Combined bacteriophages and antibiotics as an efficient therapy against VRE Enterococcus faecalis in a mouse model

Abstract

Clinical applications of bacteriophage therapy have been recently gathering significant attention worldwide, used mostly as rescue therapy in cases of near-fatal antibiotic failure. Thus, clinically relevant in-vivo models presenting both short- and long-term implications of phage therapy given as rescue treatment for fulminant infections are of highest importance. In this study, a cocktail consisting of two lytic bacteriophages was used to evaluate the therapeutic efficacy of phage therapy as a rescue treatment for severe septic peritonitis in a mouse model. We established that a single injection of the bacteriophage cocktail was sufficient to completely reverse a 100% mortality trend caused by Vancomycin-Resistant Enterococcus faecalis, with significant improvement in both the clinical state and laboratory test results, and without harmful effects on the microbiome. The combination of bacteriophages with a suboptimal antibiotic regimen imparts an additional beneficial effect on the treatment success.

Keywords: EFDG1; EFLK1; Mouse peritonitis model; Phage therapy; Phage-antibiotic combination; VRE Enterococcus faecalis.