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Published on: March 3, 2023

Characterization of macrolide efflux pump mef subclasses detected in clinical isolates of Streptococcus pyogenes

J Blackman Northwood1, M Del Grosso, L R Cossins

  • 1Quotient Bioresearch Limited, Newmarket Road, Fordham CB7 5WW, United Kingdom. John.BlackmanNorthwood@quotientbioresearch.com

Antimicrobial Agents and Chemotherapy
|March 5, 2009
PubMed

Insights

Macrolide efflux (mef) resistance in Streptococcus pyogenes is more diverse than previously known. New variants, including mef(I) and mosaic mef(A)-mef(E), were identified in respiratory infections, highlighting global mef(E) distribution.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • Macrolide resistance is a growing concern in bacterial infections.
  • The mef (macrolide efflux) gene is a primary mechanism for macrolide resistance.
  • Streptococcus pyogenes is a common cause of community-acquired respiratory tract infections.

Purpose of the Study:

  • To characterize the macrolide efflux (mef) resistance mechanism in Streptococcus pyogenes.
  • To investigate the prevalence and diversity of mef genes in clinical isolates.

Main Methods:

  • Phenotypic screening of M phenotype isolates for mef genes.
  • Molecular characterization of novel mef variants and subclasses.

Main Results:

  • Fifty-four M phenotype isolates of S. pyogenes were analyzed.
  • mef(A) was negative in all tested isolates.
  • mef(E) was definitively present and globally distributed.
  • Novel variants mef(I) (0.4%) and a mosaic mef(A)-mef(E) (2.3%) were identified.
  • A novel subclass of mef was also detected (0.1%).

Conclusions:

  • Streptococcus pyogenes exhibits a diverse range of mef-mediated macrolide resistance mechanisms.
  • The presence of mef(E) and novel variants like mef(I) and mosaic mef(A)-mef(E) is significant.
  • These findings underscore the evolving landscape of antibiotic resistance in S. pyogenes.

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