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Genome instability in Lactobacillus rhamnosus GG
Wilbert Sybesma1, Douwe Molenaar, Wilfred van IJcken
1Yoba for Life foundation, Amsterdam, The Netherlands. wilbert.sybesma@yoba4life.com
Applied and Environmental Microbiology
|January 29, 2013
Summary
Genomic analysis of Lactobacillus rhamnosus GG (LGG) probiotics reveals significant DNA deletions in some isolates, impacting adhesion genes. This highlights the need for quality control to ensure probiotic efficacy and stability.
Area of Science:
- Microbiology
- Genomics
- Probiotics
Background:
- Lactobacillus rhamnosus GG (LGG) is a widely used probiotic.
- Genome stability is crucial for probiotic efficacy.
Purpose of the Study:
- To compare the genomes of LGG isolates from dairy products with the reference strain.
- To investigate the presence of genetic variations in commercial LGG probiotic products.
Main Methods:
- Comparative genome analysis of three dairy product isolates and the ATCC 53103 reference strain.
- Identification of deleted DNA segments and associated genes using genomic island analysis.
- Quantitative PCR to assess the prevalence of specific genotypes in commercial probiotic products.
Main Results:
- Two of three dairy isolates showed major DNA deletions in genomic islands LGGISL1,2, involving 34 and 84 genes respectively.
- Deleted segments included the spaCBA genes, crucial for bacterial adhesion and intestinal persistence.
- Quantitative PCR confirmed heterogeneity in commercial LGG products, with some containing variants lacking spaC.
Conclusions:
- Genetic instability, including significant DNA deletions, exists within Lactobacillus rhamnosus GG strains.
- The loss of key genes like spaCBA may affect the adhesive and persistent properties of probiotic bacteria.
- Quality assurance and control measures are essential to monitor genome stability in probiotic production to ensure consistent efficacy.
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