ABSTRACT
Objective: To analyze the drug resistance of Escherichia coli (E.coli) from bloodstream infection (BSI) and the predictors of mortality in E. coli bloodstream infection (BSI). Methods: The clinical data of 139 E. coli BSI cases diagnosed from January 2012 to December 2015 in The Second Affiliated Hospital of Zhejiang University School of Medicine, Lanxi Branch (Lanxi People's Hospital), Zhejiang Province, were retrospectively analyzed. The antimicrobial susceptibility testing was performed using Vitek 2 system. Extended-spectrum beta-lactamases (ESBLs) were detected by disk diffusion confirmatory testing. The factors associated with ESBLs-producing strains were identified by univariate analysis. Multivariate analysis was used to identify independent predictors of infection mortality by applying Logistic regression. Results: 42.4% of E. coli isolates were ESBLs-producing. The resistant rate of imipenem was 0.7%. The percent of ESBLs in hospital-acquired infection was higher than that in community-acquired infection but without statistical significance (48.7% versus 40.0%, P=0.350). Univariate analysis suggested that the percent of ESBLs-producing strains in BSI happened on ≥15 d after admission and in BSI of biliary tract infection source was 76.9% and 68.0%, which were much higher than those in BSI happened on <15 d after admission and in BSI of non-biliary tract infection source (34.6% and 36.8%, P=0.013 and 0.004). The overall mortality of E. coli BSI was 13.7%. Multivariate Logistic regression analysis indicated that Sequential Organ Failure Assessment (SOFA ) score (OR=1.393, P<0.001), ceftazidime non-susceptibility (OR=4.444, P=0.018) and liver cirrhosis (OR=13.513, P=0.001) were independent risk factors of mortality. Conclusions: The frequency of ESBLs-producing E. coli was high in primary hospital of Zhejiang Province. SOFA score, ceftazidime non-susceptibility and cirrhosis were predictors of poor outcome in E. coli BSI.
