[Biological and histopathological characterization together with nucleic acids analysis of a Trypanosoma cruzi strain from Marília, São Paulo State]. / Caracterização biológica, histopatológica e análise de ácido nucléico de uma cepa Trypanosoma cruzi da região de Marília, SP, Brasil.

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/5mul of blood of the 20th 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.

Caracterizaçäo biológica, histopatológica e análise de ácido nucléico de uma cepa Trypanosoma cruzi da regiäo de Marília, SP / Biological and histopathological characterization together with nucleic acids analysis of a Trypanosoma cruzi strain from Marília, São Paulo State

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 realizaçäo da curva parasitêmica e observaçäo da morfologia dos tripomastigotas e 14 foram sacrificados após o 17, 23, 30, 60 e 180 dias pós-infecçäo e coletados coraçäo, 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/5mil de sangue ao redor do 20º dia de infecçäo. Nenhum camundongo morreu na fase aguda da infecçäo. Exame histopatológico mostrou poucos ninhos de amastigotas em coraçäo, raros em músculo esquelético e cólon com discreto processo inflamatório. Comparada com a cepa Y, que foi isolada de uma paciente da mesma regiäo, notamos diferentes características biológicas e comportamentais, porém a análise de DNA as coloca no mesmo grupo, demonstrando a proximidade dessas cepas