Background and Aim:Pseudomonas aeruginosa, is a gram negative and opportunistic pathogen in immune-compromised patients such as burn wound infections. Due to increasing of antibiotic resistance, this study investigated the prevalence of qnrB , aac(6’) and rmtA
genes in multi-drug resistance (MDR)P. aeruginosa isolates from burn wound infections.Methods:92 isolates of P. aeruginosa from patients with burn wound infections of Motahhari hospital in Tehran during 2017-2018 based on standard tests were collected. According to CLSI protocol, antibiotic susceptibility test (AST) was performed by using the disk diffusion method. Then, the PCR and Multiplex PCR was used to evaluate of qnrB , aac(6’) and rmtA
genes. P. aeruginosa ATCC 27853, qnrB+,aac(6’) + and rmtA+ strains were used, simultaneously.Results:Among 92 isolates of P. aeruginosa, 75 (81.88%) were resistant to Amikacin, 79(85.56%) to Cefepime, 80 (87.4%) to Meropenem, 63 (69%) to Ceftazidime, 81 (88.32%) to Ciprofloxacin, 66 (71.74%) to Aztreonam, , 78 (84.64%) to Gentamicin, and 0(0%) to Colistin. By PCR results 0(0%) ,8(9.2%) and 38(41.4%) of the isolates had QnrB, aac(6’) and rmtA
genes.By multiplex PCR result 2 (1.84%) concurrent presence of aac(6’) and rmtA
genes.Conclusion:The results of this study showed the high rate of antibiotic resistance. Among the most of antibiotics that were tested, Colistin is the best choice for treatment. The frequency of rmtA gene is higher than QnrB, aac(6’) in P. aeruginosa by PCR. To reduce the rate of resistance it is necessary to control bacterial dissemination.