Abstract
Background: Pseudomonas aeruginosa is an opportunistic gram-negative bacterium that is a major cause of nosocomial infections such as severe burns. Curcumin is the main component of turmeric (Curcuma longa) that has anti-cancer and anti-inflammatory effects. The aim of this study was to evaluate antibacterial effect of curcumin in ciprofloxacin resistant isolates of Pseudomonas aeruginosa through mexC and mexD gene expression.
Materials and Methods: In this descriptive-analytical study, Pseudomonas aeruginosa strains were obtained from hospitals and laboratories in Guilan province. After disc difusion and MIC tests, four ciprofloxacin resistant strains of Pseudomonas aeruginosa were treated by ciprofloxacin (1/2MIC) only (control sample) and in the combination with curcumin encapsulated in micelle nanoparticles (test sample). After 24h, RNA extraction and cDNA synthesis was performed. Then, the expression of mexC and mexD genes was evaluated quantitatively by Real-time PCR method in curcumin treated and un-treated cells
Results: This study showed that combination of ciprofloxacin (1/2 MIC) with curcumin encapsulated in micelle nanoparticles led to approximately 50% of growth inhibition in Pseudomonas aeruginosa. In treated cells with curcumin and ciprofloxacin compared to treated cells with ciprofloxacin alone, mexC and mexD genes were significantly (p<0.05) downregulated >0.65 fold in three isolates and >0.1 fold in four isolates, respectively.
Conclusion: Our results suggested that curcumin encapsulated in micelle nanoparticles combined with 1/2 MIC value of ciprofloxacin inhibits the growth of Pseudomonas aeruginosa through reducing mexC and mexD expression.
