Inhibition of vancomycin and high-level aminoglycoside-resistant enterococci strains and Listeria monocytogenes by bacteriocin-like substance produced by Enterococcus faecium E86.

Three hundred and thirty nine lactic bacteria strains isolated from food samples were screened for antimicrobial activity. Only one strain isolated from meat pie and identified as Enterococcus faecium produced a bacteriocin-like inhibitory substance (BLIS) showing activity against Enterococcus, Leuconostoc, Lactobacillus, Listeria, Corynebacterium and Staphylococcus aureus. The BLIS produced was resistant to acid and alkali treatment and 121 masculineC for 15 min. The addition of BLIS in BHI contaminated with Listeria monocytogenes decreased the contamination in 4.8 log cycles in 24 h. The inhibition of listeria was also obtained in milk. Forty multiresistant enterococci strains were inhibited in the well-diffusion test. Two vancomycin resistant strains tested in liquid with BLIS were also inhibited. The BLIS producer showed no pathogenicity marker.