Possible Role of Curcumin as an Efflux Pump Inhibitor in Multi Drug Resistant Clinical Isolates of Pseudomonas aeruginosa.

Abstract

Multidrug resistant non-fermenters are continuously increasing in hospital and ICU settings. One of the mechanisms of developing drug resistance is possession of efflux pump through which bacteria extrude antimicrobial agents and other toxic substances. If these efflux channels are blocked or inhibited, increased drug concentration can be achieved in a bacterial cell with optimal drug dose. Present study was aimed to investigate role of curcumin as efflux pump inhibitor (EPI) and to compare its activity with a known EPI like phe-arg-beta-naphthylamide (PAβN). A total of 170 clinical isolates of Pseudomonas aeruginosa were taken, antimicrobial susceptibility was performed by disc diffusion test and minimum inhibitory concentration (MIC) against selected drugs before and after adding known synthetic EPI, PAβN (20mg/L). Out of these, 30 multidrug resistant strains were taken and MIC was performed with curcumin (50mg/L) with and without selected drugs. Results : Significant reduction in MIC was observed after adding curcumin (50mg/L) with selected antimicrobial agents in 9/30 (30%) of multi drug resistant (MDR) isolates of Pseudomonas aeruginosa, while no change in MIC was observed when curcumin (50mg/L) was used alone, indicating its efflux pump inhibitor activity. This study suggests role of efflux pump in development of drug resistance which can be overcome by use of an efflux pump inhibitor, with more emphasis on compound like curcumin which will have less or no adverse effects if used in vivo.