Overexpression of Efflux Pump in Multiresistant Pseudomonas aeruginosa: How You Will Discover and Treat It?

which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Editorial The Emergence and spread of multiresistant strains of Pseu-domonas aeruginosa is increasing problem, because it is associated with high morbidity and mortality. P. aeruginosa has intrinsic resistance to a wide variety of antibiotics, including most β-lactams, chloramphenicol, tetracyclines and fluoro-quinolones through its impermeable outer membrane. Recently , P. aeruginosa strains, which has acquired resistance to antipseudomonal antibiotics such as ciprofloxacin, ceftazi-dime, imipenem, and piperacillin, has been frequently reported [1]. In addition to impermeability of membrane, efflux, target alteration, enzyme inactivation, salvage pathway, and target protein protection are known mechanisms of antibiotic resistance. Among these mechanisms, active efflux of drug through efflux pump system is thought to be associated with acquired resistance in P. aeruginosa. There are various efflux pump systems in bacteria. The resistance -nodular-cell division (RND) family type of secondary multidrug transporters, which use the transmembrane elec-trochemical gradient of protons or sodium ions to drive the extrusion of drugs from the cell, has been found in P. aerugi-nosa [2]. Especially, 4 out of 12 RND efflux pump system is thought to play a role in the exportation of antimicrobial agents in P. aeruginosa [3]. MexAB-OprM is expressed consti-tutively and related to fluoroquinolones, β-lactams, tetracy-cline, macrolides, novobiocin, chloramphenicol, trimetho-prim, sulfonamides, meropenem resistance, but not imipenem. MexXY-OprM is also constitutively expressed and known to cause resistant to aminoglycosides, ciprofloxacin, levofloxacin, cefepime, but not ceftazidime. Unlike Mex-AB-OprM and MexXY-OprM, MexCD-OprJ and MexEF-OprN are induced by their substrates. MexCD-OprJ is not detectable in wild type cell and it cause resistant to tetracycline, macro-lides, chloramphenicol, novobiocin, trimethorpim and some β-lactams. MexEF-OprN is quiescent in wild type cell and related to fluoroquinolones, chloramphenicol, trimethorpim and imipenem resistance [4]. JDumas, et al. [5] reported that gene expression changes of efflux pump in P. aeruginosa cause resistant to antimicrobial agents. Using quantitative realtime-PCR, they observed several fold increasing of efflux pump genes, mexA, mexB and