Distribution and drug resistance of Escherichia coli producing extended-spectrum β lactamases in a hospital

Objectives To study the distribution and characteristics of antibiotic resistance of Escherichia coli producing extended-spectrum β-lactamases(ESBLs) in a hospital and to guide clinical drug use.Methods The antibiotic resistance of E.coli to antibiotics was detected using the K-B disc diffusion method.ESBL-producing strains were detected,and susceptibility to all antibiotics were determined in accordance with criteria of the CLSI.Results A total of 297 strains of E.coli were isolated,with 135 strains isolated in 2010 and 162 strains isolated in 2011.Of the total strains,118 were isolated from respiratory tract specimens and 64 were isolated from urinary tract specimens.E.coli and ESBL-producing strains of E.coli had severe multidrug resistance.E.coli had resistance to amoxicillin and ampicillin of more than 70%,resistance to imipenem of 0%,resistance to piperacillin and tazobactam of 7.41%,and resistance to amikacin of 15.49%.E.coli was more resistant in 2011 than in 2010.A total of 71 strains of ESBL-producing bacteria were detected at a rate of 23.91%.ESBL-producing bacteria had greater resistance than non-ESBL-producing bacteria.Conclusion ESBL-producing strains of E.coli have severe multidrug resistance.Antibiotics should be chosen and used rationally in accordance with results of drug susceptibility testing.