Course of infection and histopathological lesions in mice infected with seventeen Trypanosoma cruzi strains isolated from chronic patients

• Main Authors: B R Schlemper Jr, C M Ávila, J R Coura, Z Brener
• Format: Article in Journal/Newspaper
• Language: English; Spanish; Portuguese
• Published: Sociedade Brasileira de Medicina Tropical (SBMT) 1983
• Subjects: Trypanosoma cruzi; Cepas; Histopatologia; Camundongo; Strains; Histopathology; Mouse; Arctic medicine. Tropical medicine; RC955-962; Arctic; Alta; Aguda
• Online Access: https://doaj.org/article/7961e367177e431a9413a94374820436

Mice were infected with blood forms of 17 Trypanosoma cruzi strains recently isolated from chronic patients, which were dassified as of low, medium or high virulence on grounds of the prepatent period, parasitemia and mortality at the acute phase. A total of 212 mice were studied after 3, 6, 9 and 12 months of infection. In the chronic phase, intracellular parasites were detected in 11.0%,27.9%and 54.0,% of mice inoculated, respectively, with the low, medium and high virulent strains (r= 0.98, p < 0.005). Heart fibrosis was also related to virulence, affecting 5.7%, 11.6%and30.8% (r = 0.98, p < 0.001) of the mice inoculated with the above strains; a similar relationship was observed between intensity and frequency of the heart inflammatory reaction and the severity of infection at its early stage. Necrotizing arteritis was detected in 12.2% of the inoculated animals and this lesion was related to the infection duration rather than to strain characteristics. Inflammatory lesions and tissue parasitism were stable within the period of observation, whereas fibrosis was Progressive. The findings suggest that mice may reproduce heart lesions resembling human pathology and that organ damage apparently depends on the parasite virulence. Camundongos foram inoculados com formas sangüíneas de 17 cepas de T. cruzi recentemente isoladas de pacientes chagásicos crônicos e que foram classificadas como de alta, média e baixa virulência através da determinação do período pré-patente, parasitemia e mortalidade na fase aguda da infecção. Cerca de 212 animais inoculados com as diferentes cepas foram estudados após 3,6,9 e 12 meses de in fecção. Na fase crônica da infecção parasitas intracelulares foram observados em 11.0%, 27.0% e 54.0% dos camundongos inoculados respectivamente com as cepas de baixa, médiaealta virulência (r = 0.99, p < 0.001). A fibrose cardíaca também esteve relacionada à virulência sendo encontrada em 5.7%, 11.6% e 30.8% das mesmas cepas (r = 0.98, p < u.005); relação similar foi encontrada entre a ...