Farnesol Emulsion as an Effective Broad-Spectrum Agent against ESKAPE Biofilms.

Area of Science:

• Microbiology
• Antimicrobial Research
• Biofilm Science

Background:

• ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter) are major causes of nosocomial infections.
• These bacteria are known for their ability to develop antibiotic resistance, complicating treatment.
• Farnesol, an FDA-approved agent, possesses anti-biofilm properties and has shown efficacy against some ESKAPE pathogens.

Purpose of the Study:

• To evaluate the efficacy of a farnesol emulsion against the remaining ESKAPE pathogens: Enterococcus faecium, Klebsiella pneumoniae, and Enterobacter.
• To assess farnesol's impact on both biofilm development and established biofilms in vitro and in an ex vivo human skin model.
• To investigate the potential for resistance development to farnesol in these bacteria.

Main Methods:

• Testing farnesol emulsion at various concentrations (0.2-1 mg/mL) against E. faecium, K. pneumoniae, and E. cloacae.
• In vitro and ex vivo human skin model experiments to assess biofilm reduction and bacterial viability.
• Live/Dead image analysis to confirm biofilm detachment and bacterial killing.
• Resistance testing for E. faecium and K. pneumoniae exposed to farnesol.

Main Results:

• Farnesol emulsion (0.5 mg/mL) effectively impeded biofilm development for all tested ESKAPE pathogens.
• Established biofilms were reduced, with specific concentrations effective for killing bacteria (1 mg/mL for E. faecium/K. pneumoniae, 0.2 mg/mL for E. cloacae).
• No farnesol resistance was observed in E. faecium or K. pneumoniae, unlike with conventional antibiotics.
• Farnesol demonstrated direct cell killing and induced biofilm detachment from surfaces.

Conclusions:

• Farnesol emulsion is a broad-spectrum agent effective against ESKAPE pathogen biofilms.
• It reduces bacterial viability, biomass, and promotes biofilm detachment.
• The lack of observed resistance suggests farnesol as a promising alternative or adjunct therapy for nosocomial infections.