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Molecular Epidemiology of Vancomycin-Resistant Enterococci: A 2-Year Perspective

Published online by Cambridge University Press:  02 January 2015

Valentina Stosor*
Affiliation:
Division of Clinical Microbiology, Department of Pathology, Northwestern University Medical School, Northwestern Memorial Hospital, Chicago, Illinois Division of Infection Diseases, Department of Medicine, Northwestern University Medical School, Northwestern Memorial Hospital, Chicago, Illinois
Julie Kruszynski
Affiliation:
Clinical Microbiology Laboratory, Northwestern Memorial Hospital, Chicago, Illinois
Terra Suriano
Affiliation:
Infection Control Department, Northwestern Memorial Hospital, Chicago, Illinois NMH Infection Control and Prevention Project, Northwestern Memorial Hospital, Chicago, Illinois
Gary A. Noskin
Affiliation:
Division of Clinical Microbiology, Department of Pathology, Northwestern University Medical School, Northwestern Memorial Hospital, Chicago, Illinois Division of Infection Diseases, Department of Medicine, Northwestern University Medical School, Northwestern Memorial Hospital, Chicago, Illinois Infection Control Department, Northwestern Memorial Hospital, Chicago, Illinois NMH Infection Control and Prevention Project, Northwestern Memorial Hospital, Chicago, Illinois
Lance R. Peterson
Affiliation:
Division of Clinical Microbiology, Department of Pathology, Northwestern University Medical School, Northwestern Memorial Hospital, Chicago, Illinois Division of Infection Diseases, Department of Medicine, Northwestern University Medical School, Northwestern Memorial Hospital, Chicago, Illinois Clinical Microbiology Laboratory, Northwestern Memorial Hospital, Chicago, Illinois NMH Infection Control and Prevention Project, Northwestern Memorial Hospital, Chicago, Illinois
*
Northwestern University Medical School, Clinical Microbiology Section, Wesley Pavilion, Room 565, 250 East Superior St, Chicago, IL 60611

Abstract

Objective:

To determine the molecular epidemiology of vancomycin-resistant enterococci (VRE) at our medical center in order to identify the extent of strain clonality and possible transmission patterns of this pathogen.

Design:

An important facet of our infection control program includes molecular typing of all clinical and surveillance isolates of VRE to determine transmission patterns in the hospital. Molecular strain typing is performed by restriction endonuclease analysis (REA) of genomic DNA. REA patterns are visually compared to categorize VRE strains into type and subtype designations.

Setting:

A 588-bed, university-affiliated, tertiary-care hospital and a neighboring 155-bed rehabilitation facility.

Results:

From January 1995 through December 1996, 379 VRE isolates were collected from 197 patients. Thirty-three genotypes were determined by REA typing; 15 genotypes were implicated in 29 instances of potential nosocomial transmission. Three major clusters of VRE involving patients on multiple nursing units and two adjacent hospitals were identified. The remaining instances of nosocomial transmission occurred in small patient clusters.

Conclusions:

In conclusion, the VRE epidemic at this medical center is polyclonal. VRE transmission patterns are complex, and, while large clusters do occur, the usual pattern of nosocomial acquisition of this pathogen occurs in the setting of “mini-clusters”.

Type
Original Articles
Copyright
Copyright © The Society for Healthcare Epidemiology of America 1999

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