Comparison of detection and resistance rates of ESBLs among Escherichia coli,Klebsiella pneumonia and Enterobacter cloacae isolates

Objective To understand the detection and drug resistance of ESBLs producing strains in Escherichia coli,Klebsiella pneumoiaeor and Enterobacter cloacae isolated from bile in suppurative cholangitis patients.Methods Minimuminhibitory concentration was used to carry out experiments on E.coli,K.pneumoiae,and E.cloacae isolated from bile in suppurative cholangitis patients who accepted ERCP examination and treatment in the department of gastroenterology from June 2009 to June 2012.And double disc synergy test was used as the confirmatory test.Susceptibility paper such as cefotaxime paper,cefotaxime / clavulanic acid paper,ceftazidime,ceftazidime / clavulanic acid paper was selected.Only when the difference of the zone of inhibition between the paper with clavulanic acid and the one without clavulanic acid should be above 5 mm,could it be recognized as the ESBLs producing strain.Then susceptibility test was carried out to detect drug resistance.Results 130 of 297 were ESBLs producing strains,with the detection rate of 43.77%.The number of strains in E.coli,K.pneumoiae,and E.cloacae were 71,43,16 respectively,with the detection rate of 56.80%,36.44% and 29.63%.The highest detection rate came from ESBLs producing Klebsiella pneumoniae in choledocholithiasis patients,which was 93.02%.Detection rate of ESBLs producing E.coli in malignant biliary obstruction patients was 39.44%.ESBLs bacteria had no resistance to imipenem,meropenem and had high resistance rates to cephalosporins.Drug resistance rates of ESBLs producing E.cloacae were higher than those of ESBLs producing E.coli and K.pneumoiae.Conclusion ESBLs strains are the main pathogens of biliary infection.To understand their mechanisms of resistance and detect its resistance in a timely and effective manner will help guide the rational use of antibiotics,and delay the occurrence of bacterial resistance to control drug-resistant strains epidemic and outbreak.