Evaluation of an ELISA for detection of antibodies to Babesia bigemina in cattle and it's application in an epidemiological survey in Brazil
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Data
2001-06-01
Autores
Madruga, Cláudio R.
Marques, Ana Paula C.
Araújo, Flábio R.
Miguita, M.
Carvalho, Cristiano M.E.
Araújo, Fábio S.
Umaki, Adriana C.S.
Crocci, Adalberto J. [UNESP]
Queiróz, Rosângela A.
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Editor
Colégio Brasileiro de Patologia Animal - CBPA
Resumo
Um ensaio de imunoadsorção enzimática (ELISA) baseado em antígeno bruto foi avaliado na detecção de anticorpos contra Babesia bigemina. A sensibilidade e a especificidade do teste foram de 98,0% e 99,0%, respectivamente. Concordando com a alta especificidade do teste, não foram verificadas reações cruzadas com soros de bezerros inoculados três vezes com 10(7) merozoítos de Babesia bovis. Com relação à comparação do ELISA com a imunofluorescência indireta (IFAT) na detecção de anticorpos contra B. bigemina em bezerros experimentalmente infectados com cinco isolados brasileiros geograficamente distintos deste hemoparasito, o IFAT foi capaz de detectar anticorpos um dia antes do ELISA na maioria dos soros dos animais. Houve uma boa concordância entre os resultados encontrados no ELISA e no IFAT com soros de bovinos de região de estabilidade enzoótica (k=0.61). No entanto, não houve concordância entre os testes sorológicos com soros de animais de área de instabilidade enzoótica (k=0.33). O ELISA foi empregado em um inquérito epidemiológico com 1.367 soros de quatro municípios do Pantanal de Mato Grosso do Sul e caracterizou esta região como uma área de estabilidade enzoótica, uma vez que as prevalências variaram de 87,7 a 98,9%. Dessa forma, este ELISA, que apresentou alta sensibilidade, especificidade e desempenho similar ao IFAT, pode ser utilizado no diagnóstico sorológico de B. bigemina.
An indirect enzyme-linked immunosorbent assay (ELISA) using a crude antigen was evaluated for its performance to detect Babesia bigemina antibodies. The sensitivity and specificity were 98.0% and 99.0%, respectively. In agreement with the high specificity, no cross-reactions were verified with sera from calves inoculated three times with 10(7) Babesia bovis organisms. With regard to the comparison of ELISA and indirect fluorescent antibody test (IFAT) in detecting antibodies against B. bigemina in calves experimentally infected with five Brazilian geographical isolates of this hemoparasite, IFAT was able to detect antibodies one day earlier in most of the calves' sera. There was a good agreement between results shown by ELISA and IFAT with sera from an enzootically stable area (k=0.61). However, there was no agreement between these serological tests with sera from an enzootically unstable area (k=0.33). The ELISA was employed in an epidemiological survey using with 1,367 sera from four counties in the Pantanal of Mato Grosso do Sul and characterized this region as an enzootically stable area, since the prevalences ranged from 87.7 to 98.9%. Therefore, this ELISA with high sensitivity, specificity and performance similar to IFAT can be employed in serological diagnosis of B. bigemina.
An indirect enzyme-linked immunosorbent assay (ELISA) using a crude antigen was evaluated for its performance to detect Babesia bigemina antibodies. The sensitivity and specificity were 98.0% and 99.0%, respectively. In agreement with the high specificity, no cross-reactions were verified with sera from calves inoculated three times with 10(7) Babesia bovis organisms. With regard to the comparison of ELISA and indirect fluorescent antibody test (IFAT) in detecting antibodies against B. bigemina in calves experimentally infected with five Brazilian geographical isolates of this hemoparasite, IFAT was able to detect antibodies one day earlier in most of the calves' sera. There was a good agreement between results shown by ELISA and IFAT with sera from an enzootically stable area (k=0.61). However, there was no agreement between these serological tests with sera from an enzootically unstable area (k=0.33). The ELISA was employed in an epidemiological survey using with 1,367 sera from four counties in the Pantanal of Mato Grosso do Sul and characterized this region as an enzootically stable area, since the prevalences ranged from 87.7 to 98.9%. Therefore, this ELISA with high sensitivity, specificity and performance similar to IFAT can be employed in serological diagnosis of B. bigemina.
Descrição
Palavras-chave
Babesia bigemina, ELISA, testes sorológicos, bovinos, Pantanal, Babesia bigemina, ELISA, serological tests, cattle, Pantanal
Como citar
Pesquisa Veterinária Brasileira. Colégio Brasileiro de Patologia Animal - CBPA, v. 21, n. 2, p. 72-76, 2001.