Detection of antimicrobial activities and bacteriocin structural genes in faecal enterococci of wild animals

The production of antimicrobial activities as well as the presence of bacteriocin structural genes (entA, entB, entP, entQ, cylL, entAS-48, bac31, and entL50A/B) were studied in 140 non-selected faecal enterococcal isolates recovered from wild animals. Eight different indicator strains (including Listeria monocytogenes, Pediococcus pentosaceus, and different enterococcal species) were used for antimicrobial activity detection. Twenty-five of the 140 enterococci (18%) showed antimicrobial activity against L. monocytogenes and 33 additional isolates (24%) showed antimicrobial activity against other indicator strains, but Listeria. At least one bacteriocin structural gene was detected in 17 of the 25 enterococci with antimicrobial activity against L. monocytogenes and different combinations of entA, entB, entP, entQ, entL50A/B, and cylL genes were detected; entA and entB were the most prevalent detected genes, and they were generally associated. Bacteriocin structural genes were detected in 10 of 33 isolates with antimicrobial activity against indicator strains other than Listeria, and the cylL gene was the most prevalent one, especially in E. faecalis isolates.