Family: Inoviridae

Genus: Habenivirus

Distinguishing features

The phages of this genus possess genomes of 7.6−9.0 kb (59−60 % G+C), and encode 13−15 proteins. They share 56−91% DNA sequence identity and 60−80% proteome homology (as determined using CoreGenes 3.0). Members of the species Ralstonia virus RSM1 are filamentous phages about 1,400 nm in length and 10 nm in width (Yamada 2013, Van et al., 2014). Phages in the genus are integrative but do not possess their own integrase. Infection of Ralstonia solanacearum with Ralstonia phage RSM3 decreases the host growth rate, twitching motility, movement in tomato plant stems, extracellular polysaccharide production, and expression of  the global virulence regulator phcA, resulting in a loss of bacterial virulence. However, phage infection can enhance cell aggregative properties and antibiotic resistance (Addy et al., 2012, Addy et al., 2012c). 

Virion

See discussion under family description. 

Genome organisation and replication

See discussion under family description. 

Biology

Members of the genus infect Ralstonia solanacearum. 

Species demarcation criteria

Members of different species are >5% different in the DNA sequence of their genomes as assessed using the BLASTn algorithm.