Evolutionary origins of the emergent ST796 clone of vancomycin resistant Enterococcus faecium
Andrew H. Buultjens,
Margaret M.C. Lam,
Susan Ballard,
Ian R. Monk,
Andrew A. Mahony,
Elizabeth A. Grabsch,
M. Lindsay Grayson,
Stanley Pang,
Geoffrey W. Coombs,
J. Owen Robinson,
Torsten Seemann,
Paul D.R. Johnson,
Benjamin P. Howden,
Timothy P. Stinear
Affiliations
Andrew H. Buultjens
Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
Margaret M.C. Lam
Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
Susan Ballard
Microbiology Diagnostic Unit, Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
Ian R. Monk
Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
Andrew A. Mahony
Infectious Diseases Department, Austin Health, Heidelberg, Victoria, Australia
Elizabeth A. Grabsch
Infectious Diseases Department, Austin Health, Heidelberg, Victoria, Australia
M. Lindsay Grayson
Infectious Diseases Department, Austin Health, Heidelberg, Victoria, Australia
Stanley Pang
School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
Geoffrey W. Coombs
School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
J. Owen Robinson
School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
Torsten Seemann
Victorian Life Sciences Computation Initiative, University of Melbourne, Carlton, Victoria, Australia
Paul D.R. Johnson
Infectious Diseases Department, Austin Health, Heidelberg, Victoria, Australia
Benjamin P. Howden
Microbiology Diagnostic Unit, Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
Timothy P. Stinear
Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
From early 2012, a novel clone of vancomycin resistant Enterococcus faecium (assigned the multi locus sequence type ST796) was simultaneously isolated from geographically separate hospitals in south eastern Australia and New Zealand. Here we describe the complete genome sequence of Ef_aus0233, a representative ST796 E. faecium isolate. We used PacBio single molecule real-time sequencing to establish a high quality, fully assembled genome comprising a circular chromosome of 2,888,087 bp and five plasmids. Comparison of Ef_aus0233 to other E. faecium genomes shows Ef_aus0233 is a member of the epidemic hospital-adapted lineage and has evolved from an ST555-like ancestral progenitor by the accumulation or modification of five mosaic plasmids and five putative prophage, acquisition of two cryptic genomic islands, accrued chromosomal single nucleotide polymorphisms and a 80 kb region of recombination, also gaining Tn1549 and Tn916, transposons conferring resistance to vancomycin and tetracycline respectively. The genomic dissection of this new clone presented here underscores the propensity of the hospital E. faecium lineage to change, presumably in response to the specific conditions of hospital and healthcare environments.
