Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 5 1 2013 03 15 19 23 EN Amir Ghasemi Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Hossein Salari Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Amir Hassan Zarnani Nanobiotechnology Research Center, Avecina Research Institue, ACECR, Tehran, Iran AND Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Reza Pourmand Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Hojat Ahmadi Department of Bacterial Vaccine and Antigen Production, Pasteur Institute of Iran, Tehran, Iran. Abbas Mirshafiey Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Mahmood Jeddi-Tehrani Monoclonal Antibody Research Center, Avicenna Research Institute, ACECR, Tehran, Iran. 2015 10 16 Background and objectives: Brucella melitensis infection is still a major health problem for human and cattle in developing countries and the Middle East. Materials and Methods: In this study, in order to screen immunogenic candidate antigens for the development of a Brucella subunit vaccine, a cytoplasmic protein (DnaK) and an outer membrane protein (Omp31) of B. melitensis were cloned, expressed in E.coli BL21 and then purified using Ni-NTA agarose. Immunized serum was prepared from a rabbit inoculated with attenuated B. melitensis. Results and Conclusion: It was proved that immunized serum contains antibodies against recombinant Omp31 (rOmp31) and DnaK (rDnaK) by Western blot and ELISA assays. The results may suggest the importance of these proteins as subunit vaccines against B. melitensis as well as targets for immunotherapy. https://ijm.tums.ac.ir/index.php/ijm/article/view/636 https://ijm.tums.ac.ir/index.php/ijm/article/download/636/409