Characterization of functional properties of Enterococcus faecium strains isolated from human gut.
The aim of this work was to characterize the functional properties of Enterococcus faecium strains identified after isolation from human faeces. Of these isolates, strain R13 showed the best resistance to low pH, bile salts, and survival in the simulated in vitro digestion assay, and demonstrated an important level of adhesion to hexadecane as a potential probiotic candidate. Analysis of the antibiotic resistance of E. faecium strains indicated that in general these isolates were sensitive to the tested antibiotics and no strain appeared to be resistant to vancomycin. Examination of the virulence determinants for E. faecium strains demonstrated that all strains contained the virulence genes common in gut- and food-originated enterococci, and strain R13 harboured the lowest number of virulence genes. Additionally, no strain contained the genes related to cytolysin metabolism and showed hemolytic activity. The antimicrobial role of E. faecium strains was tested against several pathogens, in which different levels of inhibitory effects were observed, and strain R13 was inhibitory to all tested pathogens. PCR screening of genes encoding enterocin A and B indicated the presence of these genes in E. faecium strains. Preliminary characterization of bacteriocins revealed that their activity was lost after proteolytic enzyme treatments, but no alteration in antimicrobial activity was observed at different pHs (3.5 to 9.5) and after heat treatments. In conclusion, this study revealed the functional characteristics of E. faecium R13 as a gut isolate, and this strain could be developed as a new probiotic after further tests.
Department of Food Engineering, Faculty of Engineering, Bayburt University, Bayburt 69000, Turkey.|Department of Food Engineering, Faculty of Engineering, Bayburt University, Bayburt 69000, Turkey.
Hümeyra
H
İspirli
Department of Food Engineering, Faculty of Engineering, Bayburt University, Bayburt 69000, Turkey.|Department of Food Engineering, Faculty of Engineering, Bayburt University, Bayburt 69000, Turkey.
Fatmanur
F
Demirbaş
Department of Food Engineering, Faculty of Engineering, Bayburt University, Bayburt 69000, Turkey.|Department of Food Engineering, Faculty of Engineering, Bayburt University, Bayburt 69000, Turkey.
Enes
E
Dertli
D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology; D001430:Bacteriocins / Q000235:genetics / Q000302:isolation & purification; D001647:Bile Acids and Salts / Q000737:chemistry; D004352:Drug Resistance, Microbial; D016984:Enterococcus faecium / Q000187:drug effects / Q000302:isolation & purification* / Q000472:pathogenicity; D005243:Feces / Q000382:microbiology; D006461:Hemolysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D054353:Perforin / Q000378:metabolism; D016133:Polymerase Chain Reaction; D019936:Probiotics; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D014640:Vancomycin / Q000494:pharmacology; D014774:Virulence / Q000187:drug effects; D037521:Virulence Factors / Q000235:genetics; D055815:Young Adult
D000890:Anti-Infective Agents; D001430:Bacteriocins; D001647:Bile Acids and Salts; D012336:RNA, Ribosomal, 16S; D037521:Virulence Factors; D054353:Perforin; D014640:Vancomycin
Enterococcus faecium; antibiorésistance; antibiotic resistance; bactéries intestinales; gut bacteria; probiotic; probiotique; virulence determinants; éléments de virulence