Detection of Antibodies to Excretory-Secretory Antigen of Toxocara vitiilorum Infective Larvae in Buffalo Calves by ELISA

In the current research, -immunogenic binding activities of Toxocara vitulorum second larvae somatic antigen and excretory secretory antigen (TvL2ESA) were studied by ELISA using hyperimmune serum. As, the excretoiy secretory antigen was the most potent one. So, it was selected for diagnosis of toxocariasis in buffalo calves, whereas it recorded infection percentages of 73.8. Structural characterization of TvL2ESA was done by SDS-PAGE and it revealed 8 bands of molecular weights ranged from 5 - 135 KDa. Further characterization of this antigen was carried out by immunoblot assay in which naturally infected buffalo calves sera were utilized. Only three bands of molecular weights 71, 51, 24 KDa were identified. Free amino acid analysis of the same antigen revealed 18 amino acids with high proportion of only two of tyrosine and aspartic. In conclusion: ES products of T. vitulorum second larvae was the most diagnostic antigen and was successful in the detection of high infection percentage of toxocariasis among buffalo calves in Egypt.