Detection of mexB Multidrug Efflux Gene in Some Local Isolates of Pseudomonas aeruginosa

Abstract

      According to the prevalence of multidrug resistance bacteria, especially Pseudomonas aeruginosa, in which the essential mechanism of drug resistance is the ability to possess an efflux pump by which extrusion of antimicrobial agents usually occurs, this study aims to detect the presence of mexB multidrug efflux gene in some local isolates of this bacteria that show resistance towards three antibiotics, out of five. Sensitivity test to antibiotics was performed on all isolates by using meropenem (10µg/disc), imipenem (10µg/disc), amikacin (30 μg/disc), ciprofloxacin (5µg/disc) and ceftazidime (30 µg/disc). Conventional PCR results showed the presence of mexB gene (244bp) in four isolates out of ten (40%). In addition,25, 50μg/ml of curcumin was used to detect its efficacy with the antibiotics that the bacteria showed resistance towards. Results showed the highest resistance for ciprofloxacin (80%), while all of them were sensitive to imipenem. In addition, the present results show that both concentrations of curcumin (25, 50μg/ml) were effective in increasing the zone of inhibition from zero to 10 mm for isolates towards amikacin. Same result was obtained towards ciprofloxacin, except for an increase of inhibition zone from zero to 7 mm to one isolate (38T) when treated with 50 μg/ml, and finally an increase in sensitivity to ceftazidime was found and inhibition zone was increased from 8 to 11 for the second isolate (42E), which revealed that curcumin potentiates antibiotics activity by inhibition of efflux pump mechanisms that can be related to the synergetic activity between antibiotics and curcumin.