Synergistic effect of copper oxide nanoparticles and chloramphenicol antibiotic on MexA gene expression of pump efflux system in drug-resistant Pseudomonas aeruginosa isolates

Background. Pseudomonas aeruginosa is a causative agent of nosocomial infections. Chloramphenicol broad-spectrum, inexpensive, and common antibiotic. MexAB-OprM secretory pump that causes the innate resistance this bacterium. This study aimed to evaluate expression MexA gene under treatment copper nanoparticles chloramphenicol. Methods. In study, 49 samples were collected from 11 laboratories in Mashhad, Iran.Abundance Me was done by polymerase chain reaction (PCR) method, antibiotic susceptibility assessment performed disk diffusion method. To calculate minimal inhibitory concentration (MIC) bactericidal (MBC), nanoparticles, combination both, broth dilution method performed. Microdilution real time PCR technique used determine effective oxide chloramphenicol antibiotics gene, respectively. Result. The identity strains confirmed. All had resistant more than two antibiotics. MIC bacterial 250 μg/ml for 62.50 Compared antibiotics, greater effect on MIC, though it lower combined nanoparticles. Conclusion. Copper or synergistic are reducing expression. Practical Implications. Nanoparticles an important option use as alternative supplement Also, inhibit growth when with