To investigate the clinical distribution characteristics and drug-resistance trend to commonly used antibiotics, and to provide evidence for clinical prevention and control of E. coli infection.

Total of 2 743 strains of E. coli isolated from clinical specimens during 2013-2015 in Clinical Medical College of Yangzhou University were performed with drug-sensitivity test, the bacteria identification results were analyzed by the French bio-Merieux ATB Expression automatic bacterial identification instrument and the drug-sensitivity test was conducted with diffusion method (K-B), then the infection sites, the detection rates of ESBLs-producing E. coli, the resistance rates of ESBLs-producing and non-ESBLs-producing E. coli were analyzed; the drug-resistance trend of 19 kinds of antibiotics were compared, respectively.

The specimens were isolated from urine (56.4%) and blood specimens (17.0%). Among the 20 departments from which the specimens were isolated, the proportion of nephrology department of internal medicine was the most (accounting for 13.5%), and secondly was the urology surgery (8.9%). The patients under 65 yesrs old accounted for 54.68%, and those above 65 years old accounted for 45.32%; among whom 40.90% were male and 59.10% were female. The community acquired infection accounted for 69.30%, while hospital-acquired infections was 13.20%. Urinary tract infection accounted for the highest proportion (45.9%), secondly was bacteremia (14.47%). The detection rates of ESBLs-producing E. coli was 52.6%, the resistance rates of ESBLs-producing E. coli to cefazolin and ampicillin were both above 75%. The resistance rates of non-ESBLs-producing E. coli to tigecycline, imipenem and cefotetan were higher than those of ESBLs-producing E. coli; The antibiotic resistance rates to compound sulfamethoxazole and levofloxacin were significantly different (all P < 0.05). The resistance level of E. coli to ampicillin-sulbactam was 73.86%, which was 0.11% to tigecycline. Although the resistance to imipenem was rising, while the resistance to cefepime, ceftazidime and ampicillin-sullbactam were without significant rising trend.

Through the standard microbiological specimens collection, specimens distribution and infection sites of E. coli changed, which were mainly urinary tract and bloodstream infection. The detection rate of E. coli and drug resistance rate increased year by year. Application of piperacillin/tazobactam, cefoxitin to kidney and urology could be used empirically, and the use of fluoroquinolone antimicrobial drugs should be reduced. Great importance to the rational use of carbapenem drugs such as imipenem should be attached .