Postbiotic Substance Durancin-like ED26E/7 as a Tool for In Vitro Treatment of Water-Derived Strains Enterococcus haemoperoxidus and Enterococcus moraviensis

Enterococci are found not only in warm-blooded animals but also as a resident population of water and an indicator of fecal pollution. The species Enterococcus haemoperoxidus and E. moraviensis are relatively new, having been detected in water. Strains with genes for biofilm formation can serve as reservoirs for gene transfer. The aim and novelty of this study were to determine whether the postbiotic substance (PS) of proteinaceous character (Durancin-like) produced by our strain Enterococcus durans ED26E/7 can inhibit in vitro the growth of biofilm-forming E. haemoperoxidus and E. moraviensis isolated from water sources. E. haemoperoxidus and E. moraviensis lacked the biofilm-forming genes ica, bap, ace, and fsrA. The bopD gene was found only in three strains of E. haemoperoxidus. The srtA gene was present in two strains of E. haemoperoxidus and E. moraviensis. Using the quantitative test, three strains showed low-grade biofilm-forming ability. They exhibited ɤ-hemolysis, and they were mostly susceptible to antibiotics. However, they were susceptible to PS Durancin-like ED26E/7. E. haemoperoxidus, the strains EHae466 and EMo494, showed the highest susceptibility to Durancin-like ED26E/7.