The Characterization of a Novel Phage, pPa_SNUABM_DT01, Infecting Pseudomonas aeruginosa.

The bacterial genus Pseudomonas is a common causative agent of infections in veterinary medicine. In this study, we focused on Pseudomonas aeruginosa canine otitis externa isolates. Due to prolonged antibiotic treatment of otitis externa, antibiotic resistance is common and has become a major complication. Many alternatives to antibiotics have been studied, with bacteriophages emerging as the most promising alternatives. Here, we isolated and characterized a novel phage, pPa_SNUABM_DT01, by investigating its morphology, growth, lysis kinetics, and genomic characteristics. Phages have a vigorous capacity to eliminate bacterial cells through bacterial lysis. This capacity is dependent on the multiplicity of infection (MOI), but even at low MOIs, the phage successfully inhibited bacterial regrowth. The phage genome was 265,520 bp in size and comprised 312 putative open reading frames (ORFs). Comparative genome analysis demonstrated that the phage is a novel species in Myoviridae. The nucleotide similarity was moderately high compared with the Pseudomonas virus, Noxifer. However, a phylogenetic analysis and a dot plot indicated that pPa_SNUABM_DT01 is not closely related to the Phikzvirus or Noxifervirus genus but, instead, belongs to a novel one. The genome comparisons also indicate that the phage, pPa_SNUABM_DT01, could be a novel genus.