Detection of antigen and DNA from Toxoplasma Gondii acute phase infection in man

Toxoplasma gondii is a protozoan parasite infecting humans and warm-blooded animals. Toxoplasmosis in pregnancy could cause neurologic disorders in the fetus. In immunocompromised hosts, the infection can be reactivated with life-threatening consequences. Detection of the parasite or its components would constitute a better definition of acute infection. To detect T. gondii antigen and DNA, twenty serum samples in the acute phase of infection were tested. Polyclonal antibodies were isolated from immunized rabbits and SDS-page and immunoblotting were performed. Also, PCR was done with amplification of the B1 gene with two primers. In one patient T. gondii antigen band with a molecular weight of 30 kDa was detected. Parasitemia was detected in the same patient and the 570 bp amplified DNA fragment was isolated. Others had negative results in both immunoblotting and PCR. The patient with positive results had been infected accidentally with a rather virulent C56 strain in the laboratory. The results indicate that antigen and DNA of T. gondii can be detected during the short acute phase of infection.