Genotyping of Toxoplasma gondii Strains from Goats in Jahrom District, Southern Iran.

PURPOSE: Toxoplasma gondii is transmitted congenitally or acquired by consumption of food and water contaminated with cysts or oocysts. This study aimed at genotyping T. gondii strains from slaughtered goats in Jahrom. METHODS: A total of 561 specimens (heart, diaphragm, and tongue) from 187 slaughtered goats were collected from Jahrom slaughterhouse. After DNA extraction, the T. gondii strains were genotyped by the nested PCR-RFLP based on GRA6 and 3', and 5' ends of the SAG2 gene. RESULTS: T. gondii infection was present in 18.2% of cases. Among the examined organs, the diaphragm was more disposed to the infection (10.2%). Furthermore, infection rates of the heart and tongue were 8.6% and 3.7%, respectively. Concurrent infection in the heart and diaphragm, tongue and diaphragm, and heart and tongue were 3.2%, 0.5%, and 0.5%, respectively. In genotyping experiments, genotype I was the most frequent genotype of T. gondii (58.8%), followed by type II (23.5%), type III (11.8%), and a combination of type I and II (5.9%). CONCLUSIONS: The results of this study showed the presence of different genotypes of T. gondii in goats including three major and mixed genotypes. These results can be useful in toxoplasmosis control and prevention.

The effect of betamethasone and IFN-gamma on replication of Toxoplasma gondii (RH strain) and nitric oxide production in Hela cell culture.

Toxoplasmosis is a protozoal infection caused by Toxoplasma gondii. Toxoplasmosis produce severe damage in patients who are immunosuppressed. In those who are immunosuppressed, latent infection can be reactivated resulting in acute disseminating disease. Betamethasone is a synthetic glycocorticoid, used as an anti-inflammatory and immunosuppressant in a wide variety of disorders. The aim of this study was evaluation of betamethasone as an immunosuppressor drug on infected cells by Toxoplasma gondii. In this study, at first HeLa cells were grown in 24 well culture plates in culture medium . When confluent monolayer was obtained, we compared 6 groups to evaluate the effect of betamethasone as a corticosteroid drug (two concentrations 4 and 40 micro g/ml) and the effect of IFN-gamma (100 IU/ml ) on growth, replication and Nitric Oxide (NO) production. The results showed, that high number of plaques were seen in group with 40 mug/ml of betamethasone and the lowest number of plaques were seen in group with 100 IU of IFN-gamma. The difference between plaque number in control and groups treated with IFN-gamma and betamethasone was significant (P<0.05). The groups with betamethasone or IFN-gamma without tachyzoites did not show any effect on cell structures. Replication rates in the wells treated with IFN-gamma were decreased significantly 72 h post inoculation in comparison with control group (P<0.05). There was no significant difference among different groups in NO production. The results indicated that betamethasone increase the invasion of tachyzoites to host cells in vitro.