high prevalence of metallo-beta-lactamase producing acinetobacter baumannii isolated from two hospitals of tehran, iran

conclusions: the prevalence of metallo-beta-lactamase-producing a. baumannii strains detected in this study is of great concern and highlights the need of infection control measures including antibacterial management and prompt identification of beta-lactamase-producing isolates. results: the resistance of a. baumannii isolates against tested antibiotics were as follow: 108 (100%) to cefotaxime, 103 (95.4%) to ceftazidime, 99 (91.7%) to meropenem, 99 (91.7%) to imipenem, 44 (40.7%) to gentamicin, 87 (80.6%) to amikacin, 100 (92.6%) to ciprofloxacin, 105 (95.7%) to cefepime, 105 (97.2%) to piperacillin, 103 (95.4%) to piperacillin/tazobactam, 106 (98.1%) to ampicillin/sulbactam, 106 (98.1%) to co-trimoxazole, 87 (80.6%) to tetracycline and 1 (1.8%) to colistin. using combined disk diffusion test, it was found that out of 99 imipenem non-susceptible a. baumannii strains, 86 (86.86%) were mbl producers. the prevalence of imp-1 gene among metallo-beta-lactamase-producing a. baumannii isolates was 3 of 86 (3.48%). objectives: the aim of this study was to determine the frequency of spm and imp type genes among a. baumannii isolates from hospitalized patients in loghman hakim and milad hospitals, tehran-iran from 2012 to 2013. patients and methods: this study was conducted on 108 a. baumannii isolates collected from two hospitals in tehran, iran. antibiotic susceptibility tests were performed by kirby-bauer disc diffusion and broth microdilution methods according to clinical laboratory standards institute (clsi) guidelines, and combined disk diffusion test (cddt) was performed for identification of metallo-beta-lactamases (mbls). the blaimp and blaspm genes were detected by pcr and sequencing methods. background: metallo-beta-lactamase (mbl)-producing acinetobacter baumannii is a growing therapeutic concern, worldwide.