<b>Weak relation between genetic and biological diversity of natural populations of <em>Trypanosoma cruzi</em></b> - DOI: 10.4025/actascibiolsci.v28i2.1044

Abstract

This paper studies the relation between genetic and biological diversity of natural populations of Trypanosoma cruzi (in Parana State, Brazil) isolated from humans (H), classified as T. cruzi II, and from sylvatic reservoirs (G) and triatomines (T), classified as T. cruzi I. Twenty-five biological parameters were evaluated concerning the kinetic of growth and of metacyclogenesis in mediums LIT and M16, to the infectivity to BALB/c mice, and to the susceptibility to benznidazole. The data support the conclusion of a weak relation between genetic distance and biological diversity using strains. The statistical comparison of the means of each parameter, with regard to the different hosts, showed that group T. cruzi II (H) was significantly different from group T. cruzi I (G and/or T) in 13 of the 25 parameters studied: group H differed from G and T in three parameters, and from G or T in 10 parameters. The major differences found in those parameters were related to the kinetic of growth and of metacyclogenesis. One biological implication from these differences is that the lowest growth of parasite observed in group T. cruzi II (H) makes parasitological diagnoses more difficult and provides lower pathogenicity for mice.