Macrophage activation and histopathological findings in Calomys callosus and Swiss mice infected with several strains of Trypanosoma cruzi

Abstract

Peritoneal macrophage activation as measured by H2O2 release and histopathology was compared between Swiss mice and Calomys callosus, a wild rodent, reservoir of Trypanosoma cruzi, during the course of infection with four strains of this parasite. In mice F and Y strain infections result in high parasitemia and mortality while with silvatic strains Costalimai and M226 parasitemia is sub-patent, with very low mortality. H2O2 release peaked at 33.6 and 59 nM/2 x 10(6) cells for strains Y and F, respectively, 48 and 50 nM/2 x 10(6) for strains Costalimai and M226, at different days after infection. Histopathological findings of myositis, myocarditis, necrotizing arteritis and absence of macrophage parasitism were found for strains F and Costalimai. Y strain infection presented moderate myocarditis and myositis, with parasites multiplying within macrophages. In C. callosus all four strains resulted in patent parasitemia which was eventually overcome, with scarce mortality. H2O2 release for strains Y and F was comparable to that of mice-peaks of 27 and 53 nM/2 x 10(6) cells, with lower values for strains Costalimai and M226-16.5 and 4.6 nM/2 x 10(6) cells, respectively. Histopathological lesions with Y and F strain injected animals were comparable to those of mice at the onset of infections; they subsided completely at the later stages with Y strain and partially with F strain infected C. callosus. In Costalimai infected C. callosus practically no histopathological alterations were observed.

Experimental Infection of Calomys callosus (Rodentia, Cricetidae) by Toxoplasma gondii

“…Homology between human and C. callosus complement components, particularly C 3 , C 4 and B, has already been demonstrated (Vaz de Lima et al 1992). The profile of hydrogen peroxide release from peritoneal macrophages from Trypanosoma cruzi infected mice and C. callosus shows some noteworthy differences, even though a parallel between macrophage activation and histopathological findings was observed in this two models (Borges et al 1992). …”

“…However, the experimental infection of wild rodents is poorly explored. On the other hand, it has been demonstrated that wild animal species present unique aspects when they are studied in investigation focusing host-parasite interactions (Deane et al 1984, Jansen et al 1985, Borges et al 1992.…”

“…Calomys callosus (Rodentia, Cricetidae) has been described as a reservoir for various infectious agents (Petter et al 1967, Justines & Johnson 1970, Ribeiro 1973, Borges et al 1992, Vaz-de-Lima et al 1992). This rodent was also studied in its biology and breeding aspects, and since then this animal is being used in experiments with T. cruzi (Mello 1978, Mello et al 1979.…”

Evolution and pathology in Chagas disease: a review

“…In one study, the prevalence of parasite infection reached 9.1% of captured wild rodents (Raccurt 1996). Calomys callosus (Rodentia: Cricetidae) are resistant to T. cruzi, surviving inocula that normally kill mice (Borges et al 1992). The histopathological analysis of sections from T. cruzi-infected rodents showed parasitism of liver cells and of striated muscles.…”

Infection of Calomys callosus (Rodentia Cricetidae) with strains of different Trypanosoma cruzi biodemes: pathogenicity, histotropism, and fibrosis induction

“…In the murine model, a diversity of responses were also observed in relation to high or low susceptibility of the inbred strains used . Comparative studies on the influence of several strains of T. cruzi in Calomys callosus and mouse infections have been previously performed by Borges et al (1992). They used inoculation with the Y strain from human origin, and with the Costalimai and M226 strains, from silvatic origin.…”