Genetic structure of Trypanosoma cruzi in Central America and its comparison with South American strains.

Genetic characterization by isozyme analysis was performed on 68 isolates of Trypanosoma cruzi; 57 from Guatemala in Central America and 11 from South American countries. Ten zymodemes (isozyme patterns) were identified by examining zymograms of 12 enzymes (13 loci). These zymodemes were classified to 3 major distinctive groups: (1) major Guatemalan, (2) minor Guatemalan and (3) unique South American, by the genetic distances and the phylogenetic dendrogram drawn by UPGMA. Based on the results obtained, genetic structures and phylogenetic relations of T. cruzi in Guatemala and South America are discussed. Clonal reproduction seemed to be consistent with the observation of deviation from Hardy-Weinberg equilibrium in several loci.