Diversification on drug resistance of ESBL-producing E. coli among 651 strains

Objective To analyze the clinical distribution and resistance changes of extended-spectrum β-lactamase(ESBLs)E.coli from January 2011 to December 2013 so as to provide a basis for rational use of antimicrobial drugs. Methods Automated microbial identification system of Bio Merieux(France) was used to identify the ESBLs-producing E. coli isolated from a variety of infections specimens in hospitals, and analysis of the clinical commonly used antimicrobial drug resistance was conducted. The software of Whonet5.4 conducted the statistical analysis. Results The detection rates of ESBLs-producing E.coli were 52.92%,51.76% and 48.25% in 2011, 2012, and 2013, respectively. ESBLs-producing Escherichia coli was mainly in internal medicine in the three years, among which the proportions of Nephrology and Endocrinology, accounting for 27.04% and 18.43%, respectively,while the proportion of gynecological surgery was also high(16.90%). The main specimens was urine, and 287 strains were isolated from the urine, accounting for 44.09%. The drug susceptibility test revealed that Imipenem, Meropenem, Piperacillin/tazobactam,and Cefotetan kept high antibacterial activity against ESBLs-producing E.coli, and the overall resistance rates among three years were 0.00%, 0.31%, 6.14% and 3.84% respectively. The resistance rates of ESBLs-producing E.coli to Ciprofloxacin, Cefazolin,Cefuroxime Sodium, Cefuroxime Axetil, Ampicillin, and Piperacillin were higher than 75.00%, and resistance rate of ESBLs-producing E.coli to Ampicillin was higher than 90.00%. In addition, the resistance rates of ESBLs- producing E.coli to Aztreonam, Ceftazidime, and Cefepime were decreasing. Conclusion The ESBLs-producing E.coli were mainly isolated from urine specimens obtained from patients with urinary tract infections, which were highly resistant to multiple drugs. It is necessary to strengthen the monitoring of drug resistance and regulate clinical drug to guide the reasonable use of antibiotics and control nosocomial infections effectively.