Population Polymorphism of Trypanosoma cruzi in Latin America indicated by Proteome analysis and by in vitro amastigote proliferation

Nineteen stocks of Trypanosoma cruzi originating from several endemic countries for Chagas’ disease in Central and South America were subjected to two-dimensional protein electrophoresis analysis. The presence or absence of a total of 492 polypeptide spots among 19 gel profiles was determined. The stocks were classified into three major distinctive groups derived from (I) Central America and the northern part of South America; (IIa) Central America and the northern part of South America; and (IIb) central and southern parts of South America, which showed perfect concordance with the previously reported classification based on isozyme and DNA sequence analyses. Late log phase of each epimastigote was inoculated to human cell lines WI-38 and Hs 224.T originating from the lung and muscle, respectively, and the number of trypomastigotes released was counted. The number of trypomastigotes from T . cruzi in group I released from the two cell lines was significantly higher than that in group III (p<0.05). The findings suggested that the phenetic distance appearing within the T . cruzi may, to some extent, be associated with the intracellular growth of T . cruzi, one of the characteristic features of growth found in the species. keywords: Trypanosoma cruzi; Two-dimensional gel electrophoresis; in vitro amastigote proliferation, genetic polymorphism, Latin America