Draft genomes of Vancomycin-resistant isolates of animal Enterococcus faecium

Enterococci are Gram-positive bacteria that inhabit the gastrointestinal tract of humans and animals as commensal flora. In recent years two species, Enterococcus faecalis and Enterococcus faecium, have become an increasing medical concern by virtue of their ability to gain and spread antibiotic resistance. In this study, genomes of vancomycin-resistant isolates of E. faecium from pig, chicken and calf were sequenced using 454 platforms. The assembled genomes were annotated and compared with human E. faecium isolates to identify their repertoire of genes potentially associated with colonising each host. Phylogenomics of E. faecium was used to investigate the relationship between animal and human strains. The genomes of the chicken, pig and calf isolates differed in size (2.5 Mb to 3.3 Mb) with the size difference due to horizontally-acquired elements (mostly phage, transposons and insertion sequences); the chicken isolate genome contained five prophages. The aims were to sequence the genomes of three vancomycin-resistant isolates of E. faecium from chicken, calf and pig using next generation pyrosequencing on the Roche 454 titanium platform. These genomes were selected specifically to investigate host adaptation in mammalian hosts.