Abstract
BACKGROUND: Pseudomonas aeruginosa (P. aeruginosa) is a leading cause of healthcare-associated infection and is prone to antibiotic resistance. Treating infections caused by antibiotic-resistant P. aeruginosa remains clinically challenging. The increasing prevalence of multidrug-resistant (MDR) bacteria has prompted the development of alternatives to antibiotics. Bacteriophage (phage) therapy has been regarded as a promising antibacterial alternative in many cases of MDR bacterial infections. This study aimed to isolate and characterize phages with therapeutic potential against MDR P. aeruginosa. METHODS: Phage PUTH1 was isolated from filtered sewage water collected at Peking University Third Hospital using the double-layer agar spot method. The phage morphology was characterized using transmission electron microscopy (TEM). Subsequently, key biological properties were evaluated, including temperature and pH stability, one-step growth curve, adsorption rate, and optimal multiplicity of infection (MOI). Additionally, the anti-biofilm activity was assessed using crystal violet staining assays. Finally, whole genome sequencing was conducted, followed by comprehensive bioinformatics analysis. RESULTS: Morphological and genomic characterization confirmed that the phage PUTH1 belongs to the Podoviridae family. The phage exhibits remarkable thermal stability (active up to 60 °C) and across a broad pH range (pH 4.0–9.0). Furthermore, the phage is characterized by a short latent period (approximately 30 min), a large burst size (54.5 PFU/cell), and rapid adsorption efficiency, achieving approximately 80% adsorption after 6 min. PUTH1 exhibits significant anti-biofilm activity. The genome of phage was 45,483 bp with 52.25% GC content and contained 70 putative genes; functions were predicted for 32 of them. Phylogenetic analysis revealed that PUTH1 is distinct from currently known phages and belongs to a novel species. The genome sequencing analysis suggested that it does not exist any known virulence and antibiotic resistant genes. CONCLUSION: Therefore, our findings demonstrate that this novel phage represents a promising therapeutic candidate for treating MDR P. aeruginosa infections. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12985-025-02859-8.