en میکروب شناسی Microbiology <p style="text-align: justify;"><em><strong>Background:</strong></em> <em>Acinetobacter baumannii</em> is commonly resistant to nearly all antibiotics due to presence of antibiotic resistance genes and biofilm formation. In this study we determined the presence of certain antibiotic-resistance genes associated with biofilm production and the influence of low iron concentration on expression of the biofilm-associated protein gene <em>(bap)</em> in development of biofilm among multi-drug-resistant <em>A. baumannii</em> (MDRAB).</p> <p style="text-align: justify;"><em><strong>Methods:</strong></em> Sixty-five MDRAB isolates from clinical samples were collected. Molecular typing was carried out by random amplified polymorphism DNA polymerase chain reaction (RAPD-PCR). Biofilm formation was assayed by the microtiter method.</p> <p style="text-align: justify;"><em><strong>Results:</strong></em> The sequence of <em>bap</em> was determined and deposited in the GenBank database (accession no. KR080550.1). Expression of <em>bap</em> in the presence of low iron was analyzed by relative quantitative real time PCR (rqRT-PCR). Nearly half of the isolates belonged to RAPD-types A and B remaining were either small clusters or singleton. The results of biofilm formation revealed that 23 (35.4%), 18 (27.7%), 13 (20%), and 11 (16.9%) of the isolates had strong, moderate, weak, and no biofilm activities, respectively. ompA and csuE genes were detected in all, while bap and<em> bla</em>_PER-1 were detected in 43 (66%) and 42 (64%) of the isolates that showed strong and moderate biofilm activities (p &le; 0.05), respectively. Analysis of bap expression by rqRT-PCR revealed five isolates with four-fold bap overexpression in the presence of low iron concentration (20 &mu;M).</p> <p style="text-align: justify;"><em><strong>Conclusion: </strong></em>The results suggest that <em>bap</em> overexpression may influence biofilm formation in presence of low iron concentration.</p> Acinetobacter baumannii, Biofilm, Biofilm-associated Protein (bap), Iron, rqRT-PCR 62 72 http://rbmb.net/browse.php?a_code=A-10-1-67&slc_lang=en&sid=1 Omid Azizi 10031947532846006193 10031947532846006193 No Department of Microbiology and Virology, Kerman University of Medical Sciences, Kerman, Iran Fereshteh Shahcheraghi 10031947532846006194 10031947532846006194 No Department of Bacteriology, Pasteur institute of Iran, Tehran, Iran Himen Salimizand 10031947532846006195 10031947532846006195 No Department of Microbiology and Virology, Kurdistan University of Medical Sciences, Kurdistan, Iran Farzan Modarresi 10031947532846006196 10031947532846006196 No Department of Microbiology, School of Medicine, Jahrom University of Medical Sciences, Jahrom, Iran Mohammad Reza Shakibaie mr_shakibaei@kmu.ac.ir 10031947532846006197 10031947532846006197 Yes Department of Microbiology and Virology, Kerman University of Medical Sciences, Kerman, Iran - Environmental Health Sciences and Engineering Research Center; Kerman University of Medical Sciences, Kerman, Iran - Research Center for Infectious Diseases and Tropical Medicine, Kerman University of Medical Sciences Shahla Mansouri 10031947532846006198 10031947532846006198 No Department of Microbiology and Virology, Kerman University of Medical Sciences, Kerman, Iran Rashid Ramazanzadeh 10031947532846006199 10031947532846006199 No Department of Bacteriology, Pasteur institute of Iran, Tehran, Iran - Cellular & Molecular Research Center and Microbiology Department, Faculty of Medicine, Kurdistan University of Medical Sciences, Iran Farzad Badmasti 10031947532846006200 10031947532846006200 No Department of Bacteriology, Pasteur institute of Iran, Tehran, Iran Vajihe Nikbin 10031947532846006201 10031947532846006201 No