Detection of ESBLs or AmpC β-lactamase in Escherichia coli and drug resistance

Objective To investigate extended-spectrum β-lactamases (ESBLs),AmpC β-lactamase and drug resistance in Escherichia coli (E.coli) for instructing rational medication uses.Methods 287 E.coli strains were isolated in our hospital from January 2011 to June 2012.ESBLs were detected by the double-disk method; AmpC were detected by the three dimensional extract test; and the drug sensitivity was tested by the KB method.Results Of the 287 E.coli strains,119 (41.5％) strains produced ESBLs and 47 (16.4％) strains produced AmpC,and ESBLs and AmpC were simultaneously detectable in 16 strains (accounting for 5.6％).ESBLs-or AmpC-producing strains had a higher drug resistance; ESBLs-and AmpC-producing strains had multiple drug resistance.All the strains had susceptibility to imipenem.Conclusions The rates of isolation and drug resistance are higher for ESBLs-or AmpC-producing E.coli; ESBLs-and AmpC-producing strains have multiple drug resistance.Imipenem has good antibacterial activity.Detection of ESBLs and AmpC and monitoring of drug resistance should be strengthened clinically and effective measures must be taken to prevent resistant strains. Key words: Escherichia coli;  Extended spectrum β-lactamase;  AmpC;  Drug resistance