Detection of Extended-spectrum Beta-lactamases and Resistance in Gram-negative Bacilli Isolates in Department of Respiratory During 2003～2005 in Our Hospital

Objective: To investigate the resistance and extended-spectrum β-lactamases(ESBLs) in gram-negative bacilli isolates, which were isolated from patients with lower respiratory tract infection in department of respiratory medicine during 2003～2005 in our hospital. Methods: ESBLs production was dected by NCCLS phenotypic confirmatory test in gram-negative bacilli isolates. Antibiotic susceptibility was tested by Kirby-Bauer method. The results were interpreted according to NCCLS 2003. Results: A total of 692 strains of gram-negative bacilli isolates. The prevalence of ESBLs was 23.8% Escherichia coli, 20.0% Enterobacter cloacae and 23.5% Klebsiella pneumoniae. All ESBLs producing strains were susceptible to imipenem. The resistance rate of to most antibiotics was much higher than those of non-ESBLs producing strains. The susceptibilty rate of ESBLs producing strains to imipenem and cefoperazone-sulbactam were higher than other antimicrobial agents. Conclusions:The increase in ESBLs positive pathogens is one of the reasons for higher resistance. Surveillance of resistance and ESBLs detection are of great importance to both rational use of antibiotics and control of ESBLs producers.