New viruses infecting hyperthermophilic bacteriumThermus thermophilus

Abstract

Highly diverse phages infecting thermophilic bacteria of theThermusgenus have been isolated over the years from hot springs around the world. Many of these phages are unique, rely on highly unusual developmental strategies, and encode novel enzymes. The variety ofThermusphages is clearly undersampled, as evidenced, for example, by a paucity of phage-matching spacers inThermusCRISPR arrays. Using water samples collected from hot springs in the Kunashir Island from the Kuril archipelago and from the Tsaishi and Nokalakevi districts in the Republic of Georgia we isolated several distinct phages infecting laboratory strains ofThermus thermophilus. Genomic sequence analysis of 11 phages revealed both close relatives of previously describedThermusphages isolated from geographically distant sites, as well as phages with very limited similarity to earlier isolates. Comparative analysis allowed us to predict several accessory phage genes whose products may be involved in host defense/interviral warfare, including a putative Type V CRISPR-cassystem.