Isolation of Escherichia coli and analysis on its extended spectrum -lactamases production and drug resistance in patients with urinary tract infection in Xiaoshan, Zhejiang, 2007-2011

Objective To investigate clinical distribution of Escherichia coli isolated from urinary tract infection(UTI) patients and its drug resistance in our hospital from 2007 to 2011 and provide evidence for the rational clinical drug use and reduction of extended spectrum lactamases(ESBLs) production. Methods Retrospective survey was carried out on the clinical distribution of the E. coli strains isolated during this period and related drug susceptibility test was conducted by using VITEK-60 automatic microbio analyzer and K-B agar diffusion method. Results Totally 405 strains of E. coli producing ESBLs were isolated from 771 urine samples(52.5%). The strains were mainly isolated from the departments of urology, internal medicine and nephropathy, accounting for60.0% of the total. The isolation rate of ESBLs positive E. coli increased from 44.2% in 2007 to 61.2% in 2011(P0.01). The resistance rates of E. coli to common antibiotics were in upward trend, especially for the 3rd and 4th generation cephalosporin. The drug resistance rates of ESBLs positive strains to 16 antibiotics, including ampicillin, cefazolin and ceftazidime, were higher than ESBLs negative strains. Conclusion E. coli infection in urinary tract showed increased resistance to cephalosporin year by year, the detection rate of ESBLs producing strains with multi drug resistance were in increase. Clinicians should pay attention to the rational use of antibiotics.