DOCSLIB.ORG

Title Page Discovery of Genes Encoding a Streptolysin S-Like Toxin

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Title Page Discovery of Genes Encoding a Streptolysin S-Like Toxin bioRxiv preprint doi: https://doi.org/10.1101/752204; this version posted August 31, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Title Page 2 Discovery of genes encoding a Streptolysin S-like toxin biosynthetic cluster in a 3 select highly pathogenic methicillin resistant Staphylococcus aureus JKD6159 4 strain 5 Trevor Kane *1, Katelyn E. Carothers*+ 2,5, Yunjuan Bao3, Won-Sik Yeo4, Taeok Bae4, 6 Claudia Park2, Francisco R. Fields2, Henry M. Vu2, Daniel E. Hammers2, Jessica N. 7 Ross2, Victoria A. Ploplis3, Francis J. Castellino3, Shaun W. Lee 2,3,5 8 1Present address, Kraig Biocraft Laboratories, Inc. 9 2Department of Biological Sciences, University of Notre Dame, Notre Dame. 10 3W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, 11 IN 12 4School of Medicine, Indiana University, Gary, IN 13 5Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 14 * Contributed equally to work 15 + Corresponding author: [email protected] 16 17 18 19 1 bioRxiv preprint doi: https://doi.org/10.1101/752204; this version posted August 31, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 20 Abstract 21 22 Background: Staphylococcus aureus (S. aureus) is a major human pathogen owing to 23 its arsenal of virulence factors, as well as its acquisition of multi-antibiotic resistance. 24 Here we report the identification of a Streptolysin S (SLS) like biosynthetic gene cluster 25 in a highly virulent community-acquired methicillin resistant S. aureus (MRSA) isolate, 26 JKD6159. Examination of the SLS-like gene cluster in JKD6159 shows significant 27 homology and gene organization to the SLS-associated biosynthetic gene (sag) cluster 28 responsible for the production of the major hemolysin SLS in Group A Streptococcus. 29 Results: We took a comprehensive approach to elucidating the putative role of the sag 30 gene cluster in JKD6159 by constructing a mutant in which one of the biosynthesis 31 genes (sagB homologue) was deleted in the parent JKD6159 strain. Assays to evaluate 32 bacterial gene regulation, biofilm formation, antimicrobial activity, as well as complete 33 host cell response profile and comparative in vivo infections in Balb/Cj mice were 34 conducted. 35 Conclusions: Although no significant phenotypic changes were observed in our 36 assays, we postulate that the SLS-like toxin produced by this strain of S. aureus may be 37 a highly specialized virulence factor utilized in specific environments for selective 38 advantage; studies to better understand the role of this newly discovered virulence 39 factor in S. aureus warrant further investigation. 40 Keywords: Staphylococcus aureus, Streptolysin S, bacteriocins, biosynthetic gene 41 cluster 2 bioRxiv preprint doi: https://doi.org/10.1101/752204; this version posted August 31, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 42 Background 43 44 Staphylococcus aureus (S. aureus) is a pathogenic bacterium that is capable of causing 45 severe human diseases including skin infections, pneumonia, and blood sepsis [1–4]. 46 Of particular concern is the ability of S. aureus to acquire resistance to antibiotics. S. 47 aureus presents as resistant to the frontline β-lactam antibiotic methicillin in roughly half 48 of all infections in the United States [5]. Based on where the infection is acquired, 49 methicillin-resistant S. aureus (MRSA) is classified as community acquired MRSA (CA- 50 MRSA) or hospital acquired MRSA (HA-MRSA), accounting for some 84% and 16%, 51 respectively, of clinical isolates in the United States [4]. CA-MRSA tends to be highly 52 virulent and can produce toxins that are exclusive to CA-MRSA such as Panton 53 Valentine leucocidin [6]. S. aureus typically encodes a wide range of virulence factors 54 including protein A, enterotoxins, and α-toxin among others. This work examines S. 55 aureus JKD6159, a highly virulent strain of CA-MRSA from Australia. The JKD6159 56 strain has become the dominant strain of MRSA found in Australia despite the initial 57 isolation of the strain only 15 years ago [7, 8]. Our initial bioinformatic survey of this CA- 58 MRSA strain indicated that this strain possesses a biosynthetic gene cluster 59 homologous to the Streptolysin S associated gene (sag) cluster found in a related 60 human pathogen, Group A Streptococcus (GAS). The sag cluster in GAS encodes the 61 biosynthetic machinery required for production of Streptolysin S (SLS), a potent 62 hemolysin and a major virulence factor in GAS pathogenesis [9, 10]. 63 The Streptolysin S-associated gene (sag) cluster was initially identified by Nizet and 64 colleagues using transposon mutagenesis in GAS [9, 10]. The operon responsible for 3 bioRxiv preprint doi: https://doi.org/10.1101/752204; this version posted August 31, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 65 SLS production was found to consist of nine genes that when disrupted individually 66 resulted in the loss of the hemolytic phenotype [9]. SLS is the most well-studied 67 member of a family of post-translationally modified peptides known as linear azole 68 containing peptides (LAPs) [11–13]. These peptides are ribosomally synthesized and 69 subsequently post-translationally modified via the installation of azole heterocycles on 70 cysteine, serine, or threonine residues [12]. Peptides in the LAP family demonstrate a 71 range of functions, including toxins such as SLS, and antimicrobial peptides such as 72 Microcin B17 [9, 10, 14]. 73 Although SLS has long been studied as a major lysin of red blood cells, recent studies 74 have demonstrated that SLS may have specific and multiple cellular targets [15–20]. 75 SLS has been identified as major contributing factor in successful translocation of 76 Group A Streptococcus across the epithelial barrier during the early stages of infection 77 [17]. Specifically, SLS facilitated breakdown of intracellular junctions through 78 recruitment of the cysteine protease calpain, which cleaves host proteins such as 79 occludin and E-cadherin [17]. SLS has also been implicated in the induction of 80 programmed cell death in macrophages and neutrophils as well as inhibition of 81 neutrophil recruitment during infection [18–20]. SLS has also been shown to induce 82 several specific host cell signaling changes in human keratinocytes. Infection of HaCaT 83 cells with wild-type and SLS-deficient GAS results in differential phosphorylation of p38 84 MAPK and NF-κB [15]. These recent insights into additional roles for pore-forming 85 hemolysins highlight the potential contribution of SLS and SLS-like toxins in bacterial 86 pathogenesis at the cellular level under conditions that more closely mimic the infection 87 process. 4 bioRxiv preprint doi: https://doi.org/10.1101/752204; this version posted August 31, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 88 Following our initial discovery of a sag-like biosynthetic gene cluster in a highly virulent 89 methicillin resistant strain of S. aureus JKD6159, we assessed a possible role of the 90 sag-like gene cluster in this S. aureus isolate, by using a comprehensive series of tests 91 to evaluate a potential functional role for this genetic cluster using the wt and a genetic 92 mutant of JKD6159 where the SLS-like biosynthetic gene sagB was inactivated. The wt 93 JKD6159 strain and the sagB isogenic mutant displayed no significant differences in 94 hemolysis, antibacterial activity, biofilm formation, host cytotoxicity or in vivo pathology. 95 However, we noted changes in host cell signaling profiles between wt and the sagB 96 mutant using a cell culture infection model, as well as differences in proteomic profiles 97 between wt JKD6159 strain and the sagB isogenic mutants. We propose that further 98 studies are needed to better define context-dependent conditions under which the SLS- 99 like toxin will contribute to S. aureus pathogenesis and fitness in this highly virulent 100 patient isolate. 101 102 103 104 105 106 107 108 5 bioRxiv preprint doi: https://doi.org/10.1101/752204; this version posted August 31, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 109 Results 110 111 Identification of the sag cluster in S. aureus JKD6159 112 To identify the presence of a sag-like biosynthetic gene cluster in possible methicillin 113 resistant strain human isolates of S. aureus, the gene and protein sequence from GAS 114 strain M1 sagB were used to query non-redundant gene or protein sequences in NCBI 115 using BLAST. We observed a match on the S. aureus strain JKD6159 containing a sag 116 cluster with architecture similar to the sag cluster in GAS (Figure 1A). The gene cluster 117 observed in the S. aureus strain contained all of the components of the sag cluster as 118 found in GAS including the sagB, sagC, and sagD modifying enzymes as well as ABC 119 transporters (Figure 1A). We also observed several putative small open reading frames 120 in the vicinity of the modifying genes that could serve as the protoxin gene (Figure 1A). 121 Analysis of the GC content in the gene cluster indicates it was likely horizontally 122 acquired and integrated between the gnd gene and the gloxalase gene (Figure 1B).
Load more

Recommended publications
  • The Role of Streptococcal and Staphylococcal Exotoxins and Proteases in Human Necrotizing Soft Tissue Infections
    toxins Review The Role of Streptococcal and Staphylococcal Exotoxins and Proteases in Human Necrotizing Soft Tissue Infections Patience Shumba 1, Srikanth Mairpady Shambat 2 and Nikolai Siemens 1,* 1 Center for Functional Genomics of Microbes, Department of Molecular Genetics and Infection Biology, University of Greifswald, D-17489 Greifswald, Germany; [email protected] 2 Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland; [email protected] * Correspondence: [email protected]; Tel.: +49-3834-420-5711 Received: 20 May 2019; Accepted: 10 June 2019; Published: 11 June 2019 Abstract: Necrotizing soft tissue infections (NSTIs) are critical clinical conditions characterized by extensive necrosis of any layer of the soft tissue and systemic toxicity. Group A streptococci (GAS) and Staphylococcus aureus are two major pathogens associated with monomicrobial NSTIs. In the tissue environment, both Gram-positive bacteria secrete a variety of molecules, including pore-forming exotoxins, superantigens, and proteases with cytolytic and immunomodulatory functions. The present review summarizes the current knowledge about streptococcal and staphylococcal toxins in NSTIs with a special focus on their contribution to disease progression, tissue pathology, and immune evasion strategies. Keywords: Streptococcus pyogenes; group A streptococcus; Staphylococcus aureus; skin infections; necrotizing soft tissue infections; pore-forming toxins; superantigens; immunomodulatory proteases; immune responses Key Contribution: Group A streptococcal and Staphylococcus aureus toxins manipulate host physiological and immunological responses to promote disease severity and progression. 1. Introduction Necrotizing soft tissue infections (NSTIs) are rare and represent a more severe rapidly progressing form of soft tissue infections that account for significant morbidity and mortality [1].
    [Show full text]
  • Biosafety Level 1 and Rdna Training
    Biosafety Level 1and rDNA Training Office of Biological Safety Biosafety Level 1 and rDNA Training • Difference between Risk Group and Biosafety Level • NIH and UC policy on recombinant DNA • Work conducted at Biosafety Level 1 • UC Code of Conduct for researchers Biosafety Level 1 and rDNA Training What is the difference between risk group and biosafety level? Risk Groups vs Biosafety Level • Risk Groups: Assigned to infectious organisms by global agencies (NIH, CDC, WHO, etc.) • In US, only assigned to human pathogens (NIH) • Biosafety Level (BSL): How the organisms are managed/contained (increasing levels of protection) Risk Groups vs Biosafety Level • RG1: Not associated with disease in healthy adults (non‐pathogenic E. coli; S. cerevisiae) • RG2: Cause diseases not usually serious and are often treatable (S. aureus; Legionella; Toxoplasma gondii) • RG3: Serious diseases that may be treatable (Y. pestis; B. anthracis; Rickettsia rickettsii; HIV) • RG4: Serious diseases with no treatment/cure (Hemorrhagic fever viruses, e.g., Ebola; no bacteria) Risk Groups vs Biosafety Level • BSL‐1: Usually corresponds to RG1 – Good microbiological technique – No additional safety equipment required for biological work (may still need chemical/radiation protection) – Ability to destroy recombinant organisms (even if they are RG1) Risk Groups vs Biosafety Level • BSL‐2: Same as BSL‐1, PLUS… – Biohazard signs – Protective clothing (lab coat, gloves, eye protection, etc.) – Biosafety cabinet (BSC) for aerosols is recommended but not always required – Negative airflow into room is recommended, but not always required Risk Groups vs Biosafety Level • BSL‐3: Same as BSL‐2, PLUS… – Specialized clothing (respiratory protection, Tyvek, etc.) – Directional air flow is required.
    [Show full text]
  • Report from the 26Th Meeting on Toxinology,“Bioengineering Of
    toxins Meeting Report Report from the 26th Meeting on Toxinology, “Bioengineering of Toxins”, Organized by the French Society of Toxinology (SFET) and Held in Paris, France, 4–5 December 2019 Pascale Marchot 1,* , Sylvie Diochot 2, Michel R. Popoff 3 and Evelyne Benoit 4 1 Laboratoire ‘Architecture et Fonction des Macromolécules Biologiques’, CNRS/Aix-Marseille Université, Faculté des Sciences-Campus Luminy, 13288 Marseille CEDEX 09, France 2 Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d’Azur, CNRS, Sophia Antipolis, 06550 Valbonne, France; [email protected] 3 Bacterial Toxins, Institut Pasteur, 75015 Paris, France; michel-robert.popoff@pasteur.fr 4 Service d’Ingénierie Moléculaire des Protéines (SIMOPRO), CEA de Saclay, Université Paris-Saclay, 91191 Gif-sur-Yvette, France; [email protected] * Correspondence: [email protected]; Tel.: +33-4-9182-5579 Received: 18 December 2019; Accepted: 27 December 2019; Published: 3 January 2020 1. Preface This 26th edition of the annual Meeting on Toxinology (RT26) of the SFET (http://sfet.asso.fr/ international) was held at the Institut Pasteur of Paris on 4–5 December 2019. The central theme selected for this meeting, “Bioengineering of Toxins”, gave rise to two thematic sessions: one on animal and plant toxins (one of our “core” themes), and a second one on bacterial toxins in honour of Dr. Michel R. Popoff (Institut Pasteur, Paris, France), both sessions being aimed at emphasizing the latest findings on their respective topics. Nine speakers from eight countries (Belgium, Denmark, France, Germany, Russia, Singapore, the United Kingdom, and the United States of America) were invited as international experts to present their work, and other researchers and students presented theirs through 23 shorter lectures and 27 posters.
    [Show full text]
  • Penetration of Stratified Mucosa Cytolysins Augment Superantigen
    Cytolysins Augment Superantigen Penetration of Stratified Mucosa Amanda J. Brosnahan, Mary J. Mantz, Christopher A. Squier, Marnie L. Peterson and Patrick M. Schlievert This information is current as of September 25, 2021. J Immunol 2009; 182:2364-2373; ; doi: 10.4049/jimmunol.0803283 http://www.jimmunol.org/content/182/4/2364 Downloaded from References This article cites 76 articles, 24 of which you can access for free at: http://www.jimmunol.org/content/182/4/2364.full#ref-list-1 Why The JI? Submit online. http://www.jimmunol.org/ • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication *average by guest on September 25, 2021 Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2009 by The American Association of Immunologists, Inc. All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. The Journal of Immunology Cytolysins Augment Superantigen Penetration of Stratified Mucosa1 Amanda J. Brosnahan,* Mary J. Mantz,† Christopher A. Squier,† Marnie L. Peterson,‡ and Patrick M. Schlievert2* Staphylococcus aureus and Streptococcus pyogenes colonize mucosal surfaces of the human body to cause disease. A group of virulence factors known as superantigens are produced by both of these organisms that allows them to cause serious diseases from the vaginal (staphylococci) or oral mucosa (streptococci) of the body.
    [Show full text]
  • Response of Cellular Innate Immunity to Cnidarian Pore-Forming Toxins
    Review Response of Cellular Innate Immunity to Cnidarian Pore-Forming Toxins Wei Yuen Yap 1 and Jung Shan Hwang 2,* 1 Department of Biological Sciences, School of Science and Technology, Sunway University, No. 5 Jalan Universiti, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia; [email protected] 2 Department of Medical Sciences, School of Healthcare and Medical Sciences, Sunway University, No. 5 Jalan Universiti, Bandar Sunway, Selangor Darul Ehsan 47500, Malaysia * Correspondence: [email protected]; Tel.: +603-7491-8622 (ext. 7414) Academic Editor: Jean-Marc Sabatier Received: 23 August 2018; Accepted: 28 September 2018; Published: 4 October 2018 Abstract: A group of stable, water-soluble and membrane-bound proteins constitute the pore forming toxins (PFTs) in cnidarians. They interact with membranes to physically alter the membrane structure and permeability, resulting in the formation of pores. These lesions on the plasma membrane causes an imbalance of cellular ionic gradients, resulting in swelling of the cell and eventually its rupture. Of all cnidarian PFTs, actinoporins are by far the best studied subgroup with established knowledge of their molecular structure and their mode of pore-forming action. However, the current view of necrotic action by actinoporins may not be the only mechanism that induces cell death since there is increasing evidence showing that pore-forming toxins can induce either necrosis or apoptosis in a cell-type, receptor and dose-dependent manner. In this review, we focus on the response of the cellular immune system to the cnidarian pore-forming toxins and the signaling pathways that might be involved in these cellular responses.
    [Show full text]
  • Hemolysin CB with Human C5a Receptors Γ Valentine Leukocidin
    Differential Interaction of the Staphylococcal Toxins Panton−Valentine Leukocidin and γ -Hemolysin CB with Human C5a Receptors This information is current as András N. Spaan, Ariën Schiepers, Carla J. C. de Haas, of October 1, 2021. Davy D. J. J. van Hooijdonk, Cédric Badiou, Hugues Contamin, François Vandenesch, Gérard Lina, Norma P. Gerard, Craig Gerard, Kok P. M. van Kessel, Thomas Henry and Jos A. G. van Strijp J Immunol 2015; 195:1034-1043; Prepublished online 19 June 2015; Downloaded from doi: 10.4049/jimmunol.1500604 http://www.jimmunol.org/content/195/3/1034 http://www.jimmunol.org/ Supplementary http://www.jimmunol.org/content/suppl/2015/06/19/jimmunol.150060 Material 4.DCSupplemental References This article cites 46 articles, 14 of which you can access for free at: http://www.jimmunol.org/content/195/3/1034.full#ref-list-1 Why The JI? Submit online. by guest on October 1, 2021 • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2015 by The American Association of Immunologists, Inc.
    [Show full text]
  • Panton-Valentine Leukocidin: a Review
    Reprinted from www.antimicrobe.org Panton-Valentine Leukocidin: A Review Marina Morgan F.R.C.Path. Venkata Meka, M.D. Panton-Valentine leukocidin (PVL) is a bi-component, pore-forming exotoxin produced by some strains of Staphylococcus aureus. Also termed a synergohymenotropic toxin (i.e. acts on membranes through the synergistic activity of 2 non-associated secretory proteins, component S and component F) (9), PVL toxin components assemble into heptamers on the neutrophil membrane, resulting in lytic pores and membrane damage. Injection of purified PVL induces histamine release from human basophilic granulocytes, enzymes (such as β-glucuronidase and lysozyme), chemotactic factors (such as leukotriene B4 and interleukin (IL-) 8), and oxygen metabolites from human neutrophilic granulocytes (5). Intradermal injection of purified PVL in rabbits causes severe inflammatory lesions with capillary dilation, chemotaxis, polymorphonuclear (PMN) infiltration, PMN karyorrhexis, and skin necrosis (17). PVL production is encoded by two contiguous and cotranscribed genes, lukS-PV and lukF-PV, found in a prophage segment integrated in the S. aureus chromosome (9). Traditionally some 2% of S. aureus produce PVL, however in certain groups in close contact with each other, such as military personnel, prisoners, and families of patients with infected skin lesions, skin to skin transmission is common resulting in a far higher carriage rates. Different PVL-positive S. aureus strains carry differing phage sequences, which can move into other strains methicillin and resistant, empowering them with PVl production genes (15). Many patients with PVL-positive necrotizing pneumonia have a preceding illness resembling influenza, with rigors pyrexia and myalgia. Expression of most S.
    [Show full text]
  • Impact of Bacterial Toxins in the Lungs
    toxins Review Impact of Bacterial Toxins in the Lungs 1,2,3, , 4,5, 3 2 Rudolf Lucas * y, Yalda Hadizamani y, Joyce Gonzales , Boris Gorshkov , Thomas Bodmer 6, Yves Berthiaume 7, Ueli Moehrlen 8, Hartmut Lode 9, Hanno Huwer 10, Martina Hudel 11, Mobarak Abu Mraheil 11, Haroldo Alfredo Flores Toque 1,2, 11 4,5,12,13, , Trinad Chakraborty and Jürg Hamacher * y 1 Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; hfl[email protected] 2 Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; [email protected] 3 Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; [email protected] 4 Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland; [email protected] 5 Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland 6 Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland; [email protected] 7 Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada; [email protected] 8 Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland; [email protected] 9 Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany; [email protected] 10 Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333
    [Show full text]
  • A Novel Superantigen Isolated from Pathogenic Strains of Streptococcus Pyogenes with Aminoterminal Homology to Staphylococcal Enterotoxins B and C
    A novel superantigen isolated from pathogenic strains of Streptococcus pyogenes with aminoterminal homology to staphylococcal enterotoxins B and C. J A Mollick, … , D Grossman, R R Rich J Clin Invest. 1993;92(2):710-719. https://doi.org/10.1172/JCI116641. Research Article Streptococcus pyogenes (group A Streptococcus) has re-emerged in recent years as a cause of severe human disease. Because extracellular products are involved in streptococcal pathogenesis, we explored the possibility that a disease isolate expresses an uncharacterized superantigen. We screened culture supernatants for superantigen activity with a major histocompatibility complex class II-dependent T cell proliferation assay. Initial fractionation with red dye A chromatography indicated production of a class II-dependent T cell mitogen by a toxic shock-like syndrome (TSLS) strain. The amino terminus of the purified streptococcal superantigen was more homologous to the amino termini of staphylococcal enterotoxins B, C1, and C3 (SEB, SEC1, and SEC3), than to those of pyrogenic exotoxins A, B, C or other streptococcal toxins. The molecule, designated SSA, had the same pattern of class II isotype usage as SEB in T cell proliferation assays. However, it differed in its pattern of human T cell activation, as measured by quantitative polymerase chain reaction with V beta-specific primers. SSA activated human T cells that express V beta 1, 3, 15 with a minor increase of V beta 5.2-bearing cells, whereas SEB activated V beta 3, 12, 15, and 17-bearing T cells. Immunoblot analysis of 75 disease isolates from several localities detected SSA production only in group A streptococci, and found that SSA is apparently confined to only three clonal […] Find the latest version: https://jci.me/116641/pdf A Novel Superantigen Isolated from Pathogenic Strains of Streptococcus pyogenes with Aminoterminal Homology to Staphylococcal Enterotoxins B and C Joseph A.
    [Show full text]
  • Retrograde Transport of Mutant Ricin to the Endoplasmic Reticulum with Subsequent Translocation to Cytosol (Ricin͞toxin͞translocation͞retrograde Transport͞sulfation)
    Proc. Natl. Acad. Sci. USA Vol. 94, pp. 3783–3788, April 1997 Cell Biology Retrograde transport of mutant ricin to the endoplasmic reticulum with subsequent translocation to cytosol (ricinytoxinytranslocationyretrograde transportysulfation) ANDRZEJ RAPAK,PÅL Ø. FALNES, AND SJUR OLSNES* Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, 0310 Oslo, Norway Communicated by R. John Collier, Harvard Medical School, Boston, MA, January 30, 1997 (received for review November 25, 1996) ABSTRACT Translocation of ricin A chain to the cytosol (20). Because this labeling takes place in the Golgi apparatus, only has been proposed to take place from the endoplasmic reticulum molecules that have already been transported retrograde to the (ER), but attempts to visualize ricin in this organelle have failed. Golgi complex will be labeled. Furthermore, because only the A Here we modified ricin A chain to contain a tyrosine sulfation chain carrying the sulfation site will be labeled, the B chain, which site alone or in combination with N-glycosylation sites. When migrates at almost the same rate as the modified A chain, will not reconstituted with ricin B chain and incubated with cells in the complicate the interpretation of the data. We here present 35 presence of Na2 SO4, the modified A chains were labeled. The evidence that sulfated ricin A chain is transported retrograde to labeling was prevented by brefeldin A and ilimaquinone, and it the ER and then translocated to the cytosol. appears to take place in the Golgi apparatus. This method allows selective labeling of ricin molecules that have already been MATERIALS AND METHODS 35 transported retrograde to this organelle.
    [Show full text]
  • Multiple Roles of Staphylococcus Aureus Enterotoxins: Pathogenicity, Superantigenic Activity, and Correlation to Antibiotic Resistance
    Toxins 2010, 2, 2117-2131; doi:10.3390/toxins2082117 OPEN ACCESS toxins ISSN 2072-6651 www.mdpi.com/journal/toxins Review Multiple Roles of Staphylococcus aureus Enterotoxins: Pathogenicity, Superantigenic Activity, and Correlation to Antibiotic Resistance Elena Ortega, Hikmate Abriouel, Rosario Lucas and Antonio Gálvez * Area de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071-Jaén, Spain; E-Mails: [email protected] (E.O.); [email protected] (H.A.); [email protected] (R.L.) * Author to whom correspondence should be addressed: E-Mail: [email protected]; Tel.: +34 953 212160; Fax: +34 953 212943. Received: 3 July 2010 / Accepted: 9 August 2010 / Published: 10 August 2010 Abstract: Heat-stable enterotoxins are the most notable virulence factors associated with Staphylococcus aureus, a common pathogen associated with serious community and hospital acquired diseases. Staphylococcal enterotoxins (SEs) cause toxic shock-like syndromes and have been implicated in food poisoning. But SEs also act as superantigens that stimulate T-cell proliferation, and a high correlation between these activities has been detected. Most of the nosocomial S. aureus infections are caused by methicillin-resistant S. aureus (MRSA) strains, and those resistant to quinolones or multiresistant to other antibiotics are emerging, leaving a limited choice for their control. This review focuses on these diverse roles of SE, their possible correlations and the influence in disease progression and therapy. Keywords: enterotoxins; Staphylococcus aureus; superantigens; MRSA; immune response 1. Introduction Staphylococcus aureus is a common pathogen associated with serious community and hospital acquired diseases and has for a long time been considered as a major problem of Public Health [1].
    [Show full text]
  • Panton-Valentine Leukocidin Exotoxin Found in Intermediate Methicillin Resistant Staphylococcus Aureus Samples on Belmont University’S Campus
    Panton-Valentine Leukocidin Exotoxin Found in Intermediate Methicillin Resistant Staphylococcus aureus Samples on Belmont University’s Campus Jordan D. Helms and Jennifer T. Thomas, Ph.D. Methicillin-Resistant Staphylococcus aureus (MRSA), a pathogenic strain of Staphylococcus aureus, results in thousands of infections and associated deaths each year. A strain of MRSA, USA300, has been identified as the most common cause of skin and soft tissue infections acquired from the community in the United States. The goal of our study is to determine the prevalence of the USA300 strain, responsible for new community-associated MRSA infections, on Belmont University’s campus via PCR detection of the Panton-Valentine Leukocidin (PVL) gene, a bacterial toxin. We collected isolates from different locations on Belmont’s campus, confirmed them as MRSA using Gram staining, coagulase testing, and the use of the Kirby-Bauer disk diffusion assay. Bacterial DNA was isolated and PCR analysis performed to identify the PVL gene. We found PVL in Intermediate Methicillin Resistant Staphylococcus aureus isolates. This is surprising because the presence of PVL causes otherwise harmless Staph infections more severe and lethal if left untreated. In addition, there is very little literature on Intermediate Staphylococcus aureus infections alone, as well as its relationship with PVL. The presence of this exotoxin on Belmont’s campus puts individuals at greater risk of a severe infection and proper preventive protocol needs to be followed to ensure safety. INTRODUCTION Staphylococcus aureus and Staph infections Staphylococcus aureus (S. aureus) is a gram-positive, coccus shaped bacterium. Microscopically, it appears in tetrads and grapelike clusters and forms large, convex, golden colonies on growth plates (aureus is Latin for “gold”).
    [Show full text]