Abstract:Objective: Pseudomonas aeruginosa is a Gram-negative opportunistic pathogenic bacterium capable of causing various infectious diseases including pneumonia, urethritis, keratitis, and sepsis. The current misuse of antibiotics and the increasing annual isolation of multidrug-resistant (MDR) strains have posed significant challenges to clinical treatment. Recent studies highlight phage therapy as a promising therapeutic strategy. Our study aims to isolate and purify novel P. aeruginosa bacteriophages. Methods: Bacteriophages were isolated from campus lake water, followed by genome sequencing and biological characterization of purified phages. In vitro antibacterial assays including growth inhibition curves and biofilm eradication experiments were conducted. Results: A novel P. aeruginosa phage named PAPX was successfully isolated from campus pond water. Genomic analysis revealed 98% identity with Pseudomonas phage Epa12, classifying it within the Pbunavirus genus. Transmission electron microscopy demonstrated its myoviral morphology featuring an icosahedral head (~90 nm diameter) and a contractile tail (~50 nm length, 26 nm diameter). Biological characterization showed strong lytic activity against 17 of 24 clinical strains. In vitro experiments confirmed its ability to suppress bacterial growth during early proliferation phase and effectively eradicate P. aeruginosa biofilms. Conclusion: The successful isolation and characterization of phage PAPX, validated through biological profiling and in vitro assays, demonstrates its promising clinical potential for treating P. aeruginosa infections, particularly in combating antibiotic-resistant strains and biofilm-associated infections.