Changes in Antimicrobial Resistance among Clinical Isolates of Escherichia coli and Klebsiella pneumoniae in Anhui Province 2006-2007

OBJECTIVE To investigate the trend of resistance to antimicrobial agents among clinical isolates of Escherichia coli and Klebsiella pneumoniae in 2006-2007.METHODS Agar diffusion test was used to analyze the changes in drug susceptibility of E.coli and K.pneumoniae from 30 hospitals in Anhui in 2006-2007.The resistant rate,intermediate rate and susceptibility rate of drugs were calculated according to the criteria in guidelines of CLSI(2007).RESULTS Carbapenems were the most active antimicrobial agents tested against E.coli and K.pneumoniae.Cefepime,ceftazidime,piperacillin/tazobactam and amikacin showed excellent activity against E.coli and K.pneumoniae.E.coli and K.pneumoniae were still resistant to cefuroxime,ceftriaxone,cefotaxime and aztreonam.ESBLs-producing E.coli strains accounted for 48.9% in the year of 2006 and for 47.2% in the year of 2007.ESBLs-producing K.pneumoniae strains accounted for 36.6% in the year of 2006 and for 40.0% in the year of 2007.CONCLUSIONS Imipenem remains highly active against E.coli and K.pneumoniae.