Characterization and Therapeutic Potential of a Novel Lytic Phage‐Derived Endolysin PA16cLys Against Uropathogenic Pseudomonas aeruginosa Biofilms

Pseudomonas aeruginosa (P. aeruginosa) is a leading cause of urinary tract infections (UTIs). The escalating misuse of antibiotics has led to the emergence of multidrug-resistant strains, necessitating novel therapeutic approaches. Bacteriophages and their encoded lytic enzymes offer unique advantages for antimicrobial therapy and show promising potential for future applications. This study focuses on the characterization of uropathogenic P. aeruginosa phages and their lytic enzymes, investigating their biological properties and potential therapeutic applications. We isolated a novel lytic bacteriophage, vB_PaeS_PA16c (PPA16c), which demonstrated favorable biological characteristics, including a 34% biofilm eradication capacity within 6 h. The phage-encoded endolysin PA16cLys exhibited superior antibacterial efficacy compared to the phage itself. Notably, it achieved significant biofilm reduction (~63%) after 1 h treatment without requiring outer membrane permeabilizers. This endolysin exhibited enhanced antibacterial efficacy in eradicating mature P. aeruginosa biofilms. Regarding host range, PA16cLys displayed broader lytic activity. Both the phage and endolysin demonstrated cross-order lytic activity against other pathogenic bacteria. Crucially, PA16cLys maintained potent inhibitory activity against phage-resistant mutants. These findings provide a theoretical foundation for utilizing phages and lytic enzymes against uropathogenic P. aeruginosa and establish a research basis for developing novel antimicrobial therapy.