Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 13 5 2021 10 08 642 652 Zahra Davoudi Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Amirhossein Taromchi Department of Medical Biotechnology and Nanotechnology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran Bahram Kazemi Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mojgan Bandehpour Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Nariman Mosaffa Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2021 04 23 2021 09 20 Background and Objectives: Immunization is a promising strategy to combat against the life-threatening infections by Multi Drug Resistance Acinetobacter baumannii. In this study, we directed to design and evaluate the efficacy of a recombinant multi-epitope protein against this pathogen. Materials and Methods: Epitopes prediction was performed for candidate proteins OmpA and BAM complex (BamA, BamB, BamC, BamD, BamE) from A. baumannii, using immune-informatics tools with high affinity for the human HLA alleles. After expression and purification of the recombinant protein, its functional activity was confirmed by interaction with positive sera. Results: Cloning and expression of the desired multi-epitopes protein were verified. Circular Dichroism study showed the secondary structure and proper refolding of the recombinant protein was achieved and matched with computational prediction. There was a significant interaction between designed protein with antibodies presented in ICU patients' and staff's sera. Conclusion: The interaction of the recombinant protein with patients' sera antibodies suggests that it may be a promising determinant protein for immunization against of MDR A. baumannii. https://ijm.tums.ac.ir/index.php/ijm/article/view/3112 https://ijm.tums.ac.ir/index.php/ijm/article/download/3112/1389