ABSTRACT
Pseudoinonas aeruginosa [P. aeruginosa] represents a phenomenon of antibiotic resistance, and demonstrates practically all known mechanisms of bacterial resistance. Active efflux is an important mechanism of resistance in P. aeruginosa. It contributes to the development of multiple resistances to all strategic antipseudonional antibiotics. More than five hundred urine samples were collected from patients in Assiut University Hospital. Fifty P. aeruginosa isolates were identified by conventional methods. The antibiotic susceptihity testing of isolates showed that 68% of isolates were resistant to ciprofloxacin and 62% were resistant to levofloxacin. A comparison between the effect of three efflux pump inhibitors [Reserpine, Pantoprazole and Carbonyl cyanide m-chlorophenylhydrazone [CCCP]] on the activity of ciprofloxacin and levofloxacin was done by measuring ability of these agents to potentiate effect of ciprofloxacin and levofloxacin against resistant P. aeruginosa isolates. Outer membrane profile of P. aeruginosa isolates was also done using sodium dodecyl sulfate polyacrylamide gel electrophoresis [SDS-PAGE]. Reserpine was able to potentiate effect of ciprofloxacin in 50% of isolates, and in 5.5% for levofloxacin. Pantoprazole results were 33.3% for ciprofloxacin, 16 7% for levofloxacin. Finally CCCP potentiate. Regarding the SDS-PAGE of P. aeruginosa isolates, all isolates produced proteins with apparent molecular masses in the range of 50-54kDa.Reserpine-ciprofloxacin proved to be the best combination against multidrug resistant P. aeruginosa. Over production of 50-54 KDa outer membrane proteins is responsible for emergence of P. aeruginosa strains highly resistant to fluoroquinolones in clinical settings