fa Original article Original article <div style="text-align: justify;"><strong>Introduction:</strong> <em>Acinetobacter baumannii</em>&nbsp;as a Gram-negative coccobacillus has become a major cause of hospital-acquired infections. The virulence factors involved in serum resistance are important targets in the development of an effective vaccine against this pathogen. Our aim in this project was <em>in silico</em> analyses of <em>A. baumannii</em> proteins involved in serum resistance which could potentially be used as efficient vaccines. <strong>Methods:</strong> Based on computational procedures, we evaluated all <em>A. baumannii </em>proteins involved in serum resistance, namely AbOmpA, PKF, PLD , PBP 7/8, CipA and Tuf SurA1, as vaccine candidates. Subcellular localization, sequence conservation, domain prediction and 3D modelings were analyzed by online tools. Moreover, the prevalence of serum resistance factors in 5 strains of <em>A. baumannii </em>was characterized. The MHC-binding sites of class I and II were detected. Linear and conformational B cell epitopes were analyzed by 2 prediction servers. <strong>R</strong><strong>esults: </strong>The MetaLocGramN server showed that AbOmpA, PKF, PBP7/8, phospholipase D, CipA, Tuf and SurA1 were outer membrane protein (56.32%), extracellular protein (58.74%), extracellular protein (52.59%), cytoplasmic protein (45.08%), extracellular protein (53.8%), Cytoplasmic protein (96.36%) and extracellular protein (58.23%), respectively. The OMD of AbOmpA, PKF, PBP7/8 and phospholipase D, CipA, Tuf and SurA1 were 0.060, 0.076, 0.08, 0.101, 0.09, 0.06 and 0.103, respectively. The numbers of immunogenic linear and conformational epitopes with high score (P &ge; 0.6), extracted from beta-barrel of AbOmpA were 6 and 4; whereas these values for PKF were 10 and 4, respectively. <strong>Conclusion: </strong>The <em>in silico</em> analyses and reverse vaccinology criteria showed that AbOmpA and PKF had better attributes as vaccine targets and they could be considered as promising vaccine candidates against <em>A. baumannii</em>.</div> Acinetobacter baumannii, in silico analysis, serum resistance factors. 64 71 http://vacres.pasteur.ac.ir/browse.php?a_code=A-10-1-44&slc_lang=fa&sid=1 A Soltani Shirazi 0000-0003-0208-5741 No Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran. O Azizi 0000-0001-7759-8029 No Department of Basic Sciences, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran. N Bolourchi 0000-0001-9893-6656 No Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran. Sh Aghamohammad 0000-0003-1832-3695 No Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran. F Badmasti fbadmasti2008@gmail.com 0000-0003- 3502-147X Yes Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran.