Study on the efflux pump of quinolone resistantpseudomonas aeruginosa drugs

Objective This study aims to investigate the efflux system in fluoroquinolone resistance of pseudomonas aeruginosa. Methods MIC values of ciprofloxacin were detected by MH flat containing sub-inhibitory concentration( 20 mg / L) efflux pump inhibitor carbonyl cyanide chlorophenylhydrazone( carbonyl cyanide 3-chlorophenylhydrazone,CCCP) and MH flat without CCCP.Then compare the MIC. Results Efflux pump in 14 strains of pseudomonas aeruginosa was overexpressed,which were mainly mex ABOpr M and mex CD-Opr J. MIC value of ciprofloxacin decressed 1 / 2-1 / 8 times. MexR regulated by mex AB-Opr Mexisted V126 E mutation and Nfx B regulated by mex CD-Opr J existed H109 Y mutation. Conclusion The efflux pump is overexpressed in nearly 50% of fluoroquinolone resistant strains of pseudomonas aeruginosa,which is higher than the domestic and foreign reports. The mechanism and drug target change improve the resistance of pseudomonas aeruginosa to fluoroquinolones. The overexpression of efflux pump also enhance the resistance of the bacteria to cefepime and other drugs( this is not listed),which need us pay close attention and take measures to control this trend.