Objective: To investigate superantigen gene profiles of group A Streptococcus (GAS) isolated in Beijing pediatric patients in 2014, and to explore the the relationship between superantigen gene profiles with emm types, and GAS infections with diseases.
Methods: A total of 259 GAS strains were isolated from pediatric patients clinically who diagnosed with scarlet fever and pharyngitis from 36 hospitals in Beijing from May to July, 2014.The Superantigens genes of strains were performed by Real-time PCR (speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, ssa). PCR amplification of GAS strain M protein N gene segments were carried ort; products after sequencing comparison were analyzed to determine the GAS types of emm. The differences in distributions of superantigen genes and emm types of GAS isolates were compared between subgroups.
Results: Among the 259 GAS strains, the detection rates of 13 superantigens were as the following: speA 48.6% (126), speB 99.2% (257), speC 99.2% (257), speF 98.8% (256), speG 98.5% (255), speH 43.6% (113), speI 46.3% (120), speJ 49.0% (127), smeZ 99.2% (257) and ssa 98.5% (255), respectively, however, speK, speL, and speM were not found. Eleven superantigen gene profiles in all were observed (A-K). The percentage of emm1 strains harbored spe A and speJ were 94.2% (113/120), 95.0% (114/120), respectively, which were significantly higher than those of emm12 strains (5.6% (7/124), 5.6% (7/124), respectively; χ(2) = 191.20, 194.80, P < 0.001). The percentage of emm12 strains harbored speH and speI were 83.9% (104/124), 88.7% (110/124), respectively, which were significantly higher than those of emm1 strains (3.3% (4/120), 4.2% (5/120), respectively; χ(2) = 160.30, 174.90, P < 0.001).The superantigen genotypes of GAS strains and emm types, which were isolated from scarlet fever and pharyngitis cases, were not significant different (P > 0.05).
Conclusion: The GSA strains isolated in Beijing pediatric patients in 2014, the relevance ratio of speB, speC, speF, smeZ, speG, ssa were higher than others, while speK, speL, and speM were no detected in any GAS strains. The superantigen genes appeared to be associated with the emm type. Furthermore, emm type distribution and superantigen genes were not different between scalet fever and pharyngitis.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Genome Analysis of Japanese Yersinia pseudotuberculosis Strains Isolated From Kawasaki Disease Patients and Other Sources and Their Phylogenetic Positions in the Global Y. pseudotuberculosis Population.
Microbiol Immunol
January 2025
Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Yersinia pseudotuberculosis (Ypt) is a gram-negative bacterium that infects both humans and animals primarily through fecal‒oral transmission. While Ypt causes acute gastroenteritis in humans, an association with Kawasaki disease (KD), a disease that primarily affects infants and young children and causes multisystemic vasculitis, has also been suspected. Although KD represents a significant health concern worldwide, the highest annual incidence rate is reported in Japan.
View Article and Find Full Text PDFDevelopment of high-performance inducible and secretory expression vector and host system for enhanced recombinant protein production.
Sci Rep
December 2024
Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi state, MS, 39762, USA.
The production of lipopolysaccharide (LPS)-free recombinant proteins from culture supernatants is of great interest to biomedical research and industry. Due to the LPS-free cell wall structure and the well-defined secretion factor B (SecB)-dependent secretion pathway, Gram-positive bacteria are a superior alternative to Escherichia coli expression systems. However, the lack of inducible expression systems for high yields has been a bottleneck.
View Article and Find Full Text PDFClinical Snapshot of Group A Streptococcal Isolates from an Australian Tertiary Hospital.
Pathogens
November 2024
Australian Infectious Diseases Research Centre, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4067, Australia.
(Group A , GAS) is a human-restricted pathogen that causes a wide range of diseases from pharyngitis and scarlet fever to more severe, invasive infections such as necrotising fasciitis and streptococcal toxic shock syndrome. There has been a global increase in both scarlet fever and invasive infections during the COVID-19 post-pandemic period. The aim of this study was the molecular characterisation of 17 invasive and non-invasive clinical non-1 GAS isolates from an Australian tertiary hospital collected between 2021 and 2022.
View Article and Find Full Text PDFEndogenous antigens shape the transcriptome and TCR repertoire in an autoimmune arthritis model.
J Clin Invest
November 2024
Rosalind Russell and Ephraim P. Engleman Rheumatology Research Center, Department of Medicine.
Article Synopsis
- - The study investigates how impaired signaling in naïve CD4+ T cells leads to the development of pathogenic autoreactive cells, which play a role in autoimmune arthritis, specifically using SKG mice with a mutated Zap70 gene.
- - Researchers found these pathogenic T cells had increased expression of activation and cytokine-related genes, but reduced expression of markers that usually promote tolerance compared to healthy cells.
- - The presence of specific TCR variable beta chains linked to superantigens from mouse retroviruses suggests that these viral elements may disrupt normal immune tolerance, fostering the development of self-reactive CD4+ T cells into harmful effector cells, with potential therapeutic implications.
Staphylococcal Enterotoxins: Description and Importance in Food.
Pathogens
August 2024
Department of Food Science and Nutrition, School of Food Engineering, University of Campinas (UNICAMP), Campinas 13083-862, Brazil.
stands out as one of the most virulent pathogens in the genus . This characteristic is due to its ability to produce a wide variety of staphylococcal enterotoxins (SEs) and exotoxins, which in turn can cause staphylococcal food poisoning (SFP), clinical syndromes such as skin infections, inflammation, pneumonia, and sepsis, in addition to being associated with the development of inflammation in the mammary glands of dairy cattle, which results in chronic mastitis and cell necrosis. SEs are small globular proteins that combine superantigenic and emetic activities; they are resistant to heat, low temperatures, and proteolytic enzymes and are tolerant to a wide pH range.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!