Preliminary characterization of an adult worm "vomit" preparation of Schistosoma mansoni and its potential use as antigen for diagnosis.

Schistosoma mansoni is a parasitic trematode of the portal-mesenteric veins with a closed-end intestine. Adult worms regurgitate their intestinal content after digestion, together with constituents of the lining gut. Some of these molecules circulate in the blood and are antigenic. We obtain a "vomit" preparation and preliminary evaluate its biochemical composition and antigenic capacity. The "vomit" preparation was obtained after changes in temperature and solutions of incubation of adult worms between 4 and 37 degrees C. Supernatant was assayed for protein, carbohydrate concentration and enzymatic activities associated to the intestine and to the worm tegument. The antigenicity of the product was evaluated using Western blot (WB) analysis against sera of experimentally infected mice, before and after drug cure, sera from people infected with S. mansoni and from individuals infected with other parasitoses. More carbohydrate than protein was detected in the preparations. Cysteine proteinase (CP), N-acetyl-beta-D: -glucosaminidase and alkaline phosphatase activities were detected. The latter enzyme activity is a marker of the tegument, suggesting that in spite of careful conditions used to avoid the presence of tegumental material, manipulation of the worms always resulted in the release of tegumental molecules. Cationic exchange chromatography was useful to separate various components of this "vomit" preparation, particularly enzymes responsible for CP activity. Two highly immunogenic and specific duplets were observed in the WB analysis, 31/32- and 38/40-kDa components, the former probably referring to the intestinal CPs Sm31/Sm32. None of the two duplets disappeared after successful chemotherapy during the time of evaluation in mice or humans.

Preliminary antigenic characterisation of an adult worm vomit preparation of Fasciola hepatica by infected human sera

Fascioliasis is an emerging/re-emerging vector-borne disease with the widest known distribution. Approximately 17 million people are infected around the world, being the Andean region the most affected area. There is an important necessity to develop sensitive and specific diagnostic tools to treat patients early and to avoid complications. In this paper we evaluated the immune response of infected humans against two antigenic preparations: the total soluble extract (FhTSE) and the adult worm vomit (FhAWV) in order to identify antigenic fractions specific for Fasciola hepatica. Both preparations were processed by SDS-PAGE and Western blot with human sera with fascioliasis (F), other parasitosis and healthy individuals. In the immunoblot of FhTSE, sera F recognised 16 bands with MW between eight and 110 kDa, from which those of 8, 9, 10, 38, 45 and 57 kDa were specific. In the preparation FhAWV, sera F recognised nine bands with MW from eight to 85 kDa, from which those of 8, 12, 15 and 24 kDa were specific. Some bands of cross-reaction were evident with sera from patients with other parasitoses, more frequent with the FhTSE. Bands within the MW mentioned, particularly that of eight kDa, have been shown to be specific by others, and deserve additional characterisation for their potential use in immunodiagnosis.

Fasciolíase é uma doença emergente/re-emergente transmitida por vetores com a distribuição sabidamente mais ampla. Existem aproximadamente 17 milhões de pessoas infectadas em todo mundo, sendo a região andina a área mais afetada. Há uma necessidade importante para desenvolver ferramentas diagnósticas sensíveis e específicas para tratar cedo os pacientes e para evitar complicações. Neste trabalho avaliamos a resposta imune de seres humanos infectados comparando a duas preparações antigênicas: o extrato solúvel total (FhTSE) e o vômito (FhAWV) do verme adulto a fim de identificar as frações antigênicas específicas para Fasciola hepatica. Ambas as preparações foram processadas por SDS-PAGE e Western blot com os soros humanos de portadores de fasciolíase (F), outras parasitoses e indivíduos saudáveis. No immunoblot de FhTSE, os soros F reconheceram 16 faixas com PM entre 8 e 110 kDa, das quais as de 8, 9, 10, 38, 45 e 57 kDa foram específicas. Na preparação de FhAWV, os soros F reconheceram 9 faixas com PM entre 8 e 85 kDa, das quais as de 8, 12, 15 e 24 kDa foram específicas. Algumas faixas com reação cruzada foram evidentes com os soros dos pacientes com outras parasitoses, mais freqüentes com o FhTSE. As faixas dentro do PM mencionado, particularmente aquela de 8 kDa, mostraram ser específicas por outros autores, e merecem a caracterização adicional para seu uso potencial no diagnóstico imunológico.

Human infection by fasciola hepatica in Venezuela: report of a geriatric case

Se reporta para la literatura parasitológica venezolana, un nuevo caso de infección humana por Fasciola hepatica. Se trata de una paciente de 81 años, asintomática, quien presentó durante exámenes de rutina, una eosinofilia de 21 por ciento y una eritsedimentación de 26 mm/h. Estos valores fueron normales para el momento del tratamiento (4 meses después), así como también lo eran varias pruebas de funcionamiento hepático, química sanguínea y valores hematológicos. El número de huevos del paciente fue de 90 a 130/g de heces. La paciente fue exitosamente tratada con la formulación humana de triclabendazol en 2 dosis simples de 10 mg/kg cada una separadas por 24h, resultado negativas las evaluaciones coproparasitológicas realizadas a los 12,18,60 y 120 días post-tratamiento. Los mismos tests de laboratorio arriba mencionados no mostraron modificaciones excepto por un incremento leve en el contaje de eosinófilos en los días 2 y 11, así como un incremento en los valores de eritrosedimentación al día 11 post-tratamiento. Así mismo, no.

Evaluation of the double diffusion, enzyme immunoassay and immunoblotting techniques, for the diagnosis of human hydatid disease in tropical areas

La hidatidosis en areas tropicales representa un serio problema diagnostico por la alta frecuencia de reactividad cruzada con otras infecciones helminticas. Las tecnicas de immunoensayo (ELISA) y doble difusion arco 5 (DD5) mostraron una sensibilidad de 73 y 57 per cent y una especificidad de 84-95 per cent y 100 per cent, respectivamente. La especificidad en la tecnica de ELISA, fue mejorada sustancialmente al emplear como diluyente de los sueros una solucion buffer conteniendo suero ovino normal y fosforilcolina. En liquido obtenido de hidatides de Echinococcus granulosus de origen ovino, se demostraron tres bandas de origen proteico de 64, 58 y 30 KDa de peso molecular, empleando SDS e inmunoblotting....