Comparison of the Clinical Characteristics and Outcomes Associated with Vancomycin-Resistant Enterococcus faecalis and Vancomycin-Resistant E. faecium Bacteremia

Abstract

ABSTRACTIn published studies, cohorts of patients with bacteremia due to vancomycin-resistantEnterococcus(VRE) have predominantly been infected withEnterococcus faecium. Little is known about the epidemiology and outcomes associated with bacteremia due to VREnterococcus faecalis. A retrospective study of isolates obtained from January 2008 to October 2010 was conducted at Detroit Medical Center (DMC). Unique patients with blood cultures positive for VRE were reviewed. Outcomes were analyzed using logistic regression. During the study period, 105 cases of bacteremia due to VRE. faecalisand 197 cases of bacteremia due to VRE. faeciumwere identified. The mean age in the study cohort was 61.5 ± 15 years; 162 subjects (53.6%) were male. After controlling for a propensity score, bacteremia due to VRE. faecaliswas associated with >2-fold-lower in-hospital mortality than bacteremia due to VRE. faecium. Interestingly, bacteremia due to VRE. faecaliswas associated with longer hospital stay after VRE isolation, although total length of stay was similar for groups with VRE. faecalisand VRE. faecium. Bacteremia due to VRE. faecaliswas associated with a >2-fold-lower risk for mortality than bacteremia due to VRE. faecium, possibly due to the availability of β-lactam therapeutics for treatment of VRE. faecalis.