Isolation and characterization of Pseudomonas phage HJ01 and its therapeutic efficacy in canine pyoderma.

BACKGROUND

Pseudomonas aeruginosa is a major pathogen in canine pyoderma, with increasing antibiotic resistance necessitating the development of alternative therapies. This study aimed to isolate and characterize a lytic phage targeting multidrug-resistant P. aeruginosa and evaluate its therapeutic efficacy in a canine pyoderma model. The key methods include isolation of phage HJ01 from wastewater, identification of genomic and biological characteristics, and subcutaneous injection of HJ01 in a canine pyoderma model induced by P. aeruginosa.

RESULTS

The host strain GDPA-01 exhibited multidrug resistance, with a 75% resistance gene detection rate, and harbored virulence genes such as exoU and exoT. Phage HJ01, classified as Pakpunavirus, exhibited optimal activity at pH 6.0-8.0, thermal stability up to 50 °C, a latent period of 20 min, and a burst size of 52 PFU/cell. In vivo, compared with the controls, HJ01 significantly reduced pruritus, cytology, and skin lesion scores (p < 0.05). Histopathology confirmed that in dogs treated with HJ01, epidermal repair was accelerated and inflammation was reduced.

CONCLUSIONS

HJ01 emerges as a promising therapeutic candidate for managing multidrug-resistant P. aeruginosa infections in companion animals. This study pioneers the application of phage therapy in canine pyoderma, highlighting its potential to mitigate antibiotic overuse and address public health risks associated with zoonotic multidrug-resistant bacteria.