THE ANTIGENS OF TOXOPLASMA GONDII

Publisher Summary This chapter describes the antigens of Toxoplasma gondii. Many different tests for antibody to Toxoplasma gondii have been used in the diagnosis of toxoplasmosis. Many different workers have shown that toxoplasma suspensions have produced different antiserum titers in the test. Experiments, in which light antigens prepared from various sources were mixed with heavy antigens from different sources, showed that inhibition did not occur. In one study, filtration of crude toxoplasma lysates through membrane filters showed that the heavy antigen was removed by filters of an average pore diameter of 100 mu leaving a light antigen. Filtration through a 10 mu filter removed all complement fixing material. Agar gel double diffusion experiments did not show any lines with the so called heavy antigen. This could be explained by its not being able to diffuse through the agar. Agar gel double diffusion experiments with the light antigen showed at least two lines. It seems likely that there are at least three toxoplasma antigens of which two are capable of fixing complement.