Antibacterial efficacy of casein-derived peptides against Enterococcus faecalis

Background : The aim of this study was to test a casein peptide in its glycosylated form (kappa‐casein glycopeptide, KCGP) and its non‐glycosylated form (kappa‐casein peptide, KCP) for antibacterial efficacy against Enterococcus faecalis in planktonic and biofilm cultures. Methods : E. faecalis strain JKD 15036 was exposed to different concentrations of KCGP and KCP in a 96‐well culture plate. The effect of the peptides on the growth of E. faecalis in planktonic culture was monitored by measuring optical density over 7 hours. Biofilm formation was measured after 24 hours using a crystal violet assay. All experiments were performed in triplicate. Results : KCGP and KCP inhibited growth of E. faecalis in planktonic culture with no significant difference in activity between the peptides. KCGP at 0.16% w/v was significantly better at inhibiting E. faecalis biofilm formation than KCP at the same concentration and significantly better than NaOCl at 1.0% w/v. Conclusions : KCGP effectively inhibited E. faecalis biofilm formation and may have potential to augment the efficacy of traditional antiseptic agents.