Contribution of MexAB-OprM Active Efflux System in Multidrug-resistant Pseudomonas aeruginosa

OBJECTIVE To investigate the effect of MexAB-OprM active efflux system in multidrug-resistant Pseudomonas aeruginosa.METHODS Totally 26 strains of multidrug-resistant P.aeruginosa,15 strains of susceptible P.aeruginosa and ATCC27853.were selected the levels of mexB mRNA of 15 standard susceptible strains and 26 multidrug-resistant strains were detected by RT-PCR,and the 16S rRNA gene was also amplified as control.The levels of mexB mRNA were analyzed according to the ratio of electrophoresis scan results of their PCR products and the 16S rRNA′s.RESULTS The drug-resistant rates of 26 strains of multidrug-resistant P.aeruginosa against 14 kinds of antibiotics were 100%.The mexB mRNA were examined in all strains.The levels of mexB mRNA in multidrug-resistant strains(2.41±1.10) were significantly higher than that of standard susceptible strains(1.47±0.83)(P0.01).CONCLUSIONS The overexpression of MexAB-OprM active efflux system is associated with multidrug resistance of P.aeruginosa.