A Novel Subcluster of Closely Related Phages with Distinct Tail Fiber/Lysin Gene Combinations.

Bacteriophages (phages) are the most numerous entities on Earth, but we have only scratched the surface of describing phage diversity. We isolated seven phages from desert soil in the southwest United States and then sequenced and characterized their genomes. Comparative analyses revealed high nucleotide and amino acid similarity between these seven phages, which constitute a novel subcluster.

Comparative Genomics of Six Lytic Phages from the Southwest United States.

Background: Despite their importance to microbial dynamics involving , we have a limited understanding of the diversity of phages that can lyse this model organism.

Materials And Methods: Phages were isolated from soil samples collected from various sites in the southwest U.S.

Genomic and phenotypic signatures of bacteriophage coevolution with the phytopathogen Pseudomonas syringae.

The rate and trajectory of evolution in an obligate parasite is critically dependent on those of its host(s). Adaptation to a genetically homogeneous host population should theoretically result in specialization, while adaptation to an evolving host population (i.e.

Forty Years without Family: Three Novel Bacteriophages with High Similarity to SPP1 Reveal Decades of Evolutionary Stasis since the Isolation of Their Famous Relative.

SPP1, an extensively studied bacteriophage of the Gram-positive , is a model system for the study of phage-host interactions. Despite progress in the isolation and characterization of phages, no previously fully sequenced phages have shared more than passing genetic similarity to SPP1. Here, we describe three virulent phages very similar to SPP1; SPP1 has greater than 80% nucleotide sequence identity and shares more that 85% of its protein coding genes with these phages.

Complete Genome Sequences of Two Temperate Bacillus subtilis Phages Isolated at Tumamoc Hill Desert Laboratory.

Bacteriophages are important in structuring bacterial communities, including desert soils dominated by species. Here, we describe two genetically similar temperate phages isolated on a Bacillus subtilis strain from soil in Tucson, Arizona. Their double-stranded DNA (dsDNA) genomes contain 98 and 102 genes, with a set of 4 genes being found in only one phage.

Complete Genome Sequence of the Phage AH07.

Bacteriophages of the phyllosphere have not been extensively described, despite their role in bacterial communities on this plant organ. Here, we describe a temperate phage, AH07, that was isolated from the leaves of horse chestnut trees. The 37,859-bp linear double-stranded DNA genome contains 58 putative genes, including an integration cassette.

Complete Genome Sequences of Four Phages of the Horse Chestnut Phyllosphere.

Bacteriophages play important roles in determining bacterial communities, including plant microbiota. Here, we describe four lytic phages, three and one , isolated from four different bacterial species found on the leaves of horse chestnut trees. Their double-stranded DNA (dsDNA) genomes range from 39,095 to 46,062 bp and contain 51 to 70 genes.

Genome Sequences of Phyllophages AH04 and AH06.

Although crucial in shaping bacterial communities, few bacteriophages of the phyllosphere have been described. We provide genome data for two phages, AH04 and AH06, isolated on Erwinia billingiae strains. AH04 shares limited genetic similarity with previously described phages, while AH06 shares over 75% similarity with various phages.

Testing hypotheses for the presence of tRNA genes in mycobacteriophage genomes.

The presence of tRNA genes in bacteriophages has been explained on the basis of codon usage (tRNA genes are retained in the phage genome if they correspond to codons more common in the phage than in its host) or amino acid usage (independent of codon, the amino acid corresponding to the retained tRNA gene is more common in the phage genome than in the bacterial host). The existence of a large database of sequenced mycobacteriophages, isolated on the common host , allows us to test the above hypotheses as well as explore other hypotheses for the presence of tRNA genes. Our analyses suggest that amino acid rather than codon usage better explains the presence of tRNA genes in mycobacteriophages.

Comparative genomics of Cluster O mycobacteriophages.

Mycobacteriophages--viruses of mycobacterial hosts--are genetically diverse but morphologically are all classified in the Caudovirales with double-stranded DNA and tails. We describe here a group of five closely related mycobacteriophages--Corndog, Catdawg, Dylan, Firecracker, and YungJamal--designated as Cluster O with long flexible tails but with unusual prolate capsids. Proteomic analysis of phage Corndog particles, Catdawg particles, and Corndog-infected cells confirms expression of half of the predicted gene products and indicates a non-canonical mechanism for translation of the Corndog tape measure protein.

Cluster M mycobacteriophages Bongo, PegLeg, and Rey with unusually large repertoires of tRNA isotypes.

Unlabelled: Genomic analysis of a large set of phages infecting the common host Mycobacterium smegmatis mc(2)155 shows that they span considerable genetic diversity. There are more than 20 distinct types that lack nucleotide similarity with each other, and there is considerable diversity within most of the groups. Three newly isolated temperate mycobacteriophages, Bongo, PegLeg, and Rey, constitute a new group (cluster M), with the closely related phages Bongo and PegLeg forming subcluster M1 and the more distantly related Rey forming subcluster M2.