IMG/VR database: genomes of cultivated and uncultivated viruses

Virome graphic art

Recent experimental and computational improvements have led to a dramatic increase in the number of viral genome sequences identified primarily from metagenomic samples. On this page, the viral sequences publicly released in IMG/VR, which have been collected from NCBI RefSeq and IMG metagenomes, can be downloaded in bulk (see Download tab). The IMG/VR system ( serves as a starting point for the analysis of viral genome fragments derived from metagenomic samples: virus detection methods and host assignment approaches in IMG/VR are fully described in Paez-Espino et al. Nature, 2016 "Uncovering Earth's virome" and in Paez-Espino et al. Nature Protocols, 2017 "Nontargeted virus sequence discovery pipeline and virus clustering for metagenomic data". 

Files are available for each IMG/VR release in separate folders identified by the release date. Available files include:

  • nucleotide sequences from viral genomes and contigs (fasta format)
  • protein sequences predicted from viral genomes and contigs (fasta format)
  • a table listing the characteristics of each viral sequence such as its origin, affiliation, and predicted host (tsv format).

If you use this resource, please cite "IMG/VR: a database of cultured and uncultured DNA Viruses and retroviruses".