Horizontal Gene Transfer in Staphylococcus aureus

Staphylococcus aureus is renowned for its capacity to acquire and disseminate genetic traits that underpin antibiotic resistance and virulence. Horizontal gene transfer (HGT) in this species occurs primarily by three mechanisms: natural transformation, bacteriophage-mediated transduction and conjugation facilitated by mobile genetic elements such as plasmids, transposons and genomic islands. These processes enable rapid adaptation to selective pressures in clinical, community and agricultural settings, driving the emergence of multidrug-resistant lineages, including methicillin-resistant S. aureus (MRSA). Central to transformation is the development of genetic competence, a transient physiological state that allows uptake of exogenous DNA. Bacteriophages can package and transfer virulence or resistance genes between strains, while conjugative plasmids and integrative elements such as the staphylococcal cassette chromosome mec (SCCmec) mediate direct cell-to-cell gene flow. The interplay among these routes shapes the global epidemiology of S. aureus, blurring distinctions between healthcare and livestock reservoirs and challenging infection control. Recent advances in high-throughput sequencing and functional genomics have illuminated the regulatory networks governing competence, the diversity of mobile elements and the ecological contexts in which HGT thrives, underlining its pivotal role in the pathogen’s evolution and persistence.

Research from Nature Portfolio

Recent studies have elucidated the regulatory architecture of natural transformation in S. aureus under microaerobic conditions. By optimising planktonic culture protocols, researchers achieved high levels of competence induction and transformation efficiency. Transcriptomic analysis revealed that the sigma factor SigH and the transcriptional regulator ComK1 are essential for activating core transformation genes, while ComK2 overlaps a subset of SigH- and ComK1-regulated functions. Activation of competence is triggered by microaerobic signals sensed via the SrrAB two-component system, linking environmental oxygen levels to the HGT machinery. This work provides a detailed map of the competence regulon and highlights the physiological conditions that promote DNA uptake, offering new targets to modulate gene flow in this pathogen.

Horizontal Gene Transfer in Staphylococcus aureus publication trend

The graph below shows the total number of articles in horizontal gene transfer in staphylococcus aureus across all publications each year (not limited to Nature Index journals).

Technical terms

Horizontal gene transfer: Movement of genetic material between organisms without reproduction, enabling rapid acquisition of new traits.

Natural transformation: Uptake and integration of free DNA from the environment by competent bacterial cells.

Mobile genetic element: DNA sequences such as plasmids, transposons or phages that can move within or between genomes.

Staphylococcal cassette chromosome mec (SCCmec): A genomic island carrying the mecA gene complex responsible for methicillin resistance.

Competence: A regulated physiological state permitting a bacterium to bind, uptake and recombine exogenous DNA.

Two-component system: A signal transduction mechanism comprising a sensor kinase and response regulator that modulates gene expression in response to environmental cues.

References

1. The complex regulation of competence in Staphylococcus aureus under microaerobic conditions. Communications Biology (2023).
2. The interplay between mobilome and resistome in Staphylococcus aureus. mBio (2024).
3. SCCmec transformation requires living donor cells in mixed biofilms. Biofilm (2024).