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Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus
10:39

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

Published on: March 10, 2017

A type III-like restriction endonuclease functions as a major barrier to horizontal gene transfer in clinical

Anna R Corvaglia1, Patrice François, David Hernandez

  • 1Department of Microbiology and Molecular Medicine, University Medical Center, University of Geneva, 1211 Geneva 4, Switzerland.

Proceedings of the National Academy of Sciences of the United States of America
|June 16, 2010
PubMed

Insights

Certain Staphylococcus aureus strains, particularly MRSA, possess a restriction system hindering DNA transfer. Some MRSA strains lack this system, increasing their susceptibility to acquiring antibiotic resistance genes from other bacteria.

Area of Science:

  • Microbiology
  • Genetics
  • Infectious Diseases

Background:

  • Staphylococcus aureus is a significant pathogen causing severe infections, with methicillin-resistant strains (MRSA) posing treatment challenges due to multidrug resistance.
  • Horizontal gene transfer is a key factor in the spread of antibiotic resistance and virulence in bacteria.
  • Community-acquired MRSA has increased the incidence of these difficult-to-treat infections.

Purpose of the Study:

  • To identify and characterize a DNA restriction system in clinical Staphylococcus aureus strains.
  • To investigate the role of this system in preventing horizontal gene transfer.
  • To determine if MRSA strains exhibit deficiencies in this system and the implications for acquiring resistance.

Main Methods:

  • Identification and characterization of a type III-like restriction system in clinical S. aureus.
  • Comparative analysis of restriction system presence/absence in MRSA and non-MRSA strains.
  • Transformation efficiency assays using DNA from other bacterial species (e.g., Escherichia coli).

Main Results:

  • A type III-like restriction system was identified in clinical S. aureus strains, inhibiting interspecies DNA transformation.
  • Certain clinical MRSA strains were found to be deficient in this restriction system.
  • These deficient MRSA strains showed hypersusceptibility to horizontal DNA transfer, enabling acquisition of genes like vancomycin resistance from enterococci.
  • Inactivation of the restriction system significantly enhanced transformation efficiency in clinical S. aureus.

Conclusions:

  • The identified restriction system acts as a barrier to horizontal gene transfer in Staphylococcus aureus.
  • Deficiencies in this system in some MRSA strains facilitate the acquisition of antibiotic resistance genes, contributing to their epidemiology.
  • Targeting or understanding this restriction system could offer new avenues for manipulating MRSA strains and combating antibiotic resistance.

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