Targeting Enterococcus faecalis Biofilms with Phage Therapy

Abstract

Phage therapy has been proven to be more effective, in some cases, than conventional antibiotics, especially regarding multidrug-resistant biofilm infections. The objective here was to isolate an anti-Enterococcus faecalis bacteriophage and to evaluate its efficacy against planktonic and biofilm cultures. E. faecalis is an important pathogen found in many infections, including endocarditis and persistent infections associated with root canal treatment failure. The difficulty in E. faecalis treatment has been attributed to the lack of anti-infective strategies to eradicate its biofilm and to the frequent emergence of multidrug-resistant strains. To this end, an anti-E. faecalis and E. faecium phage, termed EFDG1, was isolated from sewage effluents. The phage was visualized by electron microscopy. EFDG1 coding sequences and phylogeny were determined by whole genome sequencing (GenBank accession number KP339049), revealing it belongs to the Spounavirinae subfamily of the Myoviridae phages, which includes promising candidates for therapy against Gram-positive pathogens. This analysis also showed that the EFDG1 genome does not contain apparent harmful genes. EFDG1 antibacterial efficacy was evaluated in vitro against planktonic and biofilm cultures, showing effective lytic activity against various E. faecalis and E. faecium isolates, regardless of their antibiotic resistance profile. In addition, EFDG1 efficiently prevented ex vivo E. faecalis root canal infection. These findings suggest that phage therapy using EFDG1 might be efficacious to prevent E. faecalis infection after root canal treatment.

Propagation method for persistent high yield of diverse Listeria phages on permissive hosts at refrigeration temperatures

“…High host specificity, bacterial susceptibility and potential for bioengineering for even more refined targeting and resilience to acquired resistance make phages particularly promising antimicrobials in contexts where antibiotics are ineffective or inappropriate [1,29]. Phage research offers promise for advancements both in historical applications of medical phage therapy against infection [13,19] and novel applications throughout biotechnology and agriculture [3,5,10].…”

Physiology and Pathology of Multidrug-Resistant Bacteria: Phage-Related Therapy

“…Biofilm-associated VRE infections are challenging for treatment. EFDG1, isolated from sewage water, was efficient not only in nearly eliminating 2-week old E. faecalis biofilms of around 100 μm thickness but also in prevention of E. faecalis root canal infection [52,56].…”

Current Research Approaches to Target Biofilm Infections.

“…Two lytic phages were recently described that were found to reduce Staphylococcal biofilms by 2 logs and the frequency of bacteriophage resistance developing in the bacteria was sufficiently low to merit these bacteriophages as potential candidates for therapy (42). Another recent study found a bacteriophage, EFDG1, to have effective lytic activity against planktonic and biofilm cultures of Enterococcus faecalis and E. faecium isolates, regardless of their antibiotic resistance profile (43). In addition, EFDG1 efficiently prevented an ex vivo E. faecalis root canal infection (43).…”

“…Another recent study found a bacteriophage, EFDG1, to have effective lytic activity against planktonic and biofilm cultures of Enterococcus faecalis and E. faecium isolates, regardless of their antibiotic resistance profile (43). In addition, EFDG1 efficiently prevented an ex vivo E. faecalis root canal infection (43). There are a number of advantages in using bacteriophages to treat biofilm-related infections.…”