Enterococcal surface protein, Esp, enhances biofilm formation by Enterococcus faecalis

Area of Science:

• Microbiology
• Infectious Diseases
• Molecular Biology

Background:

• Enterococci are commensal gut bacteria and a major cause of antibiotic-resistant hospital-acquired infections.
• Biofilm formation by microorganisms is a key factor in many nosocomial infections.
• The molecular mechanisms of enterococcal biofilm development are not fully understood, with conflicting reports on the role of Enterococcal surface protein (Esp).

Purpose of the Study:

• To precisely determine the role of Enterococcal surface protein (Esp) in Enterococcus faecalis biofilm formation.
• To investigate whether Esp expression is essential for biofilm development in E. faecalis.

Main Methods:

• Genetically defined, natively Esp-deficient E. faecalis strains were engineered to express Esp on their cell surface.
• Isogenic Esp-positive and Esp-deficient strains were compared for their biofilm-forming capabilities.
• Biofilm formation was assessed under varying glucose concentrations.

Main Results:

• Esp expression significantly increased biofilm formation in E. faecalis, regardless of the strain background.
• The contribution of Esp to biofilm formation was most pronounced at glucose concentrations of 0.5% (wt/vol) or higher.
• These findings confirm Esp as a critical factor in E. faecalis biofilm development.

Conclusions:

• Enterococcal surface protein (Esp) is a key determinant of Enterococcus faecalis biofilm formation.
• Esp-mediated biofilm enhancement is significant, particularly in the presence of sufficient glucose.
• Understanding Esp's role is vital for developing strategies to combat enterococcal hospital-acquired infections.