ارزيابي روش الايزا با استفاده از آنتي ژن هاي دفعي - ترشحي توكسوپلاسما براي تشخيص توكسوپلاسموزيس در موش صحرايي

Evaluation of ELISA Method Using the Excreted / Secreted Antigens of Toxoplasma for Toxoplasmosis Serodiagnosis in Rat

Background: Many studies have reported that Toxoplasma gondii excreted/secreted antigens (EISA) appear to be a suitable marker for toxoplasmosis serodiagnosis. Most of those studies have used E/SA obtained from supernatent of toxoplasma cell culture, or by incubating tachyzoites in cell free media (RPM1- 1640). The present study, evaluated the ELISA method, using the components of peritoneal fluid of infected mice (as another source of EISA), for toxoplasmosis diagnosis in rat. Materials and Methods: Peritoneal fluids of infected mice by interaperitoneal inoculation (IP) with toxoplasma tachyzoits were collected after 3 days of infection and centrifuged at 750xg for 15 min, then the supernatant was precipitated with ammonium solphate soulution (30% saturated) Forty noninfected (male) rats (7-10 weeks old) were injected with 4x106 toxoplasma tachyzoits IP and their serum samples were collected at 8, 15, 22 and 60 days after the infection. Then 10 samples from each day were tested by Dye- test. The sera of 15 and 60 days after infection of all animals were selected as suitable samples. Then the sera of these days were tested by the dye-test and [LISA using EISA. Results: The cut-off point of ELISA with 99% confidence was found to be 0.33 and optical density (OD) of all the sera samples of 15 and 60 days after infection and 2 negative sera were over than test cut-off. Moreover, sensitivity and specificity of the method were determined to be 100% and 95%, respectively. Conclusion: Our findings showed that ELISA in the condition of using ammonium sulphate precipitation has a good enough sensitivity and specificity for toxoplasmosis diagnosis in rat.