RESUMO
Antigenic differentiation between three stages of the life cycle of Toxoplasma gondii by fluorescent antibodies. Antisera were prepared in three groups of twenty mice each with three different antigens of Toxoplasma gondii: the first group was inoculated with tachyzoites of RH strain and received sulfadiazine treatment; the second with tissue cysts of T-100-cat-6751 strain and the third with oocysts of the same strain, both without treatment. In the indirect immunofluorescent antibody technique each antigen was tested with its homologous and heterologous antisera, determining qualitative and quantitative antigenic differences according to the fluorescence patterns. Some stages of Toxoplasma when reacting with their heterologous antibodies showed a central, partial posterior or total fluorescence during a certain period of development. The difference in fluorescence was sufficient to distinguish whether the origin of the infection was via cyst, oocysts and/or via tachyzoite when observation was made before day 65 post-infection.
Assuntos
Antígenos de Protozoários/análise , Imunofluorescência , Toxoplasma/crescimento & desenvolvimento , Animais , Anticorpos Antiprotozoários/imunologia , Camundongos , Toxoplasma/imunologia , Toxoplasmose Animal/parasitologia , Toxoplasmose Cerebral/parasitologiaRESUMO
Two groups of patients were examined for anti-Trypanosoma cruzi antibodies by immunofluorescence and ELISA (i) inhabitants of the village and surrounding rural area of Tibu, Norte de Santander, Columbia (n = 327) and (ii) employees of the Empresa Colombiana de Petroleos (ECOPETROL, n = 849). The latter group had a lower rate of positive serology (12 as compared to 29%) but the distributions of antibody titres were very similar in the two groups. A total of 119 serum samples (37 village and 82 ECOPETROL, including 25 seronegative controls) were analysed for their ability to immunoprecipitate the 7 major polypeptides of T. cruzi trypomastigotes of Mr greater than 72 kDa. Although 10 sera from positive patients showed no immunoprecipitation, all of the remaining positive sera contained antibodies which reacted with the 150, 90 and 85 kDa polypeptides. When the T. cruzi immunofluorescence positive, immunoprecipitation negative sera were retested by ELISA using GP90, all were negative thus suggesting that the patients had had a misdiagnosed T. rangeli infection. The new diagnosis was confirmed by immunofluorescence and ELISA with T. rangeli epimastigotes. Longitudinal studies were carried out on 19 patients from the ECOPETROL group for up to 3.5 years. Five seropositive patients showed a change in their anti-trypomastigote immunoprecipitation profiles over this period; one by loss of a previously recognized high molecular weight band and four others by conversion from a negative to a positive immunoprecipitation profile. These latter patients presented initially with uncomplicated T. rangeli infection but then acquired a T. cruzi superinfection. These patients represent the nucleus of a group in which prospective studies will identify the effect of T. rangeli infection on the course of subsequent South American trypanosomiasis and Chagas' disease.
Assuntos
Anticorpos Antiprotozoários/análise , Doença de Chagas/imunologia , Trypanosoma cruzi/imunologia , Tripanossomíase/imunologia , Animais , Colômbia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Humanos , Estudos Longitudinais , Estudos Prospectivos , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
Two laboratory maintenance systems of Trypanosoma rangeli were compared. The maintenance by weekly subinoculations in Tobie's culture medium and the intrafemoral inoculation of Rhodnius prolixus with cultured flagellates, resulted in loss of infectivity of the metacyclic salivarian trypomastigotes for mice, ten months after maintenance in culture. With the system of cyclical passes through culture-Rhodnius-mouse-culture-Rhodnius, the infectivity of the metacyclic trypomastigotes for mice, was maintained during the three years of the experiment. The number and percentage of metacyclic trypomastigotes formed in the salivary glands of R. prolixus, previously inoculated intrafemorally or intracoelomically with culture forms of T. rangeli, did not show correlation with the inoculated dose, however the inoculated quantity demonstrated a direct relation with the mortality rate of the insects. The results indicate that T. rangeli requires an adequate maintenance system, so that under experimental condition the biological characteristics, normally expressed under natural conditions, are conserved.
Assuntos
Meios de Cultura , Rhodnius/parasitologia , Triatominae/parasitologia , Trypanosoma/crescimento & desenvolvimento , Animais , Trypanosoma/patogenicidadeAssuntos
Vetores Artrópodes/parasitologia , Proteínas do Sistema Complemento/fisiologia , Trypanosoma cruzi/fisiologia , Trypanosoma/classificação , Animais , Cobaias/sangue , Cobaias/imunologia , Intestinos/parasitologia , Especificidade da Espécie , Trypanosoma/crescimento & desenvolvimento , Trypanosoma/fisiologia , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
A new, monomorphic trypanosome, Trypanosoma magdalenae sp. n. was found in five of 38 fish, Petenia kraussii, from the Río Magdalena in Colombia, South America. It is the first trypanosome species designated from freshwater teleosts in Colombia. The trypomastigotes measured in 42.4 micron +/- 2.05 SD (range, 39.8 - 45.6) by 2.1 micron +/- 0.20 (2.0 - 2.5). Their nuclear index was 1.6 micron +/- 0.22 (1.25 - 1.84) and their kinetoplastic index equaled 1.1 micron +/- 0.02 (1.08 - 1.15). Infection intensity was usually limited to two or three flagellates per 40 microliter of packed blood cells.