Effect of a genetically engineered bacteriophage on Enterococcus faecalis biofilms

Area of Science:

• Microbiology
• Bacteriophage Therapy
• Biofilm Research

Background:

• Enterococcus faecalis is a common cause of persistent infections, particularly in endodontics and healthcare settings.
• E. faecalis forms robust biofilms and exhibits antibiotic resistance, complicating treatment with conventional methods.
• Phage therapy presents a potential alternative to antibiotics for combating E. faecalis infections.

Purpose of the Study:

• To evaluate the efficacy of a genetically modified bacteriophage, ϕEf11/ϕFL1C(Δ36)^PnisA, in disrupting Enterococcus faecalis biofilms.
• To assess the phage's effectiveness against both vancomycin-sensitive (JH2-2) and vancomycin-resistant (V583) strains of E. faecalis.

Main Methods:

• Static biofilms of E. faecalis strains JH2-2 and V583 were established on cover slips.
• Biofilms were treated with the engineered bacteriophage ϕEf11/ϕFL1C(Δ36)^PnisA for 24 and 48 hours.
• Bacterial biomass was quantified using colony-forming unit (CFU) measurements and visualized via confocal microscopy.

Main Results:

• Phage treatment resulted in a significant 10- to 100-fold reduction in viable E. faecalis cells within biofilms.
• Confocal microscopy imaging corroborated the CFU data, showing a marked decrease in biofilm biomass after phage application.
• The efficacy of the phage was demonstrated against both vancomycin-sensitive and vancomycin-resistant E. faecalis strains.

Conclusions:

• The bacteriophage ϕEf11/ϕFL1C(Δ36)^PnisA effectively reduces the biomass of Enterococcus faecalis biofilms.
• This engineered phage holds potential as a therapeutic agent against challenging E. faecalis infections, including those involving antibiotic-resistant strains.