scholarly journals Streptococcus invasive locus (sil) in Group A Streptococcus causing non-invasive infections in Chennai, South India

2012 ◽  
Vol 12 (S1) ◽  
Author(s):  
B Divya Bajoria ◽  
Thangam Menon
Keyword(s):  
South India ◽  
Group A Streptococcus ◽  
Non Invasive ◽  
Invasive Infections ◽  
Group A

scholarly journals Superantigen gene profile, emm type and antibiotic resistance genes among group A streptococcal isolates from Barcelona, Spain

2006 ◽  
Vol 55 (8) ◽  
pp. 1115-1123 ◽  
Author(s):  
Alba Rivera ◽  
Montserrat Rebollo ◽  
Elisenda Miró ◽  
Míriam Mateo ◽  
Ferran Navarro ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Group A Streptococcus ◽  
Genetic Resistance ◽  
Antibiotic Resistance Genes ◽  
Clinical Information ◽  
Gene Profile ◽  
Non Invasive ◽  
Invasive Infections ◽  
Group A

Group A streptococcus (GAS) has been described as an emerging cause of severe invasive infections. A retrospective hospital-based study was conducted, including GAS isolates causing invasive or non-invasive infections from January 1999 to June 2003 in Barcelona. Demographic and clinical information on the invasive cases was obtained from medical files. GAS isolates collected from 27 patients with invasive infections and 99 patients with non-invasive infections were characterized by emm type and subtype, superantigen (SAg) gene profile (speA–C, speF–J, speL, speM, ssa and smeZ), allelic variants of speA and smeZ genes, antibiotic susceptibility and genetic resistance determinants. The most prevalent emm type was emm1 (17.5 %), followed by emm3 (8.7 %), emm4 (8.7 %), emm12 (7.1 %) and emm28 (7.1 %). The smeZ allele and SAg gene profiles were closely associated with the emm type. The speA2, speA3 and speA4 alleles were found in emm1, emm3 and emm6 isolates, respectively. Overall, 27.8, 25.4 and 11.9 % of isolates were resistant to erythromycin, tetracycline or both agents, respectively. Reduced susceptibility to ciprofloxacin and levofloxacin (MIC 2–4 μg ml−1) was found in 3.2 % of isolates. mef(A)-positive emm types 4, 12 and 75, and erm(B)-positive emm types 11 and 25 were responsible for up to 80 % of the erythromycin-resistant isolates. No significant differences in emm-type distribution, SAg gene profile or resistance rates were found between invasive and non-invasive isolates. The SAg and antibiotic resistance genes appeared to be associated with the emm type and were independent of the disease type.

Diverse disease processes of group A Streptococcus infection including severe invasive infections among members of a family

2021 ◽  
Vol 14 (4) ◽  
pp. e241339
Author(s):  
Kaori Amari ◽  
Masaki Tago ◽  
Naoko E Katsuki ◽  
Shu-ichi Yamashita
Keyword(s):  
Septic Shock ◽  
Distress Syndrome ◽  
Clinical Course ◽  
Group A Streptococcus ◽  
Bloody Stool ◽  
Laryngeal Oedema ◽  
Invasive Infections ◽  
Group A ◽  
The Right ◽  
Close Contacts

We herein report three cases of group A Streptococcus (GAS) infection in a family. Patient 1, a 50-year-old woman, was transferred to our hospital in shock with acute respiratory distress syndrome, swelling in the right neck and erythemata on both lower extremities. She required intubation because of laryngeal oedema. At the same time, patient 2, a 48-year-old man, was admitted because of septic shock, pneumonia and a pulmonary abscess. Five days later, patient 3, a 91-year-old woman, visited our clinic with bloody stool. All three patients were cured by antibiotics, and GAS was detected by specimen cultures. During these patients’ clinical course, an 84-year-old woman was found dead at home after having been diagnosed with type A influenza. All four patients lived in the same apartment. The GAS genotypes detected in the first three patients were identical. When treating patients with GAS, appropriate management of close contacts is mandatory.

scholarly journals Characterization ofsilin Invasive Group A and G Streptococci: Antibodies against Bacterial Pheromone Peptide SilCR Result in Severe Infection

2013 ◽  
Vol 81 (11) ◽  
pp. 4121-4127 ◽  
Author(s):  
Ayelet Michael-Gayego ◽  
Mary Dan-Goor ◽  
Joseph Jaffe ◽  
Carlos Hidalgo-Grass ◽  
Allon E. Moses
Keyword(s):  
Murine Model ◽  
Group A Streptococcus ◽  
Severe Infection ◽  
Gene Arrangement ◽  
Severe Illness ◽  
Virulence Attenuation ◽  
Bacterial Quorum Sensing ◽  
Invasive Infections ◽  
Group A ◽  
Bacterial Quorum

ABSTRACTGroup G beta-hemolytic streptococcus (GGS) strains cause severe invasive infections, mostly in patients with comorbidities. GGS is known to possess virulence factors similar to those of its more virulent counterpart group A streptococcus (GAS). A streptococcal invasion locus,sil, was identified in GAS.silencodes a competence-stimulating peptide named SilCR that activates bacterial quorum sensing and has the ability to attenuate virulence in GAS infections. We found thatsilis present in most GGS strains (82%) but in only 25% of GAS strains, with a similar gene arrangement. GGS strains that containedsilexpressed the SilCR peptide and secreted it into the growth medium. In a modified murine model of GGS soft tissue infection, GGS grown in the presence of SilCR caused a milder disease than GGS grown in the absence of SilCR. To further study the role of the peptide in bacterial virulence attenuation, we vaccinated mice with SilCR to produce specific anti-SilCR antibodies. Vaccinated mice developed a significantly more severe illness than nonvaccinated mice. Our results indicate that thesillocus is much more prevalent among the less virulent GGS strains than among GAS strains. GGS strains express and secrete SilCR, which has a role in attenuation of virulence in a murine model. We show that the SilCR peptide can protect mice from infection caused by GGS. Furthermore, vaccinated mice that produce specific anti-SilCR antibodies develop a significantly more severe infection. To our knowledge, this is a novel report demonstrating that specific antibodies against a bacterial component cause more severe infection by those bacteria.

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.

scholarly journals Human Disease Isolates of Serotype M4 and M22 Group A Streptococcus Lack Genes Required for Hyaluronic Acid Capsule Biosynthesis

mBio ◽  
2012 ◽  
Vol 3 (6) ◽  
Author(s):  
Anthony R. Flores ◽  
Brittany E. Jewell ◽  
Nahuel Fittipaldi ◽  
Stephen B. Beres ◽  
James M. Musser
Keyword(s):  
Hyaluronic Acid ◽  
Virulence Factor ◽  
Group A Streptococcus ◽  
Ex Vivo ◽  
Upper Respiratory Tract ◽  
Major Virulence Factor ◽  
Invasive Infections ◽  
Group A ◽  
Human Infections ◽  
Hyaluronic Acid Capsule

ABSTRACTGroup A streptococcus (GAS) causes human pharyngitis and invasive infections and frequently colonizes individuals asymptomatically. Many lines of evidence generated over decades have shown that the hyaluronic acid capsule is a major virulence factor contributing to these infections. While conducting a whole-genome analysis of thein vivomolecular genetic changes that occur in GAS during longitudinal human pharyngeal interaction, we discovered that serotypes M4 and M22 GAS strains lack thehasABCgenes necessary for hyaluronic acid capsule biosynthesis. Using targeted PCR, we found that all 491 temporally and geographically diverse disease isolates of these two serotypes studied lack thehasABCgenes. Consistent with the lack of capsule synthesis genes, none of the strains produced detectable hyaluronic acid. Despite the lack of a hyaluronic acid capsule, all strains tested multiplied extensivelyex vivoin human blood. Thus, counter to the prevailing concept in GAS pathogenesis research, strains of these two serotypes do not require hyaluronic acid to colonize the upper respiratory tract or cause abundant mucosal or invasive human infections. We speculate that serotype M4 and M22 GAS have alternative, compensatory mechanisms that promote virulence.IMPORTANCEA century of study of the antiphagocytic hyaluronic acid capsule made by group A streptococcus has led to the concept that it is a major virulence factor contributing to human pharyngeal and invasive infections. However, the discovery that some strains that cause abundant human infections lack hyaluronic acid biosynthetic genes and fail to produce this capsule provides a new stimulus for research designed to understand the group A streptococcus factors contributing to pharyngeal infection and invasive disease episodes.

scholarly journals Canada-Wide Epidemic of emm74 Group A Streptococcus Invasive Disease

2018 ◽  
Vol 5 (5) ◽  
Author(s):  
Sarah Teatero ◽  
Allison McGeer ◽  
Gregory J Tyrrell ◽  
Linda Hoang ◽  
Hanan Smadi ◽  
...  
Keyword(s):  
Group A Streptococcus ◽  
Invasive Disease ◽  
Drug Usage ◽  
Rare Type ◽  
Invasive Group ◽  
Intravenous Drug Usage ◽  
Clinical Data Analysis ◽  
Invasive Infections ◽  
Group A ◽  
Canadian Provinces

Abstract Background The number of invasive group A Streptococcus (iGAS) infections due to hitherto extremely rare type emm74 strains has increased in several Canadian provinces since late 2015. We hypothesized that the cases recorded in the different provinces are linked and caused by strains of an emm74 clone that recently emerged and expanded explosively. Methods We analyzed both active and passive surveillance data for iGAS infections and used whole-genome sequencing to investigate the phylogenetic relationships of the emm74 strains responsible for these invasive infections country-wide. Results Genome analysis showed that highly clonal emm74 strains, genetically different from emm74 organisms previously circulating in Canada, were responsible for a country-wide epidemic of >160 invasive disease cases. The emerging clone belonged to multilocus sequence typing ST120. The analysis also revealed dissemination patterns of emm74 subclonal lineages across Canadian provinces. Clinical data analysis indicated that the emm74 epidemic disproportionally affected middle-aged or older male individuals. Homelessness, alcohol abuse, and intravenous drug usage were significantly associated with invasive emm74 infections. Conclusions In a period of 20 months, an emm74 GAS clone emerged and rapidly spread across several Canadian provinces located more than 4500 km apart, causing invasive infections primarily among disadvantaged persons.

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