Determination of the safety of Enterococcus species bacteria that use potential as probiotic

Consumed white cheeses are a continuous supply of lactic acid bacteria, including enterococci with probiotic potentials. In this study, to use potential probiotic of twelve Enterococcus faecalis strains and eight Enterococcus faecium strains which is isolated from traditional white cheese, it is researched theirs production capability of cytolysin, production capability of gelatinase, capability of forming biofilm and sensitivity against ten antibiotic determined. E. faecalis and E. faecium strains were determined of cytolysin production by using blood agar, gelatinase production by nutrient gelatin medium, biofilm production by using 96 well plate method and susceptibility to antibiotics were tested by agar disc diffusion method. Vancomycin resistance genes (vanA and vanB) and virulence factors genes like cytolysin (cylA and cylB), enterococcal surface protein (esp), cell aggregation and conjugation (agg), aggregation factor (asa1), E. faecalis antigen A protein (EfaAfs), E. faecium antigen A protein (EfaAfm), sex pheromones (cob and ccf) and hyaluronidase (hly) are determined by polymerase chain reaction (PCR). In addition, the presence of resistance and virulence genes was confirmed by sequence analysis It ıs checked existence plasmid DNA in bacteria because of transferable possibility of some resistances and virulence genes by plasmid. E. faecalis and E. faecium strains are sensitive against many antibiotics which is used in study and have resistance against Polymyxin antibiotic. No complete cytolysin activity was observed for E. faecalis and E. faecium strains. It is obtained gelatinase activity of E. faecalis RI 11, RI 17, RI 21, RT 84 strains and biofilm activity of E. faecalis RI 11, RI 17, RI 21, RT 102 strains. Virulence and resistance genes differed in the rate of presence. In all strains, ccf (100%) and asa1 (100%) genes and 5% of the strains were identified as clyA gene. As for EfaAfm and clyB gene, they could not have been determined in any strain. It is determined that while the strain that has the most virulence and resistance genes is E. faecalis RI 6, the strain that has the fewest gene is E. faecalis RT 98. Plasmid DNA of E. faecium RI 56, RI 58 and RI 59 strains were detected in the study for the presence of plasmid DNA. As a result of this study, the characteristics of E.faecalis and E. faecium strains were determined in terms of functional and safety perspectives.