Analysis of multiply resistance of extended-spectrum β-lactamase-producing strains to antimicrobial agents

Objective To evaluate the antimicrobial resistant characteristics of extended spectrum β lactamases (ESBLs) producing strains of Klebsiella pneumoniae, Escherichia coli, and Enterobacter cloacae, and to provide the reference for the clinical antimicrobial agents usage. Methods Bacteria isolated from patients in a hospital from January 2000 to December 2002 were identified, and antimicrobial susceptibility test was performed. Results One hundred and seventy two strains of Klebsiella pneumoniae, 241 strains of Escherichia coli and 46 strains of Enterobacter cloacae were isolated, 58.14% (100/172) of Klebsiella pneumoniae strains, 30.71% (74/241) of Escherichia coli and 52.17% (24/46) of Enterobacter cloacae strains produced ESBLs. ESBLs producing strains had higher resistance to antimicrobial agents than non ESBLs producing strains. Conclusion Antimicrobial resistance of the ESBLs producing strains is a serious problem, regular monitoring of bacteria resistance to antimicrobial agents is helpful to the rational use of antimicrobial agents in clinic.