Characterization of bacteriophage JD929 targeting Staphylococcus aureus from chronic otitis media and its ability to inhibit biofilm.

BACKGROUND

Staphylococcus aureus (S. aureus) is a key pathogen involved in chronic suppurative otitis media (CSOM). Antibiotic resistance and biofilm formation complicate CSOM treatment. Therefore, alternative therapies are urgently needed. Bacteriophage therapy, which specifically targets and destroys methicillin-resistant S. aureus (MRSA) and degrades biofilms, presents a promising option.

METHODS

In this study, a lytic bacteriophage targeting S. aureus was isolated and named JD929. Its biological properties were analyzed, including its stability across different pH levels and temperatures, host range, and growth kinetics. Whole-genome sequencing and bioinformatics analyses were performed for taxonomic classification. Additionally, structural prediction and homology analysis of the tail protein (ORF8) were conducted using AlphaFold. The antibiofilm activity of JD929 against CSOM-associated S. aureus was also assessed.

RESULTS

JD929 demonstrated high stability across a broad range of pH levels and temperatures and exhibited a distinct host spectrum from that of phage SLPW. One-step growth analysis showed a latent period of 30 min and a burst size of 156 PFU per cell. Genomic analysis identified JD929 as a member of the Rountreeviridae family. Structural prediction revealed that the tail protein has unique sequence and structural features, indicating a potential role in host recognition. Functionally, JD929 significantly inhibited biofilm formation and disrupted mature biofilms of CSOM-associated S. aureus.

CONCLUSIONS

The newly isolated bacteriophage JD929 exhibits beneficial biological properties and strong, strain-specific antibiofilm activity, highlighting its potential as an alternative treatment for CSOM-associated S. aureus infections.