The probiotic potential and evaluation of the safety aspects of Enterococcus sp. strains isolated from traditionally made Serbian cheese

Abstract

The purpose of this research paper was the evaluation of the safety aspects and probiotic potential of six isolates from the genus Enterococcus isolated from traditionally made cheese. The isolates represented part of the unexplored microflora of the cheese. The tolerance of Enterococcus isolates to different gastrointestinal conditions (low pH, the presence of pepsin, pancreatin and bile salts) were investigated. Using the microdilution method, sensitivity to clinically relevant antimicrobial agents (tetracycline, ampicillin, gentamicin, vancomycin and polymyxin B) was evaluated. The adhesion ability of autochthonous Enterococcus isolates to solvents, as well as the ability of auto-aggregation and co-aggregation between them and Escherichia coli clinical isolates, was investigated. The results indicated that isolates showed tolerance to the simulated gastrointestinal condition in a high percentage. Isolates were sensitive to all the tested antibiotics, especially to ampicillin, with MIC values obtained from 0.19-2.5 μg/mL. The isolates showed the ability of growth in medium with phenol and showed no ability to synthesize histamine and tyramine. The highest percentage of adhesion was detected with chloroform, and the lowest with xylene. The isolates showed moderate auto-aggregation ability, while a different degree of co-aggregation with E. coli was observed. The results indicated that the potential application of investigated Enterococcus isolates is selective and limited.