Authors Tan and H. Xu contributed equally to this work.
M: FOOD MICROBIOLOGY AND SAFETY
Safety Assessment and Probiotic Evaluation of Enterococcus Faecium YF5 Isolated from Sourdough
Article first published online: 12 MAR 2013
© 2013 Institute of Food Technologists®
Journal of Food Science
Volume 78, Issue 4, pages M587–M593, April 2013
How to Cite
Tan, Q., Xu, H., Aguilar, Z. P., Peng, S., Dong, S., Wang, B., Li, P., Chen, T., Xu, F. and Wei, H. (2013), Safety Assessment and Probiotic Evaluation of Enterococcus Faecium YF5 Isolated from Sourdough. Journal of Food Science, 78: M587–M593. doi: 10.1111/1750-3841.12079
- Issue published online: 5 APR 2013
- Article first published online: 12 MAR 2013
- Manuscript Accepted: 14 JAN 2013
- Manuscript Received: 26 NOV 2012
- Natl. Natural Science Foundation of China. Grant Number: (NSFC31170091, 31000048, and 30900038)
- Enterococcus faecium;
- probiotic evaluation;
- safety assessment;
Enterococcus faecium YF5, a strain previously isolated from sourdough, was assessed for safety and probiotic potential. Its virulence and antibiotic resistant phenotypes (cytolysin and gelatinase production, antibiotic susceptibility) and genes (cylA, gelE, ace, agg, esp, and vanA) were surveyed. Results indicated that the tested virulence determinants were nontoxic. In addition, E. faecium YF5 was sensitive to 3 antibiotics such as amoxicillin, vancomycin, and chloramphenicol. Furthermore, results of in vivo animal acute oral toxicity of E. faecium YF5 studies were similar to the control group that indicated no abnormalities. In addition, E. faecium YF5 stably survived in low pH, bile salts, gastric, and intestinal fluids in vitro. Moreover, E. faecium YF5 was found to adhere to human colon cancer cell line HT-29 at 3.39 (±0.67) × 105 CFU/mL. When cocultured with pathogenic organisms (Enterobacter sakazakii CMCC45402, Escherichia coli CMCC44102, enterohemorrhage Escherichia coli O157: H7 CMCC44828, Salmonella Typhimurium CMCC50071, Shigella flexneri 301, and Shigella sonnei ATCC 29930) and 2 gram-positive strains (Listeria monocytogenes CMCC54001 and Staphylococcus aureus CMCC 26003), it inhibited these foodborne pathogens with exception of S. aureus. Therefore, E. faecium YF5 can be regarded as a safe strain and it may be used as a probiotic preparation or for microecologics.
Enterococcus faecium is well known as the normal resident in human gastrointestinal tract and successfully used as probiotic preparations in clinical treatment. However, Enterococcus species might harbor virulence genes and resulted in the harmful infection in patients. In our previous study, an E. faecium strain YF5 from sourdough was isolated, and in this study, we assessed its safety and probiotic properties in order to develop a new probiotic.