An In house ELISA using recombinant GRA1 and BAG1 proteins as antigen successfully detected Toxoplasma gondii infection in a flock of sheep suffering from abortions.

Toxoplasma gondii is one of the main pathogens causing abortion in sheep. In this study, an in house ELISA using recombinant GRA1 and BAG1 proteins as antigen was used to detect T. gondii infection in a flock of sheep suffering from abortions. Serum samples collected from sheep (n = 23) the day after abortion were initially analyzed with a commercial ELISA using recombinant P30 (SAG1) protein as antigen and then by the in house ELISA using recombinant GRA1 and BAG1 proteins as antigen. Commercial ELISA detected anti-T. gondii IgG antibodies in 20 samples whereas in house ELISA detected anti-T. gondii IgG antibodies in 19 samples. The results of the remaining three serum samples that were seronegative by commercial ELISA were also seronegative by in house ELISA. According to the results of commercial ELISA and in house ELISA, the seroprevalence of ovine toxoplasmosis was 86.9% and 82.6%, respectively. When we accept the validated commercial ELISA as a reference method, the sensitivity and specificity of in house ELISA can be considered as 95% and 100%. These preliminary results show that in house ELISA using recombinant GRA1 and BAG1 proteins as antigen can detect ovine toxoplasmosis successfully.