Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 12 4 2024 11 04 9 16 Hossein Esmaeili Department of Microbiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Mona Hamedi Department of Immunopathology, Faculty of Veterinary Medicine, Islamic Azad University, Science and Research branch, Tehran, Iran Seyed Ahmad Madani 3. Department of Animal Nutrition Plant Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Abbas Barin Department of Pathology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Fatemeh Haji Agha Khiyabani Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. 2024 06 07 2024 06 22 Background:   Ovine enzootic abortion (OEA) caused by Chlamyidia abortus is one of the most important abortive disease in small ruminants. Diagnosis of Ovine enzootic abortion depends on the isolation and detection of the agent or its nucleic acid. The aim of the present study was to detect Chlamydia abortus using both isolation method and real-time PCR in Brucella free flocks in Iran. Methods:   Twenty-eight vaginal and conjunctival swab samples which were Chlamydia abortus seropositive, were selected from ewes and does with recent abortion. Then the samples were tested by real-time PCR and positive molecular samples were inoculated into McCoy cells. Results:   Using real-time PCR, 18 samples (64.3%) were positive and 7 (25%) of them were isolated in cell culture. Conclusion:   The present results indicate that Chlamydia can play a relatively significant role in the abortion in does and ewes in Iran. Although the isolation of Chlamydia abortus have 100% specificity, because of low sensitivity, time consuming, cost and high probability of contamination, it is not suitable for routine laboratory diagnosis. Therefore, applying real-time PCR which have high sensitivity and specificity is recommended. https://jmb.tums.ac.ir/index.php/jmb/article/view/526