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Characterization of enterococcus strains contained in probiotic products

Norihisa Noguchi1, Hidemasa Nakaminami, Keisuke Nakase

  • 1Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan. noguchin@toyaku.ac.jp

Biological & Pharmaceutical Bulletin
|September 2, 2011
PubMed

Insights

Probiotic products containing Enterococcus faecium strains are safe and do not cause opportunistic infections in immunocompromised patients. Genetic analysis confirmed these strains differ from clinical isolates, indicating no transmission risk.

Area of Science:

  • Microbiology
  • Probiotics
  • Infectious Diseases

Background:

  • Probiotics, live microbial additives, offer health benefits by modulating gut microflora.
  • Increased immunocompromised populations raise concerns about opportunistic infections from normally non-pathogenic bacteria like Enterococcus species.

Purpose of the Study:

  • To assess the safety of Enterococcus strains in probiotic products.
  • To compare the pathogenic potential and genetic profiles of probiotic Enterococcus strains with clinical isolates.

Main Methods:

  • Isolation of Enterococcus from six probiotic products.
  • Analysis of pathogenic genes (e.g., ace, agg, esp) and antimicrobial susceptibility.
  • Pulsed-field gel electrophoresis (PFGE) for genetic profiling.

Main Results:

  • All probiotic strains identified as Enterococcus faecium (E. faecium).
  • No vancomycin resistance or specific pathogenic genes were detected in probiotic strains.
  • PFGE revealed significant genetic distinctions between probiotic and clinical Enterococcus isolates.

Conclusions:

  • Probiotic E. faecium strains lack key virulence factors and genetic similarity to clinical strains.
  • The study suggests probiotic products are unlikely to be a source of opportunistic Enterococcus infections.

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