assessment of carbapenem susceptibility and multidrug-resistance in pseudomonas aeruginosa burn isolates in tehran

background pseudomonas aeruginosais an opportunistic pathogen which causes severe, acute and chronic nosocomial infections. these infections are difficult to eradicate since the organisms are usually multidrug-resistant. carbapenems are considered as the most effective drugs against these isolates. however, recent emergence of carbapenem-resistant p. aeruginosa has become a major healthcare problem. objectives the present study was conducted to determine the antibiotic susceptibility of p. aeruginosa burn isolates to 13 antibiotics including imipemen and meropenem. materials and methods one hundred and thirty three p. aeruginosa burn isolates were collected from shahid motahari burn hospital between july and december 2011. the majority of the isolates were from wounds (88.7%), followed by 5.26% from blood, 4.15% from subclavian catheters and 1.5% from urine. the antibiotic susceptibility profiles were studied by the agar disc diffusion. results the results showed 99.2% resistance to carbenicillin, 98.4% to ticarcillin, 96.2% to ciprofloxacin, 95.4% to co-trimoxazole, 94.7% to imipenem and meropenem, 93.9% to piperacillin, 93.2% to azetronam, 92.4% to tobramycin, 91.7% to cefepime, 89.4% to amikacin and ceftazidime, and finally 87.2% to piperacillin-tazobactam. overall, 100% of the isolates showed multidrug-resistance (resistance to ≥ 3 classes of antibiotics) including theimipenem- resistant isolates. conclusions the high rate of multidrug-resistance is alarming and it is crucial to screen for carbapenem resistance prior to - antibiotic therapy.