scholarly journals Signaling Peptide SpoV Is Essential for Streptococcus pyogenes Virulence, and Prophylaxis with Anti-SpoV Decreases Disease Severity

2021 ◽  
Vol 9 (11) ◽  
pp. 2321
Author(s):  
Andrea L. Herrera ◽  
Michael S. Chaussee
Keyword(s):  
Streptococcus Pyogenes ◽  
Therapeutic Potential ◽  
Group A Streptococcus ◽  
Ex Vivo ◽  
Invasive Disease ◽  
Human Model ◽  
Streptolysin S ◽  
Streptolysin O ◽  
Group A ◽  
Specific Peptide

Streptococcal peptide of virulence (SpoV) is a Streptococcus pyogenes (group A streptococcus (GAS))-specific peptide that is important for GAS survival in murine blood, and the expression of the virulence factors streptolysin O (slo) and streptolysin S (sagA). We used a spoV mutant in isolate MGAS315 to assess the contribution of the SpoV peptide to virulence by using a murine model of invasive disease and an ex vivo human model (Lancefield assay). We then used antibodies to SpoV in both models to evaluate their ability to decrease morbidity and mortality. Results showed that SpoV is essential for GAS virulence, and targeting the peptide has therapeutic potential.

scholarly journals Hemolytic mutants of group A Streptococcus pyogenes

1978 ◽  
Vol 7 (2) ◽  
pp. 153-157
Author(s):  
W Owens ◽  
F Henley ◽  
B D Barridge
Keyword(s):  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Nicotinamide Adenine ◽  
Streptolysin S ◽  
Naturally Occurring ◽  
Streptolysin O ◽  
Group A ◽  
The Dead

Hemolytic mutants of Lancefield strain SS-95 and ATCC 19615 Streptococcus pyogenes were produced by treatment with N-methyl-N'-nitro-N-nitrosoguanidine. These mutants contained the same levels of streptolysin O, nicotinamide adenine dinucleotidase, deoxyribonuclease, and hyaluronidase. The mutants were deficient in streptolysin S, as was the naturally occurring nonhemolytic Lowry strain. The mutants retained their pathogenicity for mice and, when reisolated from the dead animals, produced the mutant hemolytic pattern.

scholarly journals A Response Regulator That Represses Transcription of Several Virulence Operons in the Group A Streptococcus

1999 ◽  
Vol 181 (12) ◽  
pp. 3649-3657 ◽  
Author(s):  
Michael J. Federle ◽  
Kevin S. McIver ◽  
June R. Scott
Keyword(s):  
Group A Streptococcus ◽  
Response Regulator ◽  
Regulatory System ◽  
Insertion Mutant ◽  
Multiple Gene ◽  
Streptolysin S ◽  
Streptolysin O ◽  
Group A ◽  
Complement C5a ◽  
Global Regulatory System

ABSTRACT A search for homologs of the Bacillus subtilis PhoP response regulator in the group A streptococcus (GAS) genome revealed three good candidates. Inactivation of one of these, recently identified as csrR (J. C. Levin and M. R. Wessels, Mol. Microbiol. 30:209–219, 1998), caused the strain to produce mucoid colonies and to increase transcription ofhasA, the first gene in the operon for capsule synthesis. We report here that a nonpolar insertion in this gene also increased transcription of ska (encoding streptokinase),sagA (streptolysin S), and speMF (mitogenic factor) but did not affect transcription of slo(streptolysin O), mga (multiple gene regulator of GAS),emm (M protein), scpA (complement C5a peptidase), or speB or speC (pyrogenic exotoxins B and C). The amounts of streptokinase, streptolysin S, and capsule paralleled the levels of transcription of their genes in all cases. Because CsrR represses genes unrelated to those for capsule synthesis, and because CsrA-CsrB is a global regulatory system inEscherichia coli whose mechanism is unrelated to that of these genes in GAS, the locus has been renamed covR, for “control of virulence genes” in GAS. Transcription of thecovR operon was also increased in the nonpolar insertion mutant, indicating that CovR represses its own synthesis as well. All phenotypes of the covR nonpolar insertion mutant were complemented by the covR gene on a plasmid. CovR acts on operons expressed both in exponential and in stationary phase, demonstrating that the CovR-CovS pathway is separate from growth phase-dependent regulation in GAS. Therefore, CovR is the first multiple-gene repressor of virulence factors described for this important human pathogen.

scholarly journals Streptococcus pyogenes prtFII, but not sfbI, sfbII or fbp54, is represented more frequently among invasive-disease isolates of tropical Australia

2002 ◽  
Vol 128 (3) ◽  
pp. 391-396 ◽  
Author(s):  
A. DELVECCHIO ◽  
B. J. CURRIE ◽  
J. D. McARTHUR ◽  
M. J. WALKER ◽  
K. S. SRIPRAKASH
Keyword(s):  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Invasive Disease ◽  
Host Cells ◽  
Non Invasive ◽  
Invasive Diseases ◽  
Genetic Endowment ◽  
Group A ◽  
Tropical Australia

Streptococcus pyogenes (group A streptococcus) strains may express several distinct fibronectin-binding proteins (FBPs) which are considered as major streptococcal adhesins. Of the FBPs, SfbI was shown in vitro to promote internalization of the bacterium into host cells and has been implicated in persistence. In the tropical Northern Territory, where group A streptococcal infection is common, multiple genotypes of the organism were found among isolates from invasive disease cases and no dominant strains were observed. To determine whether any FBPs is associated with invasive disease propensity of S. pyogenes, we have screened streptococcal isolates from bacteraemic and necrotizing fasciitis patients and isolates from uncomplicated infections for genetic endowment of 4 FBPs. No difference was observed in the distribution of sfbII, fbp54 and sfbI between the blood isolates and isolates from uncomplicated infection. We conclude that the presence of sfbI does not appear to promote invasive diseases, despite its association with persistence. We also show a higher proportion of group A streptococcus strains isolated from invasive disease cases possess prtFII when compared to strains isolated from non-invasive disease cases. We suggest that S. pyogenes may recruit different FBPs for different purposes.

scholarly journals The Shock of Strep: Rapid Deaths Due to Group a Streptococcus

2018 ◽  
Vol 8 (1) ◽  
pp. 136-149 ◽  
Author(s):  
Katrina M. Thompson ◽  
Alana K. Sterkel ◽  
Joseph A. McBride ◽  
Robert F. Corliss
Keyword(s):  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Invasive Disease ◽  
Significant Morbidity ◽  
Invasive Group ◽  
Life Threatening ◽  
Group A ◽  
Severe Infections ◽  
Microscopic Findings ◽  
Positive Coccus

Streptococcus pyogenes, also known as group A beta-hemolytic strep, is a Gram positive coccus responsible for several million infections every year. The types of infections vary widely from pharyngitis to myositis, but all can advance to severe life threatening invasive disease. Of those infected, approximately 1100 to 1600 people die each year due to invasive disease. Why certain individuals contract severe infections is not known, but many strains of Streptococcus pyogenes are known to produce toxins and superantigens. Invasive Streptococcus pyogenes infections have been shown to cause significant morbidity and rapid mortality. In many cases, patients expire before full antemortem testing can be performed, causing physicians and families to look to forensic pathologists for answers. Understanding the pathogenesis of invasive group A strep infections, relevant gross and microscopic findings, and proper culturing techniques is critical for forensic pathologists to diagnosis this condition and assist in the education and protection of the communities they serve.

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.

Single-chain variable fragment (scFv) targeting streptolysin O controls group A Streptococcus infection

2021 ◽  
Vol 566 ◽  
pp. 177-183
Author(s):  
Chihiro Aikawa ◽  
Kiyosumi Kawashima ◽  
Chihiro Fukuzaki ◽  
Makoto Nakakido ◽  
Kazunori Murase ◽  
...  
Keyword(s):  
Group A Streptococcus ◽  
Single Chain Variable Fragment ◽  
Single Chain ◽  
Streptolysin O ◽  
Group A

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.

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