Objective This study aimed to examine the characteristics of Group A Streptococcus (GAS) infection and identify the emm genotypes and the superantigen gene of GAS strains isolated from children from 2011 to 2019 in Tongzhou District, Beijing.

Methods Pharyngeal swab samples from children with scarlet fever or pharyngeal infection were collected and tested for GAS. In GAS isolates, emm genotypes and superantigen genes were identified. Logistic regression models were used to explore the correlations between demographic characteristics, clinical manifestations, and GAS infection.

Results In total, 172/1,214 (14.2%) GAS were isolated. The GAS infection rate in children with scarlet fever was 47.5%, higher than 8.5% in children with pharyngeal infection (p < 0.001). The risk of GAS infection was associated with oral mucosal congestion in children with scarlet fever, and older age, tonsillitis, and rash in children with pharyngeal infection. Seven emm genotypes were detected in 164 GAS isolated strains, of which emm12 and emm1 accounted for 47.0 and 46.3%, respectively. Among 112 GAS isolates, the top 5 detection rates of superantigen genes were speF 100.0%, speG 100.0%, speB 98.2%, speC 94.6%, and smeZ 82.1%. Higher proportions of speA, speJ, and speK were detected in emm1 isolates, while speH and speI were more common in emm12 isolates (p < 0.001).

Conclusion The changing predominant type expanded the knowledge of the circulating emm types, which should be considered in future vaccine development.

The original dataset presented in this study is included in the supplementary material, further inquiries can be directed to the corresponding authors.

The Peking University Institutional Review Board Office granted Ethical approval to carry out the study within its facilities (IRB00001052-19005). Written informed consent from the participants' legal guardian was not required and oral informed consent was given to participate in this study in accordance with the national legislation and the institutional requirements.

Q-B.L. and F.C. conceived and designed the experiments, reviewed drafts of the paper, and approved the final draft. H-J.L. and T-T.W. collected and analyzed the data, prepared figures and tables, authored drafts of the paper, and approved the final draft. H-M.S., Y.C., M-L.T., L.Z., L.X., J.D., and G-F.Z. collected the data and performed the investigations. All authors have approved the final draft and agreed to the published version of the manuscript.

*These authors contributed equally to this work and share the first authorship.

Received: 20 October 2023

Accepted: 22 April 2024

Article published online:
29 May 2024

© 2024. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany