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Updated: Jun 5, 2026
Multiplex PCR and Reverse Line Blot Hybridization Assay (mPCR/RLB)
Published on: August 6, 2011
Molecular analysis of Streptococcus pyogenes strains isolated from Chinese children with pharyngitis
Hesheng Chang1, Xuzhuang Shen, Guoying Huang
1Beijing Children's Hospital affiliated to Capital Medical University, Beijing 100045, China.
Insights
Streptococcus pyogenes strains causing pharyngitis in Chinese children were analyzed. The prevalent emm types, emm1 and emm12, showed distinct superantigen gene profiles, suggesting vaccine potential.
Area of Science:
- Microbiology
- Infectious Diseases
- Genetics
Background:
- Streptococcus pyogenes is a significant bacterial pathogen responsible for numerous human illnesses, with streptococcal pharyngitis being the most frequent.
- Understanding the genetic diversity and virulence factors of S. pyogenes is crucial for developing effective prevention and treatment strategies.
Purpose of the Study:
- To characterize Streptococcus pyogenes isolates from children with pharyngitis in China.
- To investigate the distribution of superantigen (SAg) genes, emm genotypes, and pulsed-field gel electrophoresis (PFGE) types.
- To determine the relationship between these genetic markers and their implications for vaccine development.
Main Methods:
- Analysis of 185 S. pyogenes isolates using SAg gene detection, emm genotyping, and PFGE.
- Multilocus sequence typing (MLST) was performed on a subset of isolates (n=58).
- Correlation analysis between emm types, SAg profiles, and PFGE types.
Main Results:
- emm1 and emm12 were identified as the predominant genotypes in the studied population.
- Distinct SAg gene profiles were observed for emm1 and emm12 isolates, with emm1 isolates frequently carrying speA and speJ, while emm12 isolates predominantly carried speI.
- PFGE analysis revealed 25 distinct clusters, and MLST identified ST28 for emm1 and ST36 for emm12 isolates.
- A strong association was found between emm type and SAg/PFGE profiles, but not in the reverse direction.
Conclusions:
- emm1 and emm12 are the dominant S. pyogenes genotypes associated with pharyngitis in Chinese children.
- The observed genetic diversity and SAg profiles provide insights into the pathogen's epidemiology.
- A significant portion of the analyzed strains could potentially be covered by a 26-valent vaccine, highlighting its potential efficacy.
Abstract:
Streptococcus pyogenes is an important gram-positive bacterial pathogen that causes various human diseases, of which streptococcal pharyngitis is the most common. In this work, a total of 185 S. pyogenes isolated from Chinese children with pharyngitis was analyzed by superantigen (SAg) genes, emm genotyping, and pulsed-field gel electrophoresis (PFGE). Fifty-eight (31.4%) isolates were also typed by multilocus sequence typing (MLST). The results indicate that most of the emm1 isolates possessed speA (88.5%) and speJ (83.6%), and few isolates possessed speI gene (13.1%). In contrast, none of the emm12-type isolates possessed speJ; few isolates possessed speA (5.2%); and most of the isolates possessed speI (91.7%). PFGE analysis revealed 25 different clusters, and MLST was performed for 2 predominant emm-type isolates; emm12 isolates belonged to ST36 while emm1 isolates belonged to ST28. As far as this collection is concerned, emm1 and emm12 are the prevalent genotypes among S. pyogenes strains associated with children's pharyngitis in China. Most of the pharyngitis strains can be covered by a 26-valent vaccine. A strong correspondence is found only in the direction of emm type for both SAg profiles and PFGE types but not in the reverse direction.
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Acute pharyngitis is the inflammation of the back of the throat (pharynx), commonly resulting in a sore throat. It is a frequently encountered condition that prompts individuals to seek medical advice.
Classification
Acute pharyngitis can be categorized based on its underlying cause: