, ME, MP trees. Evolutionary distances were computed using the Kimura 2-parameter method [29]. ▴ = the 17 US TcI isolates that were identical; • = the 24 or 27 US TcIIa isolates that were identical. * = reference strains: SilvioX10 cl1, Colombiana, P209 (TcI); X110/8 (TcIII); CANIII cl1, Dog Theis, Ecua6 (TcIV); CL Brener (TcVI).