Effects of Curcumin on Biofilm Production and Associated Gene in Multidrug-Resistant Acinetobacter baumannii Isolated from Hospitalized Patients.

Abstract

Multi-drug-resistant (MDR) Acinetobacter baumannii has become a major global healthcare concern due to its opportunistic infections and high antibiotic resistance. This investigation is intended to investigate curcumin's potential anti-bacterial and antibiofilm impacts on MDR A. baumannii and to present a promising strategy for fighting against infections caused by this pathogen. This cross-sectional investigation comprised 34 MDR A. baumannii clinical isolates. The Kirby-Bauer disc diffusion method evaluated the sensitivity of isolates to multifaceted anti-bacterial agents. The microdilution broth method quantified curcumin's minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The efficacy of curcumin in inhibiting MDR A. baumannii biofilm was assessed via 96-well microtiter plates. The expression of the biofilm-associated protein (bap) gene was evaluated by employing quantitative real-time PCR (qRT-PCR). Within the 34 MDR A. baumannii isolates, the highest resistance was noted for trimethoprim/sulfamethoxazole and ciprofloxacin, with all 34 isolates (100%) indicating resistance. The lowest resistance was noted for ampicillin/sulbactam, with 22 isolates (64.7%) exhibiting resistance. The MICs of curcumin ranged from 0.625 to 2.5 mg/ml, while the MBCs varied between 1.25 to 5 mg/ml. Curcumin reduced biofilm formation by 25% to 91%, depending on the concentration. In contrast to the untreated control, the average relative activity of the bap gene in MDR A. baumannii isolates declined by 62.07%. The findings indicate that curcumin demonstrates antimicrobial and anti-biofilm activities against MDR A. baumannii. The downregulation noted in the bap gene further supports the curcumin's anti-biofilm impact.