Anti-Listeria effect of enterocin A, produced by cheese-isolated Enterococcus faecium EFM01, relative to other bacteriocins from lactic acid bacteria

Abstract

Enterocin A produced by Enterococcus faecium EFM01 displayed a narrow antimicrobial spectrum, mainly directed against Listeria spp. In particular, the bacteriocin was extremely active against 13 Listeria monocytogenes strains. This high specificity of action of enterocin A for Listeria spp. relative to lactic acid bacteria, together with its broad range of activity from pH 4·0 to pH 9·0, are factors which may be of great interest with respect to the potential antilisterial use of this bacteriocin in fermented foods. Assessment of the effect of enterocin A concentration on the extent and kinetics of bactericidal activity on L. monocytogenes Lm 6 (107 cfu ml−1 in culture broth), suggested that viability losses of higher than 5 log10, and time intervals necessary for maximum loss of viability of less than 2 h, could not be obtained. Moreover, it was shown that both parameters are closely dependent on the Listeria strain used. On the other hand, at concentrations inducing destruction of approximately 2 log10 cycles, maximum loss of viability was achieved within time intervals which varied widely from one lactic acid bacteria bacteriocin to another.

Cloning, Production, and Functional Expression of the Bacteriocin Enterocin A, Produced by Enterococcus faecium T136, by the Yeasts Pichia pastoris, Kluyveromyces lactis, Hansenula polymorpha, and Arxula adeninivorans

“…However, since enterocins may be produced by enterococcal species carrying antibiotic resistance genes and/or genes that code for potential virulence factors, for hygienic, safety, and biotechnological reasons, the production of enterocins in other microbial hosts is being evaluated (9,20,21,22). The enterocin A (EntA) produced by Enterococcus faecium T136 (11) is a class IIa bacteriocin with high antilisterial activity (14,16). The presence of Listeria monocytogenes in food can be reduced by in situ EntA production (23,29), by the addition of semipurified or purified preparations of EntA (1,24), or by the incorporation of EntA into biodegradable packaging films (31).…”

Molecular analysis of artisanal Italian cheeses reveals Enterococcus italicus sp. nov.

“…The presence of enterococci in dairy products has long been considered as an indicator of inadequate sanitary conditions during the production and processing of milk. In contrast, many authors suggest that enterococci may have a potentially desirable role in some cheeses, because of their proteolytic and lipolytic activities, in the development of typical flavours and for the production of enterocins with anti-Listeria activity (Ennahar & Deschamps, 2000;Giraffa et al, 1997). The important question is whether enterococci originating from food and from community sources possess an equally pathogenic potential, or whether differences in pathogenicity exists, perhaps in relation to the different species.…”

Differences in Susceptibility of Listeria monocytogenes Strains to Sakacin P, Sakacin A, Pediocin PA-1, and Nisin

“…The class I bacteriocin nisin, which is commercially available as a food preservative (14), and bacteriocins of class IIa (pediocin-like) are of special interest as inhibitors of Listeria spp. (19,47). The addition of bacteriocinogenic LAB or purified bacteriocins to inhibit the growth of Listeria spp.…”