Abstract: Objective To investigate the drug resistance of carbapenem resistant Escherichia coli (CREco), and the risk factors of carbapenem-resistant CREco urinary tract infection. Methods Data of 120 cases with urinary tract infection occurred in the second hospital of Tianjin Medical University from January 2015 to December 2017 were collected, and the results of those urine cultures were Escherichia coli. A case-control study was conducted, and 24 patients with CREco infection were divided into the case group. The controls were selected among patients with carbapenem sensitive CREco infection in the same ward at the same time and were matched with CREco cases for gender and age. The number of control patients was four times than that of case group. The resistance of pathogenic bacteria to 18 kinds of antimicrobial agents were compared between the two groups. The risk factors of CREco urinary tract infection in the inpatients in our hospital were investigated. Results Patients with CREco infection showed strong resistance to ampicillin and other 11 antimicrobial agents, and the drug resistance rate was higher than 70%. The drug resistance rates of 14 other antimicrobial agents except ampicillin, gentamicin, compound sulfamide and tigecycline were significantly higher than those in CSEco group (P＜0.05).Multivariate regression analysis showed that patients with indwelling catheters (OR=5.719, 95%CI: 2.084-15.697, P＜0.01)and the longer hospitalization time before detection (OR=9.325, 95%CI: 1.962-44.330, P＜0.01) were both the independent risk factors of CREco urinary tract infection in inpatients. Conclusion The CREco resistance of urinary tract infection in inpatients is severe. Indwelling catheters should be strictly observed the standardized operation and clinical indications. It is important to short the time of hospitalization and decrease the exposure in the hospital environment, which may help to reduce the risk of urinary tract infection caused by CREco.

Key words: carbapenem, escherichia coli, drug resistance, urinary tract infection, risk factors