γ Irradiation Alters the Staphylococcus aureus Proteome and Enhances Pathogenicity

Area of Science:

• Microbiology
• Radiation Biology
• Proteomics

Background:

• Staphylococcus aureus (S. aureus) infections are a severe complication for cancer patients undergoing radiotherapy.
• The precise effects of gamma (γ) radiation on S. aureus virulence remain incompletely understood.

Purpose of the Study:

• To investigate the impact of γ radiation on S. aureus growth, proteome, and virulence.
• To analyze the long-term effects on S. aureus descendants following irradiation.

Main Methods:

• Exposure of S. aureus to 100 Gy γ radiation.
• Proteomic analysis using data-independent acquisition (DIA) on irradiated and descendant strains.
• Functional enrichment, pathway analysis, and protein-protein interaction network analysis.

Main Results:

• γ irradiation induced significant proteome alterations in S. aureus and its descendants.
• Key changes were observed in lipoteichoic acid biosynthesis, S. aureus infection pathways, two-component systems, and antimicrobial peptide resistance.
• Both proteomic data and biofilm assays indicated enhanced S. aureus infection ability and pathogenicity post-irradiation.

Conclusions:

• γ irradiation potentiates the infection capabilities of S. aureus.
• Irradiated S. aureus strains and their descendants exhibit increased virulence, suggesting a heightened risk in immunocompromised cancer patients.
• Findings highlight the need to consider radiation's effect on microbial pathogens in clinical settings.