In Vitro Anti-Biofilm Activity of Curcumin Nanoparticles in <i>Acinetobacter baumannii</i>: A Culture-Based and Molecular Approach

Abstract

Background: Acinetobacter baumannii is one of the most important opportunistic and biofilms-forming microorganisms. Its biofilm structure provides an effective barrier against the antimicrobial penetration and increases the drug resistance of Acinetobacter baumannii by 1000× compared with plankton cells. However, nanoparticles have recently reported as suitable tools to prevent biofilm formation. Objectives: The aim of this study was to investigate the effect of curcumin nanoparticles on biofilm gene expression in Acinetobacter baumannii strains in vitro. Methods: Seventy clinical isolates of Acinetobacter baumannii were collected from different specimens and all specimens were diagnosed biochemically. Antibiotic resistance pattern was detected by disc diffusion method. Isolates of high biofilm producers were selected to investigate the effect of curcumin nanoparticles. The antibiofilm activity of curcumin nanoparticles was studied using Real-time PCR technique in the molecular level. Results: This bacterium showed high resistance to most antibiotics, except for polymyxin B. Twenty-five strains had high biofilm formation capacity. MIC for curcumin was 128 µg/mL in all 25 strains. The expression results showed that CsuE gene was downregulated to 0.31 fold in curcumin-treated samples compared to untreated samples. Conclusions: The study findings suggest that curcumin nanoparticles can be helpful as a candidate for inhibiting the formation of Acinetobacter biofilms.