Detecção de anticorpos IgG aos antígenos extratos solúveis (Ex) de larvas de Toxocara vitulorum pelo Western Blotting no colostro e no soro de vacas e bezerros búfalos

Toxocara vitulorum is a nematode parasite of the small intestine of cattle and water buffaloes, particularly buffalo calves between one and three months old, causing high morbidity and mortality. The purpose of this research was the characterization of soluble larval extract (Ex) antigen of T. vitulorum by Sds-page and Western blotting (WB) using immune sera and colostrum of buffaloes naturally infected by T. vitulorum. The parasitological status of the buffalo calves was also evaluated using sequential fecal examinations. The results showed that this antigen revealed eleven (11, 13, 16, 22, 25, 32, 43, 53, 68, 82 and 96 kDa) polypeptide bands by SDS-PAGE. Five polypeptide bands of higher molecular weight (43, 53, 68, 82 and 96 kDa) were recognized by sera and colostrum of all groups of infected animals when analyzed by WB. But only the fractions of 53, 68, 82, and 96 kDa that were more prominent persisted in the groups of buffalo calves during the beginning of the infection, at the peak of egg output, as well as during the period of rejection and post-rejection of T. vitulorum by the feces of the calves. On the other hand, sera of buffalo calves at one day old, after suckling the colostrum and at the beginning of infection, reacted with the same bands detected by serum and by colostrum of the buffalo cows.