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.

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.

scholarly journals Functional analysis of a group A streptococcal glycoside hydrolase Spy1600 from family 84 reveals it is a β-N-acetylglucosaminidase and not a hyaluronidase

2006 ◽  
Vol 399 (2) ◽  
pp. 241-247 ◽  
Author(s):  
William L. Sheldon ◽  
Matthew S. Macauley ◽  
Edward J. Taylor ◽  
Charlotte E. Robinson ◽  
Simon J. Charnock ◽  
...  
Keyword(s):  
Glycoside Hydrolase ◽  
Catalytic Mechanism ◽  
Group A Streptococcus ◽  
Competitive Inhibitor ◽  
Glycoside Hydrolases ◽  
Glycoside Hydrolase Family ◽  
Toxic Shock ◽  
Nmr Studies ◽  
Invasive Infections ◽  
Group A

Group A streptococcus (Streptococcus pyogenes) is the causative agent of severe invasive infections such as necrotizing fasciitis (the so-called ‘flesh eating disease’) and toxic-shock syndrome. Spy1600, a glycoside hydrolase from family 84 of the large superfamily of glycoside hydrolases, has been proposed to be a virulence factor. In the present study we show that Spy1600 has no activity toward galactosaminides or hyaluronan, but does remove β-O-linked N-acetylglucosamine from mammalian glycoproteins – an observation consistent with the inclusion of eukaryotic O-glycoprotein 2-acetamido-2-deoxy-β-D-glucopyranosidases within glycoside hydrolase family 84. Proton NMR studies, structure–reactivity studies for a series of fluorinated analogues and analysis of 1,2-dideoxy-2′-methyl-α-D-glucopyranoso-[2,1-d]-Δ2′-thiazoline as a competitive inhibitor reveals that Spy1600 uses a double-displacement mechanism involving substrate-assisted catalysis. Family 84 glycoside hydrolases are therefore comprised of both prokaryotic and eukaryotic β-N-acetylglucosaminidases using a conserved catalytic mechanism involving substrate-assisted catalysis. Since these enzymes do not have detectable hyaluronidase activity, many family 84 glycoside hydrolases are most likely incorrectly annotated as hyaluronidases.

Synthesis of Multicomponent Peptide-Based Vaccine Candidates against Group A Streptococcus

2017 ◽  
Vol 70 (2) ◽  
pp. 184
Author(s):  
Waleed M. Hussein ◽  
Jiaxin Xu ◽  
Pavla Simerska ◽  
Istvan Toth
Keyword(s):  
Vaccine Candidate ◽  
Group A Streptococcus ◽  
Cycloaddition Reaction ◽  
Bacterial Pathogen ◽  
T Helper ◽  
Toxic Shock ◽  
Helper Epitope ◽  
Invasive Infections ◽  
Group A ◽  
Universal Expression

Group A streptococcus (GAS; Streptococcus pyogenes), known as the ‘flesh-eating bacterium’, is a human bacterial pathogen that normally causes benign infections (e.g. sore throat and pyoderma), but is also responsible for severe invasive infections (e.g. ‘flesh-eating’ disease and toxic shock syndrome), heart disease, and kidney failure. A safe commercial GAS vaccine is yet to be developed. Individual GAS antigens demonstrate potential universal expression across all GAS serotypes (>200 known), with dramatically reduced concern for autoimmune complications, and compelling efficacy in preclinical testing in mice. In this study, we developed a stepwise conjugation strategy, copper-catalysed alkyne–azide cycloaddition reaction (CuAAC), followed by mercapto–maleimide conjugation, to synthesise a multiantigenic, self-adjuvanting, peptide-based vaccine candidate against GAS. This multiantigenic vaccine includes two GAS antigens, J8 and NS1, a T-helper epitope, PADRE, and a self-adjuvanting moiety, dipalmitoyl serine.

Dunkelreaktivierung von UV-Schäden und Nitrosoguanidinresistenz bei Streptococcus pyogenes

1967 ◽  
Vol 22 (11) ◽  
pp. 1139-1143 ◽  
Author(s):  
Horst Malke
Keyword(s):  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Resistance Mutation ◽  
Single Step ◽  
Group A ◽  
Resistant Strains ◽  
Free Media ◽  
Host Cell Reactivation ◽  
Higher Doses ◽  
Extra Resistance

The resistance to N-methyl-N'-nitro-N-nitrosoguanidine (NG) of five single-step mutants of a lysogenic group A Streptococcus after several cycles of growth in NG-free media was within the range of 1.5 to 3.7 times that of the parent. After ultraviolet irradiation (UV) these mutants had a higher chance to survive than the wild type, giving dose reduction factors of 1.4 to 2.4.In prophage induction experiments using UV and NG as inducing agents, the dose induction functions of the NG-resistant strains were either shifted toward higher doses or the efficiency of induction was decreased. In the strains examined caffeine and acriflavine (which are already known to block host cell reactivation) greatly enhanced both the killing and the inducing effect of UV, indicating the ability of Streptococcus pyogenes to perform dark repair of UV damaged DNA. The extra resistance to UV conferred on the strains carrying the NG-resistance mutation was not decreased by UV enhancers, moreover, their action on dark reactivation seemed to be less efficient in these strains.

scholarly journals Streptococcus pyogenes emm Types and Clusters during a 7-Year Period (2007 to 2013) in Pharyngeal and Nonpharyngeal Pediatric Isolates

2015 ◽  
Vol 53 (7) ◽  
pp. 2015-2021 ◽  
Author(s):  
F. Koutouzi ◽  
A. Tsakris ◽  
P. Chatzichristou ◽  
E. Koutouzis ◽  
G. L. Daikos ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Temporal Changes ◽  
Morbidity And Mortality ◽  
M Protein ◽  
Preclinical Studies ◽  
Seasonal Fluctuations ◽  
Baseline Information ◽  
Group A ◽  
Resistant Strains

Group A streptococcus (GAS) is an important cause of morbidity and mortality worldwide. Surveillance ofemmtypes has important implications, as it can provide baseline information for possible implementation of vaccination. A total of 1,349 GAS pediatric isolates were collected during a 7-year period (2007 to 2013);emmtyping was completed for 1,282 pharyngeal (84%) or nonpharyngeal (16%) isolates, andemmclusters and temporal changes were analyzed. Thirty-five differentemmtypes, including 14 subtypes, were identified. The most prevalentemmtypes identified were 1 (16.7%), 12 (13.6%), 77 (10.9%), 4 (10.8%), 28 (10.4%), 6 (6.8%), 3 (6.6%), and 89 (6.6%), accounting for 82.3% of total isolates. Rheumatogenicemmtypes comprised 16.3% of total isolates. Theemmtypes 12, 4, and 77 were more prevalent among pharyngeal isolates, and theemmtypes 1, 89, 6, 75, and 11 were more prevalent among nonpharyngeal isolates. Theemmtypes identified belonged to 13emmclusters, and the 8 most prevalent clusters comprised 97% of all isolates. There were statistically significant decreases in the prevalence ofemmtypes 12, 4, 5, and 61 and increases in the prevalence ofemmtypes 89, 75, and 11, compared with the period 2001 to 2006. The proposed 30-valent GAS vaccine, which is currently in preclinical studies, encompasses 97.2% of theemmtypes detected in our study and 97.4% of the erythromycin-resistant strains. In addition, it includes 93.3% of theemmtypes involved in bacteremia. A much greater diversity of GASemmtypes was identified in our area than described previously. Seasonal fluctuations and the introduction of newemmtypes were observed. Continuous surveillance ofemmtypes is needed in order to evaluate the possible benefits of an M protein-based GAS vaccine.

Development of a DNA aptamer that binds specifically to group A Streptococcus serotype M3

2017 ◽  
Vol 63 (2) ◽  
pp. 160-168 ◽  
Author(s):  
Hanif Alfavian ◽  
Seyed Latif Mousavi Gargari ◽  
Samaneh Rasoulinejad ◽  
Arvin Medhat
Keyword(s):  
Group A Streptococcus ◽  
Dna Aptamer ◽  
Live Cells ◽  
Streptococcal Toxic Shock Syndrome ◽  
Toxic Shock ◽  
Apparent Dissociation Constant ◽  
Invasive Infections ◽  
Group A ◽  
High Degree ◽  
High Binding Affinity

Group A streptococcus (GAS) is an important Gram-positive pathogen that causes various human diseases ranging from peripheral lesions to invasive infections. The M protein is one of the main virulence factors present on the cell surface and is associated with invasive GAS infections. Compared with other M types, serotype M3 has a predominant role in lethal infections and demonstrates epidemic behaviors, including streptococcal toxic shock syndrome, bacteremia, and necrotizing fasciitis. Traditional methods for M typing are time-consuming, tedious, contradictory, and generally restricted to reference laboratories. Therefore, development of a new M-typing technique is needed. Aptamers with the ability to detect their target with a high degree of accuracy and specificity can be ideal candidates for specific M-typing of Streptococcus pyogenes. In this study DNA aptamers with a high binding affinity towards S. pyogenes serotype M3 were selected through 12 iterative rounds of the Systematic Evolution of Ligands by EXponential (SELEX) enrichment procedure using live cells as a target. We monitored the progress of the SELEX procedure by flow cytometry analysis. Of several aptamer sequences analyzed, 12L18A showed the highest binding efficiency towards S. pyogenes type M3, with an apparent dissociation constant (Kd) of 7.47 ± 1.72 pmol/L being the lowest. Therefore the isolated aptamer can be used in any tool, such as a biosensor, for the detection of S. pyogenes and can be used in the development of a novel M-typing system.

scholarly journals Playing With Fire: Proinflammatory Virulence Mechanisms of Group A Streptococcus

2021 ◽  
Vol 11 ◽  
Author(s):  
Shyra Wilde ◽  
Anders F. Johnson ◽  
Christopher N. LaRock
Keyword(s):  
Virulence Factors ◽  
Group A Streptococcus ◽  
Severe Disease ◽  
Fatal Outcome ◽  
Toxic Shock ◽  
Autoreactive Antibodies ◽  
Invasive Infections ◽  
Group A ◽  
Disease Understanding

Group A Streptococcus is an obligate human pathogen that is a major cause of infectious morbidity and mortality. It has a natural tropism for the oropharynx and skin, where it causes infections with excessive inflammation due to its expression of proinflammatory toxins and other virulence factors. Inflammation directly contributes to the severity of invasive infections, toxic shock syndrome, and the induction of severe post-infection autoimmune disease caused by autoreactive antibodies. This review discusses what is known about how the virulence factors of Group A Streptococcus induce inflammation and how this inflammation can promote disease. Understanding of streptococcal pathogenesis and the role of hyper-immune activation during infection may provide new therapeutic targets to treat the often-fatal outcome of severe disease.

scholarly journals Antibiotic Treatment, Mechanisms for Failure, and Adjunctive Therapies for Infections by Group A Streptococcus

2021 ◽  
Vol 12 ◽  
Author(s):  
Anders F. Johnson ◽  
Christopher N. LaRock
Keyword(s):  
Streptococcus Pyogenes ◽  
Disease Burden ◽  
Group A Streptococcus ◽  
Human Pathogen ◽  
Invasive Infections ◽  
Group A ◽  
Severe Infections ◽  
Treatment Mechanisms ◽  
Antibiotic Failure ◽  
Global Disease Burden

Group A Streptococcus (GAS; Streptococcus pyogenes) is a nearly ubiquitous human pathogen responsible for a significant global disease burden. No vaccine exists, so antibiotics are essential for effective treatment. Despite a lower incidence of antimicrobial resistance than many pathogens, GAS is still a top 10 cause of death due to infections worldwide. The morbidity and mortality are primarily a consequence of the immune sequelae and invasive infections that are difficult to treat with antibiotics. GAS has remained susceptible to penicillin and other β-lactams, despite their widespread use for 80 years. However, the failure of treatment for invasive infections with penicillin has been consistently reported since the introduction of antibiotics, and strains with reduced susceptibility to β-lactams have emerged. Furthermore, isolates responsible for outbreaks of severe infections are increasingly resistant to other antibiotics of choice, such as clindamycin and macrolides. This review focuses on the challenges in the treatment of GAS infection, the mechanisms that contribute to antibiotic failure, and adjunctive therapeutics. Further understanding of these processes will be necessary for improving the treatment of high-risk GAS infections and surveillance for non-susceptible or resistant isolates. These insights will also help guide treatments against other leading pathogens for which conventional antibiotic strategies are increasingly failing.

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.

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