Caracterização biológica, histopatológica e análise de ácido nucléico de uma cepa Trypanosoma cruzi da região de Marília, SP

Abstract

Resumo Estudou-se o comportamento biológico e histopatológico de uma cepa genuínamente mariliense de Trypanosoma cruzi, isolada em 1997 através de xenodiagnóstico artificial. Vinte e cinco camundongos swiss foram infectados intraperitonealmente, sendo 11 utilizados para a realização da curva parasitêmica e observação da morfologia dos tripomastigotas e 14 foram sacrificados após o 17, 23, 30, 60 e 180 dias pós-infecção e coletados coração, esôfago, fígado, cólon, e músculo esquelético (fragmento da coxa direita) para análise histopatológica. Cultura em meio LIT foi realizada para análise de DNA. Os resultados mostraram predomínio de formas largas, baixa parasitemia com picos médios de 860 tripomastigotas/5µl de sangue ao redor do 20º dia de infecção. Nenhum camundongo morreu na fase aguda da infecção. Exame histopatológico mostrou poucos ninhos de amastigotas em coração, raros em músculo esquelético e cólon com discreto processo inflamatório. Comparada com a cepa Y, que foi isolada de uma paciente da mesma região, notamos diferentes características biológicas e comportamentais, porém a análise de DNA as coloca no mesmo grupo, demonstrando a proximidade dessas cepas. Palavras-chaves: Trypanosoma cruzi. DNA. Histopatológico. Cepa Famema. Infecção experimental.Abstract The aim of this report was to study the biological and histopathological behavior of a Trypanosoma cruzi strain, which is found in the region of Marília. The strain was isolated in 1997, by artificial xenodiagnosis. Twenty-five swiss mice were intraperitoneally inoculated. Eleven were used for observation of parasitemia and trypomastigotes morphology and 14 were sacrificed after 17, 23, 30, 60 and 180 days post-infection. Heart, esophagus, liver, colon, and skeletal muscle (fragment of the right thigh) were collected for histopathological study. LIT culture medium was accomplished for DNA analysis. The results showed predominance of broad forms, low parasitemia with mean peaks of 860 trypomastigotes/5µl of blood of the 20 th day of infection. No animal died in the acute phase of infection. Histopathological analysis showed several pseudocysts of amastigotes in heart, rare in skeletal muscle and colon with discreet inflammatory process. When Famema strain was compared with Y strain, which was isolated from a patient who lived in the same area, a distinct behaviour and biological characteristics were observed. However, DNA analysis placed them in same group, hence displaying the proximity of these strains.

Morphological, biological and molecular characterization of three strains ofTrypanosoma cruziChagas, 1909 (Kinetoplastida, Trypanosomatidae) isolated fromTriatoma sordida(Stal) 1859 (Hemiptera, Reduviidae) and a domestic cat

“…The existence of T. cruzi strains with tropism for different tissues was reported by Melo and Brener in 1978. The study of the density of parasites in the organs of vertebrates may help to understand the pathogenesis of the disease because neuronal destruction and inflammatory processes may be directly influenced by local parasitism (Koeberle, 1968 However, tissue parasitism also depends on the intrinsic characteristics of the parasite, as well as the standardization of initial inoculation (Melo and Brener, 1978;Andrade and Magalhães, 1997;Martins et al 2003). These authors used higher initial inoculation of 10 000 parasites/ml for histopathological study.…”

Evaluation of antioxidant therapy in experimental Chagas disease

“…This observation reflects the complex interactions that occur between different components involved in the regulation of plasma antioxidant capacity components to enhance protection against free radicals under certain circumstances 21,36 . Our results indicate that supplementation with vitamin C, an important component of FRAP, could either directly or indirectly stimulate this defense mechanism.…”

“…Beginning on the 8 th day after infection, measurements were performed twice weekly for 60 days using the Brenner 20 method adapted by Martins et al 21 .…”

Using Captive Sentinels to Collect Wild Triatomines in the Region of Marília-Sp, Brazil

“…In addition to these two species, Rhodnius neglectus, Triatoma arthurneivai, Panstrongylus diasi, Panstrongylus geniculatus, Rhodnius domesticus and Triatoma tibiamaculata were also found (Wanderley, 1991 Silva et al (2003Silva et al ( , 2008 did not find high levels of infestation in the city of Marília, a region that was part of the endemic area in the State, with large numbers of patients affected by Chagas disease, where a Y strain (Silva & Nussenzweig, 1953) was isolated from a patient. More recently, the FAMEMA strain (Martins, 2003) was isolated by artificial xenodiagnosis from a chronic chagasic patient from that same region.…”