Are genotypes of Trypanosoma cruzi involved in the challenge of chagasic cardiomyopathy?

Abstract

Myocardial damage in Chagas' disease differs, depending on the particular Trypanosoma cruzi stock. It is reasonable to expect that the extent of phylogenetic divergence between lineages will have an impact on the biological properties of the parasite. The aim of the present work was to evaluate this impact on the cardiac damage produced by this protozoan. Heart histopathologic lesions were studied in mice infected with 15 cloned stocks of T. cruzi of various origins pertaining to 3 major clones or genotypes (19, 20, and 39) that share 3 different profiles for a given set of genetic markers. Sets of mice were infected intraperitoneally with 10(6) blood trypomastigotes of each of the T. cruzi clones. The macroscopy study showed a cardiac index (CI) higher than 0.6 (cardiomegaly) in 5 of the 15 stocks studied (33.33%). Inflammatory infiltrates appeared in stocks pertaining to the three genotypes studied without relation to the genetic pattern. Pseudocysts were present at higher levels (83%) in stocks pertaining to genotype 39. A lower rate could be seen in stocks pertaining to genotype 19 (50%). Only one stock pertaining to genotype 20 presented myocardial parasites (20%). Hearts were also studied for lesions in the different cardiac chambers. Inflammatory foci as well as pseudocysts appeared mainly in ventricles, with the left ventricle sharing the highest percentage of pathologic findings. In summary, in spite of the similar inflammatory pattern demonstrated for all stocks studied, the parasite's presence seemed to be related to the genotype of reference, but no relation could be demonstrated with the genetic distances.

Trypanosoma cruzi burden, genotypes, and clinical evaluation of Chilean patients with chronic Chagas cardiopathy

“…Our results agree with an experimental survey in mice inoculated with three main T. cruzi genotypes, in which all resulted with cardiomyopathy (De Diego et al 1998 ) and TcV, the most frequent genotype in Argentina (Burgos et al 2007 ; Cura et al 2012 ). They differ from the genotypes more frequently observed in patients with cardiomyopathy, TcI in Colombia and Venezuela,, TcII in Brazil (Ramírez et al 2010 ; Segovia et al 2013 ) Therefore, ECG alterations are not related to the number or genotype of parasites.…”

Differential infectivity and immunopathology in murine experimental infections by two natural clones belonging to theTrypanosoma cruziI lineage

“…Further subdivision of T. cruzi II into 5 subgroups is described while no subdivision is apparent within T. cruzi I (Barnabé, Brisse & Tibayrenc, 2000 ;Brisse, Dujardin & Tibayrenc, 2000). Although a number of studies have reported that genetic variability among parasite strains could be related to the disease phenotype during murine experimental infections (parasitaemia, histopathology, mortality) other investigators have demonstrated that significant differences occurred even in the case of genetically related T. cruzi clones (Carneiro, Romanha & Chiari, 1991 ;Andrade & Magalhaes, 1996 ;Laurent et al 1997 ;de Diego, Paulau & Penin, 1998 ;Revollo et al 1998 ;Toledo et al 2002). On the other hand, current biological and epidemiological data support the existence of a link between T. cruzi II and human infection, whereas T. cruzi I is essentially detected in the sylvatic cycle (Clark & Pung, 1994 ;Zingales et al 1999 ;Di Noia et al 2002).…”