Evaluation of the prevalence and risk factors for colonization by vancomycin-resistant Enterococcus among patients on dialysis

Abstract

Background: Vancomycin-resistant Enterococcus (VRE) has been reported among long-term dialysis patients, although risk factors for VRE colonization are not well defined. This study aims to appraise the prevalence and risk factors for VRE colonization among patients on long-term dialysis therapy, as well as the mechanisms for dissemination of vancomycin resistance. Methods: This is a cross-sectional survey of 320 patients on long-term dialysis therapy at 2 hospitals of the Federal University of São Paulo from June 2001 to March 2003. Fecal samples were collected from each patient once a week for 1 month. Samples with positive test results for VRE were submitted to molecular typing through automated ribotyping. Results: VRE prevalence was 14.4%. There were significant associations between VRE and dialysis type (hemodialysis, P = 0.04), number of hospitalizations (P = 0.03), low hemoglobin level (P = 0.03), and leukocytosis (P = 0.05). Among samples with VRE (n = 56), 25% were Enterococcus faecium; 10.7%, Enterococcus casseliflavus; 57.1%, Enterococcus gallinarum; and 3.6%, Enterococcus faecalis. All samples isolated were sensitive to teicoplanin, except for E faecium samples, which were strongly resistant, although 9 of 14 patients with this isolate presented the same ribogroup (111-S-4). Typing of 6 samples from 8 dialysis patients with E gallinarum was performed, showing a predominant ribogroup (112-S-4). Conclusion: Hospital environment, hemodialysis, anemia, and leukocytosis appear to be associated with VRE colonization. These results suggest that dissemination of these bacteria among patients on long-term dialysis therapy may be taking place.