Vancomycin-resistant Enterococcal Bacteremia in a Hematology Unit: Molecular Epidemiology and Analysis of Clinical Course

Abstract

An increase in vancomycin-resistant enterococcal (VRE) bacteremia in hemato-oncological patients (n=19) in our institution from 2000 through 2001 led us to analyze the molecular epidemiologic patterns and clinical features unique to our cases. The pulsed field gel electrophoresis of the isolates revealed that the bacteremia was not originated from a single clone but rather showed endemic pattern of diverse clones with small clusters. A different DNA pattern of blood and stool isolates from one patient suggested exogenous rather than endogenous route of infection. Enterococcus faecium carrying vanA gene was the causative pathogen in all cases. Patients with VRE bacteremia showed similar clinical courses compared with those with vancomycin-susceptible enterococcal (VSE) bacteremia. Vancomycin resistance did not seem to be a poor prognostic factor because of similar mortality (5/8, 62.5%) noted in VSE bacteremia. Initial disease severity and neutropenic status may be major determinants of prognosis in patients with VRE bacteraemia.