Emergence of vanA Enterococcus faecium in Denmark, 2005-15

J Antimicrob Chemother. 2017 Aug 1;72(8):2184-2190. doi: 10.1093/jac/dkx138.

Abstract

Objectives: To describe the changing epidemiology of vancomycin-resistant Enterococcus faecium and Enterococcus faecalis in clinical samples in Denmark 2005-15 according to species and van type, and, furthermore, to investigate the genetic relatedness of the clinical E. faecium isolates from 2015.

Methods: During 2005-14, all clinical VRE isolates were tested for the presence of vanA/B/C genes by PCR. In 2015, all clinical VRE isolates were whole-genome sequenced. From the WGS data, the presence of van genes and MLST STs were extracted in silico . Core-genome MLST (cgMLST) analysis was performed for the vancomycin-resistant E. faecium isolates.

Results: During 2005-15, 1043 vanA E. faecium , 25 vanB E. faecium , 4 vanA E. faecalis and 28 vanB E. faecalis were detected. The number of VRE was <50 isolates/year until 2012 to > 200 isolates/year in 2013-15. In 2015, 368 vanA E. faecium and 1 vanB E. faecium were detected along with 1 vanA E. faecalis and 1 vanB E. faecalis . cgMLST subdivided the 368 vanA E. faecium isolates into 33 cluster types (CTs), whereas the vanB E. faecium isolate belonged to a different CT. ST203-CT859 was most prevalent (51%), followed by ST80-CT14 (22%), ST117-CT24 (6%), ST80-CT866 (4%) and ST80-CT860 (2%). Comparison with the cgMLST.org database, previous studies and personal communications with neighbouring countries revealed that the novel cluster ST203-CT859 emerged in December 2014 and spread to the south of Sweden and the Faroe Islands during 2015.

Conclusions: VRE increased in Denmark during 2005-15 due to the emergence of several vanA E. faecium clones.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Carbon-Oxygen Ligases / genetics*
  • DNA, Bacterial / genetics
  • Denmark / epidemiology
  • Enterococcus faecium / genetics*
  • Enterococcus faecium / isolation & purification
  • Gram-Positive Bacterial Infections / epidemiology*
  • Gram-Positive Bacterial Infections / microbiology*
  • Humans
  • Multilocus Sequence Typing
  • Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Vancomycin-Resistant Enterococci / genetics*
  • Vancomycin-Resistant Enterococci / isolation & purification

Substances

  • Bacterial Proteins
  • DNA, Bacterial
  • VanA ligase, Bacteria
  • Carbon-Oxygen Ligases