Extensive phage dynamics in Staphylococcus aureus contributes to adaptation to the human host during infection

Mol Microbiol. 2006 Sep;61(6):1673-85. doi: 10.1111/j.1365-2958.2006.05354.x.


Bacteriophages serve as a driving force in microbial evolution, adaptation to new environments and the pathogenesis of human bacterial infections. In Staphylococcus aureus phages encoding immune evasion molecules (SAK, SCIN, CHIPS), which integrate specifically into the beta-haemolysin (Hlb) gene, are widely distributed. When comparing S. aureus strain collections from infectious and colonizing situations we could detect a translocation of sak-encoding phages to atypical genomic integration sites in the bacterium only in the disease-related isolates. Additionally, significantly more Hlb producing strains were detected in the infectious strain collection. Extensive phage dynamics (intragenomic translocation, duplication, transfer between hosts, recombination events) during infection was shown by analysing cocolonizing and consecutive isolates of patients. This activity leads to the splitting of the strain population into various subfractions exhibiting different virulence potentials (Hlb-production and/or production of immune evasion molecules). Thus, phage-inducing conditions and strong selection for survival of the bacterial host after phage movement are typical for the infectious situation. Further in vitro characterization of phages revealed that: (i) SAK is encoded not only on serogroup F phages showing a conserved tropism for hlb but also on serogroup B phages which always integrate in a distinct intergenic region, (ii) the level of sak transcription correlates to phage inducibility but is independent of the phage localization in the chromosome, and (iii) phages can be stabilized extra-chromosomally during their life cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Attachment Sites, Microbiological
  • Bacterial Toxins / genetics
  • Gene Expression Regulation, Bacterial
  • Genes, Viral
  • Hemolysin Proteins / genetics
  • Humans
  • Sphingomyelin Phosphodiesterase / genetics
  • Staphylococcal Infections / microbiology*
  • Staphylococcus Phages / genetics
  • Staphylococcus Phages / physiology*
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / pathogenicity*
  • Staphylococcus aureus / virology*
  • Viral Proteins / genetics
  • Virulence / genetics
  • Virus Integration*


  • Bacterial Toxins
  • Hemolysin Proteins
  • Viral Proteins
  • Sphingomyelin Phosphodiesterase
  • hlb protein, Staphylococcus aureus