Imunoreatividade do antígeno liofilizado de Corynebacterium pseudotuberculosis em teste ELISA indireto para diagnóstico da linfadenite caseosa em caprinos

Abstract

Caseous lymphadenitis is a chronic infectious disease caused by the bacterium Corynebacterium pseudotuberculosis, affecting several species of domestic animals. It has zoonotic potential, which causes major economic losses for goat farming, such as decreased meat production, milk and leather devaluation. The aim of this study was to evaluate the immunoreactive capacity of the lyophilized antigen of Corynebacterium pseudotuberculosis for an indirect ELISA test to diagnose caseous lymphadenitis in goats. In this sense, the lyophilized antigen was produced from Corynebacterium pseudotuberculosis strain 1002, which was tested using the indirect ELISA technique to evaluate the immunoreactive capacity and its best dilution. Subsequently, 1:400 was determined as the dilution of choice, afterwards the indirect ELISA was performed using 45 samples positive and 45 negative goat lymphadenitis, for perform the Cut off and cutoff calculations. parameters such as cut-off parameters, sensitivity, specificity, positive predictive value, negative predictive value, accuracy and Kappa index. The results showed cut off (optical density) value of 0.252, whereas the sensitivity of the test as 91.1% and specificity of 84.4% with positive predictive value of 98.5%, negative redictive value of 92.8%. accuracy of 87.1% and Kappa index of 0.898. The lyophilized Corynebacterium pseudotuberculosis antigen presented immunoreactive capacity, with recognition of anti-Corynebacterium pseudotuberculosis antibodies in goat serum in the indirect ELISA test, being possible its application as a diagnostic tool for caffeine caseous lymphadenitis.