Use of recombinant antigens for detection of Toxoplasma gondii infection in swine

Five recombinant Toxoplasma gondii antigens, designated B427, C51, C55, V22 , and MBP30 were assessed for their potential use in an enzyme-linked immun oassay (EIA) for detection of T. gondii infection in swine. The antigens we re evaluated with sera from young pigs that had been fed 1-10,000 T. gondii oocysts of the VEG or GT-I strains. Results were compared with an EIA usin g a native T. gondii antigen extract. All 5 recombinant antigens, as well a s native antigen, detected antibody responses as soon as 3 wk after infecti on in pigs inoculated with 1 or 10 oocysts of the VEG strain. This antibody response persisted, at varying levels, for 14 wk when the experiment was t erminated. All antigens also detected antibody responses in pigs 4 wk after inoculation with 10,000 oocysts of the GT-I strain. The antibody response recognized by native antigen remained high through 51 wk after inoculation. However, there was considerable animal-to-animal variation in responses to the individual recombinant antigens. Only antigens C51 and MBP30 consisten tly detected a positive antibody response over the entire 51-wk course of t he experiment. These results suggest that these antigens might be useful fo r the serological detection of T; gondii infection in pigs.