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The rpoN gene of Enterococcus faecalis directs sensitivity to subclass IIa bacteriocins

K Dalet1, C Briand, Y Cenatiempo

  • 1Laboratoire de Biologie Moléculaire, CNRS ESA 6031, IBMIG, Université de Poitiers, 40 avenue du recteur Pineau, 86022 Poitiers Cedex, France.

Current Microbiology
|November 18, 2000
PubMed

Insights

The sigma 54 factor (RpoN) in Enterococcus faecalis mediates sensitivity to subclass IIa bacteriocins. Disrupting the rpoN gene confers resistance to these specific antimicrobial peptides.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacteriocin Research

Background:

  • Subclass IIa bacteriocins are antimicrobial peptides with activity against Gram-positive bacteria.
  • Listeria monocytogenes sensitivity to mesentericin Y105 involves the sigma 54 factor.
  • Enterococcus faecalis is a common bacterium that can be pathogenic.

Purpose of the Study:

  • To identify and characterize the rpoN gene encoding the sigma 54 factor in Enterococcus faecalis JH2-2.
  • To investigate the role of the sigma 54 factor in Enterococcus faecalis sensitivity to bacteriocins.
  • To determine if sigma 54 specifically affects sensitivity to subclass IIa bacteriocins.

Main Methods:

  • Gene identification and knockout of the rpoN gene in Enterococcus faecalis JH2-2.
  • Bacteriocin susceptibility testing using subclass IIa bacteriocins (e.g., mesentericin Y105) and class I bacteriocins (e.g., nisin).
  • Phenotypic analysis of the rpoN mutant compared to the wild-type strain.

Main Results:

  • The rpoN gene, encoding sigma 54, was identified in Enterococcus faecalis JH2-2.
  • Interruption of the rpoN gene resulted in Enterococcus faecalis resistance to various subclass IIa bacteriocins.
  • The rpoN mutant retained sensitivity to nisin, a class I bacteriocin, indicating specificity.

Conclusions:

  • The sigma 54 factor (RpoN) plays a crucial role in Enterococcus faecalis sensitivity to subclass IIa bacteriocins.
  • Targeting the sigma 54 factor could be a strategy to overcome resistance to specific bacteriocins.
  • This finding highlights the specific involvement of sigma 54 in the bacteriocin response pathway.

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