Enterococcus faecalis is a life-threatening pathogen causing endocarditis, bacteremia, urinary tract infection, meningitis, and post treatment root canal infections. E. faecalis is a highly durable strain, which is specifically hard to target in biofilms.
A possible antibacterial solution against E. faecalis is phage-therapy. The advantages of phage therapy are high specificity, efficacy against biofilms and no evident effect on the microbiome.
Two bacteriophages, termed EFDG1 and EFLK1 against E. faecalis were isolated, visualized by electron microscopy, and fully sequenced. Anti E. faecalis efficiently was tested at different bacterial growth stages. Results showed EFDG1 efficiently eradicates E. faecalis in logarithmic phase while EFLK1 is highly effective against stationary phase.
We hypothesized that efficient anti-E. faecalis treatment against cultures at all growth stages can be achieved using phage cocktails. For this purpose optimal EFDG1/EFLK1 cocktail ratios were evaluated. This analysis revealed that combinations of 1:1 and 1:3 respectively produce the most potent anti-E. faecalis effect. These cocktails were also efficient in an ex-vivo post treatment human root canal model against E. faecalis.
In conclusions, phage therapy is a promising antibacterial approach against multidrug resistant bacteria. Additionally, we suggest that the efficiency of phage therapy would be increased by infection with cocktails of two or more phages instead of one.
