Vancomycin-resistant and vancomycin-susceptible enterococcal bacteremia: comparison of clinical features and outcomes.

Vancomycin-resistant Enterococcus (VRE) is a major nosocomial pathogen. We collected clinical and laboratory data on 93 hospitalized adults with VRE bacteremia and 101 adults with vancomycin-susceptible enterococcal (VSE) bacteremia. Risk factors for VRE bacteremia included central venous catheterization, hyperalimentation, and prolonged hospitalization prior to the initial blood culture. VRE-infected patients were less likely to have undergone recent surgery or have polymicrobial bacteremia, suggesting a pathogenesis distinct from traditional VSE bacteremia. Prior exposure to metronidazole was the only significant pharmacologic risk factor for VRE bacteremia. Animal studies suggest metronidazole potentiates enterococcal overgrowth in the gastrointestinal tract and translocation into the bloodstream. An increasing APACHE II score was the major risk factor for death in a multivariate analysis, with VRE status being of only borderline significance.