Genomic Epidemiology of Vancomycin-Resistant Enterococcus faecium (VREfm) in Latin America: Revisiting The Global VRE Population Structure

<jats:title>Abstract</jats:title><jats:p>Little is known about the population structure of vancomycin-resistant <jats:italic>Enterococcus faecium</jats:italic> (VR<jats:italic>Efm</jats:italic>) in Latin America (LATAM). Here, we provide a complete genomic characterization of 55 representative Latin American VR<jats:italic>Efm</jats:italic> recovered from 1998–2015 in 5 countries. The LATAM VR<jats:italic>Efm</jats:italic> population is structured into two main clinical clades without geographical clustering. Using the LATAM genomes, we reconstructed the global population of VR<jats:italic>Efm</jats:italic> by including 285 genomes from 36 countries spanning from 1946 to 2017. In contrast to previous studies, our results show an early branching of animal related isolates and a further split of clinical isolates into two sub-clades within clade A. The overall phylogenomic structure of clade A was highly dependent on recombination (54% of the genome) and the split between clades A and B was estimated to have occurred more than 2,765 years ago. Furthermore, our molecular clock calculations suggest the branching of animal isolates and clinical clades occurred ~502 years ago whereas the split within the clinical clade occurred ~302 years ago (previous studies showed a more recent split between clinical an animal branches around ~74 years ago). By including isolates from Latin America, we present novel insights into the population structure of VR<jats:italic>Efm</jats:italic> and revisit the evolution of these pathogens.</jats:p>