ABSTRACT
Nineteen stocks of <I>Trypanosoma cruzi</I> 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 of492polypeptide spots among19gel 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-38and Hs224.T originating from the lung and muscle, respectively, and the number of trypomastigotes released was counted. The number of trypomastigotes from <I>T</I>. <I>cruzi</I> in group I released from the two cell lines was significantly higher than that in group III (p&It;0.05). The findings suggested that the phenetic distance appearing within the <I>T</I>. <I>cruzi</I> may, to some extent, be associated with the intracellular growth of <I>T</I>. <I>cruzi</I>, one of the characteristic features of growth found in the species.