DETECTION OF EXTENDED-SPECTRUM β-LACTAMASES AND RESISTANT ANALYSIS

Objective: To determine the prevalence of strains producing ESBL among Klebsiella pneumoniae, Escherichia coli and Enterobacter cloacae, and investigate the antibiotic resistance of these strains. Methods: 215 isolates of gram-negative bacilli from clinical infectious specimens were determined for the strains producing ESBL by double-disk synergy tests and antibiotic susceptibility test by Kirby-Bauer test. In vitro antibacterical activity of 14 kinds of antibiotics against those strains producing ESBL were compared. Results: Incidence rate of ESBL was 34.4%totally,and incidence rate of ESBL in E.coli, K.pneumoniae and E.cloacae was 47.3%,28.4%,24.3% respectively.Incidence rate of ESBL in E.coli, K.pneumoniae and E.cloacae was 31.8%,39.6%,34.6% respectively in every bacilli.In ESBL-producing strains, there was 2 strains of K.pneumoniae and 3 strains of E.coli which were susceptible to cefotaxime and ceftazidime simultaneously.Imipenem has the potent antibacterial activity to resistant strain producing ESBL .Cefoxitin has higher antibacterial activity to K.pneumoniae and E.coli producing ESBL,E.cloacae producing ESBL were all resistant to cefoxitin. All ESBL-producing strains had higher cross resistance rate to aminoglycosides, fluoroquinolones, sulfonamides.Conclusion: Due to gram-negative producing ESBL,infections should not be neglected.Imipenem should be the first choice to treat this kind of infections.\;