Influence of the long-term Trypanosoma cruzi infection in vertebrate host on the genetic and biological diversity of the parasite

Abstract

The influence of the long-term Trypanosoma cruzi infection in vertebrate host on the biological and genetic properties of the parasite was evaluated. Four T. cruzi isolates obtained from different chronic chagasic dogs infected with Berenice-78 T. cruzi strain during 2 and 7 years were comparatively analyzed. The long-term T. cruzi infection has led to alterations in parasitemia, virulence and pathogenicity of Be-78 strain for mice. These biological parameters varied from low to high in realation to the parental strain. Randomly amplified polymorphic DNA and isoenzyme profiles detected two distinct genetic groups of parasites. The first group included the parental strain and two T. cruzi isolates, and the second group the two other isolates. Interestingly, the isolates of the second group showed a reversibility of the genetic profile to the parental strain after 25 passages in mice. No correlation between the genetic groups and biological properties of the isolates was observed. Our findings confirmed the population heterogeneity of the Be-78 strain, and showed how differently it responds to the long-term infection in the same vertebrate hosts.

Croton cajucara crude extract and isolated terpenes: activity on Trypanosoma cruzi

“…We examined parasite subpopulations of two genotypes: TCI, comprising clone Dm28c and the strains GLT291 and C45 from wild reservoirs, and TCII, Y strain. The GLT291 and C45 strains were recently isolated and being less submitted to the selective process induced by successive passages in laboratory, preserving their original characteristics (Veloso et al 2005).…”

Unequivocal Identification of Subpopulations in Putative Multiclonal Trypanosoma cruzi Strains by FACs Single Cell Sorting and Genotyping

“…However, because only two alleles were detected for the molecular markers used in their characterization, both strains were initially supposed to be monoclonal [34]. Even so, after being inoculated in dogs and mice and re-isolated, major changes in RAPD and isoenzyme profiles were observed in the Be-78 profile, raising the question whether this strain could be indeed a multiclonal population [20]. To answer this query we used the methodology proposed here for sorting Be-78 1B and Be-78 25B, two of the isolates from the Be-78 strain obtained after passages in dog and then in mice.…”

“…The A316A R7 strain was isolated from a Triatoma sordida circulating in northwestern Paraná state, Brazil [17], [18]. The Be-78 1B and Be-78 25B are two populations derived from a chronic chagasic outbred dog infected with Be-78, originally isolated from Berenice, the first patient of Carlos Chagas [19], harvested after 1 or 25 successive blood passages in mice [20].…”

Trypanosoma cruzi high infectivity in vitro is related to cardiac lesions during long-term infection in Beagledogs

“…Infection with Y strain produced higher parasitaemia and shorter PPP in comparison with Berenice-78 strain. The influence of those biological aspects in vivo infections had been previously described for mice (Marques-Araújo & Chiari 1988, Veloso et al 2005) and mongrel dogs using T. cruzi Y and Berenice-78 strains (Guedes 2001. Also blood stream forms of the Y and CL strains had been shown to diversely interact in vitro with anti-sera from chronically infected mice (Krettli & Brener 1976).…”