Anti-biofilm Activity of a Lytic Phage Against Vancomycin-Resistant Enterococcus faecalis

This study aims to isolate a lytic bacteriophage against planktonic Enterococcus faecalis V583 culture and evaluate its ability to disrupt and inhibit biofilm.

An anti-E. faecalis phage was isolated from sewage and visualized by electron microscopy, the vB_EfsS_V583 (V583) host range was determined by spot test on 13 E. faecalis clinical strains. Inhibition and degradation experiments were designed to investigate the effect of phage on biofilm. In the inhibition and degradation assay, biofilms were formed in the presence and absence of phage, respectively. Finally, crystal violet method tested the effect of phage on biofilm.

Phage V583 belongs to the Siphoviridae family and can infect all E. faecalis strains. Antibacterial activity has been shown to degrade and inhibit biofilm produced by V583. The study results showed that phage v583 is more efficient in biofilm inhibition than biofilm degradation. In both assays, phage-treated wells' absorption is less than untreated wells. These results were confirmed by Colony-forming unit reduction in the treated biofilm.

The anti-biofilm activity showed that phage therapy using phage V583 might be an alternative tool to remove E. faecalis biofilms.