Phenotypic and genotypic biofilm formation characteristic of acinetobacter baumannii isolated from intensive care units

Acinetobacter baumannii is a significant pathogen commonly associated with nosocomial infections. Its ability to form biofilms enables it to survive in hospital settings and poses challenges for eradication. This study aimed to investigate the structural characteristics of biofilm formation in imipenem, meropenem, amikacin, gentamicin, levofloxacin, ciprofloxacin, trimethoprim/sulfamethoxazole, tigecycline and colistin resistant A. baumannii isolates from intensive care units (ICUs) and identify the genetic backgrounds contributing to biofilm formation. A total of 52 clinical A. baumannii isolates obtained from ICUs at Baskent University Ankara Hospital were included in the study. Antibiotic susceptibilities were tested, and biofilm formation ability was assessed using the crystal violet staining method. Additionally, biofilms were visualized under scanning electron microscope (SEM). Biofilm viability was measured using the MTT assay, and the presence of biofilm-related genes, including blaCsuE, blaOmpA, blaabaI, blapgaA, blabap, and blaPer1, was detected using PCR. Among the 52 A. baumannii isolates, 96.1% demonstrated biofilm formation ability. The biofilm-related genes blabap and blaabaI were detected in 98% of the isolates. Following these, blaOmpA and blaCsuE were present in 96.1% and 94.0% of the isolates, respectively. The presence of blapgaA and blaPer1 was observed in 50.0% and 40.3% of the isolates, respectively. The MTT assay revealed varying viability percentages ranging from 13.5% to 112.4%. Understanding the presence and relationships between these factors is crucial for developing novel approaches to prevent and manage A. baumannii infections. Attention should be directed towards the genes involved in biofilm formation to devise effective strategies for combating this pathogen