scholarly journals Prime-Pull Immunization with a Bivalent M-Protein and Spy-CEP Peptide Vaccine Adjuvanted with CAF®01 Liposomes Induces Both Mucosal and Peripheral Protection from covR/S Mutant Streptococcus pyogenes

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Victoria Ozberk ◽  
Simone Reynolds ◽  
Yongbao Huo ◽  
Ainslie Calcutt ◽  
Sharareh Eskandari ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Defense Mechanism ◽  
Peptide Vaccine ◽  
Female Rats ◽  
M Protein ◽  
Mutant Form ◽  
Upper Respiratory Tract ◽  
Content Type ◽  
Peptide Epitopes ◽  
Male And Female Rats

ABSTRACT Infections with Streptococcus pyogenes and their sequelae are responsible for an estimated 18 million cases of serious disease with >700 million new primary cases and 500,000 deaths per year. Despite the burden of disease, there is currently no vaccine available for this organism. Here, we define a combination vaccine P*17/K4S2 comprising of 20-mer B-cell peptide epitopes, p*17 (a mutant derived from the highly conserved C3-repeat region of the M-protein), and K4S2 (derived from the streptococcal anti-neutrophil factor, Spy-CEP). The peptides are chemically conjugated to either diphtheria toxoid (DT) or a nontoxic mutant form of diphtheria toxin, CRM197. We demonstrate that a prime-pull immunization regimen involving two intramuscular inoculations with P*17/K4S2 adjuvanted with a two-component liposomal adjuvant system (CAF01; developed by Statens Serum Institut [SSI], Denmark), followed by an intranasal inoculation of unadjuvanted vaccine (in Tris) induces peptide- and S. pyogenes-binding antibodies and protects from mucosal and skin infection with hypervirulent covR/S mutant organisms. Prior vaccination with DT does not diminish the response to the conjugate peptide vaccines. Detailed Good Laboratory Practice (GLP) toxicological evaluation in male and female rats did not reveal any gross or histopathological adverse effects. IMPORTANCE A vaccine to control S. pyogenes infection is desperately warranted. S. pyogenes colonizes the upper respiratory tract (URT) and skin, from where it can progress to invasive and immune-mediated diseases. Global mortality estimates for S. pyogenes-associated diseases exceeds 500,000 deaths per year. S. pyogenes utilizes antigenic variation as a defense mechanism to circumvent host immune responses and thus a successful vaccine needs to provide strain-transcending and multicompartment (mucosal and skin) immunity. By defining highly conserved and protective epitopes from two critical virulence factors (M-protein and Spy-CEP) and combining them with a potent immunostimulant, CAF®01, we are addressing an unmet clinical need for a mucosally and skin-active subunit vaccine. We demonstrate that prime-pull immunization (2× intramuscular injections followed by intranasal immunization) promotes high sustained antibody levels in the airway mucosa and serum and protects against URT and invasive disease.

scholarly journals Acquisition of the Sda1-Encoding Bacteriophage Does Not Enhance Virulence of the Serotype M1 Streptococcus pyogenes Strain SF370

2013 ◽  
Vol 81 (6) ◽  
pp. 2062-2069 ◽  
Author(s):  
Carola Venturini ◽  
Cheryl-lynn Y. Ong ◽  
Christine M. Gillen ◽  
Nouri L. Ben-Zakour ◽  
Peter G. Maamary ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Invasive Disease ◽  
Mutant Form ◽  
Transfer Event ◽  
Content Type ◽  
Lethal Infection ◽  
Group A ◽  
The Impact ◽  
Acting In Concert

ABSTRACTThe resurgence of invasive disease caused byStreptococcus pyogenes(group AStreptococcus[GAS]) in the past 30 years has paralleled the emergence and global dissemination of the highly virulent M1T1 clone. The GAS M1T1 clone has diverged from the ancestral M1 serotype by horizontal acquisition of two unique bacteriophages, encoding the potent DNase Sda1/SdaD2 and the superantigen SpeA, respectively. The phage-encoded DNase promotes escape from neutrophil extracellular traps and is linked to enhanced virulence of the M1T1 clone. In this study, we successfully usedin vitrolysogenic conversion to transfer the Sda1-encoding phage from the M1T1 clonal strain 5448 to the nonclonal M1 isolate SF370 and determined the impact of this horizontal gene transfer event on virulence. Although Sda1 was expressed in SF370 lysogens, no capacity of the phage-converted strain to survive human neutrophil killing, switch to a hyperinvasivecovRSmutant form, or cause invasive lethal infection in a humanized plasminogen mouse model was observed. This work suggests that the hypervirulence of the M1T1 clone is due to the unique synergic effect of the M1T1 clone bacteriophage-specific virulence factor Sda1 acting in concert with the M1T1 clone-specific genetic scaffold.

scholarly journals Citrulline Protects Streptococcus pyogenes from Acid Stress Using the Arginine Deiminase Pathway and the F1Fo-ATPase

2015 ◽  
Vol 197 (7) ◽  
pp. 1288-1296 ◽  
Author(s):  
Zachary T. Cusumano ◽  
Michael G. Caparon
Keyword(s):  
Soft Tissue ◽  
Streptococcus Pyogenes ◽  
Soft Tissue Infection ◽  
Bacterial Infections ◽  
Defense Mechanism ◽  
Acid Stress ◽  
Low Ph ◽  
Arginine Deiminase ◽  
Tissue Infection ◽  
Content Type

ABSTRACTA common stress encountered by both pathogenic and environmental bacteria is exposure to a low-pH environment, which can inhibit cell growth and lead to cell death. One major defense mechanism against this stress is the arginine deiminase (ADI) pathway, which catabolizes arginine to generate two ammonia molecules and one molecule of ATP. While this pathway typically relies on the utilization of arginine, citrulline has also been shown to enter into the pathway and contribute to protection against acid stress. In the pathogenic bacteriumStreptococcus pyogenes, the utilization of citrulline has been demonstrated to contribute to pathogenesis in a murine model of soft tissue infection, although the mechanism underlying its role in infection is unknown. To gain insight into this question, we analyzed a panel of mutants defective in different steps in the ADI pathway to dissect how arginine and citrulline protectS. pyogenesin a low-pH environment. While protection provided by arginine utilization occurred through the buffering of the extracellular environment, citrulline catabolism protection was pH independent, requiring the generation of ATP via the ADI pathway and a functional F1Fo-ATP synthase. This work demonstrates that arginine and citrulline catabolism protect against acid stress through distinct mechanisms and have unique contributions to virulence during an infection.IMPORTANCEAn important aspect of bacterial pathogenesis is the utilization of host-derived nutrients during an infection for growth and virulence. Previously published work from our lab identified a unique role for citrulline catabolism inStreptococcus pyogenesduring a soft tissue infection. The present article probes the role of citrulline utilization during this infection and its contribution to protection against acid stress. This work reveals a unique and concerted action between the catabolism of citrulline and the F1Fo-ATPase that function together to provide protection for bacteria in a low-pH environment. Dissection of these collaborative pathways highlights the complexity of bacterial infections and the contribution of atypical nutrients, such as citrulline, to pathogenesis.

Recent advances in sensors for early detection of pathogens causing rheumatic heart disease

Sensor Review ◽  
2018 ◽  
Vol 38 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Swati Singh ◽  
Ankur Kaushal ◽  
Ashok Kumar
Keyword(s):  
Heart Disease ◽  
Rheumatic Heart Disease ◽  
Streptococcus Pyogenes ◽  
Detection System ◽  
Early Stage ◽  
Ease Of Use ◽  
Diagnostic Methods ◽  
Upper Respiratory Tract ◽  
Content Type ◽  
Rheumatic Heart

Purpose There is an immense concern in the international community about controlling the outburst of infectious diseases. An essential step towards diminishing it is the development of an adequate detection system. Among the huge plethora of microorganisms which may infect the human body, Streptococcus pyogenes is important one which infects the upper respiratory tract leading to sore throat, which eventually develops into rheumatic heart disease (RHD) in the absence of timely treatment. A major process in controlling the infection is to detect it at an early stage. Hence, there is a need to develop detection tools which are both rapid and reliable. Design/methodology/approach Different types of diagnostic methods are available for identification, but the most commonly used are culturing, staining and rapid antigen detection tests. For better sensitivity and specificity, this review describes the development of biosensor. Compared with the current available methods, which are usually cumbersome, time-consuming and expensive, this approach features sequence specificity, cost efficiency, rapid and ease of use. Findings This review outlines various sensors which are available for the detection of Streptococcus pyogenes which causes human RHD. The working scheme of the sensors, their sensitivity and limitation of detection has been described in the review. Originality/value The review fulfills an acknowledged the need to study various sensors that are available for the detection of Streptococcus pyogenes, causing human RHD.

scholarly journals M-Protein Analysis of Streptococcus pyogenes Isolates Associated with Acute Rheumatic Fever in New Zealand

2015 ◽  
Vol 53 (11) ◽  
pp. 3618-3620 ◽  
Author(s):  
Deborah A. Williamson ◽  
Pierre R. Smeesters ◽  
Andrew C. Steer ◽  
John D. Steemson ◽  
Adrian C. H. Ng ◽  
...  
Keyword(s):  
New Zealand ◽  
Rheumatic Fever ◽  
Streptococcus Pyogenes ◽  
Acute Rheumatic Fever ◽  
Skin Infection ◽  
Protein Analysis ◽  
M Protein ◽  
Content Type ◽  
Typing System ◽  
Group A

We applied anemmcluster typing system to group AStreptococcusstrains in New Zealand, including those associated with acute rheumatic fever (ARF). We observed few so-called rheumatogenicemmtypes but found a high proportion ofemmtypes previously associated with pyoderma, further suggesting a role for skin infection in ARF.

scholarly journals Acrylamide reduces plasma antioxidant vitamin levels in rats due to increased oxidative damage

2020 ◽  
Vol 33 ◽  
Author(s):  
Yeşim YENER ◽  
Fatma Hümeyra YERLİKAYA
Keyword(s):  
Retinoic Acid ◽  
Sialic Acid ◽  
High Performance ◽  
Defense Mechanism ◽  
Female Rats ◽  
Heating Process ◽  
Antioxidant Vitamin ◽  
Serum Samples ◽  
Male And Female Rats ◽  
Serum Sialic Acid

ABSTRACT Objective Acrylamide is a potentially neurotoxic and carcinogenic chemical and naturally creates during the heating process of carbohydrate-rich foods, such as potato chips and breakfast cereals. Acrylamide might be ingested by people via consuming food that contains it. Therefore, we investigated the effect of acrylamidegiven orally to male and female rats on plasma retinoic acid and α-tocopherol and serum sialic acid and malondialdehyde levels. Method A total of 50 Wistar rats were used (25 female and 25 male, three-four weeks old). The rats of each sex were given 2 and 5mg/kg/day acrylamide via drinking water for 90 days. At the end of the treatment, the animals were euthanized by cervical dislocation. Blood specimens were collected through cardiac puncture, and serum and plasma samples were analysed using the high-performance liquid chromatography technique with a Ultraviolet detector. Results The analysis of the plasma and serum samples revealed that serum sialic acid and malondialdehyde levels in both sexes given 5mg/kg/day acrylamide were significantly increased, and the serum sialic acid levels were higher in female rats given 2mg/kg/day acrylamide. The plasma retinoic acid and α-tocopherol levels significantly decreased in both sexes given only the highest dose. Conclusion The results show that acrylamide causes an increase in oxidative stress and leads to a decrease in the levels of retinoic acid and α-tocopherol which play a role in the defense mechanism against this stress.

scholarly journals Protective Mechanisms of Respiratory Tract Streptococci against Streptococcus pyogenes Biofilm Formation and Epithelial Cell Infection

2012 ◽  
Vol 79 (4) ◽  
pp. 1265-1276 ◽  
Author(s):  
Tomas Fiedler ◽  
Catur Riani ◽  
Dirk Koczan ◽  
Kerstin Standar ◽  
Bernd Kreikemeyer ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Streptococcus Pyogenes ◽  
Layer Structure ◽  
Artificial Saliva ◽  
Protective Effects ◽  
Upper Respiratory Tract ◽  
Cell Infection ◽  
Anatomic Site ◽  
Content Type

ABSTRACTStreptococcus pyogenes(group A streptococci [GAS]) encounter many streptococcal species of the physiological microbial biome when entering the upper respiratory tract of humans, leading to the question how GAS interact with these bacteria in order to establish themselves at this anatomic site and initiate infection. Here we show thatS. oralisandS. salivariusin direct contact assays inhibit growth of GAS in a strain-specific manner and thatS. salivarius, most likely via bacteriocin secretion, also exerts this effect in transwell experiments. Utilizing scanning electron microscopy documentation, we identified the tested strains as potent biofilm producers except for GAS M49. In mixed-species biofilms,S. salivariusdominated the GAS strains, whileS. oralisacted as initial colonizer, building the bottom layer in mixed biofilms and thereby allowing even GAS M49 to form substantial biofilms on top. With the exception ofS. oralis, artificial saliva reduced single-species biofilms and allowed GAS to dominate in mixed biofilms, although the overall two-layer structure was unchanged. When covered byS. oralisandS. salivariusbiofilms, epithelial cells were protected from GAS adherence, internalization, and cytotoxic effects. Apparently, these species can have probiotic effects. The use of Affymetrix array technology to assess HEp-2 cell transcription levels revealed modest changes after exposure toS. oralisandS. salivariusbiofilms which could explain some of the protective effects against GAS attack. In summary, our study revealed a protection effect of respiratory tract bacteria against an important airway pathogen and allowed a firstin vitroinsight into local environmental processes after GAS enter the respiratory tract.

scholarly journals Colonization of the Murine Oropharynx by Streptococcus pyogenes Is Governed by the Rgg2/3 Quorum Sensing System

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Artemis Gogos ◽  
Michael J. Federle
Keyword(s):  
Quorum Sensing ◽  
Streptococcus Pyogenes ◽  
Vaccine Development ◽  
Regulatory System ◽  
Upper Respiratory Tract ◽  
Content Type ◽  
Reverse Transcription Pcr ◽  
System A ◽  
Bacterial Rna ◽  
Transcriptional Regulatory

ABSTRACT Streptococcus pyogenes is a human-restricted pathogen most often found in the human nasopharynx. Multiple bacterial factors are known to contribute to persistent colonization of this niche, and many are important in mucosal immunity and vaccine development. In this work, mice were infected intranasally with transcriptional regulator mutants of the Rgg2/3 quorum sensing (QS) system—a peptide-based signaling system conserved in sequenced isolates of S. pyogenes. Deletion of the QS system’s transcriptional activator (Δrgg2) dramatically diminished the percentage of colonized mice, while deletion of the transcriptional repressor (Δrgg3) increased the percentage of colonized mice compared to that of the wild type (WT). Stimulation of the QS system using synthetic pheromones prior to inoculation did not significantly increase the percentage of animals colonized, indicating that QS-dependent colonization is responsive to the intrinsic conditions within the host upper respiratory tract. Bacterial RNA extracted directly from oropharyngeal swabs and evaluated by quantitative reverse transcription-PCR (qRT-PCR) subsequently confirmed QS upregulation within 1 h of inoculation. In the nasal-associated lymphoid tissue (NALT), a muted inflammatory response to the Δrgg2 bacteria suggests that their rapid elimination failed to elicit the previously characterized response to intranasal inoculation of GAS. This work identifies a new transcriptional regulatory system governing the ability of S. pyogenes to colonize the nasopharynx and provides knowledge that could help lead to decolonization therapeutics.

scholarly journals The M Protein of Streptococcus pyogenes Strain AP53 Retains Cell Surface Functional Plasminogen Binding after Inactivation of the Sortase A Gene

2020 ◽  
Vol 202 (10) ◽  
Author(s):  
Brady T. Russo ◽  
Yetunde A. Ayinuola ◽  
Damini Singh ◽  
Katelyn Carothers ◽  
Vincent A. Fischetti ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Membrane ◽  
Cell Surface ◽  
Streptococcus Pyogenes ◽  
Cytoplasmic Membrane ◽  
M Protein ◽  
Sortase A ◽  
Content Type ◽  
M Proteins ◽  
Group A

ABSTRACT Streptococcus pyogenes (Lancefield group A Streptococcus [GAS]) is a β-hemolytic human-selective pathogen that is responsible for a large number of morbid and mortal infections in humans. For efficient infection, GAS requires different types of surface proteins that provide various mechanisms for evading human innate immune responses, thus enhancing pathogenicity of the bacteria. Many such virulence-promoting proteins, including the major surface signature M protein, are translocated after biosynthesis through the cytoplasmic membrane and temporarily tethered to this membrane via a type 1 transmembrane domain (TMD) positioned near the COOH terminus. In these proteins, a sorting signal, LPXTG, is positioned immediately upstream of the TMD, which is cleaved by the membrane-associated transpeptidase, sortase A (SrtA), leading to the covalent anchoring of these proteins to newly emerging l-Ala–l-Ala cross-bridges of the growing peptidoglycan cell wall. Herein, we show that inactivation of the srtA gene in a skin-tropic pattern D GAS strain (AP53) results in retention of the M protein in the cell membrane. However, while the isogenic AP53 ΔsrtA strain is attenuated in overall pathogenic properties due to effects on the integrity of the cell membrane, our data show that the M protein nonetheless can extend from the cytoplasmic membrane through the cell wall and then to the surface of the bacteria and thereby retain its important properties of productively binding and activating fluid-phase host plasminogen (hPg). The studies presented herein demonstrate an underappreciated additional mechanism of cell surface display of bacterial virulence proteins via their retention in the cell membrane and extension to the GAS surface. IMPORTANCE Group A Streptococcus pyogenes (GAS) is a human-specific pathogen that produces many surface factors, including its signature M protein, that contribute to its pathogenicity. M proteins undergo specific membrane localization and anchoring to the cell wall via the transpeptidase sortase A. Herein, we explored the role of sortase A function on M protein localization, architecture, and function, employing, a skin-tropic GAS isolate, AP53, which expresses a human plasminogen (hPg)-binding M (PAM) Protein. We showed that PAM anchored in the cell membrane, due to the targeted inactivation of sortase A, was nonetheless exposed on the cell surface and functionally interacted with host hPg. We demonstrate that M proteins, and possibly other sortase A-processed proteins that are retained in the cell membrane, can still function to initiate pathogenic processes by this underappreciated mechanism.

Monosodium glutamate administration early in life alters pineal melatonin nocturnal profile in adulthood

2021 ◽  
Vol 4 (1) ◽  
pp. 99-114
Author(s):  
Janaína B Garcia ◽  
Fernanda G Do Amaral ◽  
Daniela C Buonfiglio ◽  
Rafaela FA Vendrame ◽  
Patrícia L Alves ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Weight ◽  
Pineal Gland ◽  
Serum Insulin ◽  
Monosodium Glutamate ◽  
Female Rats ◽  
Pineal Melatonin ◽  
Melatonin Synthesis ◽  
Male And Female Rats ◽  
Melatonin Production

The pineal gland synthesizes melatonin exclusively at night, which gives melatonin the characteristic of a temporal synchronizer of the physiological systems. Melatonin is a regulator of insulin activities centrally and also peripherally and its synthesis is reduced in diabetes.  Since monosodium glutamate (MSG) is often used to induce the type 2 diabetic and metabolic syndrome in animal models, the purpose of this work is to evaluate the potential effects of MSG given to neonates on the pineal melatonin synthesis in different aged male and female rats. Wistar rats were subcutaneously injected with MSG (4mg/g/day) or saline solution (0.9%) from the second to eighth post-natal day. The circadian profiles both melatonin levels and AANAT activity were monitored at different ages. Body weight, naso-anal length, adipose tissues weight, GTT, ITT and serum insulin levels were also evaluated. Typical obesity with the neonatal MSG treatment was observed, indicated by a great increase in adipose depots without a concurrent increase in body weight. MSG treatment did not cause hyperglycemia or glucose intolerance, but induced insulin resistance. An increase of melatonin synthesis at ZT 15 with phase advance was observed in in some animals. The AANAT activity was positively parallel to the melatonin circadian profile. It seems that MSG causes hypothalamic obesity which may increase AANAT activity and melatonin production in pineal gland. These effects were not temporally correlated with insulin resistance and hyperinsulinemia indicating the hypothalamic lesions, particularly in arcuate nucleus induced by MSG in early age, as the principal cause of the increase in melatonin production.

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