Related Experiment Videos

Erythromycin-resistant pharyngeal isolates of Streptococcus pyogenes recovered in Italy

Giordano Dicuonzo1, Ersilia Fiscarelli, Giovanni Gherardi

  • 1Department of Laboratory Medicine. Hospital Infection Control Program, Università Campus Bio-Medico, Rome, Italy.

Insights

Macrolide resistance in group A Streptococcus (GAS) is linked to the serum opacity factor (sof) gene in Italian pediatric patients. This finding highlights a potential marker for antibiotic resistance in pharyngitis cases.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Molecular Epidemiology

Background:

  • Group A Streptococcus (GAS) is a significant cause of pediatric pharyngitis.
  • Macrolide antibiotics are commonly used to treat GAS infections.
  • Emergence of antibiotic resistance in GAS is a growing public health concern.

Purpose of the Study:

  • To investigate macrolide resistance phenotypes and determinants in GAS isolates from pediatric pharyngitis patients.
  • To determine the clonal types and genetic basis of erythromycin resistance in GAS.
  • To explore the association between macrolide resistance and the presence of the serum opacity factor (sof) gene.

Main Methods:

  • Collection and analysis of 127 erythromycin-resistant GAS isolates from 355 pediatric pharyngitis patients in Rome, Italy.
  • Phenotypic characterization of macrolide resistance.
  • Molecular analysis including emm and sof sequence typing.

Main Results:

  • Three distinct macrolide resistance phenotypes and three erythromycin resistance determinants were identified.
  • Erythromycin-resistant GAS isolates belonged to 11 different clonal types based on emm and sof typing.
  • A strong association was observed between macrolide resistance and the presence of the sof gene, with 126 out of 127 resistant isolates being sof-positive.

Conclusions:

  • The study identified a significant association between macrolide resistance and the presence of the serum opacity factor (sof) gene in GAS isolates from Italian pediatric pharyngitis patients.
  • The findings suggest that sof gene presence could be a potential indicator for macrolide resistance in GAS.
  • This research contributes to understanding the epidemiology of antibiotic resistance in GAS and has implications for treatment strategies.

Related Concept Videos