Isolation of the Most Immunoreactive Antigens of Echinococcus Granulosus from Sheep Hydatid Fluid

Abstract

Abstract This paper describes a simplified procedure for obtaining purified Echinococcus granulosus antigens from sheep hydatid fluid by using affinity chromatography on concanavalin A-Sepharose. The presence of two “major” antigens (4 and 5) was confirmed. Antigen 5 was isolated by preparative polyacrylamide gel electrophoresis. Antigen 4, eluted by diffusion from the gel, was seen to be “contaminated” by antigen 5 and was isolated by using anti-5 Sepharose-linked serum. These two major antigens were then tested separately against the sera of hydatidosis patients by using very simple immunologic tests. The best results were obtained in passive hemagglutination with antigen 4. Antigen 4 is the most immunoreactive parasitic antigen; antibodies against it were found in the sera of all hydatidosis patients showing a positive reaction. Apart from the direct use of this antigen in serologic tests, it appears possible to standardize the most frequently used and commercially available antigenic materials by titrating this component.