Bacteriocin production and probiotic properties of Enterococcus spp. Isolated from raw milk

Abstract EN

Little is known about using Enterococcus strains as probiotics in the dairy industry in the Middle East.

The aim of this study was to analyze the probiotic properties of Enterococcus spp.

isolated from 75 raw milk samples.

Overall, 65 milk samples (86.66 %, 65 / 75) analyzed were contaminated with enterococci.

70 presumptive enterococcal isolates were recovered, and 60 isolates were confirmed by PCR as Enterococcus spp.

E.

faecium and E.

faecalis were detected in 28 (28 / 60) and 12 (12 / 60) of isolates, respectively.

Fifteen isolates showed negative results in safety relevant characteristics including antibiotic susceptibility and virulence gene profile.

Seven strains showed antimicrobial activities towards Staphylococcus aureus and two strains showed antimicrobial activities against Listeria monocytogenes and 6 strains showed antimicrobial activities towards both pathogens.

None of the isolates showed antimicrobial activities towards Gram negative bacteria tested in this study.

Some strains showed survival in gastric juice after 2 hours and all isolates showed survival in different degree in bile after 24 hours.

PCR analysis revealed that six strains carried both enterocins A and B.

Neither enterocin L nor enterocin P genes were detected in isolated strains.

In conclusion, the results obtained in this study showed that six E.

faecium strains have great potential to be used as probiotic organisms in human food and/or animal feed.