1Department of Medical Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
2Pediatric Infections Research Center, Institute for Children Health, Shahid Beheshti University of Medical Sciences, Tehran.

Abstract

One of the important pathogen with increasing resistance rate in hospitalized patients is Staphylococcus aureus. The useful results for antimicrobial activityof curcumin made it a proper candidate to enhance the inhibitory effect of some certain antibiotics like ciprofloxacin. The aim of this study was to investigate the Inhibitory effects of curcumin on the expression of NorA efflux pump and decrease ciprofloxacin resistance in Staphylococcus aureus. One hundred S. aureus isolates were acquired from different clinical specimens at the milad hospital (Tehran, iran). Susceptibility test to ciprofloxacin was done by Kirby-Bauer disk diffusion test and microdilution method, conforming to the CLSI guidelines. Activity of the efflux pump was recognized using CCCP as an chemical efflux pump inhibotor. MIC of curcumin was evaluated with  Broth Microdilution  method. Bacterial culture was performed near the curcumin and RNA Extraction was done. cDNA was synthesized and NorA gene expression was examined by Real-time PCR. The expression of NorA was significantly decreased in this isolated when it was treated with curcumin before RNA extraction  compared with absent of curcumin. Our results showed that curcumin can increase  ciprofloxacin  susceptibility through inhibition of the NorA efflux pump. Combination of curcumin with ciprofloxacin  can reduse the antibiotic resistanse.

Keywords: Staphylococcus aureus, curcumin, Antibiotic Resistance, Efflux Pump Inhibitor, NorA