Properties of the new D3-like Pseudomonas aeruginosa bacteriophage phiPMG1: Genome structure and prospects for the use in phage therapy

Abstract

Results of studying the novel virulent phage phiPMG1 active on Pseudomonas aeruginosa are presented. phiPMG1 was shown to exhibit detectable homology and resemblance in the total genome structure with temperate converting phage D3. Phage phiPMG1 differs from D3 in that it fails to stably lysogenize bacteria and can grow on strains carrying plasmids that cause growth inhibition of phage D3 and some other phages. This significantly diminishes the probability of horizontal gene transfer with phage phiPMG1 and suggests the possible employment of this phage in phage therapy. A comparison of genome structures in phages phiPMG1 and D3 demonstrated not only high homology of 65 genes, but also the presence in the phiPMG1 genome of 16 genes that were not recorded in the files of NCBI database. Apparently, the evolution of genomes in phages of this species is mostly associated with migrations into other species of bacteria and recombinations with phages of other species (for example, F116). Detailed structural analysis a genome region in which the essential nonhomology is exhibited between three D3-like phages (D3, phiPMG1, and PAJU2) revealed that the phiPMG1 genome supposedly is phylogenetically closer than the others to the genome of a hypothetical ancestor phage belonging to this species.