Serological Evaluation of Experimental Toxoplasma gondii Infection in Cats by Using Immunoblotting Based on an Affinity Purified Surface Antigen

Toxoplasma gondii is an apicomplexan parasite that infects human and almost all warm-blooded animals. The life cycle of the parasite includes an asexual reproduction in intermediate hosts (Mammals and birds) and a sexual reproduction in definitive hosts (Felidae). Cats are both the intermediate and the definitive host for T. gondii. The aim of this study was to investigate anti-T. gondii antibodies in cats by using an immunoblot method based on a major surface antigen; SAG1. Six sero-negative kittens were infected intra-peritoneally by Rh strain of T. gondii. Serum samples were collected and evaluated for the presence of IgG antibodies by using two techniques; immunoblotting and indirect fluorescent antibody test (IFAT).SAG1 based immunoblotting was able to detect anti-T. gondii antibodies at least eight days after infection. Comparative evaluation showed that this method is as sensitive as IFAT to diagnose T. gondii infection in cats.