Article open access publication

Multiple hospital outbreaks of vanA Enterococcus faecium in Denmark, 2012–13, investigated by WGS, MLST and PFGE

Journal of Antimicrobial Chemotherapy, Oxford University Press (OUP), ISSN 1460-2091

Volume 70, 9, 2015

DOI:10.1093/jac/dkv142, Dimensions: pub.1013442426, PMID: 26031466,



  1. (1) University of Copenhagen, grid.5254.6, KU
  2. (2) Hvidovre Hospital, grid.411905.8, Capital Region
  3. (3) State Serum Institute, grid.6203.7
  4. (4) Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
  5. (5) Herlev Hospital, grid.411900.d, Capital Region
  6. (6) Aarhus University Hospital, grid.154185.c, Central Denmark Region
  7. (7) Aalborg Hospital, grid.27530.33, North Denmark Region
  8. (8) Copenhagen University Hospital, grid.4973.9, Capital Region
  9. (9) Slagelse Hospital, grid.452905.f, Zealand Region
  10. (10) Odense University Hospital, grid.7143.1, Southern Denmark Region
  11. (11) Hospital of South West Jutland, grid.414576.5, Southern Denmark Region






OBJECTIVES: In Denmark, the incidence of vancomycin-resistant Enterococcus faecium (VREfm) has increased since 2012. The aim of this study was to investigate the epidemiology and clonal relatedness of VREfm isolates in Danish hospitals in 2012-13 using WGS. The second aim was to evaluate if WGS-based typing could replace PFGE for typing of VREfm. METHODS: A population-based study was conducted including all VREfm isolates submitted for national surveillance from January 2012 to April 2013. All isolates were investigated by WGS, MLST and PFGE. RESULTS: One-hundred and thirty-two isolates were included. The majority of the isolates were from clinical samples (77%). Gastroenterology/abdominal surgery (29%) and ICUs (29%) were the predominant departments with VREfm. Genomics revealed a polyclonal structure of the VREfm outbreak. Seven subgroups of 3-44 genetically closely related isolates (separated by <17 SNPs) were identified using WGS. Direct or indirect transmission of VREfm between patients and intra- and inter-regional spreading clones was observed. We identified 10 STs. PFGE identified four major clusters (13-43 isolates) and seven minor clusters (two to three isolates). The results from the typing methods were highly concordant. However, WGS-based typing had the highest discriminatory power. CONCLUSIONS: This study emphasizes the importance of infection control measures to limit transmission of VREfm between patients. However, the diversity of the VREfm isolates points to the fact that other important factors may also affect the VREfm increase in Denmark. Finally, WGS is suitable for typing of VREfm and has replaced PFGE for typing of VREfm in Denmark.

Research Categories

Main Subject Area

Fields of Research

Links & Metrics

NORA University Profiles

University of Copenhagen

Aalborg University

Dimensions Citation Indicators

Times Cited: 50

Field Citation Ratio (FCR): 13.94

Relative Citation ratio (RCR): 3.36

Open Access Info