scholarly journals In vitro and in vivo antibiofilm potential of 2,4-Di- tert -butylphenol from seaweed surface associated bacterium Bacillus subtilis against group A streptococcus

2016 ◽  
Vol 191 ◽  
pp. 19-31 ◽  
Author(s):  
Dharmaprakash Viszwapriya ◽  
Udayakumar Prithika ◽  
Sundaresan Deebika ◽  
Krishnaswamy Balamurugan ◽  
Shunmugiah Karutha Pandian
Keyword(s):  
Bacillus Subtilis ◽  
Group A Streptococcus ◽  
Group A ◽  
Bacterium Bacillus Subtilis ◽  
Bacterium Bacillus

scholarly journals Interaction of Bacillus subtilis CsaA with SecA and precursor proteins

2000 ◽  
Vol 348 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Jörg P. MÜLLER ◽  
Jörg OZEGOWSKI ◽  
Stefan VETTERMANN ◽  
Jelto SWAVING ◽  
Karel H. M. VAN WELY ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Specific Interaction ◽  
Membrane Vesicles ◽  
Protein Export ◽  
E Coli ◽  
Bacterium Bacillus Subtilis ◽  
Bacterium Bacillus

CsaA from the Gram-positive bacterium Bacillus subtilis has been identified previously as a suppressor of the growth and protein-export defect of Escherichia coli secA(Ts) mutants. CsaA has chaperone-like activities in vivo and in vitro. To examine the role of CsaA in protein export in B. subtilis, expression of the csaA gene was repressed. While export of most proteins remained unaffected, export of at least two proteins was significantly reduced upon CsaA depletion. CsaA co-immunoprecipitates and co-purifies with the SecA proteins of E. coli and B. subtilis, and binds the B. subtilis preprotein prePhoB. Purified CsaA stimulates the translocation of prePhoB into E. coli membrane vesicles bearing the B. subtilis translocase, whereas it interferes with the SecB-mediated translocation of proOmpA into membrane vesicles of E. coli. The specific interaction with the SecA translocation ATPase and preproteins suggests that CsaA acts as a chaperone that promotes the export of a subset of preproteins in B. subtilis.

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 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 Group A Streptococcus AdcR Regulon Participates in Bacterial Defense against Host-Mediated Zinc Sequestration and Contributes to Virulence

2020 ◽  
Vol 88 (8) ◽  
Author(s):  
Nishanth Makthal ◽  
Hackwon Do ◽  
Brian M. Wendel ◽  
Randall J. Olsen ◽  
John D. Helmann ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Group A Streptococcus ◽  
Zn Deficiency ◽  
Direct Competition ◽  
Mutant Strains ◽  
Genes Encoding ◽  
Group A ◽  
Gas Interactions

ABSTRACT Colonization by pathogenic bacteria depends on their ability to overcome host nutritional defenses and acquire nutrients. The human pathogen group A streptococcus (GAS) encounters the host defense factor calprotectin (CP) during infection. CP inhibits GAS growth in vitro by imposing zinc (Zn) limitation. However, GAS counterstrategies to combat CP-mediated Zn limitation and the in vivo relevance of CP-GAS interactions to bacterial pathogenesis remain unknown. Here, we report that GAS upregulates the AdcR regulon in response to CP-mediated Zn limitation. The AdcR regulon includes genes encoding Zn import (adcABC), Zn sparing (rpsN.2), and Zn scavenging systems (adcAII, phtD, and phtY). Each gene in the AdcR regulon contributes to GAS Zn acquisition and CP resistance. The ΔadcC and ΔrpsN.2 mutant strains were the most susceptible to CP, whereas the ΔadcA, ΔadcAII, and ΔphtD mutant strains displayed less CP sensitivity during growth in vitro. However, the ΔphtY mutant strain did not display an increased CP sensitivity. The varied sensitivity of the mutant strains to CP-mediated Zn limitation suggests distinct roles for individual AdcR regulon genes in GAS Zn acquisition. GAS upregulates the AdcR regulon during necrotizing fasciitis infection in WT mice but not in S100a9−/− mice lacking CP. This suggests that CP induces Zn deficiency in the host. Finally, consistent with the in vitro results, several of the AdcR regulon genes are critical for GAS virulence in WT mice, whereas they are dispensable for virulence in S100a9−/− mice, indicating the direct competition for Zn between CP and proteins encoded by the GAS AdcR regulon during infection.

scholarly journals Identification of Group A Streptococcus Antigenic Determinants Upregulated In Vivo

2005 ◽  
Vol 73 (9) ◽  
pp. 6026-6038 ◽  
Author(s):  
Kowthar Y. Salim ◽  
Dennis G. Cvitkovitch ◽  
Peter Chang ◽  
Darrin J. Bast ◽  
Martin Handfield ◽  
...  
Keyword(s):  
Murine Model ◽  
Vibrio Vulnificus ◽  
Group A Streptococcus ◽  
Hypothetical Protein ◽  
Invasive Disease ◽  
Antigenic Determinants ◽  
Expression Library ◽  
Group A

ABSTRACT Group A Streptococcus (GAS) causes a range of diseases in humans, from mild noninvasive infections to severe invasive infections. The molecular basis for the varying severity of disease remains unclear. We identified genes expressed during invasive disease using in vivo-induced antigen technology (IVIAT), applied for the first time in a gram-positive organism. Convalescent-phase sera from patients with invasive disease were pooled, adsorbed against antigens derived from in vitro-grown GAS, and used to screen a GAS genomic expression library. A murine model of invasive GAS disease was included as an additional source of sera for screening. Sequencing DNA inserts from clones reactive with both human and mouse sera indicated 16 open reading frames with homology to genes involved in metabolic activity to genes of unknown function. Of these, seven genes were assessed for their differential expression by quantitative real-time PCR both in vivo, utilizing a murine model of invasive GAS disease, and in vitro at different time points of growth. Three gene products—a putative penicillin-binding protein 1A, a putative lipoprotein, and a conserved hypothetical protein homologous to a putative translation initiation inhibitor in Vibrio vulnificus—were upregulated in vivo, suggesting that these genes play a role during invasive disease.

scholarly journals CovR Activation of the Dipeptide Permease Promoter (PdppA) in Group A Streptococcus

2006 ◽  
Vol 189 (4) ◽  
pp. 1407-1416 ◽  
Author(s):  
Asiya A. Gusa ◽  
Barbara J. Froehlich ◽  
Devak Desai ◽  
Virginia Stringer ◽  
June R. Scott
Keyword(s):  
Group A Streptococcus ◽  
Response Regulator ◽  
Activation Of Transcription ◽  
Genes Encoding ◽  
Group A ◽  
Transcription In Vitro ◽  
Dna Template ◽  
Regulated Promoters

ABSTRACT CovR, the two-component response regulator of Streptococcus pyogenes (group A streptococcus [GAS]) directly or indirectly represses about 15% of the genome, including genes encoding many virulence factors and itself. Transcriptome analyses also showed that some genes are activated by CovR. We asked whether the regulation by CovR of one of these genes, dppA, the first gene in an operon encoding a dipeptide permease, is direct or indirect. Direct regulation by CovR was suggested by the presence of five CovR consensus binding sequences (CBs) near the putative promoter. In this study, we identified the 5′ end of the dppA transcript synthesized in vivo and showed that the start of dppA transcription in vitro is the same. We found that CovR binds specifically to the dppA promoter region (PdppA) in vitro with an affinity similar to that at which it binds to other CovR-regulated promoters. Disruption of any of the five CBs by a substitution of GG for TT inhibited CovR binding to that site in vitro, and binding at two of the CBs appeared cooperative. In vivo, CovR activation of transcription was not affected by individual mutations of any of the four CBs that we could study. This suggests that the binding sites are redundant in vivo. In vitro, CovR did not activate transcription from PdppA in experiments using purified GAS RNA polymerase and either linear or supercoiled DNA template. Therefore, we propose that in vivo, CovR may interfere with the binding of a repressor of PdppA.

scholarly journals AR-12 Has a Bactericidal Activity and a Synergistic Effect with Gentamicin against Group A Streptococcus

2021 ◽  
Vol 22 (21) ◽  
pp. 11617
Author(s):  
Nina Tsao ◽  
Ya-Chu Chang ◽  
Sung-Yuan Hsieh ◽  
Tang-Chi Li ◽  
Ching-Chen Chiu ◽  
...  
Keyword(s):  
Toxic Shock Syndrome ◽  
Group A Streptococcus ◽  
Streptococcal Toxic Shock Syndrome ◽  
Invasive Infection ◽  
Toxic Shock ◽  
Spherical Structures ◽  
Group A ◽  
Bacteria And Fungi

Streptococcus pyogenes (group A Streptococcus (GAS) is an important human pathogen that can cause severe invasive infection, such as necrotizing fasciitis and streptococcal toxic shock syndrome. The mortality rate of streptococcal toxic shock syndrome ranges from 20% to 50% in spite of antibiotics administration. AR-12, a pyrazole derivative, has been reported to inhibit the infection of viruses, intracellular bacteria, and fungi. In this report, we evaluated the bactericidal activities and mechanisms of AR-12 on GAS infection. Our in vitro results showed that AR-12 dose-dependently reduced the GAS growth, and 2.5 μg/mL of AR-12 significantly killed GAS within 2 h. AR-12 caused a remarkable reduction in nucleic acid and protein content of GAS. The expression of heat shock protein DnaK and streptococcal exotoxins was also inhibited by AR-12. Surveys of the GAS architecture by scanning electron microscopy revealed that AR-12-treated GAS displayed incomplete septa and micro-spherical structures protruding out of cell walls. Moreover, the combination of AR-12 and gentamicin had a synergistic antibacterial activity against GAS replication for both in vitro and in vivo infection. Taken together, these novel findings obtained in this study may provide a new therapeutic strategy for invasive GAS infection.

scholarly journals Characterization of an Extracellular Virulence FactorMade by Group A Streptococcus with Homology to theListeria monocytogenes Internalin Family ofProteins

2003 ◽  
Vol 71 (12) ◽  
pp. 7043-7052 ◽  
Author(s):  
Sean D. Reid ◽  
Alison G. Montgomery ◽  
Jovanka M. Voyich ◽  
Frank R. DeLeo ◽  
Benfang Lei ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Group A Streptococcus ◽  
Shigella Flexneri ◽  
Immunoblot Analysis ◽  
Invasive Infections ◽  
Isogenic Mutant Strain ◽  
Group A ◽  
And Function

ABSTRACT Leucine-rich repeats (LRR) characterize a diverse array of proteins and function to provide a versatile framework for protein-protein interactions. Importantly, each of the bacterial LRR proteins that have been well described, including those of Listeria monocytogenes, Yersinia pestis, and Shigella flexneri, have been implicated in virulence. Here we describe an 87.4-kDa group A Streptococcus (GAS) protein (designated Slr, for streptococcal leucine-rich) containing 10 1/2 sequential units of a 22-amino-acid C-terminal LRR homologous to the LRR of the L. monocytogenes internalin family of proteins. In addition to the LRR domain, slr encodes a gram-positive signal secretion sequence characteristic of a lipoprotein and a putative N-terminal domain with a repeated histidine triad motif (HxxHxH). Real-time reverse transcriptase PCR assays indicated that slr is transcribed abundantly in vitro in the exponential phase of growth. Flow cytometry confirmed that Slr was attached to the GAS cell surface. Western immunoblot analysis of sera obtained from 80 patients with invasive infections, noninvasive soft tissue infections, pharyngitis, and rheumatic fever indicated that Slr is produced in vivo. An isogenic mutant strain lacking slr was significantly less virulent in an intraperitoneal mouse model of GAS infection and was significantly more susceptible to phagocytosis by human polymorphonuclear leukocytes. These studies characterize the first GAS LRR protein as an extracellular virulence factor that contributes to pathogenesis and may participate in evasion of the innate host defense.

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