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Biological Characteristics and Safety Examination of Five Enterococcal Strains from Probiotic Products
Author(s) -
Lei Ming,
Dai Xianjun,
Liu Mingqi
Publication year - 2015
Publication title -
journal of food safety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 43
eISSN - 1745-4565
pISSN - 0149-6085
DOI - 10.1111/jfs.12179
Subject(s) - probiotic , microbiology and biotechnology , enterococcus faecium , virulence , biology , gentamicin , tetracycline , enterococcus faecalis , ciprofloxacin , antimicrobial , lactic acid , antibiotic resistance , antibiotics , bacteria , biochemistry , staphylococcus aureus , genetics , gene
Five enterococcal strains ( E nterococcus faecalis LS 15, PF 03, BF 10 and SL 13 and E nterococcus faecium MM 08) were isolated and identified from 130 probiotic products marketed in C hina. The determined biological characteristics were acid tolerance, bile tolerance, pepsin tolerance, trypsin tolerance, organic acid production and antimicrobial activity. Safety examination of potential virulence factors and antibiotic resistance were also performed. The five isolated strains showed good tolerance to biological barriers in vitro , and lactic acid was the most abundant organic acid (10–11 mg/m L ) produced by these strains. The isolates exhibited antilisterial activities. Safety examinations revealed that certain potential virulence factors ( ace , gelE and efaA ) were harbored in strains LS 15, PF 03, BF 10 and SL 13, and all of the isolates exhibited complete or intermediate resistance to gentamicin, ciprofloxacin, erythrocin and tetracycline. Compared with the other isolates, the E . faecium MM 08 played the leading role as a probiotic strain. These antilisterial probiotic enterococcal strains had good tolerance to biological barriers, mainly produced lactic acid, exhibited antibiotic resistance traits and could harbor certain virulence factors. Practical Applications This study aimed to examine the biological characteristics and safety aspects of probiotic enterococcal strains isolated from probiotic products. Five isolates showed good probiotic characteristics, but its safety aspects need to be studied in the future.