Dados do Trabalho

Título

Impact of gastrointestinal inoculation and benznidazole treatment on Trypanosoma cruzi II infection in mice

Introdução

The protozoan Trypanosoma cruzi causes Chagas disease and the most frequent form of transmission of the parasite is via the oral route, associated with greater severity and worse response to benznidazole (BZ), the drug used in its treatment.

Objetivo(s)

This study aimed to evaluate the impact of gastrointestinal infection (GI) and BZ treatment on the histopathological alterations in mice inoculated with T. cruzi II.

Material e Métodos

Swiss mice were inoculated by GI (by gavage) and intraperitoneal (IP) routes with 2x106 culture-derived metacyclic trypomastigotes of the Y strain, belonging to the discrete typing unit (DTU) T. cruzi II (TcII), and were treated with BZ (100 mg/kg/day, 20X) in the acute phase of the infection. Fresh blood examination, qPCR, histopathological and biochemical evaluations (enzymatic dosages and oxidative stress-OS) were performed.

Resultados e Conclusão

BZ treatment of uninfected animals caused changes in the liver, increased the activity of AST and ALT enzymes and OS, showing that the drug alone affects this organ. Inflammation and necrosis in the cardiac tissue were less intense and deaths occurred later in animals inoculated via the GI route than the animals inoculated via the IP route. BZ reduced the intensity of tissue lesions and avoided lethality in animals inoculated via the GI route, and decreased parasitemia and OS in those inoculated via both routes. Although BZ alone caused liver damage, it was less intense than that caused by both routes of inoculation. Infection with the TcII (Y strain) via the GI route proved to be less virulent and pathogenic and responded better to BZ-treatment than the infection acquired via the IP route, suggesting that the intensity of oral infection and its response to etiologic treatment depends on the strain/DTU of T. cruzi.

Palavras-chave

Trypanosoma cruzi, oral Chagas disease, benznidazole, qPCR, aminotransferases, oxidative stress.