Comparison of Enterococcus faecalis Biofilm Removal Efficiency among Bacteriophage PBEF129, Its Endolysin, and Cefotaxime

Abstract

Enterococcus faecalis is a Gram-positive pathogen which colonizes human intestinal surfaces, forming biofilms, and demonstrates a high resistance to many antibiotics. Especially, antibiotics are less effective for eradicating biofilms and better alternatives are needed. In this study, we have isolated and characterized a bacteriophage, PBEF129, infecting E. faecalis. PBEF129 infected a variety of strains of E. faecalis, including those exhibiting antibiotic resistance. Its genome is a linear double-stranded DNA, 144,230 base pairs in length. Its GC content is 35.9%. The closest genomic DNA sequence was found in Enterococcus phage vB_EfaM_Ef2.3, with a sequence identity of 99.06% over 95% query coverage. Furthermore, 75 open reading frames (ORFs) were functionally annotated and five tRNA-encoding genes were found. ORF 6 was annotated as a phage endolysin having an L-acetylmuramoyl-l-alanine amidase activity. We purified the enzyme as a recombinant protein and confirmed its enzymatic activity. The endolysin’s host range was observed to be wider than its parent phage PBEF129. When applied to bacterial biofilm on the surface of in vitro cultured human intestinal cells, it demonstrated a removal efficacy of the same degree as cefotaxime, but much lower than its parent bacteriophage.

Synergistic action of phages and lytic proteins with antibiotics: a combination strategy to target bacteria and biofilms

“…Phages and their encoded proteins are of great value as alternatives to antibiotic treatments. Moreover, combining them with other antimicrobial agents can not only overcome the drawbacks of unstable protein applications, but also remove bacteria and biofilms more efficiently [ 18 – 21 ]. Similar to phage cocktails, phage lytic proteins combine with other antimicrobials, such as antibiotics, to target different receptors.…”

Isolation and Characterization of Two Novel Siphoviruses Novomoskovsk and Bolokhovo, Encoding Polysaccharide Depolymerases Active against Bacillus pumilus

“…Bacteriophages and their lytic enzymes are considered promising antibacterial agents [ 28 , 29 , 30 , 31 , 32 ]. Many studies demonstrate the ability of phages and their proteins to eradicate, partially or completely, bacterial biofilms and spores [ 33 , 34 , 35 , 36 , 37 ]. Phages and their components are also notable for their higher selectivity compared to conventional antibacterial agents, and therefore can be effectively applied in medicine where the goal is to control particular bacterial strains or species without affecting the others.…”

Antibacterial Activity of Ethanolic Extracts of Aglaonema commutatum Schott and its Cultivars against Enterococcus faecalis Strains

“…Enterococcus faecalis (Andrewes and Horder) Schleifer and Kilpper-Balz 51299™ (resistant to vancomycin; sensitive to teicoplanin) and Enterococcus faecalis (Andrewes and Horder) Schleifer and Kilpper-Balz 29212™. Enterococcus faecalis is a Gram-positive pathogen that colonizes human intestinal surfaces, forming biofilms (Oh et al, 2021). It also is a common commensal organism and a prolific nosocomial pathogen that causes biofilm-associated infections and demonstrates a high resistance to many antibiotics (Willett et al, 2021).…”

“…E. faecalis is one of the most frequently isolated bacterial species in wounds yet little is known about its pathogenic mechanisms in this setting (Chong et al, 2017). Especially, antibiotics are less effective in eradicating biofilms and better alternatives are needed (Oh et al, 2021).…”