Prevalence, Antimicrobial Susceptibility, and Distribution of Virulence Genes Involved in Biofilm Formation in Multidrug-Resistant Acinetobacter baumannii Isolated from Shahrekord Medical Centers, Chaharmahal and Bakhtiari, Iran

 The ability to form biofilms is an effective way for Acinetobacter baumannii to survive in stressful conditions. The aim of this study was to investigate the prevalence, antimicrobial susceptibility, and distribution of virulence genes involved in biofilm formation in multidrug-resistant Acinetobacter baumannii isolated from Shahrekord medical centers in Chaharmahal and Bakhtiari Province, Iran.

 In this study, 150 samples from Shahrekord medical centers in Chaharmahal and Bakhtiari Province were isolated and identified using biochemical tests. Then, the antimicrobial susceptibility of A. baumannii isolates was determined using these antibiotics, Ampicillin/Sulbactam, Doxycycline, Ceftazidime, Ciprofloxacin, Erythromycin, Trimethoprim/ Sulfamethoxazole, Gentamicin, Colistin, Imipenem, and Amikacin. Finally, the rate of biofilm formation and the frequency of virulence genes associated with biofilm formation (bap, ompA, csuA, csuE, epsA, bfmS, bfmR, pgaA, pgaD, and surA) were evaluated.

Out of 150 samples, 90 were identified as A. baumannii. The results of antimicrobial susceptibility testing showed that there was the highest resistance rate to Ciprofloxacin and Imipenem (100%), followed by Ceftazidime (90%) and Ampicillin/ Sulbactam (77.77%). The highest frequency of virulence genes associated with biofilm formation was related to bap (100%), ompA (100%), and pgaA/ pgaD (98%).

 Biofilm formation significantly reduces susceptibility to antibiotic agents. Evaluation of biofilm formation showed that all isolates could produce biofilm; hence, they are very important for public health. Therefore, it is necessary to determine antibiotic susceptibility, biofilm formation capacity and the frequency of biofilm-related virulence genes in the clinical setting.