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Updated: Jun 10, 2026
10:39
Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus
Published on: March 10, 2017
Impact of recombination on genetic variability within Staphylococcus aureus clonal complexes
Nevena Basic-Hammer1, Valérie Vogel, Patrick Basset
1Service of Hospital Preventive Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, 1011 Lausanne, Switzerland.
Summary
Genetic recombination in Staphylococcus aureus, a clonal bacterium, significantly impacts diversity. While not more frequent within clonal complexes, recombination events drive evolution and potentially new complex formation.
Area of Science:
- Microbiology
- Population Genetics
- Molecular Evolution
Background:
- Staphylococcus aureus exhibits a highly clonal population structure, divided into clonal complexes (CCs).
- Previous research suggested increased recombination rates within CCs compared to between them.
Purpose of the Study:
- To investigate the frequency and impact of genetic recombination in Staphylococcus aureus population structure.
- To understand the mechanisms of genetic diversity creation within S. aureus, particularly concerning clonal complexes.
Main Methods:
- Analysis of 182 Staphylococcus aureus isolates using Multilocus Sequence Typing (MLST) and five core adhesion (ADH) genes.
- Assessment of genetic polymorphism and detection of recombination events within and among CCs.
- Application of molecular analyses of variance (MOVA) and selection pressure analysis.
Main Results:
- Adhesion genes displayed higher polymorphism than MLST genes, but both showed low within-CC diversity.
- No intra-CC recombination events were detected, refuting the hypothesis of higher within-CC recombination.
- Detected recombination events, though infrequent, significantly impacted genetic diversity within CCs.
- Evidence of positive selection was found in a recombinant group, while most ADH genes were under purifying selection.
Conclusions:
- Recombination plays a crucial role in the evolution of the clonal S. aureus population.
- Recombination, coupled with demographic factors and selection, may accelerate the emergence of novel clonal complexes.
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