Evolution of Trypanosoma cruzi infection in resistant and susceptible mice

Mice from ACA and A.Sn strains were equally susceptible (100% mortality) to intraperitoneal infection with 2000 blood trypomastigotes from Tulahuen strain of Trypanosoma cruzi, while A.Sw and HTI strains were resistant (100% survival). However mice from A.Sw and HTI strains showed significantly higher level of parasitemia than the susceptible strains. The histopathology of miocardial and skeletal muscle was evaluated in the susceptible and resistant strains of mice. In the first ten days post-infection no significant differences in tissue damage were observed. However in the third week of infection, while A.Sw and HTI mice showed recovery of tissue lessions, the susceptible A.Sn and ACA showed increased tissue damage although no blood forms and intracellular parasites were detected. Serum samples from infected mice were tested by dot-immunoradiometric assay, for reactivity against recombinant antigens 1,2,13,26,30,36' and SAPA of T cruzi. All mice sera only reacted with clones 13 and SAPA, suggesting that this reactivity seems not to be involved in susceptibility or resistance to infection with Tulahuen strain of T cruzi..