Nelson J. Alvarenga

A simplified method for sample collection and DNA isolation for polymerase chain reaction detection of Trypanosoma rangeli and Trypanosoma cruzi in triatomine vectors

Due to the overlapping distribution of Trypanosoma rangeli and T. cruzi in Central and South America, sharing several reservoirs and triatomine vectors, we herein describe a simple method to collect triatomine feces and hemolymph in filter paper for further detection and specific characterization of these two trypanosomes. Experimentally infected triatomines feces and hemolymph were collected in filter paper and specific detection of T. rangeli or T. cruzi DNA by polymerase chain reaction was achieved. This simple DNA collection method allows sample collection in the field and further specific trypanosome detection and characterization in the laboratory.

Metaciclogênese do Trypanosoma cruzi como parâmetro de interação do parasita com o triatomíneo vetor

Infection of Triatoma infestans with three different strains of Trypanosoma cruzi permited to observe: 1) numerical variability of metacyclics obtained after different times; 2) the differences of loss of infection according to each strain; 3) the relationship between ingested parasites and later obtained metacyclics.

Triatomine's embryo extracts promote growth of culture forms of Trypanosoma cruzi

A m o n g 59 s tu d ie d c h ro n ic c h a g a s ic patients, in four of them it was only possible to is o la te T r y p a n o s o m a c r u z i u s in g haemoculture, but not xenodiagnosis1. This fa ilu re in i s o la t in g T. c r u z i u s in g xenodiagnosis performed with three different triatomine species, represents an opportunity to evaluate the interaction between T. cruzi and its infection within the triatomine vector. Based on observation that a triatomine embryo-cell-line allows the differentiation of the p arasite to m etacic lic form s5 and the i n d u c t i o n o f p a r a s i t e g r o w t h a n d differentiation in cultures, when supplemented with triatomines’ intestinal extracts2 we argue that som e of the questions related to triatomine’s susceptibility and infection could be answered by studding the influence of the vector’s organ extracts on parasite growth in culture media. The present study is being conducted to a n a l y z e t he ro l e of d i f f e r e n t o r ga n homogenates, from embryos to adult stages of triatomines, on the growth and differentiation of two T. cruzi strains (Herm and Fran) isolated only by hem oculture from two chagasic patients and frozen immediately after isolation. The isolates were used after five passages in LIT media. Suspensions of four and three days old embryos, of Dipetalogaster maxim us and Rhodnius prolixus respectively, were obtained from ground eggs in PBS (pH 7.2). The extracts were filtered either with 0.22 or 0.45pm Millipore filters, in order to observe possible differences in the flagellates growrth due to the

Seqüência dos estudos sobre a produção experimental de megassíndromes em camundongos

The mega-producing capacity of three strains of Trypanosoma cruzi of widely different origins was examined using techniques previously described. A significant correlation was found for two of the strains between the volume and weight of the stomach at autopsy and measurement of the area of a barium silhouette of this organ. All three strains caused significant stomach dilatation after prolonged infection in the mice when compare with a control uninfected group. However the behavior of a strain (mega) previously studied in this model had altered, possibly as a result ofrepeated mice passage in the laboratory.

Incapacidade de evolução do Trypanosoma cruzi na hemocele de triatomíneos

Examination of haemolymph from triatomine-bugs (Triatoma infestans and Dipetalogaster maxima) harboring Trypanosoma cruzi infection for 10, 15, 20 and 30days did not reveal the presence of flagellates. Material obtained by washing out the haemocoel of infected D. maximus was also negative. Inoculation of bloodstream trypomastigotes and triatomine intestinal flagellates into the haemocoel revealed that parasites were not able to maintain a detectable infection in the haemolymph for more than 40 days and that parasites could not enter in the intestine of triatomines. Inoculation of haemolymph of infected bugs in baby-mice has not induced infection.

Human immune response to triatomine embryo extract

Dipetalogaster maximus embryo extracts were used to stimulate peripheral blood mononuclear cells (PBMC) and in ELISA with sera either from Trypanosoma cruzi infected or non-infected individuals. The results showed that there was significant proliferative response and high antibody, titers in sera of chagasic patients.

CELL GROWTH INHIBITOR FACTOR IN HEMOLYMPH OF DIPETALOGASTER MAXIMUS

Centro de Pesquisas Rene Rachou - FIOCRUZ, Av.Augusto de Lima 1715, 30190-002 Belo Horizonte,MG, Brasil *Departamento de Bioquimica eImunologia, ICB, Universidade Federal de MinasGerais, Belo Horizonte, MG, BrasilKey words: triatomine - hemolymph - Dipetalogastermaximus - cell growth inhibitor factor -Trypanosoma cruzi