Investigation of antimicrobial activity and entA and entB genes in Enterococcus faecium and Enterococcus faecalis strains isolated from naturally fermented Turkish white cheeses

In this research, the antagonistic effects of Enterococcus faecalis and E. faecium bacteria isolated from naturally fermented Turkish white cheeses, produced without starter culture, against Listeria monocytogenes, L. innocua, L. ivanovii, Staphylococcus aureus, and E. faecalis were evaluated. The presence of entA and entB genes was also detected in the isolates, which had antimicrobial activity. Total 71 strains of E. faecalis and 7 strains of E. faecium were tested; 20 of E. faecalis and none of E. faecium strains showed antimicrobial activity against the tested bacteria using agar spot method. Among E. faecalis strains, which had antimicrobial activity, three strains contained both entA and entB genes, two strains carried only entA gene, and five strains had only entB gene. These cheese-sourced enterococcal strains or their enterocins should be considered to be used for food preservation especially in the dairy industry.