Avaliação de antígenos do Trypanosoma Cruzi para a reação de hem aglutinação indireta: I. diferentes extratos antigênicos

Abstract

Alguns procedimentos descritos na literatura (ultrasom, água destilada, NaOH, TRITON x 100 e congelamento-descongelamenao) foram avaliados determinando o melhor extrato antigênico para a reação de hemaglutinação indireta (RHI) no diagnóstico sorológico da doença de Chagas. Para isso, foram ensaiados 30 soros de indivíduos chagásicos e 30 soros de indivíduos não chagásicos. A reação de imuno-fluorescência indireta foi considerada como reação de referência no cálculo dos indices de co-positividade (i.c.p.) e co-negatividade (i.cn.). O valor do i.c.p, para a RHI com antígeno obtido por NaOH foi mais elevado do que para os outros antígenos. Os cinco antígenos apresentaram valores máximos para o i.cn., indicando boa especificdade. Os títulos apresentados pelos soros chagásicos com antígeno obtido por NaOH foram, significativamente, superiores aos demais antígenos. A avaliação de cinco partidas de antígeno extraídas por NaOH em épocas diversas indicam boa sensibilidade, especificidade e reprodutibilidade de resultados, traduzidas pelos valores elevados para os i.c.p. e i.cn., além de títulos próximos entre si.

Follow-up of experimental chronic Chagas' disease in dogs: use of polymerase chain reaction (PCR) compared with parasitological and serological methods

“…cruzi specific antibodies was detected by the technique described by Voller et al (1976) modified and adapted by Lana et al (1991). ELISA plates were sensitized with T. cruzi antigen prepared by alkaline extraction (Vitor and Chiari, 1987) of Y strain obtained at exponential growth in LIT medium. Antibody binding was detected by using peroxidase-labeled anti-dog IgG, after reading in spectrophotometer, using 490 nm filter (BIO-RAD, 3550).…”

Participation of Central Muscarinic Receptors on the Nervous Form of Chagas Disease in Mice Infected via Intracerebroventricular with Colombian Trypanosoma cruzi Strain

“…Serological Method (ELISA-Enzyme Linked Immunosorbent Assay) ELISA was carried out in serum samples diluted 1:80 from surviving animals collected before necropsy (15 and 30 d.p.i) according to [61] modified and standardized as [62]. Bruit alkaline antigen [63] peroxidase-labeled anti-mouse IgG conjugate (SIGMA, St. Louis, MO, USA) and the substrate solution of ortho-phenylene diamine (OPD) were used. The reaction was read in a spectrophotometer (Bio-Rad, Berkeley, USA, Model 680-microplate manager 5.2.1) and using a filter of 490 nm.…”

Seroprevalence of Chagas disease in schoolchildren from two municipalities of Jequitinhonha Valley, Minas Gerais, Brazil; six years following the onset of epidemiological surveillance

“…Using these premises a sample estimated in 1,492 individuals was selected by single random process stratified by density of individuals in each school unit. 31 . The protein content was determined by LOWRY et al 19 .…”

“…The ELISA test was performed according to the methodology of VOLLER et al 32 modified using 4.5 µg/mL of antigen concentration, peroxidase-conjugated anti-human IgG conjugate diluted 1/1000 and BEFP diluted 1:80 in PBS-Tween 20, correspondent to the standardized methodology 31 . The OD was determined using 490 nm filter (SOFT-MAX ® PRO 4.0-Life Sciences edition).…”