EM image of Pseudomonas phage Pf, an inovirus infecting Pseudomonas hosts. Inovirus capsids are long flexible filaments visible here after sample concentration and precipitation. (Courtesy of J. Driver and P. Secor, University of Montana)

Inoviruses are filamentous viruses with small, single-stranded DNA genomes and a unique chronic infection cycle. In Nature Microbiology, a team led by DOE Joint Genome Institute (JGI) researchers applied machine learning to publicly available microbial genomes and metagenomes to search for inoviruses. The search tool combed through more than 70,000 microbial and metagenome datasets, ultimately identifying more than 10,000 inovirus-like sequences compared to the 56 previously known inovirus genomes. The results revealed inoviruses are in every major microbial habitat—including soil, water, and humans—around the world.

“We’re not sure why we systematically manage to miss them; maybe it’s due to the way we currently isolate and extract viruses,” said the study’s lead author Simon Roux, a JGI research scientist in the Environmental Genomics group. Click here to read the full story on the JGI site.