Currently, effective options are needed to fight vancomycin-resistant Enterococcus faecalis (VRE). The present study shows that combinations of phage and vancomycin are highly efficient against VRE, despite being resistant to the antibiotic. Vancomycin-phage EFLK1 (anti-E. faecalis phage) synergy was assessed against VRE planktonic and biofilm cultures. The effect of the combined treatment on VRE biofilms was determined by evaluating the viable counts and biomass and then visualized using scanning electron microscopy (SEM). The cell wall peptidoglycan was stained after phage treatment, visualized by confocal microscopy and quantified by fluorescence activated cell sorting (FACS) analysis. The combined treatment was synergistically effective compared to treatment with phage or antibiotic alone, both in planktonic and biofilm cultures. Confocal microscopy and FACS analysis showed that fluorescence intensity of phage-treated bacteria increased eight-fold, suggesting a change in the peptidoglycan of the cell wall. Our results indicate that with combined treatment, VRE strains are not more problematic than sensitive strains and thus give hope in the continuous struggle against the current emergence of multidrug resistant pathogens.
Bibliographical noteFunding Information:
This research was funded by Rosetrees Trust, grant number 0364821, the Israel Science Foundation, grant number 540/17 and a Cabakoff grant, grant number 0365076. M.S. is a fellow of the Ariane de Rothschild Women Doctoral Program
Funding: This research was funded by Rosetrees Trust, grant number 0364821, the Israel Science Foundation, grant number 540/17 and a Cabakoff grant, grant number 0365076. M.S. is a fellow of the Ariane de Rothschild Women Doctoral Program.
© 2019 by the authors. Licensee MDPI, Basel, Switzerland.
- Enterococcus faecalis (VRE)
- Phage EFLK1
- Phage therapy
- Phage-antibiotic synergy (PAS)