In vitro antagonistic, antimicrobial and antibiofilm potential of Enterococcus faecium 133v against opportunistic gut bacteria

Intestinal infections are recurrent in several countries, mainly in developing regions. The use of antibiotics to minimize the problem, for example, can lead to the development of bacterial resistance or even the elimination of several beneficial microorganisms for human or animal organisms. Thus, new methods that help in the prevention or treatment of intestinal infections are needed. In this study, aiming at a new perspective to prevent or treat infections in the intestinal tract, the use of the probiotic bacteria E. faecium 133v was analyzed, as well as its metabolites or composition against the main opportunistic bacteria of the intestine: Salmonella typhimurium, Escherichia coli, Shigella flexneri, Shigella sonnei, Listeria monocytogenes and Listeria spp. Antagonist analysis in disk diffusion demonstrated the ability of E. faecium 133v to inhibit the growth of most microorganisms, obtaining an inhibition zone between 3 mm and 6 mm, with the Listeria spp. bacterium showing greater sensitivity. Furthermore, the supernatant and EPS from E. faecium 133v had an antimicrobial effect on all six pathogenic strains. These results show the ability of E. faecium 133v as a potent helper, opposing the main opportunistic bacteria in the intestine.