Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 7 3 2012 09 15 64 72 GR Habibi Parasite Vaccine Research and Production Department, Razi Vaccine and Serum Research Institute, Karaj, Iran AR Imani Veterinary College, Islamic Azad University, Karaj, Iran MR Gholami Pathology Department, Razi Vaccine and Serum Research Institute, Karaj, Iran MH Hablolvarid Brucellosis Vaccine Research and Production Department, Razi Vaccine and Serum Research Institute, Karaj, Iran AM Behroozikhah Brucellosis Vaccine Research and Production Department, Razi Vaccine and Serum Research Institute, Karaj, Iran M Lotfi Quality Control of Biological Products group, Razi Vaccine and Serum Research Institute, Karaj, Iran M Kamalzade Quality Control of Biological Products group, Razi Vaccine and Serum Research Institute, Karaj, Iran E Najjar Veterinary Organization of Qazvin Province, Qazvin, Iran K Esmaeil-Nia Parasite Vaccine Research and Production Department, Razi Vaccine and Serum Research Institute, Karaj, Iran S Bozorgi Parasite Vaccine Research and Production Department, Razi Vaccine and Serum Research Institute, Karaj, Iran 2015 10 03 Background: The aim of this study was to apply the nested-PCR and bioassay methods in detection and genotyping of Toxoplasma gondii infection in provided sheep aborted fetus samples from Qazvin Province of Iran. Methods: Eighteen sheep aborted fetal samples were studied by nested-PCR-RFLP, histopathologi­cal observation and microbiological assay. Bioassay in mice was carried out by inoculating the brain samples intraperitoneally. Results: The results demonstrated the frequency of 66% infected sheep aborted fetal samples with T. gondii type one. Although we could not isolate any parasite from inoculated mice even after three pas­sages, but it was confirmed histopathologically formation of cyst like bodies in prepared mice brain sections. Conclusion: The results of the performed nested-PCR and formation of brain cyst in inoculated mice exhibited that T. gondii type one infection might be considered as one of the major causative agents for abortion in ewes. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/254 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/254/253