The Inhibitory Effect of Artemisa quttensis Extract on norA Efflux Pump in Ciprofloxacin Resistant Staphylococcus aureus Strains Using Ethidium Bromide and Real-Time PCR Methods

Abstract

Background and Objectives: norA efflux pump is one of the mechanisms of ciprofloxacin resistance in Staphylococcus aureus strains, and finding natural herbal compounds with the ability to inhibit efflux pumps is one of the recent challenges. The aim of this study was to determine the inhibitory effect of Artemisa quttensis extract on norA efflux pump gene expression in ciprofloxacin resistant S. aureus strains.   Methods: At first, A. quttensis ethanolic extract, was prepared by ethanol solvent. Then, existence of norA efflux pump was detected in 10 ciprofloxacin resistant clinical strains of S. aureus using polymerase chain reaction (PCR) method. Moreover, anti-efflux activity of the extract was determined using ethidium bromide method. Finally, after treatment of isolates with Sub-MIC concentration of the extract, norA gene expression level, was evaluated using real-time PCR method.   Results: The PCR results showed that all of the strains had norA efflux pump, and and ethidium bromide method revealed that the A. quttensis extract had inhibitory effect on resistant strains that had norA efflux pump. Moreover, real-time PCR results showed that norA gene expression level was down-regulated by Sub-MIC concentrations of the extract in the ciprofloxacin resistant isolates.   Conclusion: Considering the anti-efflux pump effect of A. quttensis extract, it seems that this extract has the potential to be used as a native plant in pharmaceutical industries.    

Keywords

• artemisia quttensis
• staphylococcus aureus
• nora efflux pump.