A novel bacteriocin from Enterococcus faecalis 478 exhibits a potent activity against vancomycin-resistant enterococci

Abstract

The emergence of multidrug-resistant enterococci (MDRE) and particularly vancomycin-resistant enterococci (VRE) is considered a serious health problem worldwide, causing the need for new antimicrobials. The aim of this study was to discover and characterize bacteriocin against clinical isolates of MDRE and VRE. Over 10,000 bacterial isolates from water, environment and clinical samples were screened. E. faecalis strain 478 isolated from human feces produced the highest antibacterial activity against several MDRE and VRE strains. The optimum condition for bacteriocin production was cultivation in MRS broth at 37°C, pH 5–6 for 16 hours. The bacteriocin-like substance produced from E. faecalis strain EF478 was stable at 60°C for at least 1 hour and retained its antimicrobial activity after storage at -20°C for 1 year, at 4°C for 6 months, and at 25°C for 2 months. A nano-HPLC electrospray ionization multi-stage tandem mass spectrometry (nLC-ESI-MS/MS) analysis showed that the amino acid sequences of the bacteriocin-like substance was similar to serine protease of E. faecalis, gi|488296663 (NCBI database), which has never been reported as a bacteriocin. This study reported a novel bacteriocin with high antibacterial activity against VRE and MDRE.

Characterization of bacteriocin ABC transporter ATP-binding protein produced by a newly isolated Enterococcus casseliflavus MI001 strain

“…Our results suggest that the bacterium is surviving in human body conditions; this feature helps in that this organism could be used as a probiotic. In consonance, a recent study by Phumisantiphong et al [13] reported that the bacteriocin production from Enterococcus faecalis 478 was found to be high at 37°C.…”

“…The correlation of various peaks is represented in Table 2. A previous study by Kadirvelu et al [9] reported the presence of an amide and hydroxyl group coupled with C-H. Further, 13 C NMR and 1 H NMR analyses were carried out to discover the different amino acids and carbon compounds forming the molecular structure of the bacteriocin of Enterococcus casseliflavus MI001. The NMR spectra obtained were compared with the standard 13 C NMR spectrum presented in Table 3.…”

“…13 C NMR spectra (Left) and 1 H spectra (Right) of purified bacteriocin isolated from E. casseliflavus MI001 strain…”

“…13 C NMR spectral data. Various groups of carbon being detected in purified bacteriocin ABC transporter isolated from E.…”

The Genus Enterococcus: Between Probiotic Potential and Safety Concerns—An Update

“…The spread of VRE may lead to clinical isolates resistant to all antibiotics because enterococci have become important nosocomial pathogens and a reservoir for resistance genes (Fair and Tor, 2014 ). Interestingly, two peptides produced by E. faecium DSH20 (35 kDa) and E. faecalis 478 have shown potent activities against VRE (Shokri et al, 2014 ; Phumisantiphong et al, 2017 ) which may provide an alternative therapy for drug-resistant strains. Similarly, durancin 61A was shown effective against VRE clinical isolates (Hanchi et al, 2017 ).…”