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Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
09:03

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus

Published on: September 5, 2013

mef(A) is the predominant macrolide resistance determinant in Streptococcus pneumoniae and Streptococcus pyogenes in

Christine Bley1, Mark van der Linden, Ralf René Reinert

  • 1National Reference Center for Streptococci and Institute of Medical Microbiology, University Hospital RWTH Aachen, Pauwelsstrasse 30, Aachen, Germany.

International Journal of Antimicrobial Agents
|March 23, 2011
PubMed

Insights

Macrolide resistance is emerging in Streptococcus pneumoniae and Streptococcus pyogenes in Germany. The mef(A) gene is a key marker in both bacteria, with a specific clone driving pneumococcal resistance.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Epidemiology

Background:

  • Macrolide resistance in Streptococcus pneumoniae and Streptococcus pyogenes poses a significant public health threat.
  • Understanding the genetic basis and clonal dissemination of resistance is crucial for effective treatment strategies.

Purpose of the Study:

  • To characterize macrolide-resistant Streptococcus pneumoniae and Streptococcus pyogenes isolates from Germany.
  • To identify prevalent macrolide resistance genes and mechanisms.
  • To investigate the clonal spread of resistant strains.

Main Methods:

  • Susceptibility testing, phenotyping, polymerase chain reaction (PCR), sequencing of resistance genes, and multilocus sequence typing (MLST) were employed.
  • Analysis included 2045 S. pneumoniae and 352 S. pyogenes isolates.

Main Results:

  • Macrolide resistance was observed in 21.4% of S. pneumoniae and 8.2% of S. pyogenes isolates.
  • The predominant resistance gene in S. pneumoniae was mef(A) (57.7%), followed by erm(B) (27.0%).
  • A significant proportion of S. pneumoniae isolates (4.1%) exhibited dual resistance mechanisms (mef(E)+erm(B)).
  • In S. pyogenes, mef(A) (31.0%), erm(B) (34.5%), and erm(A) (13.8%) were identified.
  • A specific clone, mef(A)-positive England(14)-9, was identified as a major contributor to pneumococcal macrolide resistance.

Conclusions:

  • Macrolide resistance is prevalent in S. pneumoniae and S. pyogenes in Germany, driven by specific resistance genes.
  • The emergence of dual resistance mechanisms and the dissemination of a single clone highlight the dynamic nature of antibiotic resistance.
  • Continuous surveillance and molecular characterization are essential to monitor and combat the spread of macrolide resistance.

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