Effect of heat on antimicrobial activity of the EF478 CFS.

<p>Effect of heat on antimicrobial activity of the EF478 CFS.</p

Effect of enzymatic treatments on activity of the EF478 CFS.

<p>Effect of enzymatic treatments on activity of the EF478 CFS.</p

Ribbon diagrams of EF478 bacteriocin and <i>E</i>. <i>faecalis</i> serine protease.

<p><b>WP_002367871:</b> (A) EF478 bacteriocin, (B) <i>E</i>. <i>faecalis</i> serine protease WP_002367871. The zoomed in region is the CAP superfamily domain. There is only one amino acid difference between EF478 bacteriocin and <i>E</i>. <i>faecalis</i> serine protease WP_002367871, but they have a big difference in their secondary structure and perhaps their functions. α-helices (red), β-sheets (blue) and bulge (green).</p

Effect of pH on antimicrobial activity of the EF478 CFS.

<p>Effect of pH on antimicrobial activity of the EF478 CFS.</p

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

<div><p>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. <i>E</i>. <i>faecalis</i> 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 <i>E</i>. <i>faecalis</i> 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 <i>E</i>. <i>faecalis</i>, 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.</p></div

Total proteins concentration (measured by Bradford assay) in the culture supernatants after mitomycin C treatment [27].

<p>Total proteins concentration (measured by Bradford assay) in the culture supernatants after mitomycin C treatment [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0186415#pone.0186415.ref027" target="_blank">27</a>].</p

Amino acid sequence alignment of <i>E</i>. <i>faecalis</i> serine proteases WP_002367871 and the predicted EF478, using CLUSTALW.

<p>Identical amino acids are indicated by asterisks. Conserved regions of uncharacterized N-terminal domain of peptidoglycan hydrolase CwlO1 and CAP domains were highlighted with grey and red, respectively. Substituted amino acid residues were highlighted (N to S, and N to G) in yellow.</p

Peptide fingerprinting report of EF478 using Mascot search engine.

<p>Peptide fingerprinting report of EF478 using Mascot search engine.</p

Antimicrobial activity of four CFSs against indicators <i>E</i>. <i>faecalis</i> ATCC 51299 and <i>E</i>. <i>faecium</i> ATCC 35667 as measured by agar well diffusion assay.

<p>Antimicrobial activity of four CFSs against indicators <i>E</i>. <i>faecalis</i> ATCC 51299 and <i>E</i>. <i>faecium</i> ATCC 35667 as measured by agar well diffusion assay.</p

SDS-PAGE and antimicrobial activity analysis of EF478 CFS.

<p>(A): Coomassie blue staining from SDS-PAGE of the concentrated CFS of EF478. (B): Inhibition zone on the indicator lawn from the unstained gel of 45 kDa fragment.</p