Enterococcus faecalis Modulates Immune Activation and Slows Healing During Wound Infection

Area of Science:

• Microbiology
• Immunology
• Wound Healing Research

Background:

• Enterococcus faecalis is a common wound isolate, but its pathogenic mechanisms in wounds are poorly understood.
• Understanding E. faecalis pathogenesis is crucial for treating persistent wound infections.

Purpose of the Study:

• To characterize the infection dynamics of Enterococcus faecalis in a mouse wound model.
• To investigate the factors contributing to E. faecalis persistence in wounds.

Main Methods:

• Utilized a mouse wound excisional model to study E. faecalis infection.
• Varied initial bacterial inocula (low-dose vs. high-dose) to observe infection states.
• Monitored bacterial titers, immune cell infiltration, cytokine levels, and wound healing.

Main Results:

• Low-dose E. faecalis resulted in short-term colonization; high-dose led to acute replication and long-term persistence.
• High-dose infection correlated with immune cell infiltration but suppressed inflammatory cytokines and delayed wound healing.
• The multiple peptide resistance factor (MPRF) was identified as contributing to E. faecalis fitness during high-dose infection.

Conclusions:

• Established a mouse model for studying E. faecalis wound infection determinants.
• Both immune modulation and bacterial resistance mechanisms contribute to persistent, nonhealing E. faecalis wounds.