Wikipedia
Leviviridae
Leviviridae is a family of viruses. Bacteria, including Enterobacteria, Caulobacter, Pseudomonas, and Acinetobacter serve as natural hosts for these bacteriophages. There are currently four species in this family, divided among 2 genera. They are small RNA viruses with linear, positive-sense, single-stranded RNA genomes that encode only four proteins. All phages of this family require bacterial pili to attach to and infect cells.