SpeB gene was detected in 94.1% of Streptococcus pyogenes isolates and showed 100% Specifity agree with study that showed 100% sensitivity and 100% specificity. Among the toxin genes that are thought to be chromosomally encoded, SpeB was found in all isolates. This finding differs markedly from that reported in which showed 72.4% of SpeB. And up-close to showed the presence of SpeB was 100% in their isolated Streptococcus pyogenes, also report the SAg and antibiotic resistance genes appeared to be associated with the emm type. The streptococcal pyrogenic exotoxin B gene was associated with pyrogenicity, T-lymphocyte mitogenicity, and the ability to increase susceptibility to endotoxic shock in individuals infected with group A streptococcus. Our study showed there was significant association between the patients having SpeB gene and fever. SpeA was detected in 33.3% of streptococcus pyogenes isolates. Reported the SpeA gene was found in a majority (40-90%) of S. pyogenes isolates from the USA associated with invasive disease and STSS, but only in a minority (15-20%) of isolates from noninvasive diseases. A high frequency of SpeA (80%) was found in STSS isolates collected in Australia. In study isolates from patients with pharyngotonsillitis, the frequencies were 17.2% for SpeA, 72.4% for SpeB. And in the incidence of SpeA, SpeB and SpeF were 5 (83%), 56 (933%) and 53 (883%), respectively.
Author(s) Details:
Minas Mohamed Balla
Department of Microbiology, Faculty of Science, University of Gezira, Wad Medani, Sudan.
Adil Mergani
Department of Molecular and Immunogenetics, NCI, University of Gezira, Wad Medani, Sudan.
Mohamed Elamin A. M. E. Medani
Pediatric Cardiologist Faculty of Medicine, University of Gezira, Wad Medani, Sudan.
Adam Dawoud Abakar
Department of Medical Parasitology, Faculty of Medical Laboratory Science, University of Gezira, Wad
Medani, Sudan.
Ameer Mohamed Dafalla
Department of Molecular and Immunogenetics, NCI, University of Gezira, Wad Medani, Sudan.
Recent Global Research Developments in Consequences of Group A Streptococcal (GAS) Infection: A Comprehensive Overview
Group A Streptococcus (GAS), also known as Streptococcus pyogenes, is a gram-positive bacterium responsible for various human infections, including pharyngitis, impetigo, scarlet fever, septicemia, and necrotizing fasciitis. GAS can lead to autoimmune sequelae diseases, such as rheumatic fever and rheumatic heart diseases, which pose significant morbidity and mortality risks, especially among young children and the elderly worldwide [1].
While antibiotic drugs are commonly used to control early-stage GAS infections, the emergence of clinical isolates with reduced sensitivity to penicillin-adjunctive antibiotics and increasing macrolide resistance is concerning. Vaccination remains a crucial strategy for preventing infectious diseases, and although no GAS vaccines have been approved for the market yet, recent advances in understanding GAS pathogenesis and transmission have improved vaccine design. Here are some key points:
Vaccine Development: Despite more than a century of GAS vaccine research, no approved vaccines exist. However, recent progress has enhanced our understanding of GAS pathogenic proteins, providing valuable insights for vaccine candidates.
Challenges: Developing a GAS vaccine faces challenges due to the bacterium’s serotype diversity. Different geographical regions experience varying emm-types (serotype-specific M-proteins). Antibiotics remain essential, but discrepancies in treatment and diagnosis persist between high-income countries (HIC) and low- and middle-income countries (LMIC).
Global Efforts: The World Health Organization (WHO) has taken the lead in GAS vaccine development, publishing a roadmap for the first GAS vaccine. Initiatives like the Strep A Vaccine Global Consortium (SAVAC) and the Australian Strep A Vaccine Initiative (ASAVI) aim to ensure safe, effective, and affordable GAS vaccines [2] .
Antibiotic Resistance: While no GAS resistance to beta-lactam antibiotics has been reported, reduced susceptibility exists. Surveillance shows no resistance in new clusters responsible for recent outbreaks, but general antimicrobial resistance has increased [2] .
References
- Fan J, Toth I, Stephenson RJ. Recent Scientific Advancements towards a Vaccine against Group A Streptococcus. Vaccines. 2024; 12(3):272. https://doi.org/10.3390/vaccines12030272
- Ajay Castro, S., & Dorfmueller, H. C. (2023). Update on the development of Group A Streptococcus vaccines. npj Vaccines, 8(1), 135.
