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Resistance to erythromycin and rising penicillin MIC in Streptococcus pyogenes in India

Malini Rajinder Capoor1, Deepthi Nair, Monorama Deb

  • 1Department of Microbiology, Vardhman Mahaveer Medical College, Safdarjung Hospital, New Delhi, India. rajeevmalini@rediffmail.com

Japanese Journal of Infectious Diseases
|October 25, 2006
PubMed

Insights

Worldwide resurgence of Streptococcus pyogenes infections necessitates monitoring antibiotic resistance. While most strains remain penicillin-susceptible, a significant portion exhibits erythromycin resistance, highlighting the need for ongoing surveillance of antimicrobial susceptibility patterns.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Antimicrobial Resistance

Background:

  • Global increase in Streptococcus pyogenes infections and associated complications.
  • Penicillin susceptibility in S. pyogenes has been historically consistent, but resistance patterns require current evaluation.

Purpose of the Study:

  • To investigate the prevalence and characteristics of penicillin and erythromycin resistance in clinical S. pyogenes isolates.
  • To assess the current antimicrobial susceptibility profile of S. pyogenes.

Main Methods:

  • Identification of 34 clinical S. pyogenes strains using standard microbiological techniques.
  • Antimicrobial susceptibility testing via Kirby-Bauer disk diffusion and E-test for minimum inhibitory concentration (MIC) determination.
  • Evaluation of resistance to penicillin and erythromycin.

Main Results:

  • All isolates were susceptible to penicillin, clindamycin, and vancomycin by disk diffusion.
  • Ten strains (29.4%) demonstrated erythromycin resistance, with an observed M-type macrolide resistance pattern.
  • E-test revealed 7 strains (20.6%) as penicillin nonsusceptible and 6 strains (17.6%) as erythromycin resistant.

Conclusions:

  • Continuous surveillance of Streptococcus pyogenes susceptibility is essential for tracking antibiotic resistance development.
  • Emerging resistance patterns, particularly to erythromycin, warrant attention in clinical settings.

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