carbapenem susceptibility and multidrug-resistance in pseudomonas aeruginosa isolates in egypt

conclusions multidrug resistance was significantly associated with mbl production in p. aeruginosa. early detection of mbl-producing p. aeruginosa and hospital antibiotic policy prescription helps proper antimicrobial therapy and avoidance of dissemination of these multidrug resistance isolates. background resistant pseudomonas aeruginosa is a serious concern for antimicrobial therapy, as the common isolates exhibit variable grades of resistance, involving beta-lactamase enzymes, beside native defense mechanisms. objectives the present study was designed to determine the occurrence of metallo-β- lactamases (mbl) and amp c harboring p. aeruginosa isolates from suez canal university hospital in ismailia, egypt. methods a total of 147 p. aeruginosa isolates, recovered from 311 patients during a 10-month period, were collected between may 2013 and february 2014; the isolates were collected from urine, wound and sputum. minimum inhibitory concentration (mic) determined by agar dilution methods was ≥2 μg/ml for meropenem and imipenem. identification of p. aeruginosa was confirmed using api 20ne. metallo-β- lactamases and amp c were detected based on different phenotypic methods. results overall, 26.5% of p. aeruginosa isolates (39/147) were carbapenem resistant isolates. furthermore, 64.1% (25/39) were mbl producers, these isolates were screened by the combined disc and disc diffusion methods to determine the ability of mbl production. both mbl and amp c harbored p. aeruginosa isolates were 28% (7/25). sixty-four percent of p. aeruginosa isolates were multidrug resistant (mdr) (16/25). the sensitivity toward polymyxin, imipenem, norfloxacin, piperacillin-tazobactam and gentamicin was 99%, 91%, 88%, 82% and 78%, respectively. the resistance rate towards cefotaxime, ceftazidime, cefepime, aztreonam and meropenem was 98.6%, 86%, 71.4%, 34% and 30%, respectively.