Biodemas de cepas do Trypanosoma cruzi isoladas de humanos de três áreas endêmicas de Minas Gerais

Abstract

In order to study the biological behavior of T. cruzi strains and to determine a putative association between their biodeme and the clinical forms of Chagas disease, 14 strains isolated from humans were evaluated. The individuals were from the municipalities of Pains, Iguatama and Berilo (Minas Gerais State). The biological behavior was evaluated in albino swiss mice, weighing 10 to 15 grams, which were infected with 1x10(4) blood tripomastigotes. The infectivity, parasitemia, tripomastigote morphology, virulence and the tissue distribution of the protozoan were analyzed. A behavior similar to biodeme II (São Felipe strain) was observed in 9 strains, while 5 stocks were characterized as belonging to biodeme III. It was not possible to establish a relationship between the biodeme strain and the severity of the disease in the patients.

Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice

“…Furthermore, the other 3 stocks that caused patent infections in mice produced low and late parasitemia, with peaks not exceeding 2,800 trypomastigotes/0.1 mL blood. In relation to the parasitemia, we observed that this profile was very different from those observed in endemic areas, where stocks with variable parasitemia circulate, but with frequent rates of patent infections, in particular for stocks isolated from chronic patients [14][15][16][17][18] . In this study, low parasitemia, a very long PPP, and short PP indicate the low virulence of the strains from the western Amazon region.…”

Seroprevalence of Chagas disease in schoolchildren from two municipalities of Jequitinhonha Valley, Minas Gerais, Brazil; six years following the onset of epidemiological surveillance

“…In general, considering the universe of schoolchildren evaluated (07-14), the general seropositivity was predominant in older children (09-14), with 5/6 of them with 11 to 14 years. However, when considering the two municipalities in separate analysis, Berilo showed seropositivity predominance in younger children (09-13) while José Gonçalves de Minas showed evidence of older children (11)(12)(13)(14). …”

“…Further periodical clinical and laboratorial evaluations after treatment will be performed aiming to verify the parasitological cure and the impact of chemotherapy on the evolution of the disease. Considering the age of the individuals and the genetic of the parasite detected in the area, mainly T. cruzi II isolates 11 , the expectative of the authors is optimist since the benefit effects of chemotherapy can be better in young people or recent infections in both cure 2,6,29 and prognosis of the infection 5,26,28,30 .…”

Organ tropism during the acute and chronic phases of Trypanosoma cruzi infection in BALB/c mice

“…The T. cruzi II strains are more common in the domestic transmission cycle (where triatomine bugs are found) and are best studied, they affect humans, and synanthropic animals. The infection began when humans moved to the wild ecotopes in rural houses, providing food and abundant shelter for vectors (1,3,4).…”

“…The inflammatory response in the myocardium is generally more intense and diffuse and does not correlate with parasite numbers. In combination with edema, the intense mononuclear infiltrate, which is fundamental to Chagas disease pathogenesis, dissociates cardiac fibers and results in different levels of tissue destruction that leave the parasites clearly visible (3,(8)(9)(10). In mouse lungs, amastigotes are detected only in the muscular stratum of pulmonary blood vessels, with a localized inflammatory reaction (6).…”