The First Survey of Isolation and Molecular Typing of Toxoplasma gondii by Bioassay and PCR Method in BALB/c Mice in Camels (Camelus dromedarius) from Eastern Iran

Background: We isolated Toxoplasma gondii from camels by bioassay method in mice model and detect parasitic DNA in brain mice by molecular methods. Methods: One hundred tissue samples including heart (n=50), and diaphragm (n=50) were collected from camels (n=50) slaughtered in abattoirs from Feb to Oct 2015 in three provinces located in eastern Iran. In first, blood sample from 50 camels was assayed for anti-Toxoplasma antibodies by modified agglutination test (MAT) test. Bioassay method was done in positive MAT blood camels in BALB/c mice and Nested PCR performed in seropositive tissue samples to amplify the B1 and GRA6 genes. The existence of polymorphic restriction sites for endonuclease MseI was used with PCRRFLP method and Sequencing analysis to evaluate the prevalence of type strains (I, II and III) Results: Overall, 13 (26%) of camels were positive with titer of 1:20 for toxoplasmosis and 13(26%) tissue samples of camels were found positive for the T. gondii B1 gene, including 7(14%) diaphragm, 6(12%) heart. Moreover, 3(6%) tissue samples of camels were found positive with GRA6 gene for T. gondii. There are three genotypes and mix genotype using MseI enzyme among all positive samples. Conclusion: The obtained results from serological and molecular tests demonstrated the infection of T. gondii with previously recognized genotypes in the tissues of camels for first time from Iran. Since consumption of meat camels are raising in Iran, there may be a high risk of toxoplasmosis through consumption of products from these hosts due to their susceptibility to the infection.