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08:51
Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR (RS-PCR)
Published on: November 4, 2016
Genomic differences between the food-grade Staphylococcus carnosus and pathogenic staphylococcal species
Ralf Rosenstein1, Friedrich Götz
1Lehrstuhl Mikrobielle Genetik, Universität Tübingen, Waldhäuser Strasse 70/8, D-72076 Tübingen, Germany.
International Journal of Medical Microbiology : IJMM
|October 13, 2009
Summary
The meat starter bacterium Staphylococcus carnosus genome lacks mobile genetic elements, unlike pathogenic strains. This suggests reductive evolution in S. carnosus due to adaptation to stable starter culture environments.
Area of Science:
- Microbiology
- Genomics
- Bacterial Evolution
Background:
- Staphylococcus carnosus is a non-pathogenic bacterium used as a meat starter culture.
- Pathogenic staphylococci exhibit high genomic flexibility due to mobile genetic elements.
- Comparative genomic analysis is crucial for understanding bacterial adaptation and virulence.
Purpose of the Study:
- To analyze the genome of Staphylococcus carnosus TM300.
- To compare the genomic content of S. carnosus with pathogenic staphylococci.
- To investigate the evolutionary adaptations of S. carnosus.
Main Methods:
- Whole-genome sequencing of Staphylococcus carnosus TM300.
- Comparative genomic analysis of mobile genetic elements and repetitive sequences.
- Identification and analysis of genes with similarity to known virulence factors and inactivated regulatory systems.
Main Results:
- S. carnosus genome is notably deficient in mobile genetic elements, containing only phage remnants and a genomic island.
- The S. carnosus genome has significantly fewer repetitive sequences compared to pathogenic staphylococci.
- S. carnosus possesses genes similar to virulence factors and has inactivated regulatory systems (agr, sae).
Conclusions:
- S. carnosus has undergone reductive evolution, characterized by gene loss and inactivation.
- Adaptation to stable starter culture environments likely drove the genomic streamlining of S. carnosus.
- Despite avirulence, S. carnosus retains genetic similarities to pathogenic strains, indicating a distinct evolutionary trajectory.
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