Investigation of Antimicrobial Resistant Patterns and Prevalence of Carbapenamase Genes (imp-1, vim-2, and kpc) in MDR Pseudomonas aeruginosa Strains Isolated from Patients in Mottahari Hospital in Tehran, Iran

The aim of this study was to identify antibiotic resistant patterns and the prevalence rate of carbapenem resistant genes (imp-1, vim-2, kpc) in P. aeruginosa strains isolated from burn patients in Shahid Motahari Hospital of Tehran. In this study, 63 P. aeruginosa strains were collected from infected patients.  Isolates were identified by biochemical tests and specific 16SrDNA PCR. Antibiotic susceptibility test was performed by standard Kirby-Bauer method according to the CLSI guidelines. The prevalence of imp-1, vim-2, and kpc genes were assessed by PCR. All of the isolates were confirmed as P. aeruginosa by phenotypic tests and specific 16SrDNA PCR. Totally, 14 antibiotypes were identified. The highest resistance was observed against to tobramycin, gentamicin, amoxi-clavulanic acid, and cefoxitin (100%) and the most sensitivity was shown against colistin (100%). All of the isolates were multidrug resistant (MDR), 100 and 46% were positive for Extended Spectrum β-Lactamases (ESBL) and Metallo- β-Lactamases (MBLs) respectively. The imp-1 and kpc genes were not detected (0%), while vim-2 gene was present in all of the isolates. In the current study, the high resistance rate to antibiotics might be due to their overuse for burn patients as a prophylactic or therapeutic agents. Colistin is considered a drug of choice for the treatment of wounds infected by P. aeruginosa in burn patients. In this study, the majority of P. aeruginosa isolates belonged to Antibiotype 1 and possess carbapenemase vim-2. Therefore, to stop this resistance transmission, the prevention and control are apparently essential.