Comparative Genomics of Prophages Sato and Sole Expands the Genetic Diversity Found in the Genus Betatectivirus

Abstract

Tectiviruses infecting the Bacillus cereus group represent part of the bacterial “plasmid repertoire” as they behave as linear plasmids during their lysogenic cycle. Several novel tectiviruses have been recently found infecting diverse strains belonging the B. cereus lineage. Here, we report and analyze the complete genome sequences of phages Sato and Sole. The linear dsDNA genome of Sato spans 14,852 bp with 32 coding DNA sequences (CDSs), whereas the one of Sole has 14,444 bp comprising 30 CDSs. Both phage genomes contain inverted terminal repeats and no tRNAs. Genomic comparisons and phylogenetic analyses placed these two phages within the genus Betatectivirus in the family Tectiviridae. Additional comparative genomic analyses indicated that the “gene regulation-genome replication” module of phages Sato and Sole is more diverse than previously observed among other fully sequenced betatectiviruses, displaying very low sequence similarities and containing some ORFans. Interestingly, the ssDNA binding protein encoded in this genomic module in phages Sato and Sole has very little amino acid similarity with those of reference betatectiviruses. Phylogenetic analyses showed that both Sato and Sole represent novel tectivirus species, thus we propose to include them as two novel species in the genus Betatectivirus.

Special Issue “Bacteriophage Genomics”: Editorial

“…This Special Issue “Bacteriophage Genomics” focuses on the latest achievements and problems of bacteriophage genomics. To date, 14 articles have been published on comparative and functional genomics of these viruses [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. Most articles published in the Special Issue deal with the functional and structural genomics of various phages, including the identification of phage endolysins, potentially useful for therapy.…”

“…The published studies are in the trend of general interest in phage therapy of patients with infections caused by bacterial pathogens with multidrug resistance. It can be noted that five of the 14 publications in the Special Issue are devoted to prophages found in bacterial genomes, making an important contribution to the diversity of their hosts and to the exchange of genetic information between bacteria [ 19 , 25 , 26 , 28 , 30 ].…”