Detection and Evaluation of Multidrug Resistance and the Presence of Virulence Genes Related to the Formation of ompA, epsA, and Bap Biofilms in Clinical Isolates of Acinetobacter baumannii in Tehran, Iran

Background: Acinetobacter baumannii is a prevalent pathogenic bacterium that causes nosocomial infections globally. A multitude of A. baumannii strains have acquired a broad spectrum of antibiotic resistance in recent years, primarily due to the influence of genes associated with the production of biofilms.Methods: Two hundred clinical isolates were acquired and described from Shahid Mostafa Khomeini, Tohid, and Shahid Motahari hospitals in Tehran, Iran, in 2018. The disk diffusion method was then used to determine whether genes related to the formation of outer membrane protein A (ompA), exopolysaccharide (epsA), and biofilm-associated protein (Bap) by polymerase chain reaction were present or not, as per the 2020 Clinical and Laboratory Standards Institute (CLSI) guidelines.Results: We found 60 different types of A. baumannii, all confirmed by blaOXA-51-like gene area sequencing and polymerase chain reaction (PCR) 16S rRNA. It was found that A. baumannii isolates were completely unaffected by piperacillin, meropenem, cefotaxime, ceftazidime, ceftriaxone, and ciprofloxacin. We also found that 96.6% of the A. baumannii isolates had genes related to making ompA biofilms, 85% had genes related to making epsA biofilms, and 75% had genes related to making Bap biofilms.Conclusion: After examining the elevated level of antibiotic resistance among A. baumannii isolates and the existence of biofilmassociated genes in clinical isolate, this study showed that virulence genes linked to the formation of epsA, Bap, and ompA biofilms are a major cause of antibiotic resistance.