ABSTRACT
Toxoplasma gondii is one of the most common protozoan parasites in humans and animals in all countries of the world. The aim of this study was to detect Toxoplasma parasite in the brain of wild rats in Tehran using smear preparation, Giemsa staining, Intraperitoneal injection and oral administration to Souri mice. Forty rats were collected from different areas of Tehran. Smears were prepared from rat brains on glass slides and stained using Giemsa. In the second method, a cell suspension was prepared from rat brain and was given orally and injected intraperitoneally into Souri mice. In peritoneal method, peritoneum of the mice was examined for parasites. In oral method, the titer of Toxoplasma antibody in sera of Souri mice was determined using Toxoplasma IgG antibody kit and anti-mouse conjugate of Sigma company. All results were negative in Giemsa staining method. In the second method, the results were negative and no parasites were observed in peritoneum of Souri mice. In oral administration method, after ingestion of suspensions by Souri mice and measuring the IgG titer, 50% of them showed a positive titer after one month. In detection of Toxoplasma gondii, the method of smear preparation on glass slides followed by Giemsa staining, and intraperitoneal injection of brain suspensions to Souri mice are of less value in comparison with oral administration of suspensions and determining the titer of IgG in sera of Souri mice