A case-case-control study was conducted to identify independent risk factors for recovery of Escherichia coli strains producing CTX-M-type extended-spectrum ␤-lactamases (

e Although much is known about vancomycin-resistant (VR) Enterococcus faecium, little is known about the epidemiology of VR Enterococcus faecalis. The predilection of VR E. faecalis to transfer the vancomycin resistance determinant to Staphylococcus aureus is much greater than that of VR E. faecium. The epidemiology of VR E. faecalis has important implications regarding the emergence of vancomycin-resistant S. aureus (VRSA); 8 of 13 reported VRSA cases have been from Michigan. A retrospective case-case-control study was conducted at the Detroit Medical Center, located in southeastern Michigan. Unique patients with VR E. faecalis infection were matched to patients with strains of vancomycin-susceptible (VS) E. faecalis and to uninfected controls at a 1:1:1 ratio. Five hundred thirty-two VR E. faecalis cases were identified and were matched to 532 VS E. faecalis cases and 532 uninfected controls. The overall mean age of the study cohort (n ‫؍‬ 1,596) was 63.0 ؎ 17.4 years, and 747 (46.8%) individuals were male. Independent predictors for the isolation of VR E. faecalis (but not VS E. faecalis) compared to uninfected controls were an age of >65 years, nonhome residence, diabetes mellitus, peripheral vascular disease, exposure to cephalosporins and fluoroquinolones in the prior 3 months, and immunosuppressive status. Invasive procedures and/or surgery, chronic skin ulcers, and indwelling devices were risk factors for both VR E. faecalis and VS E. faecalis isolation. Cephalosporin and fluoroquinolone exposures were unique, independent predictors for isolation of VR E. faecalis. A majority of case patients had VR E. faecalis present at the time of admission. Control of VR E. faecalis, and ultimately VRSA, will likely require regional efforts focusing on infection prevention and antimicrobial stewardship.

eIn published studies, cohorts of patients with bacteremia due to vancomycin-resistant Enterococcus (VRE) have predominantly been infected with Enterococcus faecium. Little is known about the epidemiology and outcomes associated with bacteremia due to VR Enterococcus 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 VR E. faecalis and 197 cases of bacteremia due to VR E. faecium were 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 VR E. faecalis was associated with >2-fold-lower in-hospital mortality than bacteremia due to VR E. faecium. Interestingly, bacteremia due to VR E. faecalis was associated with longer hospital stay after VRE isolation, although total length of stay was similar for groups with VR E. faecalis and VR E. faecium. Bacteremia due to VR E. faecalis was associated with a >2-fold-lower risk for mortality than bacteremia due to VR E. faecium, possibly due to the availability of ␤-lactam therapeutics for treatment of VR E. faecalis. Enterococci are the third most common type of health careassociated pathogen in the United States (17). The two most common species responsible for enterococcal infections in humans are Enterococcus faecalis and Enterococcus faecium. Enterococci are inherently resistant to several antimicrobials and also have an ability to acquire mobile genetic resistance determinants (22). The emergence of resistance to various antimicrobial agents, specifically to vancomycin, has become a major clinical and epidemiological threat. Vancomycin-resistant Enterococcus (VRE) infections are associated with increased morbidity, mortality, and costs compared to vancomycin-susceptible enterococcal infections (3).VRE infections impose a huge burden on facilities in metropolitan Detroit. At Detroit Medical Center (DMC) in 2009, 530 of 4,377 (12.1%) isolates of E. faecalis and 846 of 1,150 (73.6%) isolates of E. faecium were VRE (16). Both the proportion of total VREs accounted for by VR E. faecalis and the total absolute number of unique clinical isolates of VR E. faecalis increased significantly from 2003 to 2009 (16). The prevalence of VR E. faecalis at DMC is much higher than in other regions in North America and worldwide. According to National Healthcare Safety Network (NHSN) data, 6.9% of E. faecalis isolates reported in 2006 and 2007 were VRE, compared to over 12% of E. faecalis isolates reported at DMC (17).Past studies of the epidemiology and outcomes associated with VRE infections were conducted with cohorts consisting predominantly of E. faecium, and relatively little is known about the epidemiology of vancomycin-resistant E. faecalis (5). Only a few studies with small sample sizes have compared the epidemiology of infec...