Molecular epidemiology of macrolide resistant Group A streptococci from Puducherry, India

Macrolide resistant group A streptococci

  • Tintu Abraham Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India
  • Sujatha Sistla Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India

Abstract

Introduction: In penicillin allergic patients, macrolides are the most commonly used antibiotics for treating streptococcal infections, irrespective of the higher resistance rates. The objective of this study was to evaluate the comparative prevalence, phenotypes, and genetic determinants of macrolide resistance and associated emm types among different clinical isolates of Streptococcus pyogenes.


Methodology: A total of 173 Streptococcus pyogenes isolates were examined for macrolide resistance phenotype by double-disc test, resistance determinants by multiplex PCR and emm genotyping.


Results: Erythromycin resistance was found in 51.4% of isolates, with MIC90 ≥ 256 µg/mL Inducible phenotype was commonly found (iMLS, 67.4%) followed by the M phenotype (32.5%). Among these isolates, 65.1% harboured ermB and 32.5% mefA as sole macrolide resistance gene, whereas presence of both, ermB plus mefA was observed in 2.2% cases. The most common types among resistant strains were emm63 (11.2%), emm44 (6.7%), emm42 (5.6%), and emm75.3, emm82, emm85, emm92, emm111.1 (4.4% each). Statistically significant association was observed between emm63, emm44 and erythromycin resistance (p ≤ 0.05). Association of these emm types and macrolide resistance have not been reported earlier.


Conclusion: Higher macrolide resistance in this study can be attributed to overuse and misuse of this antibiotic. These findings indicate that macrolides should not be empirically used for treating severe streptococcal infections.

Author Biographies

Tintu Abraham, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India

PhD scholar, Department of Microbiology

Sujatha Sistla, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India

Professor and Head, Department of Microbiology

Published
2017-10-06
How to Cite
Abraham T, Sistla S (2017) Molecular epidemiology of macrolide resistant Group A streptococci from Puducherry, India. The Journal Of Infection In Developing Countries 11 (09): 679-683. https://doi.org/10.3855/jidc.9132
Section
Original Articles

Keywords

Macrolide resistance; Streptococcus pyogenes; Phenotypes and genotypes; emm types