Avaliação do comportamento de diferentes cepas do Trypanosoma cruzi na infecção de seis linhagens isogênicas de camundongos

Abstract

O estudo da infecção de camundongos de seis diferentes linhagens isogênicas (A/J, AKR, Balb/c, C3H, C57BL/10 e DBA) pelas cepas do Trypanosoma cruzi- peruana (Tipo I), 21SF (Tipo II) e colombiana (Tipo III) demonstrou que as diferentes cepas do T. cruzi conservam os seus caracteres básicos na infecção das diversas linhagens de camundongos. O grau de resistência de cada linhagem varia conforme o tipo da cepa. Todas as linhagens mostraram alta susceptibilidade à infecção pela cepa peruana; em relação às cepas 21SF e colombiana, os padrões de resistência de cada linhagem variam de acordo com a cepa, formando um espectro, que difere entre as duas cepas citadas, sendo em geral mais reistentes as linhagens DBA e B-10 e menos resistentes as linhagens AKR e A/J. Os animais de todas as linhagens infectados com quaisquer das cepas apresentaram alterações das imunoglobulinas com diminuição precoce da IgG1 e elevação de IgG2a' IgG2b e IgM. Houve uma correlação entre o aumento de IgG2a e o grau de reação inflamatória. O infiltrado inflamatório variou de acordo com as linhagens de camundongo, sendo moderado e mononuclear nas mais susceptíveis e com predomínio de polimorfonucleares nas mais resistentes. Os resultados sugerem que as características do parasito são o fator determinante do padrão básico da infecção pelo T. cruzi

Are genotypes of Trypanosoma cruzi involved in the challenge of chagasic cardiomyopathy?

“…Although our results included dierences in the intensity of heart parasitization between distantly related genotypes, great diversity among clones within each genotype or major clone was observed. These results are in agreement with previous data presented by Andrade et al (1983Andrade et al ( , 1985a and Tibayrenc (1995). Rossi L, Matturri L (1994) …”

“…Changes in histopathologic patterns are considered to depend as much on the characteristics of the host as on those of the parasite (Postan et al 1987), the latter being the factor determining the basic pattern of histologic infection by T. cruzi (Andrade et al 1985a). Dierences between T. cruzi stock types appear to be more important in determining the course of the infection than the genetic background of the host (Andrade 1984).…”

Biological comparison between three clones of Trypanosoma cruzi and the strain of origin (Bolivia) with reference to clonal evolution studies

“…No important variations were observed in virulence of any of the clones, or in the mother strain Bolivia, although recent studies in the cloning of T. cruzi show differences related mainly with the degree of virulence between those isolated from the mother strain (Andrade et al 1985, Postan et al 1987.…”

Linalool, a Piper aduncum essential oil component, has selective activity against Trypanosoma cruzi trypomastigote forms at 4°C

“…To date, no standard conditions for drug testing against T. cruzi have been defined. Therefore, differences in parasite strains, incubation times and temperatures and culture media may all account for variations observed in experimental drug testing, and are likely to delay drug development for Chagas disease treatment ( Andrade et al 1985 ).…”