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Associations of macrolide and fluoroquinolone resistance with molecular typing in Streptococcus pyogenes from

Takeaki Wajima1, Miyuki Morozumi, Naoko Chiba

  • 1Laboratory of Molecular Epidemiology for Infectious Agents, Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.

International Journal of Antimicrobial Agents
|August 31, 2013
PubMed

Insights

Eighty-five percent of invasive group A Streptococcus strains showed antibiotic resistance. Macrolide resistance was common, particularly in emm1 strains, while fluoroquinolone resistance was linked to specific genetic mutations.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Molecular Epidemiology

Background:

  • Invasive group A Streptococcus (iGAS) infections pose a significant public health threat.
  • Understanding antibiotic resistance patterns in iGAS is crucial for effective treatment and surveillance.
  • emm typing is a key method for classifying Streptococcus pyogenes strains.

Purpose of the Study:

  • To analyze the relationship between emm types and antibiotic resistance in invasive group A Streptococcus.
  • To determine the prevalence of macrolide and fluoroquinolone resistance mechanisms in iGAS strains.
  • To investigate specific genetic determinants of antibiotic resistance in relation to emm types.

Main Methods:

  • Characterization of 283 invasive group A Streptococcus strains collected from 2010-2012.
  • Utilized emm typing, multilocus sequence typing (MLST), and antimicrobial susceptibility testing.
  • Identified resistance genes (mef(A), erm(A), erm(B)) and mutations (parC, gyrA).

Main Results:

  • High rates of macrolide antibiotic resistance (54.4%) were observed, primarily mediated by mef(A), erm(A), or erm(B).
  • emm1 strains showed high prevalence (92.2%) of mef(A)-mediated macrolide resistance.
  • Fluoroquinolone resistance, including intermediate and high resistance due to parC and gyrA mutations, was detected in various emm types.

Conclusions:

  • Significant macrolide resistance exists in invasive group A Streptococcus, with specific emm types showing distinct resistance profiles.
  • The study highlights the importance of emm typing in understanding the epidemiology of antibiotic resistance in iGAS.
  • Continued surveillance is necessary to monitor evolving resistance patterns and inform clinical management strategies.
Keywords:
Fluoroquinolone resistanceMacrolide resistanceStreptococcus pyogenes

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