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Biodiversity of Enterococcus faecalis based on genomic typing.
Keren Buhnik-Rosenblau1, Vera Matsko-Efimov, Yael Danin-Poleg
1Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
International Journal of Food Microbiology
|May 21, 2013
Summary
This study genetically characterized 106 Enterococcus faecalis strains. Probiotic and cheese strains clustered together, suggesting they are non-virulent, aiding in accurate strain identification.
Area of Science:
- Microbiology
- Genetics
- Food Science
Background:
- Enterococcus faecalis is a versatile bacterium found in various environments, including the gut, soil, and food.
- Its diverse nature encompasses pathogenic, commensal, and probiotic strains, necessitating precise strain-level characterization.
- Accurate discrimination is crucial for understanding E. faecalis roles in health and industry.
Purpose of the Study:
- To investigate the genetic relationships among 106 E. faecalis strains from diverse origins.
- To differentiate strains based on virulence and source, particularly probiotic and cheese-associated isolates.
- To develop tools for accurate strain discrimination and characterization.
Main Methods:
- Strain typing using simple-sequence repeat (SSR) loci and multilocus sequence typing (MLST).
- Analysis of genetic relationships and dendrogram separation into three main clusters.
- Detection of virulence determinants: esp gene and β-hemolysis.
Main Results:
- MLST and SSR analysis successfully discriminated among E. faecalis strains, forming three distinct clusters.
- Probiotic and cheese-originated strains predominantly grouped in cluster 1.
- Cluster 1 strains showed a lower prevalence of virulence factors (esp gene, β-hemolysis) compared to other cheese strains, suggesting an association with non-virulence.
Conclusions:
- Genetic clustering provides a valuable method for differentiating E. faecalis strains based on origin and virulence.
- Cluster 1 appears to be associated with non-virulent probiotic and cheese-associated E. faecalis strains.
- Precise characterization of E. faecalis from various sources remains important and challenging.
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