scholarly journals The Histone-Like Protein Hlp Is Essential for Growth of Streptococcus pyogenes: Comparison of Genetic Approaches To Study Essential Genes

2011 ◽  
Vol 77 (13) ◽  
pp. 4422-4428 ◽  
Author(s):  
Julia V. Bugrysheva ◽  
Barbara J. Froehlich ◽  
Jeffrey A. Freiberg ◽  
June R. Scott
Keyword(s):  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Constitutive Expression ◽  
Essential Genes ◽  
Differential Growth ◽  
Content Type ◽  
Group A ◽  
Approaches To Study ◽  
Control Translation ◽  
High Level

ABSTRACTSelection of possible targets for vaccine and drug development requires an understanding of the physiology of bacterial pathogens, for which the ability to manipulate expression of essential genes is critical. ForStreptococcus pyogenes(the group A streptococcus [GAS]), an important human pathogen, the lack of genetic tools for such studies has seriously hampered research. To address this problem, we characterized variants of the inducible Ptetcassette, in both sense and antisense contexts, as tools to regulate transcription from GAS genes. We found that although the three-operator Ptetconstruct [Ptet(O)3] had low uninduced expression, its induction level was low, while the two-operator construct [Ptet(O)2] was inducible to a high level but showed significant constitutive expression. Use of Ptet(O)3in the chromosome allowed us to demonstrate previously that RNases J1 and J2 are required for growth of GAS. Here we report that the uninduced level from the chromosomally inserted Ptet(O)2construct was too high for us to observe differential growth. For the highly expressed histone-like protein (Hlp) of GAS, neither chromosomal insertion of Ptet(O)2or Ptet(O)3nor their use on a high-copy-number plasmid to produce antisense RNA specific tohlpresulted in adequate differential expression. However, by replacing the ribosome binding site ofhlpwith an engineered riboswitch to control translation of Hlp, we demonstrated for the first time that this protein is essential for GAS growth.

scholarly journals Serine/Threonine Protein Kinase Stk Is Required for Virulence, Stress Response, and Penicillin Tolerance in Streptococcus pyogenes

2011 ◽  
Vol 79 (10) ◽  
pp. 4201-4209 ◽  
Author(s):  
Julia Bugrysheva ◽  
Barbara J. Froehlich ◽  
Jeffrey A. Freiberg ◽  
June R. Scott
Keyword(s):  
Streptococcus Pyogenes ◽  
Fatty Acid Biosynthesis ◽  
Group A Streptococcus ◽  
Acid Biosynthesis ◽  
Regulation Of Expression ◽  
Content Type ◽  
Reverse Transcription Pcr ◽  
Genes Encoding ◽  
Group A

ABSTRACTGenes encoding one or more Ser/Thr protein kinases have been identified recently in many bacteria, including one (stk) in the human pathogenStreptococcus pyogenes(group A streptococcus [GAS]). We report that in GAS,stkis required to produce disease in a murine myositis model of infection. Using microarray and quantitative reverse transcription-PCR (qRT-PCR) studies, we found that Stk activates genes for virulence factors, osmoregulation, metabolism of α-glucans, and fatty acid biosynthesis, as well as genes affecting cell wall synthesis. Confirming these transcription studies, we determined that thestkdeletion mutant is more sensitive to osmotic stress and to penicillin than the wild type. We discuss several possible Stk phosphorylation targets that might explain Stk regulation of expression of specific operons and the possible role of Stk in resuscitation from quiescence.

scholarly journals Complement-mediated Opsonization of Invasive Group A Streptococcus pyogenes Strain AP53 Is Regulated by the Bacterial Two-component Cluster of Virulence Responder/Sensor (CovRS) System

2013 ◽  
Vol 288 (38) ◽  
pp. 27494-27504 ◽  
Author(s):  
Garima Agrahari ◽  
Zhong Liang ◽  
Jeffrey A. Mayfield ◽  
Rashna D. Balsara ◽  
Victoria A. Ploplis ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Death Rate ◽  
Group A Streptococcus ◽  
Regulatory System ◽  
Factor H ◽  
Human Neutrophils ◽  
Two Component ◽  
Group A ◽  
Allelic Alteration ◽  
High Level

Group A Streptococcus pyogenes (GAS) strain AP53 is a primary isolate from a patient with necrotizing fasciitis. These AP53 cells contain an inactivating mutation in the sensor component of the cluster of virulence (cov) responder (R)/sensor (S) two-component gene regulatory system (covRS), which enhances the virulence of the primary strain, AP53/covR+S−. However, specific mechanisms by which the covRS system regulates the survival of GAS in humans are incomplete. Here, we show a key role for covRS in the regulation of opsonophagocytosis of AP53 by human neutrophils. AP53/covR+S− cells displayed potent binding of host complement inhibitors of C3 convertase, viz. Factor H (FH) and C4-binding protein (C4BP), which concomitantly led to minimal C3b deposition on AP53 cells, further showing that these plasma protein inhibitors are active on GAS cells. This resulted in weak killing of the bacteria by human neutrophils and a corresponding high death rate of mice after injection of these cells. After targeted allelic alteration of covS− to wild-type covS (covS+), a dramatic loss of FH and C4BP binding to the AP53/covR+S+ cells was observed. This resulted in elevated C3b deposition on AP53/covR+S+ cells, a high level of opsonophagocytosis by human neutrophils, and a very low death rate of mice infected with AP53/covR+S+. We show that covRS is a critical transcriptional regulator of genes directing AP53 killing by neutrophils and regulates the levels of the receptors for FH and C4BP, which we identify as the products of the fba and enn genes, respectively.

scholarly journals Polyclonal dissemination of tetracycline resistance among Streptococcus pyogenes paediatric isolates from Brazil

2010 ◽  
Vol 4 (11) ◽  
pp. 704-711 ◽  
Author(s):  
Pierre Robert Smeesters ◽  
Sabina Cadar ◽  
Pierre-Alexandre Drèze ◽  
Dioclécio Campos ◽  
Laurence Van Melderen
Keyword(s):  
Phylogenetic Analysis ◽  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Tetracycline Resistance ◽  
Prospective Epidemiological Study ◽  
Group A ◽  
Antibiotic Susceptibility Patterns ◽  
High Level ◽  
Susceptibility Patterns ◽  
Scarce Data

Introduction: Scarce data are available on Group A Streptococcus (GAS) antibiotic resistance in South America. Methodology: The antibiotic susceptibility patterns of GAS recovered from symptomatic children living in the central part of Brazil during a prospective epidemiological study were analyzed. Results: No isolates were resistant to penicillin or macrolides.  Sixty-one percent of the isolates were highly resistant to tetracycline, of which 85% harboured the tetM resistance gene. Ninety-five percent of these tetracycline resistant isolates were also resistant to minocycline. Thirty different emm-types were associated with tetracycline resistance. Phylogenetic analysis indicates that tetracycline resistance arose independently in distantly related emm-types. Conclusions: A high level of GAS tetracycline resistance has been observed in the central part of Brazil due to the polyclonal dissemination of resistant emm-types.

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 Natural Disruption of Two Regulatory Networks in Serotype M3 Group A Streptococcus Isolates Contributes to the Virulence Factor Profile of This Hypervirulent Serotype

2014 ◽  
Vol 82 (5) ◽  
pp. 1744-1754 ◽  
Author(s):  
Tram N. Cao ◽  
Zhuyun Liu ◽  
Tran H. Cao ◽  
Kathryn J. Pflughoeft ◽  
Jeanette Treviño ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Group A Streptococcus ◽  
Regulatory System ◽  
Mrna Levels ◽  
Bacterial Strains ◽  
Content Type ◽  
Small Regulatory Rna ◽  
Group A

ABSTRACTDespite the public health challenges associated with the emergence of new pathogenic bacterial strains and/or serotypes, there is a dearth of information regarding the molecular mechanisms that drive this variation. Here, we began to address the mechanisms behind serotype-specific variation between serotype M1 and M3 strains of the human pathogenStreptococcus pyogenes(the group AStreptococcus[GAS]). Spatially diverse contemporary clinical serotype M3 isolates were discovered to contain identical inactivating mutations within genes encoding two regulatory systems that control the expression of important virulence factors, including the thrombolytic agent streptokinase, the protease inhibitor-binding protein-G-related α2-macroglobulin-binding (GRAB) protein, and the antiphagocytic hyaluronic acid capsule. Subsequent analysis of a larger collection of isolates determined that M3 GAS, since at least the 1920s, has harbored a 4-bp deletion in thefasCgene of thefasBCAXregulatory system and an inactivating polymorphism in therivRregulator-encoding gene. ThefasCandrivRmutations in M3 isolates directly affect the virulence factor profile of M3 GAS, as evident by a reduction in streptokinase expression and an enhancement of GRAB expression. Complementation of thefasCmutation in M3 GAS significantly enhanced levels of the small regulatory RNA FasX, which in turn enhanced streptokinase expression. Complementation of therivRmutation in M3 GAS restored the regulation ofgrabmRNA abundance but did not alter capsule mRNA levels. While important, thefasCandrivRmutations do not provide a full explanation for why serotype M3 strains are associated with unusually severe invasive infections; thus, further investigation is warranted.

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 The Transcriptional Regulator CpsY Is Important for Innate Immune Evasion in Streptococcus pyogenes

2016 ◽  
Vol 85 (3) ◽  
Author(s):  
Luis A. Vega ◽  
Kayla M. Valdes ◽  
Ganesh S. Sundar ◽  
Ashton T. Belew ◽  
Emrul Islam ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Immune Evasion ◽  
Immune Cell ◽  
Group A Streptococcus ◽  
Transcriptional Regulator ◽  
Innate Immune ◽  
Content Type ◽  
Human Host

ABSTRACTAs an exclusively human pathogen,Streptococcus pyogenes(the group A streptococcus [GAS]) has specifically adapted to evade host innate immunity and survive in multiple tissue niches, including blood. GAS can overcome the metabolic constraints of the blood environment and expresses various immunomodulatory factors necessary for survival and immune cell resistance. Here we present our investigation of one such factor, the predicted LysR family transcriptional regulator CpsY. The encoding gene,cpsY, was initially identified as being required for GAS survival in a transposon-site hybridization (TraSH) screen in whole human blood. CpsY is homologous with transcriptional regulators ofStreptococcus mutans(MetR),Streptococcus iniae(CpsY), andStreptococcus agalactiae(MtaR) that regulate methionine transport, amino acid metabolism, resistance to neutrophil-mediated killing, and survivalin vivo. Our investigation indicated that CpsY is involved in GAS resistance to innate immune cells of its human host. However, GAS CpsY does not manifest thein vitrophenotypes of its homologs in other streptococcal species. GAS CpsY appears to regulate a small set of genes that is markedly different from the regulons of its homologs. The differential expression of these genes depends on the growth medium, and CpsY modestly influences their expression. The GAS CpsY regulon includes known virulence factors (mntE,speB,spd,nga[spn],prtS[SpyCEP], andsse) and cell surface-associated factors of GAS (emm1,mur1.2,sibA[cdhA], andM5005_Spy0500). Intriguingly, the loss of CpsY in GAS does not result in virulence defects in murine models of infection, suggesting that CpsY function in immune evasion is specific to the human host.

scholarly journals SpyAD, a Moonlighting Protein of Group A Streptococcus Contributing to Bacterial Division and Host Cell Adhesion

2014 ◽  
Vol 82 (7) ◽  
pp. 2890-2901 ◽  
Author(s):  
Marilena Gallotta ◽  
Giovanni Gancitano ◽  
Giampiero Pietrocola ◽  
Marirosa Mora ◽  
Alfredo Pezzicoli ◽  
...  
Keyword(s):  
Cell Division ◽  
Mammalian Cells ◽  
Group A Streptococcus ◽  
Host Cells ◽  
Knockout Mutant ◽  
Content Type ◽  
Moonlighting Protein ◽  
Group A

ABSTRACTGroup A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of thespy0269gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interactin vitrowith the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cellsin vitroand thatLactococcus lactisexpressing Spy0269 on its cell surface could adhere to mammalian cellsin vitroand to mice nasal mucosain vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (StreptococcuspyogenesAdhesion andDivision protein).

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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