IADR Abstract Archives
Phage and Vancomycin: Joined Forces Against Vancomycin-Resistant Enterococcus Faecalis
Objectives: Currently, effective options are needed to fight vancomycin-resistant Enterococcus faecalis (VRE). Both antibiotics and bacteriophages can target effectively bacteria, and some of them can synergize enhancing the antibacterial effect. The objective here was to evaluate if an additive effect can be achieved using anti-E. faecalis phage with vancomycin against VRE.
Methods: Anti-E. faecalis activity of phage and vancomycin was evaluated separately and combined, using different timings and different order of treatments. The antibacterial activity and vancomycin MIC were evaluated using an ELISA plate reader and cells viable counts. The effect was visualized using transmission electron microscopy (TEM). The cell wall peptidoglycan was stained after phage treatment, visualized by confocal microscopy and quantified by fluorescence activated cell sorting (FACS) analysis.
Results: Anti-E. faecalis phage with vancomycin against VRE were effective when joined compared to treatment with phage or antibiotic alone. Prior treatment by phages followed by vancomycin made the bacterial killing 4 times faster than treating with vancomycin first. It was highly effective, reduced 4 logs of the viable counts. Confocal microscopy and FACS analysis showed that the fluorescence staining increased eight-fold following phage treatment, suggesting a change in the peptidoglycan of the cell wall. Additionally, phage treated bacteria showed lower vancomycin MIC.
Conclusions: An additive effect was achieved by using anti-E. faecalis phage with vancomycin against VRE. The increase in sensitivity of the resistant strain may be attributed to an alteration of vancomycin target on the cell-wall peptidoglycan.
Methods: Anti-E. faecalis activity of phage and vancomycin was evaluated separately and combined, using different timings and different order of treatments. The antibacterial activity and vancomycin MIC were evaluated using an ELISA plate reader and cells viable counts. The effect was visualized using transmission electron microscopy (TEM). The cell wall peptidoglycan was stained after phage treatment, visualized by confocal microscopy and quantified by fluorescence activated cell sorting (FACS) analysis.
Results: Anti-E. faecalis phage with vancomycin against VRE were effective when joined compared to treatment with phage or antibiotic alone. Prior treatment by phages followed by vancomycin made the bacterial killing 4 times faster than treating with vancomycin first. It was highly effective, reduced 4 logs of the viable counts. Confocal microscopy and FACS analysis showed that the fluorescence staining increased eight-fold following phage treatment, suggesting a change in the peptidoglycan of the cell wall. Additionally, phage treated bacteria showed lower vancomycin MIC.
Conclusions: An additive effect was achieved by using anti-E. faecalis phage with vancomycin against VRE. The increase in sensitivity of the resistant strain may be attributed to an alteration of vancomycin target on the cell-wall peptidoglycan.