Analysis on resistance of strains producing extended-spectrum beta-lactamases

  Objective   To analyse the resistance of strains producing ESBLs so as to give a better medicine therapy.

  Methods   Strains produing ESBLs were identified by double-disk synergy test and their MIC were detected by agar dilusion test.

  Results   The sensitivity of Imipenem was 85.8% and MIC was between 0.125-4.0μg/ml; Meropenem 94.0% and 0.125-4.0μg/ml.They had shown good antibiotic activity.Cefoperazone/Sulbactam 40.3%, MIC at 0.125-16.0μg/ml (44 strains); Piperacillin/tazobactam 56.0%, MIC 0.125-16.0μg/m(59 strains); Cefoxitin 47.0%, MIC 0.125-8.0 μg/ml(63 strains); Levofloxacin 61.9%, MIC 0.125-2.0μg/ml(83 strains); Ciproaoxacin 53.7%, MIC 0.125-1.0 μg/ml(72 strains); Amikacin 64.2%, MIC 0.125-8.0μg/ml(86 strains); Chloramphenicol, Cefotaxime, Cefepime and Aztreonam all below 40.0%.

  Conclusions   Carbapenems had the best antibiotic activity.There were increases of intermediate resistane for Cefoperazone/sulbaetam and Piperacillin/tazobactam which have enzyme inhibitor.They have been overused in clinical may be the main reason.Quinolones have better antibiotic activity on bacteria except for Escherichia coli.