Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5667109 | International Journal of Antimicrobial Agents | 2017 | 8 Pages |
â¢Purification of enterocin DD14 produced by Enterococcus faecalis strain 14 isolated from meconium.â¢Biochemical and genetic characterisation of enterocin DD14.â¢Anti-Clostridium perfringens activity.â¢No cytotoxicity of enterocin DD14 towards IPEC-1 cells.
Enterococcus faecalis 14, a strain previously isolated from meconium, displayed activity against four Clostridium perfringens isolates when co-cultured on agar plates. The anti-Clostridium activity was ascribed to the production of enterocin DD14, which was subsequently purified. The minimum inhibitory concentration (MIC) of enterocin DD14 against one collection strain and one clinical C. perfringens strain was determined at 50âµg/mL. Furthermore, using the intestinal epithelial cell line IPEC-1, it was shown that E. faecalis 14 was not cytotoxic after 24âh of contact, and no cytotoxicity was observed when IPEC-1 cells were incubated with pure enterocin DD14 for 4âh. Enterocin DD14 was characterised using mass spectrometry and was shown to consist of two small proteins of 5200.74 Da and 5206.41 Da, respectively. The two peptides (DD14A and DD14B) have highly similar amino acid sequences and no signal peptide, which classifies enterocin DD14 as a class IIb leaderless two-peptide bacteriocin. The genes encoding DD14A and DD14B were sequenced and were shown to be 100% identical to other previously described enterocins MR10A and MR10B, in contrast to the producing strains, which are different. Consequently, the present in vitro study supports the potential of this E. faecalis 14 strain and/or its purified enterocin DD14 as putative anti-C. perfringens compounds in chickens.