scholarly journals A vaccine to provide strain-transcending immunity to group A streptococci

2011 ◽  
Vol 32 (3) ◽  
pp. 125
Author(s):  
Michael F Good ◽  
Michael R Batzloff
Keyword(s):  
Streptococcus Pyogenes ◽  
Vaccine Development ◽  
Group A Streptococcus ◽  
Post Vaccination ◽  
Vast Array ◽  
Efficacy Trials ◽  
Heterologous Challenge ◽  
Obvious Reason ◽  
Group A ◽  
Main Strategy

Organisms such a Streptococcus pyogenes (group A streptococcus), Plasmodium spp parasites and HIV present significant obstacles to vaccine development. They can subvert the immune system and present dominant antigens that can display a vast array of allelic types of variants. In spite of these obvious decoys, the main strategy to develop vaccines for these organisms has been to focus on dominant antigens or epitopes. The obvious reason for this approach is that such antigens and epitopes are easy to define. Early successes are often posted largely because homologous organisms are typically used to challenge animals post-vaccination. However, success in efficacy trials with heterologous challenge is yet to be seen.

scholarly journals Streptococcus pyogenes evades adaptive immunity through specific IgG glycan hydrolysis

2019 ◽  
Vol 216 (7) ◽  
pp. 1615-1629 ◽  
Author(s):  
Andreas Naegeli ◽  
Eleni Bratanis ◽  
Christofer Karlsson ◽  
Oonagh Shannon ◽  
Raja Kalluru ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Vaccine Development ◽  
Group A Streptococcus ◽  
Invasive Infection ◽  
Invasive Infections ◽  
Life Threatening ◽  
Group A ◽  
Specific Igg

Streptococcus pyogenes (Group A streptococcus; GAS) is a human pathogen causing diseases from uncomplicated tonsillitis to life-threatening invasive infections. GAS secretes EndoS, an endoglycosidase that specifically cleaves the conserved N-glycan on IgG antibodies. In vitro, removal of this glycan impairs IgG effector functions, but its relevance to GAS infection in vivo is unclear. Using targeted mass spectrometry, we characterized the effects of EndoS on host IgG glycosylation during the course of infections in humans. Substantial IgG glycan hydrolysis occurred at the site of infection and systemically in the severe cases. We demonstrated decreased resistance to phagocytic killing of GAS lacking EndoS in vitro and decreased virulence in a mouse model of invasive infection. This is the first described example of specific bacterial IgG glycan hydrolysis during infection and thereby verifies the hypothesis that EndoS modifies antibodies in vivo. This mechanisms of immune evasion could have implications for treatment of severe GAS infections and for future efforts at vaccine development.

Etiology, clinical presentation, laboratory diagnostics, pathogenesis of impetigo and treatment methods

2020 ◽  
pp. 64-70
Author(s):  
Anastasiya Laknitskaya
Keyword(s):  
Streptococcus Pyogenes ◽  
Skin Diseases ◽  
Group A Streptococcus ◽  
Antibiotic Sensitivity ◽  
Antioxidant Defense System ◽  
Laboratory Diagnostics ◽  
Treatment Methods ◽  
Group A ◽  
The Individual

Currently, one of the priority medical and social problems is the optimization of treatment methods for pyoderma associated with Streptococcus pyogenes — group A streptococcus (GAS). To date, the proportion of pyoderma, the etiological factor of which is Streptococcus pyogenes, is about 6 % of all skin diseases and is in the range from 17.9 to 43.9 % of all dermatoses. Role of the bacterial factor in the development of streptococcal pyoderma is obvious. Traditional treatment complex includes antibacterial drugs selected individually, taking into account the antibiotic sensitivity of pathognomonic bacteria, and it is not always effective. Currently implemented immunocorrection methods often do not take into account specific immunological features of the disease, the individual, and the fact that the skin performs the function of not only a mechanical barrier, but it is also an immunocompetent organ. Such an approach makes it necessary to conduct additional studies clarifying the role of factors of innate and adaptive immunity, intercellular mediators and antioxidant defense system, that allow to optimize the treatment of this pathology.

scholarly journals Molecular Epidemiology of Group A Streptococcus Infections in The Gambia

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 124
Author(s):  
Sona Jabang ◽  
Annette Erhart ◽  
Saffiatou Darboe ◽  
Aru-Kumba Baldeh ◽  
Valerie Delforge ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Vaccine Development ◽  
Group A Streptococcus ◽  
Epidemiological Data ◽  
The Gambia ◽  
Strain Diversity ◽  
Group A ◽  
Considerable Strain

Molecular epidemiological data on Group A Streptococcus (GAS) infection in Africa is scarce. We characterized the emm-types and emm-clusters of 433 stored clinical GAS isolates from The Gambia collected between 2004 and 2018. To reduce the potential for strain mistyping, we used a newly published primer for emm-typing. There was considerable strain diversity, highlighting the need for vaccine development offering broad strain protection.

scholarly journals Association between Resistance to Erythromycin and the Presence of the Fibronectin Binding Protein F1 Gene, prtF1, in Streptococcus pyogenes Isolates from German Pediatric Patients

2005 ◽  
Vol 49 (7) ◽  
pp. 2990-2993 ◽  
Author(s):  
Maria Haller ◽  
Kirsten Fluegge ◽  
Sandra Jasminder Arri ◽  
Brit Adams ◽  
Reinhard Berner
Keyword(s):  
Streptococcus Pyogenes ◽  
Pediatric Patients ◽  
Group A Streptococcus ◽  
Binding Protein ◽  
Macrolide Resistance ◽  
Group A ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding ◽  
Cell Invasiveness

ABSTRACT A total of 301 German pediatric group A streptococcus isolates were screened for the presence of macrolide resistance and the fibronectin binding protein F1 gene (prtF1) encoding an adhesin and cell invasiveness protein. The prtF1 gene was present significantly more often among macrolide-resistant isolates. The majority of these were not clonally related.

scholarly journals Biochemical and biological activity of arginine deiminase from Streptococcus pyogenes M22

2016 ◽  
Vol 94 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Eleonora A. Starikova ◽  
Alexey V. Sokolov ◽  
Anna Yu. Vlasenko ◽  
Larisa A. Burova ◽  
Irina S. Freidlin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Bacterial Pathogen ◽  
Arginine Deiminase ◽  
Dependent Manner ◽  
Group A ◽  
Micro Organisms ◽  
Dose Dependent

Streptococcus pyogenes (group A Streptococcus; GAS) is an important gram-positive extracellular bacterial pathogen responsible for a number of suppurative infections. This micro-organism has developed complex virulence mechanisms to avoid the host’s defenses. We have previously reported that SDSC from GAS type M22 causes endothelial-cell dysfunction, and inhibits cell adhesion, migration, metabolism, and proliferation in a dose-dependent manner, without affecting cell viability. This work aimed to isolate and characterize a component from GAS type M22 supernatant that suppresses the proliferation of endothelial cells (EA.hy926). In the process of isolating a protein possessing antiproliferative activity we identified arginine deiminase (AD). Further study showed that this enzyme is most active at pH 6.8. Calculating Km and Vmax gave the values of 0.67 mmol·L–1 and 42 s−1, respectively. A distinctive feature of AD purified from GAS type M22 is that its optimum activity and the maximal rate of the catalytic process is close to neutral pH by comparison with enzymes from other micro-organisms. AD from GAS type M22 suppressed the proliferative activity of endothelial cells in a dose-dependent mode. At the same time, in the presence of AD, the proportion of cells in G0/G1 phase increased. When l-Arg was added at increasing concentrations to the culture medium containing AD (3 μg·mL–1), the enzyme’s capacity to inhibit cell proliferation became partially depressed. The proportion of cells in phases S/G2 increased concomitantly, although the cells did not fully recover their proliferation activity. This suggests that AD from GAS type M22 has potential for the suppression of excessive cell proliferation.

scholarly journals Host Pathways of Hemostasis that Regulate Group A Streptococcus pyogenes Pathogenicity

2020 ◽  
Vol 21 (2) ◽  
pp. 193-201
Author(s):  
Victoria A. Ploplis ◽  
Francis J. Castellino
Keyword(s):  
Streptococcus Pyogenes ◽  
Inflammatory Responses ◽  
Group A Streptococcus ◽  
Protein A ◽  
M Protein ◽  
Severe Group ◽  
Group A ◽  
Flow Through ◽  
Hallmark Feature ◽  
Major Target

A hallmark feature of severe Group A Streptococcus pyogenes (GAS) infection is dysregulated hemostasis. Hemostasis is the primary pathway for regulating blood flow through events that contribute towards clot formation and its dissolution. However, a number of studies have identified components of hemostasis in regulating survival and dissemination of GAS. Several proteins have been identified on the surface of GAS and they serve to either facilitate invasion to host distal sites or regulate inflammatory responses to the pathogen. GAS M-protein, a surface-exposed virulence factor, appears to be a major target for interactions with host hemostasis proteins. These interactions mediate biochemical events both on the surface of GAS and in the solution when M-protein is released into the surrounding environment through shedding or regulated proteolytic processes that dictate the fate of this pathogen. A thorough understanding of the mechanisms associated with these interactions could lead to novel approaches for altering the course of GAS pathogenicity.

scholarly journals Distribution of emm type and antibiotic susceptibility of group A streptococci causing invasive and noninvasive disease

2008 ◽  
Vol 57 (11) ◽  
pp. 1383-1388 ◽  
Author(s):  
Takeaki Wajima ◽  
Somay Y. Murayama ◽  
Katsuhiko Sunaoshi ◽  
Eiichi Nakayama ◽  
Keisuke Sunakawa ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Macrolide Antibiotic ◽  
Group A Streptococcus ◽  
Acute Otitis Media ◽  
Toxic Shock ◽  
Medical Institutions ◽  
Invasive Infections ◽  
Group A ◽  
Resistant Strains ◽  
Emm Type

To determine the prevalence of macrolide antibiotic and levofloxacin resistance in infections with Streptococcus pyogenes (group A streptococcus or GAS), strains were collected from 45 medical institutions in various parts of Japan between October 2003 and September 2006. Four hundred and eighty-two strains from patients with GAS infections were characterized genetically. Strains were classified into four groups according to the type of infection: invasive infections (n=74) including sepsis, cellulitis and toxic-shock-like syndrome; acute otitis media (AOM; n=23); abscess (n=53); and pharyngotonsillitis (n=332). Among all strains, 32 emm types were identified; emm1 was significantly more common in invasive infections (39.2 %) and AOM (43.5 %) than in abscesses (3.8 %) or pharyngotonsillitis (10.2 %). emm12 and emm4 each accounted for 23.5 % of pharyngotonsillitis cases. Susceptibility of GAS strains to eight β-lactam agents was excellent, with MICs of 0.0005–0.063 μg ml−1. Macrolide-resistant strains accounted for 16.2 % of all strains, while the percentages of strains possessing the resistance genes erm(A), erm(B) and mef(A) were 2.5 %, 6.2 % and 7.5 %, respectively. Although no strains with high resistance to levofloxacin were found, strains with an MIC of 2–4 μg ml−1 (17.4 %) had amino acid substitutions at either Ser-79 or Asp-83 in ParC. These levofloxacin-intermediately resistant strains included 16 emm types, but macrolide-resistant strains were more likely than others to represent certain emm types.

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