Related Experiment Video

Updated: Jun 18, 2026

Heuristic Mining of Hierarchical Genotypes and Accessory Genome Loci in Bacterial Populations
08:03

Heuristic Mining of Hierarchical Genotypes and Accessory Genome Loci in Bacterial Populations

Published on: December 7, 2021

Genetic commonality of macrolide-resistant group A beta hemolytic streptococcus pharyngeal strains

Angela L Myers1, Mary Anne Jackson, Rangaraj Selvarangan

  • 1Children's Mercy Hospitals and Clinics, University of Missouri-Kansas City School of Medicine, KC, MO, USA. amyers@cmh.edu

Annals of Clinical Microbiology and Antimicrobials
|December 3, 2009
PubMed

Insights

Macrolide resistance in Group A beta-hemolytic streptococcus (GABHS) pharyngitis has increased in children. This rise in erythromycin resistance may impact treatment choices for penicillin-allergic patients.

Area of Science:

  • Pediatric infectious diseases
  • Microbiology
  • Antimicrobial resistance

Background:

  • Group A beta-hemolytic streptococcus (GABHS) pharyngitis is a frequent childhood illness.
  • Penicillin is the primary treatment, while macrolides are alternatives for allergic individuals.
  • Increased macrolide use may correlate with rising resistance rates.

Purpose of the Study:

  • To assess current erythromycin resistance levels in GABHS pharyngitis isolates.
  • To compare resistance data with previous findings from 2002.
  • To investigate the genetic relatedness of resistant isolates.

Main Methods:

  • A surveillance study of children with pharyngitis and positive rapid antigen testing was conducted.
  • Erythromycin resistance was determined using disk diffusion and E-test on 500 isolates.
  • Pulse field gel electrophoresis (PFGE) analyzed the genetic relatedness of isolates.

Main Results:

  • Erythromycin resistance was 3.5% at site A and 4.5% at site B in 2005-06, compared to 0% in 2002.
  • Inducible resistance was observed in a subset of isolates.
  • PFGE revealed genetic relatedness among some resistant isolates.

Conclusions:

  • Community macrolide resistance has increased, likely due to elevated macrolide consumption.
  • The rising resistance may necessitate re-evaluation of treatment guidelines for GABHS pharyngitis.
Abstract

Related Concept Videos

Streptococcal Pharyngitis01:27

Streptococcal Pharyngitis

Streptococcal pharyngitis, commonly known as “strep throat,” is an acute infection of the oropharyngeal tissues caused by the Gram‑positive Group A Streptococcus (Streptococcus pyogenes). Transmission occurs primarily through respiratory droplets expelled during coughing, sneezing, or talking.Mechanisms of Host Entry and Immune EvasionUpon entering the host, S. pyogenes adheres to the mucosal epithelial cells of the pharynx via surface proteins, notably lipoteichoic acid and the antiphagocytic...
Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Development of Antibiotic Resistance01:30

Development of Antibiotic Resistance

Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
Bacterial Phylum Actinobacteria01:30

Bacterial Phylum Actinobacteria

Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...