Isolation, genomic characterization, and biofilm eradication activity of vB_PaP_DMTU_1, a novel lytic bacteriophage against Pseudomonas aeruginosa.

Biofilm-associated Pseudomonas aeruginosa (P. aeruginosa) infections pose significant therapeutic challenges owing to their intrinsic resistance to conventional antibiotics. With targeted bacterial lysis and biofilm degradation capabilities, bacteriophage therapy (phage therapy) has re-emerged as a promising alternative antimicrobial strategy. In this study, a novel lytic bacteriophage, vB_PaP_DMTU_1, was isolated from sewage wastewater in Nagaon, India, and characterized using transmission electron microscopy (TEM), whole-genome sequencing, and comprehensive biological assays. TEM micrographs revealed the podoviral morphology of the phage. Genomic analysis classified it within the Zobellviridae family and Paundecimvirus genus, containing a linear double-stranded DNA of 49 kbp with a GC content of 44.98%. Genome annotation identified 83 open reading frames (ORFs), with 25 encoding functional proteins related to structure, metabolism, infection, DNA replication, transcription regulation, packaging, and cell lysis, including 58 hypothetical proteins, one tRNA and ten Rho-dependent transcription terminator genes. The genome lacks lysogeny and CRISPR-associated genes. The phage demonstrated pH stability (6-10), UV resistance, thermal tolerance (up to 50℃), and robust lytic activity with a 30 min latent period and a burst size of ~ 100 virions per host cell. It achieved 93.58% eradication of 72 h mature biofilms at MOI = 10. Stability studies over 24 months revealed optimal phage preservation in liquid lysate formulations, followed by lyophilized powders and alginate beads. These findings establish bacteriophage vB_PaP_DMTU_1 as a promising phage therapy candidate against P. aeruginosa biofilms, significantly contributing to the arsenal of phage-based biocontrol strategies.