Changing pattern of antimicrobial resistance of Escherichia coli and Klebsiella pneumoniae isolated from patients with nosocomial infections

Objective To investigate the producing of extended-sepctrum β-lactamase strains and changing pattern of antimicrobial resistant rates of Escherichia coli(E.coli) and Klebsiella pneumoniae (K.pneumoniae) isolated from patients with nosocomial infections(NIS).Methods Statistical analysis was performed on the ESBLs production and changing resistant rates of E.coli and K.pneumoniae isolated from patients who were diagnosed as NI in 2002 and 2005.Results The isolation rate of ESBLs-producing strains of E.coli and K.pneumoniae was 45.39% and 29.46% respectively in 2005, there was no significant difference compared with 32.86% and 38.27% respectively in 2002(P0.05).The resistant rates of ESBLs-producing strains of E. coli and K.pneumoniae to 14 antimicrobial agents were higher than that of non-ESBLs-producing strains;piperacillin /tazobactam and imipenem showed higher antimicrobial activity to ESBLs-producing strains of E.coli and K.pneumoniae.Conclusion Antimicrobial resistance of E.coli and K.pneumoniae is serious among pathogens in NIS.The ESBLs-producing strains are still in high level.The prevention and control measures against NI should be made according to the drug resistance characteristics and changing pattern.