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Human antimicrobial peptide LL-37 induces MefE/Mel-mediated macrolide resistance in Streptococcus pneumoniae

Dorothea Zähner1, Xiaoliu Zhou, Scott T Chancey

  • 1Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.

Antimicrobial Agents and Chemotherapy
|May 26, 2010
PubMed

Insights

The human antimicrobial peptide LL-37 triggers macrolide resistance in Streptococcus pneumoniae by activating the MefE/Mel efflux pump. This finding has implications for treating pneumococcal infections and understanding host defense mechanisms.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Antimicrobial Peptides

Background:

  • Macrolide resistance in Streptococcus pneumoniae is a significant clinical challenge.
  • The MefE/Mel efflux pump mediates inducible macrolide resistance in pneumococci.

Purpose of the Study:

  • To investigate the effect of the human antimicrobial peptide LL-37 on macrolide resistance in Streptococcus pneumoniae.
  • To determine if LL-37 influences the expression of the mefE gene.

Main Methods:

  • Assessing the induction of the mefE promoter by LL-37.
  • Evaluating the resulting resistance to erythromycin and LL-37 in Streptococcus pneumoniae.

Main Results:

  • The human antimicrobial peptide LL-37 was found to induce the mefE promoter.
  • This induction resulted in conferred resistance to both erythromycin and LL-37.

Conclusions:

  • LL-37 can trigger inducible macrolide resistance in Streptococcus pneumoniae.
  • This mechanism may compromise host defenses and the effectiveness of macrolide treatments for pneumococcal diseases.

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