In vitro assessment of probiotic and virulence potential of Enterococcus faecium strains derived from artisanal goatskin casing Tulum cheeses produced in central Taurus Mountains of Turkey

In the present study, nine Enterococcus (Ent.) faecium isolates were isolated from Tulum cheese produced traditionally in the central Taurus Mountains of Turkey during ripening period and were characterized to investigate their probiotic potential via gastrointestinal resistance, and adhesion ability, functional properties tests, and safety (haemolytic activity, antibiotic resistance, biogenic amine production, and PCR detection of some virulence factors) analyses. All of these strains proved to be resistant to bile salt and simulated gastric juice. All the isolates displayed good safety assessment regarding vancomycin susceptibility except for isolate 1050. Additionally, the majority of isolates showed high exopolysaccharide production while isolate 12 showed a desirable cholesterol removal rate. Also, five of Ent. faecium isolates indicated antibacterial activity against both Listeria monocytogenes ATCC 7644 and Staphylococcus aureus ATCC 25923. Isolates 394 and 894 were examined based on the presence of virulence genes encoding for aggregation substance (asa1), cytolysin (CylL(L), CylLs, CylM, CylB, CylA), gelatinase (gelE), and hyaluronidase (hyl(efm)). Isolate 894 harbored three virulence determinants including asa1, gelE and CylA while the virulence cylL(L,S), cylM, Hyl(efm), gelE, and CylA genes were detected in isolate 394. Overall, isolate 894 was shown to be a potential candidate for further in vivo investigations as a probiotic culture.

Automated summary

Nine Enterococcus faecium isolates from Tulum cheese in Turkey were analyzed for probiotic potential through various tests, with one isolate showing promising probiotic properties and deemed worthy of further in vivo investigation.