Biological characterization and genome analysis of Pseudomonas phage ZAM-Pa99 as a promising anti-biofilm agent

Abstract

Background: The increasing prevalence of highly antibiotic-resistant pathogen Pseudomonas aeruginosa, necessitates the exploration of novel therapeutic alternatives. This study aimed to isolate and characterize a bacteriophage with potential applications against P. aeruginosa wound infection. Methods and results: The lytic phage ZAM-Pa99 was isolated from hospital sewage and subjected to comprehensive analysis, including morphological characterization, physicochemical properties, growth dynamics, biofilm degradation, genome sequencing, and bioinformatics analysis. ZAM-Pa99 was classified as a newly characterized isolate within the Pbunavirus genus, demonstrating a broad lytic host range (80 efficacy) against the tested clinical strains. This result aligns with in silico host-range predictions, which reflect the high sequence similarity of its receptor-binding proteins with those of relatedPbunavirus phages. Genomic analysis (65,139 bp) was crucial for identifying its therapeutic safety profile, confirming the absence of virulence factors or antimicrobial resistance genes. Importantly, multi-tool proteomic analysis resolved a canonical lysis cassette including a confirmed endolysin, a holin candidate and an identified tailspike-like receptor-binding protein with strong putative depolymerase activity. This mechanism correlated with functional results: ZAM-Pa99 achieved up to 95 degradation of 1-day-old P. aeruginosa biofilms, maintaining high efficacy against 3- and 5-day-old mature structures, results that were quantified and visually confirmed. Conclusion: ZAM-Pa99's promising characteristics, including its broad host range, biofilm-degrading ability, and lack of harmful genes, make it a promising candidate for phage-based therapy against P. aeruginosa infections. These findings contribute to a growing body of evidence supporting the potential of bacteriophages as valuable nature's weapons for combating antibiotic-resistant pathogens. © The Author(s), under exclusive licence to Springer Nature B.V. 2025.