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A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
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Constitutive expression of the ileS-2 gene responsible for high-level mupirocin resistance in Staphylococcus aureus

Naira Elane Moreira de Oliveira1, Elisa D'Avila Costa Cavalcanti2, Marinella Silva Laport1

  • 1Instituto de Microbiologia Prof. Paulo de Góes, Bloco I, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21491-590 Rio de Janeiro, RJ, Brazil.

Journal of Medical Microbiology
|August 15, 2009
PubMed

Insights

Mupirocin resistance in Staphylococcus aureus is increasing. This study found that the ileS-2 gene, responsible for high-level resistance, is constitutively expressed, not upregulated by mupirocin.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Antimicrobial Resistance

Background:

  • Mupirocin is a crucial topical antimicrobial for treating skin infections and preventing methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage.
  • Increasing prevalence of mupirocin resistance in S. aureus, especially MRSA, poses a significant clinical challenge.
  • High-level mupirocin resistance is primarily mediated by the ileS-2 gene, often located on conjugative plasmids.

Purpose of the Study:

  • To investigate the regulatory mechanism of the ileS-2 gene in S. aureus.
  • To determine if mupirocin exposure influences the expression of the ileS-2 gene.
  • To elucidate the basis of constitutive high-level mupirocin resistance.

Main Methods:

  • Investigated gene expression levels of ileS-2 in S. aureus.
  • Utilized molecular techniques to assess gene regulation.
  • Analyzed the role of constitutive expression in mupirocin resistance.

Main Results:

  • Evidence suggests that the ileS-2 gene is constitutively expressed in S. aureus.
  • Mupirocin does not appear to upregulate the expression of the ileS-2 gene.
  • Constitutive expression of ileS-2 is a key factor in high-level mupirocin resistance.

Conclusions:

  • The ileS-2 gene's constitutive expression, rather than upregulation by mupirocin, underlies high-level resistance in S. aureus.
  • Understanding this mechanism is vital for managing mupirocin resistance.
  • Further research into resistance mechanisms can inform treatment strategies.

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