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Published on: September 11, 2020

Emergence and spread of Streptococcus pneumoniae with erm(B) and mef(A) resistance

David J Farrell1, Stephen G Jenkins, Steven D Brown

  • 1G.R. Micro Ltd, London, United Kingdom. d.farrell@grmicro.co.uk

Emerging Infectious Diseases
|June 21, 2005
PubMed

Insights

The prevalence of multidrug-resistant Streptococcus pneumoniae strains with both erm(B) and mef(A) macrolide resistance genes significantly increased in the US. This concerning trend highlights the growing threat of antimicrobial resistance in common bacterial infections.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Antimicrobial Resistance

Background:

  • Streptococcus pneumoniae is a leading cause of community-acquired respiratory tract infections.
  • Macrolide resistance in S. pneumoniae is a significant public health concern.
  • The emergence of co-resistance to multiple antibiotic classes complicates treatment strategies.

Purpose of the Study:

  • To analyze the prevalence and characteristics of macrolide-resistant S. pneumoniae isolates in the US.
  • To investigate the genetic basis of macrolide resistance, specifically the co-occurrence of erm(B) and mef(A) genes.
  • To track the clonal spread of multidrug-resistant S. pneumoniae strains.

Main Methods:

  • Analysis of 31,001 S. pneumoniae isolates from the PROTEKT US surveillance study (2000-2003).
  • Detection and characterization of macrolide resistance genes (erm(B) and mef(A)).
  • Molecular typing to identify clonal relationships, including the Taiwan19F-14 clonal complex 271 (CC271).

Main Results:

  • Macrolide (erythromycin) resistance remained stable at ~29%, but dual erm(B) + mef(A) resistance increased from 9.7% to 16.4% over three years.
  • Nearly all dual-resistant isolates (99.2%) exhibited multidrug resistance.
  • Over 90% of erm(B)+mef(A) isolates were clonally related to the international multidrug-resistant CC271 clone, with high prevalence in the US, South Africa, and South Korea.

Conclusions:

  • The study confirms the increasing global emergence and rapid rise in US prevalence of a specific multidrug-resistant S. pneumoniae clone (CC271).
  • The co-occurrence of erm(B) and mef(A) genes is a significant driver of macrolide resistance and multidrug resistance in this clone.
  • This emerging clone poses a substantial threat to effective treatment of pneumococcal infections, particularly in children.

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