Application of recombinant antigens in serodiagnosis of swine toxoplasmosis and prevalence of Toxoplasma gondii infection among pigs in Poland

Abstract

In this study, to determine the prevalence of swine toxoplasmosis, 1754 pigs from different regions of Poland were tested for IgG antibodies by an in-house ELISA technique based on native Toxoplasma lysate antigen. Seropositive individuals were found in 19.2% of the examined population. The diagnostic usefulness of three T. gondii recombinant antigens (rMAG1, rSAG1, and rGRA7), either individually or in cocktails (M1: rMAG1 + rSAG1; M2: rMAG1 + rGRA7; M3: rSAG1 + rGRA7; M4: rMAG1 + rSAG1 + rGRA7) were also assessed with serum samples from naturally infected pigs by ELISA analysis. Both rSAG1 and rGRA7 antigens detected specific IgG antibodies with a similar sensitivity (85.3% and 81.3%, respectively), whereas the lower sensitivity was obtained for rMAG1 (only 64%). Better results of reactivity were obtained for mixtures of two antigens: M1 (86.7%), M2 (89.3%) and M3 (92%). Furthermore, the reactivity of three antigens cocktail M4 (97.3%) was much higher than that of individual proteins and combinations containing two antigens. These results suggest that the combination of three recombinant antigens might be useful for the serological detection of T. gondii infection in pigs.