1
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Tucker SK, McHugh RE, Roe AJ. One problem, multiple potential targets: Where are we now in the development of small molecule inhibitors against Shiga toxin? Cell Signal 2024; 121:111253. [PMID: 38852937 DOI: 10.1016/j.cellsig.2024.111253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/11/2024]
Abstract
Shiga toxin-producing Escherichia coli (STEC) are a group of enteric pathogens which carry phage-encoded Shiga toxins (Stx). STEC infections begin with severe abdominal pain and non-bloody diarrhoea, which can progress to bloody diarrhoea after approximately 4-days post-infection. In high-risk groups such as children and the elderly, patients may develop haemolytic uremic syndrome (HUS). HUS is characterised by microangiopathic haemolytic anaemia, thrombocytopenia, and in severe disease acute renal failure. Traditional antibiotics have been linked with increased toxin production due to the activation of recA-mediated bacterial stress response, resulting in poorer patient outcomes. Therefore, treatment relies on supportive therapies. Antivirulence strategies have been explored as an alternative treatment for bacterial infections and blockers of virulence factors such as the Type III Secretion System. Recent improvements in the mechanistic understanding of the Stx pathway have led to the design of inhibitors to disrupt the pathway, leading to toxin-mediated ribosome damage. However, compounds have yet to progress beyond Phase III clinical trials successfully. This review explores the progress in developing small molecule inhibitors by collating lead compounds derived from in-silico and experimental approaches.
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Affiliation(s)
- Samantha K Tucker
- School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Rebecca E McHugh
- School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Andrew J Roe
- School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, United Kingdom.
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2
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Sabino YNV, Cotter PD, Mantovani HC. Anti-virulence compounds against Staphylococcus aureus associated with bovine mastitis: A new therapeutic option? Microbiol Res 2023; 271:127345. [PMID: 36889204 DOI: 10.1016/j.micres.2023.127345] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/22/2023] [Accepted: 02/26/2023] [Indexed: 03/05/2023]
Abstract
Bovine mastitis represents a major economic burden faced by the dairy industry. S. aureus is an important and prevalent bovine mastitis-associated pathogen in dairy farms worldwide. The pathogenicity and persistence of S. aureus in the bovine mammary gland are associated with the expression of a range of virulence factors involved in biofilm formation and the production of several toxins. The traditional therapeutic approach to treating bovine mastitis includes the use of antibiotics, but the emergence of antibiotic-resistant strains has caused therapeutic failure. New therapeutic approaches targeting virulence factors of S. aureus rather than cell viability can have several advantages including lower selective pressure towards the development of resistance and little impact on the host commensal microbiota. This review summarizes the potential of anti-virulence therapies to control S. aureus associated with bovine mastitis focusing on anti-toxin, anti-biofilm, and anti-quorum sensing compounds. It also points to potential sources of new anti-virulence inhibitors and presents screening strategies for identifying these compounds.
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Affiliation(s)
| | | | - Hilario C Mantovani
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, USA.
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3
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Liu Y, Thaker H, Wang C, Xu Z, Dong M. Diagnosis and Treatment for Shiga Toxin-Producing Escherichia coli Associated Hemolytic Uremic Syndrome. Toxins (Basel) 2022; 15:10. [PMID: 36668830 PMCID: PMC9862836 DOI: 10.3390/toxins15010010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/13/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC)-associated hemolytic uremic syndrome (STEC-HUS) is a clinical syndrome involving hemolytic anemia (with fragmented red blood cells), low levels of platelets in the blood (thrombocytopenia), and acute kidney injury (AKI). It is the major infectious cause of AKI in children. In severe cases, neurological complications and even death may occur. Treating STEC-HUS is challenging, as patients often already have organ injuries when they seek medical treatment. Early diagnosis is of great significance for improving prognosis and reducing mortality and sequelae. In this review, we first briefly summarize the diagnostics for STEC-HUS, including history taking, clinical manifestations, fecal and serological detection methods for STEC, and complement activation monitoring. We also summarize preventive and therapeutic strategies for STEC-HUS, such as vaccines, volume expansion, renal replacement therapy (RRT), antibiotics, plasma exchange, antibodies and inhibitors that interfere with receptor binding, and the intracellular trafficking of the Shiga toxin.
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Affiliation(s)
- Yang Liu
- Department of Nephrology, The First Hospital of Jilin University, Changchun 130021, China
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
- Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Hatim Thaker
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
- Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Chunyan Wang
- Department of Nephrology, Children’s Hospital of Fudan University, Shanghai 201102, China
| | - Zhonggao Xu
- Department of Nephrology, The First Hospital of Jilin University, Changchun 130021, China
| | - Min Dong
- Department of Urology, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
- Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
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4
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Abstract
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The paradigm of antivirulence
therapy dictates that bacterial pathogens
are specifically disarmed but not killed by neutralizing their virulence
factors. Clearance of the invading pathogen by the immune system is
promoted. As compared to antibiotics, the pathogen-selective antivirulence
drugs hold promise to minimize collateral damage to the beneficial
microbiome. Also, selective pressure for resistance is expected to
be lower because bacterial viability is not directly affected. Antivirulence
drugs are being developed for stand-alone prophylactic and therapeutic
treatments but also for combinatorial use with antibiotics. This Review
focuses on drug modalities that target bacterial exotoxins after the
secretion or release-upon-lysis. Exotoxins have a significant and
sometimes the primary role as the disease-causing virulence factor,
and thereby they are attractive targets for drug development. We describe
the key pre-clinical and clinical trial data that have led to the
approval of currently used exotoxin-targeted drugs, namely the monoclonal
antibodies bezlotoxumab (toxin B/TcdB, Clostridioides difficile), raxibacumab (anthrax toxin, Bacillus anthracis), and obiltoxaximab (anthrax toxin, Bacillus anthracis), but also to challenges with some of the promising leads. We also
highlight the recent developments in pre-clinical research sector
to develop exotoxin-targeted drug modalities, i.e., monoclonal antibodies,
antibody fragments, antibody mimetics, receptor analogs, neutralizing
scaffolds, dominant-negative mutants, and small molecules. We describe
how these exotoxin-targeted drug modalities work with high-resolution
structural knowledge and highlight their advantages and disadvantages
as antibiotic alternatives.
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Affiliation(s)
- Moona Sakari
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
| | - Arttu Laisi
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
| | - Arto T. Pulliainen
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
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Hwang SB, Chelliah R, Kang JE, Rubab M, Banan-MwineDaliri E, Elahi F, Oh DH. Role of Recent Therapeutic Applications and the Infection Strategies of Shiga Toxin-Producing Escherichia coli. Front Cell Infect Microbiol 2021; 11:614963. [PMID: 34268129 PMCID: PMC8276698 DOI: 10.3389/fcimb.2021.614963] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/07/2021] [Indexed: 12/17/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a global foodborne bacterial pathogen that is often accountable for colon disorder or distress. STEC commonly induces severe diarrhea in hosts but can cause critical illnesses due to the Shiga toxin virulence factors. To date, there have been a significant number of STEC serotypes have been evolved. STECs vary from nausea and hemorrhoid (HC) to possible lethal hemolytic-based uremic syndrome (HUS), thrombotic thrombocytopenic purpura (TTP). Inflammation-based STEC is usually a foodborne illness with Shiga toxins (Stx 1 and 2) thought to be pathogenesis. The STEC's pathogenicity depends significantly on developing one or more Shiga toxins, which can constrain host cell protein synthesis leading to cytotoxicity. In managing STEC infections, antimicrobial agents are generally avoided, as bacterial damage and discharge of accumulated toxins are thought the body. It has also been documented that certain antibiotics improve toxin production and the development of these species. Many different groups have attempted various therapies, including toxin-focused antibodies, toxin-based polymers, synbiotic agents, and secondary metabolites remedies. Besides, in recent years, antibiotics' efficacy in treating STEC infections has been reassessed with some encouraging methods. Nevertheless, the primary role of synbiotic effectiveness (probiotic and prebiotic) against pathogenic STEC and other enteropathogens is less recognized. Additional studies are required to understand the mechanisms of action of probiotic bacteria and yeast against STEC infection. Because of the consensus contraindication of antimicrobials for these bacterial pathogens, the examination was focused on alternative remedy strategies for STEC infections. The rise of novel STEC serotypes and approaches employed in its treatment are highlighted.
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Affiliation(s)
- Su-bin Hwang
- Department of Food Science and Biotechnology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Ramachandran Chelliah
- Department of Food Science and Biotechnology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Ji Eun Kang
- Department of Food Science and Biotechnology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Momna Rubab
- School of Food and Agricultural Sciences, University of Management and Technology, Lahore, Pakistan
| | - Eric Banan-MwineDaliri
- Department of Food Science and Biotechnology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Fazle Elahi
- Department of Food Science and Biotechnology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Deog-Hwan Oh
- Department of Food Science and Biotechnology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
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Haksar D, Asadpoor M, Heise T, Shi J, Braber S, Folkerts G, Ballell L, Rodrigues J, Pieters RJ. Fighting Shigella by Blocking Its Disease-Causing Toxin. J Med Chem 2021; 64:6059-6069. [PMID: 33909975 PMCID: PMC8154557 DOI: 10.1021/acs.jmedchem.1c00152] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Shiga toxin is an
AB5 toxin produced by Shigella species, while related toxins are produced
by Shiga toxin-producing Escherichia coli (STEC). Infection by Shigella can lead to bloody diarrhea followed
by the often fatal hemolytic uremic syndrome (HUS). In the present
paper, we aimed for a simple and effective toxin inhibitor by comparing
three classes of carbohydrate-based inhibitors: glycodendrimers, glycopolymers,
and oligosaccharides. We observed a clear enhancement in potency for
multivalent inhibitors, with the divalent and tetravalent compounds
inhibiting in the millimolar and micromolar range, respectively. However,
the polymeric inhibitor based on galabiose was the most potent in
the series exhibiting nanomolar inhibition. Alginate and chitosan
oligosaccharides also inhibit Shiga toxin and may be used as a prophylactic
drug during shigella outbreaks.
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Affiliation(s)
- Diksha Haksar
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Mostafa Asadpoor
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Torben Heise
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Jie Shi
- Diseases of the Developing World (DDW), Global Health R&D, GlaxoSmithKline, Tres Cantos, 28760 Madrid, Spain
| | - Saskia Braber
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Gert Folkerts
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Lluis Ballell
- Diseases of the Developing World (DDW), Global Health R&D, GlaxoSmithKline, Tres Cantos, 28760 Madrid, Spain
| | - Janneth Rodrigues
- Diseases of the Developing World (DDW), Global Health R&D, GlaxoSmithKline, Tres Cantos, 28760 Madrid, Spain
| | - Roland J Pieters
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
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7
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Valid Presumption of Shiga Toxin-Mediated Damage of Developing Erythrocytes in EHEC-Associated Hemolytic Uremic Syndrome. Toxins (Basel) 2020; 12:toxins12060373. [PMID: 32512916 PMCID: PMC7354503 DOI: 10.3390/toxins12060373] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023] Open
Abstract
The global emergence of clinical diseases caused by enterohemorrhagic Escherichia coli (EHEC) is an issue of great concern. EHEC release Shiga toxins (Stxs) as their key virulence factors, and investigations on the cell-damaging mechanisms toward target cells are inevitable for the development of novel mitigation strategies. Stx-mediated hemolytic uremic syndrome (HUS), characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury, is the most severe outcome of an EHEC infection. Hemolytic anemia during HUS is defined as the loss of erythrocytes by mechanical disruption when passing through narrowed microvessels. The formation of thrombi in the microvasculature is considered an indirect effect of Stx-mediated injury mainly of the renal microvascular endothelial cells, resulting in obstructions of vessels. In this review, we summarize and discuss recent data providing evidence that HUS-associated hemolytic anemia may arise not only from intravascular rupture of erythrocytes, but also from the extravascular impairment of erythropoiesis, the development of red blood cells in the bone marrow, via direct Stx-mediated damage of maturing erythrocytes, leading to “non-hemolytic” anemia.
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8
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Lingwood C. Verotoxin Receptor-Based Pathology and Therapies. Front Cell Infect Microbiol 2020; 10:123. [PMID: 32296648 PMCID: PMC7136409 DOI: 10.3389/fcimb.2020.00123] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/05/2020] [Indexed: 12/22/2022] Open
Abstract
Verotoxin, VT (aka Shiga toxin,Stx) is produced by enterohemorrhagic E. coli (EHEC) and is the key pathogenic factor in EHEC-induced hemolytic uremic syndrome (eHUS-hemolytic anemia/thrombocytopenia/glomerular infarct) which can follow gastrointestinal EHEC infection, particularly in children. This AB5 subunit toxin family bind target cell globotriaosyl ceramide (Gb3), a glycosphingolipid (GSL) (aka CD77, pk blood group antigen) of the globoseries of neutral GSLs, initiating lipid raft-dependent plasma membrane Gb3 clustering, membrane curvature, invagination, scission, endosomal trafficking, and retrograde traffic via the TGN to the Golgi, and ER. In the ER, A/B subunits separate and the A subunit hijacks the ER reverse translocon (dislocon-used to eliminate misfolded proteins-ER associated degradation-ERAD) for cytosolic access. This property has been used to devise toxoid-based therapy to temporarily block ERAD and rescue the mutant phenotype of several genetic protein misfolding diseases. The A subunit avoids cytosolic proteosomal degradation, to block protein synthesis via its RNA glycanase activity. In humans, Gb3 is primarily expressed in the kidney, particularly in the glomerular endothelial cells. Here, Gb3 is in lipid rafts (more ordered membrane domains which accumulate GSLs/cholesterol) whereas renal tubular Gb3 is in the non-raft membrane fraction, explaining the basic pathology of eHUS (glomerular endothelial infarct). Females are more susceptible and this correlates with higher renal Gb3 expression. HUS can be associated with encephalopathy, more commonly following verotoxin 2 exposure. Gb3 is expressed in the microvasculature of the brain. All members of the VT family bind Gb3, but with varying affinity. VT2e (pig edema toxin) binds Gb4 preferentially. Verotoxin-specific therapeutics based on chemical analogs of Gb3, though effective in vitro, have failed in vivo. While some analogs are effective in animal models, there are no good rodent models of eHUS since Gb3 is not expressed in rodent glomeruli. However, the mouse mimics the neurological symptoms more closely and provides an excellent tool to assess therapeutics. In addition to direct cytotoxicity, other factors including VT–induced cytokine release and aberrant complement cascade, are now appreciated as important in eHUS. Based on atypical HUS therapy, treatment of eHUS patients with anticomplement antibodies has proven effective in some cases. A recent switch using stem cells to try to reverse, rather than prevent VT induced pathology may prove a more effective methodology.
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Affiliation(s)
- Clifford Lingwood
- Molecular Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
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9
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Huang K, Marchesi A, Hollingsworth K, Both P, Mattey AP, Pallister E, Ledru H, Charnock SJ, Galan MC, Turnbull WB, Parmeggiani F, Flitsch SL. Biochemical characterisation of an α1,4 galactosyltransferase from Neisseria weaveri for the synthesis of α1,4-linked galactosides. Org Biomol Chem 2020; 18:3142-3148. [DOI: 10.1039/d0ob00407c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new α1,4 galactosyltransferase has been characterised and used for the synthesis of natural and non-natural cell surface trisaccharide antigens.
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10
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Pohlentz G, Steil D, Rubin D, Mellmann A, Karch H, Müthing J. Pectin-derived neoglycolipids: Tools for differentiation of Shiga toxin subtypes and inhibitors of Shiga toxin-mediated cellular injury. Carbohydr Polym 2019; 212:323-333. [DOI: 10.1016/j.carbpol.2019.02.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/04/2019] [Accepted: 02/12/2019] [Indexed: 01/14/2023]
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11
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Matsuoka K, Nishikawa K, Goshu Y, Koyama T, Hatano K, Matsushita T, Watanabe-Takahashi M, Natori Y, Terunuma D. Synthetic construction of sugar-amino acid hybrid polymers involving globotriaose or lactose and evaluation of their biological activities against Shiga toxins produced by Escherichia coli O157:H7. Bioorg Med Chem 2018; 26:5792-5803. [PMID: 30420327 DOI: 10.1016/j.bmc.2018.10.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 01/09/2023]
Abstract
Synthetic assembly of sugar moieties and amino acids in order to create "sugar-amino acid hybrid polymers" was accomplished by means of simple radical polymerization of carbohydrate monomers having an amino acid-modified polymerizable aglycon. Amines derived from globotriaoside and lactoside as glycoepitopes were condensed with known carbobenzyloxy derivatives, including Z-Gly, Z-l-Ala and Z-β-Ala, which had appropriate spacer ability and a chiral center to afford fully protected sugar-amino acid hybrid compounds in good yields. After deprotection followed by acryloylation, the water-soluble glycomonomers were polymerized with or without acrylamide in the presence of a radical initiator in water to give corresponding copolymers and homopolymers, which were shown by SEC analysis to have high molecular weights. Evaluation of the biological activities of the glycopolymers against Shiga toxins (Stxs) was carried out, and the results suggested that glycopolymers having highly clustered globotriaosyl residues had high affinity against Stx2 (KD = 2.7∼4.0 µM) even though other glycopolymers did not show any affinity or showed very weak binding affinity. When Stx1 was used for the same assay, all of the glycopolymers having globotriaosyl residues showed high affinity (KD = 0.30∼1.74 µM). Interestingly, couple of glycopolymers having lactosyl moieties had weaker binding affinity against Stx1. In addition, when cytotoxicity assays were carried out for both Stxs, glycopolymers having highly clustered globotriaosyl residues showed higher affinity than that of the copolymers, and only highly clustered-type glycopolymers displayed neutralization potency against Stx2.
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Affiliation(s)
- Koji Matsuoka
- Area for Molecular Function, Division of Material Science, Graduate School of Science and Engineering, Saitama University, Sakura, Saitama 338-8570, Japan; Medical Innovation Research Unit (MiU), Advanced Institute of Innovative Technology (AIIT), Saitama University, Sakura, Saitama 338-8570, Japan.
| | - Kiyotaka Nishikawa
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, 1-3 Miyakotani, Tatara, Kyotanabe, Kyoto 610-0394, Japan
| | - Yusuke Goshu
- Area for Molecular Function, Division of Material Science, Graduate School of Science and Engineering, Saitama University, Sakura, Saitama 338-8570, Japan
| | - Tetsuo Koyama
- Area for Molecular Function, Division of Material Science, Graduate School of Science and Engineering, Saitama University, Sakura, Saitama 338-8570, Japan
| | - Ken Hatano
- Area for Molecular Function, Division of Material Science, Graduate School of Science and Engineering, Saitama University, Sakura, Saitama 338-8570, Japan; Medical Innovation Research Unit (MiU), Advanced Institute of Innovative Technology (AIIT), Saitama University, Sakura, Saitama 338-8570, Japan
| | - Takahiko Matsushita
- Area for Molecular Function, Division of Material Science, Graduate School of Science and Engineering, Saitama University, Sakura, Saitama 338-8570, Japan; Medical Innovation Research Unit (MiU), Advanced Institute of Innovative Technology (AIIT), Saitama University, Sakura, Saitama 338-8570, Japan
| | - Miho Watanabe-Takahashi
- Department of Molecular Life Sciences, Graduate School of Life and Medical Sciences, Doshisha University, 1-3 Miyakotani, Tatara, Kyotanabe, Kyoto 610-0394, Japan
| | - Yasuhiro Natori
- Department of Health Chemistry, School of Pharmacy, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-8505, Japan
| | - Daiyo Terunuma
- Area for Molecular Function, Division of Material Science, Graduate School of Science and Engineering, Saitama University, Sakura, Saitama 338-8570, Japan
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12
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Hall G, Kurosawa S, Stearns-Kurosawa DJ. Shiga Toxin Therapeutics: Beyond Neutralization. Toxins (Basel) 2017; 9:toxins9090291. [PMID: 28925976 PMCID: PMC5618224 DOI: 10.3390/toxins9090291] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 09/15/2017] [Accepted: 09/15/2017] [Indexed: 01/04/2023] Open
Abstract
Ribotoxic Shiga toxins are the primary cause of hemolytic uremic syndrome (HUS) in patients infected with Shiga toxin-producing enterohemorrhagic Escherichia coli (STEC), a pathogen class responsible for epidemic outbreaks of gastrointestinal disease around the globe. HUS is a leading cause of pediatric renal failure in otherwise healthy children, resulting in a mortality rate of 10% and a chronic morbidity rate near 25%. There are currently no available therapeutics to prevent or treat HUS in STEC patients despite decades of work elucidating the mechanisms of Shiga toxicity in sensitive cells. The preclinical development of toxin-targeted HUS therapies has been hindered by the sporadic, geographically dispersed nature of STEC outbreaks with HUS cases and the limited financial incentive for the commercial development of therapies for an acute disease with an inconsistent patient population. The following review considers potential therapeutic targeting of the downstream cellular impacts of Shiga toxicity, which include the unfolded protein response (UPR) and the ribotoxic stress response (RSR). Outcomes of the UPR and RSR are relevant to other diseases with large global incidence and prevalence rates, thus reducing barriers to the development of commercial drugs that could improve STEC and HUS patient outcomes.
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Affiliation(s)
- Gregory Hall
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Shinichiro Kurosawa
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Deborah J Stearns-Kurosawa
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA.
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13
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Dickey SW, Cheung GYC, Otto M. Different drugs for bad bugs: antivirulence strategies in the age of antibiotic resistance. Nat Rev Drug Discov 2017; 16:457-471. [PMID: 28337021 DOI: 10.1038/nrd.2017.23] [Citation(s) in RCA: 451] [Impact Index Per Article: 64.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The rapid evolution and dissemination of antibiotic resistance among bacterial pathogens are outpacing the development of new antibiotics, but antivirulence agents provide an alternative. These agents can circumvent antibiotic resistance by disarming pathogens of virulence factors that facilitate human disease while leaving bacterial growth pathways - the target of traditional antibiotics - intact. Either as stand-alone medications or together with antibiotics, these drugs are intended to treat bacterial infections in a largely pathogen-specific manner. Notably, development of antivirulence drugs requires an in-depth understanding of the roles that diverse virulence factors have in disease processes. In this Review, we outline the theory behind antivirulence strategies and provide examples of bacterial features that can be targeted by antivirulence approaches. Furthermore, we discuss the recent successes and failures of this paradigm, and new developments that are in the pipeline.
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Affiliation(s)
- Seth W Dickey
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland 20814, USA
| | - Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland 20814, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland 20814, USA
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14
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Affiliation(s)
- Megan Garland
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
| | - Sebastian Loscher
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
| | - Matthew Bogyo
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
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Zhang P, Paszkiewicz E, Wang Q, Sadowska JM, Kitov PI, Bundle DR, Ling CC. Clustering of PK-trisaccharides on amphiphilic cyclodextrin reveals unprecedented affinity for the Shiga-like toxin Stx2. Chem Commun (Camb) 2017; 53:10528-10531. [DOI: 10.1039/c7cc06299k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Amphiphilic cyclodextrin-based PK-glycoarrays show remarkable binding avidity and selectivity for Stx2 in solid phase assay formats.
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Affiliation(s)
- Ping Zhang
- Alberta Glycomics Centre
- Department of Chemistry
- University of Calgary
- Calgary
- T2N 1N4 Canada
| | - Eugenia Paszkiewicz
- Alberta Glycomics Centre
- Department of Chemistry
- University of Alberta
- Edmonton
- T6G 2G2 Canada
| | - Qifang Wang
- Alberta Glycomics Centre
- Department of Chemistry
- University of Calgary
- Calgary
- T2N 1N4 Canada
| | - Joanna M. Sadowska
- Alberta Glycomics Centre
- Department of Chemistry
- University of Alberta
- Edmonton
- T6G 2G2 Canada
| | - Pavel I. Kitov
- Alberta Glycomics Centre
- Department of Chemistry
- University of Alberta
- Edmonton
- T6G 2G2 Canada
| | - David R. Bundle
- Alberta Glycomics Centre
- Department of Chemistry
- University of Alberta
- Edmonton
- T6G 2G2 Canada
| | - Chang-Chun Ling
- Alberta Glycomics Centre
- Department of Chemistry
- University of Calgary
- Calgary
- T2N 1N4 Canada
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Abstract
Post-infectious hemolytic uremic syndrome (HUS) is caused by specific pathogens in patients with no identifiable HUS-associated genetic mutation or autoantibody. The majority of episodes is due to infections by Shiga toxin (Stx) producing Escherichia coli (STEC). This chapter reviews the epidemiology and pathogenesis of STEC-HUS, including bacterial-derived factors and host responses. STEC disease is characterized by hematological (microangiopathic hemolytic anemia), renal (acute kidney injury) and extrarenal organ involvement. Clinicians should always strive for an etiological diagnosis through the microbiological or molecular identification of Stx-producing bacteria and Stx or, if negative, serological assays. Treatment of STEC-HUS is supportive; more investigations are needed to evaluate the efficacy of putative preventive and therapeutic measures, such as non-phage-inducing antibiotics, volume expansion and anti-complement agents. The outcome of STEC-HUS is generally favorable, but chronic kidney disease, permanent extrarenal, mainly cerebral complication and death (in less than 5 %) occur and long-term follow-up is recommended. The remainder of this chapter highlights rarer forms of (post-infectious) HUS due to S. dysenteriae, S. pneumoniae, influenza A and HIV and discusses potential interactions between these pathogens and the complement system.
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Affiliation(s)
- Denis F. Geary
- Division of Nephrology, The Hospital for Sick Children, Toronto, Ontario Canada
| | - Franz Schaefer
- Division of Pediatric Nephrology, University of Heidelberg, Heidelberg, Germany
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Langdon A, Crook N, Dantas G. The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation. Genome Med 2016; 8:39. [PMID: 27074706 PMCID: PMC4831151 DOI: 10.1186/s13073-016-0294-z] [Citation(s) in RCA: 515] [Impact Index Per Article: 64.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The widespread use of antibiotics in the past 80 years has saved millions of human lives, facilitated technological progress and killed incalculable numbers of microbes, both pathogenic and commensal. Human-associated microbes perform an array of important functions, and we are now just beginning to understand the ways in which antibiotics have reshaped their ecology and the functional consequences of these changes. Mounting evidence shows that antibiotics influence the function of the immune system, our ability to resist infection, and our capacity for processing food. Therefore, it is now more important than ever to revisit how we use antibiotics. This review summarizes current research on the short-term and long-term consequences of antibiotic use on the human microbiome, from early life to adulthood, and its effect on diseases such as malnutrition, obesity, diabetes, and Clostridium difficile infection. Motivated by the consequences of inappropriate antibiotic use, we explore recent progress in the development of antivirulence approaches for resisting infection while minimizing resistance to therapy. We close the article by discussing probiotics and fecal microbiota transplants, which promise to restore the microbiota after damage of the microbiome. Together, the results of studies in this field emphasize the importance of developing a mechanistic understanding of gut ecology to enable the development of new therapeutic strategies and to rationally limit the use of antibiotic compounds.
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Affiliation(s)
- Amy Langdon
- Center for Genome Sciences, Washington University School of Medicine, Campus Box 8510, 4515 McKinley Research Building, St. Louis, MO, 63108, USA
- Clinical Research Training Center, Washington University School of Medicine, Campus Box 8051, 660 South Euclid Avenue, St. Louis, MO, 63110-1093, USA
| | - Nathan Crook
- Center for Genome Sciences, Washington University School of Medicine, Campus Box 8510, 4515 McKinley Research Building, St. Louis, MO, 63108, USA
- Department of Pathology & Immunology, Washington University School of Medicine, Campus Box 8118, 660 South Euclid Ave, St. Louis, MO, 63110, USA
| | - Gautam Dantas
- Center for Genome Sciences, Washington University School of Medicine, Campus Box 8510, 4515 McKinley Research Building, St. Louis, MO, 63108, USA.
- Department of Pathology & Immunology, Washington University School of Medicine, Campus Box 8118, 660 South Euclid Ave, St. Louis, MO, 63110, USA.
- Department of Biomedical Engineering, Washington University in Saint Louis, Campus Box 1097, 1 Brookings Drive, Saint Louis, MO, 63130, USA.
- Department of Molecular Microbiology, Washington University School of Medicine, Campus Box 8230, 660 S. Euclid Ave, St. Louis, MO, 63110, USA.
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Akhi MT, Ostadgavahi AT, Ghotaslou R, Asgharzadeh M, Pirzadeh T, Sorayaei Sowmesarayi V, Memar MY. Detection, Virulence Gene Assessment and Antibiotic Resistance Pattern of O157 Enterohemorrhagic Escherichia coli in Tabriz, Iran. Jundishapur J Microbiol 2015; 8:e25317. [PMID: 26865935 PMCID: PMC4744324 DOI: 10.5812/jjm.25317] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 07/21/2015] [Accepted: 08/01/2015] [Indexed: 12/26/2022] Open
Abstract
Background: Shiga toxin-producing Escherichia coli (STEC) is a food-borne pathogen and infection with this organism causes illnesses such as bloody diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome. Objectives: Considering the lack of any information about the prevalence rate and the antibiotic resistance pattern of O157:H7 serotype in Tabriz, finding answers to the above mentioned subjects was among the goals of this study. Materials and Methods: Two hundred E. coli strains from diarrheal or non-diarrheal stools of outpatients and hospitalized cases in Tabriz Imam Reza hospital were isolated between September and December 2014 using MacConkey agar and standard biochemical tests and then cultured on sorbitol MacConkey agar. The sorbitol-negative isolates were confirmed as the O157 serotype using O157 antisera. A multiplex polymerase chain reaction (PCR) method was used for the detection of stx-1, stx-2, eae, and mdh genes and the antibiotic resistance pattern of these isolates was determined using Kirby-Bauer method and clinical and laboratory standards institute (CLSI) standards. Results: Of the isolates 11 (5.5%) were sorbitol-negative, which were later analyzed by multiplex PCR and the results revealed that 2 (18.18%) isolates contained the stx-1 gene, 10 (90.91%) contained the stx-2 gene, and 5 (45.45%) contained the eae gene. The stx-2 and eae genes were the most commonly encountered virulence factors. All or most of the isolates were susceptible to ceftazidime (100%), gentamicin (100%), ciprofloxacin (100%), nalidixic acid (90.9%), trimetoprim sulfamethoxazole (90.9%), chloramphenicol (90.9%), ampicillin (81.8%), and cephalothin (72.7%). On the contrary, moderate susceptibility of the isolates to doxycycline (54.5%) was observed. Conclusions: Due to the low frequency of STEC O157 and the high susceptibility rates of the isolates to the tested antibiotics in this study, STEC O157 has not become a major problem in Tabriz yet, but comprehensive microbiological surveillance programs that provide early warning and limit the scale of possible outbreaks would be essential.
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Affiliation(s)
- Mohammad Taghi Akhi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran
- Research Center of Infectious and Tropical Diseases, Tabriz University of Medical Sciences, Tabriz, IR Iran
- Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, International Branch, Tabriz, IR Iran
- Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, IR Iran
| | - Ali Toloue Ostadgavahi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran
- Research Center of Infectious and Tropical Diseases, Tabriz University of Medical Sciences, Tabriz, IR Iran
- Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, International Branch, Tabriz, IR Iran
- Corresponding author: Ali Toloue Ostadgavahi, Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, International Branch, Tabriz, IR Iran. Tel/Fax: +98-5138452951, E-mail:
| | - Reza Ghotaslou
- Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, IR Iran
| | | | - Tahereh Pirzadeh
- Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, IR Iran
| | - Vida Sorayaei Sowmesarayi
- Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, International Branch, Tabriz, IR Iran
| | - Mohammad Yousef Memar
- Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, IR Iran
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Picard C, Burtey S, Bornet C, Curti C, Montana M, Vanelle P. Pathophysiology and treatment of typical and atypical hemolytic uremic syndrome. ACTA ACUST UNITED AC 2015; 63:136-43. [DOI: 10.1016/j.patbio.2015.03.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 03/03/2015] [Indexed: 12/21/2022]
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Abstract
ABSTRACT
Shiga toxin (Stx)-producing
Escherichia coli
(STEC) is an etiologic agent of bloody diarrhea. A serious sequela of disease, the hemolytic uremic syndrome (HUS) may arise in up to 25% of patients. The development of HUS after STEC infection is linked to the presence of Stx. STEC strains may produce one or more Stxs, and the Stxs come in two major immunological groups, Stx1 and Stx2. A multitude of possible therapeutics designed to inhibit the actions of the Stxs have been developed over the past 30 years. Such therapeutics are important because antibiotic treatment of STEC infections is contraindicated due to an increased potential for development of HUS. The reason for the increased risk of HUS after antibiotic treatment is likely because certain antibiotics induce expression of the Stxs, which are generally associated with lysogenic bacteriophages. There are a few potential therapeutics that either try to kill STEC without inducing Stx expression or target gene expression within STEC. However, the vast majority of the treatments under development are designed to limit Stx receptor generation or to prevent toxin binding, trafficking, processing, or activity within the cell. The potential therapies described in this review include some that have only been tested in vitro and several that demonstrate efficacy in animals. The therapeutics that are currently the furthest along in development (completed phase I and II trials) are monoclonal antibodies directed against Stx1 and Stx2.
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Yamashita A, Hashimoto H, Fujita K, Okada M, Mori S, Kitahata S. Reverse Reaction ofAspergillus nigerAPC-9319 α-Galactosidase in a Supersaturated Substrate Solution: Production of α-Linked Galactooligosaccharide (α-GOS). Biosci Biotechnol Biochem 2014; 69:1381-8. [PMID: 16041145 DOI: 10.1271/bbb.69.1381] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The alpha-galactosidase that effectively catalyzes a reverse reaction of galactose, Aspergillus niger APC-9319 alpha-galactosidase, was screened from industrial enzyme preparations for food processing containing alpha-galactosidase activity. Reverse reaction of A. niger APC-9319 alpha-galactosidase was performed using a supersaturated solution (90% galactose [w/v]). A. niger APC-9319 alpha-galactosidase was not inhibited even in high substrate concentration, and effectively catalyzed the reverse reaction. The yield of the reaction product, alpha-linked galactooligosaccharide (alpha-GOS), increased greatly as the initial concentration of galactose increased to 90% (w/v), and was more than 50%. Furthermore, the half life of enzyme activity was about three times as long as that using 60% galactose (w/v). alpha-GOS (1.4 g) was prepared from galactose (3.0 g) by reverse reaction of A. niger APC-9319 alpha-galactosidase. The alpha-GOS contained 58% alpha-galactobiose (alpha-Gal2), 28% alpha-galactotriose, and 14% oligosaccharides larger than alpha-galactotriose. The main component of positional isomers in alpha-Gal2 was alpha-1,6Gal2.
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Affiliation(s)
- Akiko Yamashita
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Shinshu University, 8304 Minamiminowa, Nagano 399-4598, Japan
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22
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Goldwater PN. Treatment and prevention of enterohemorrhagicEscherichia coliinfection and hemolytic uremic syndrome. Expert Rev Anti Infect Ther 2014; 5:653-63. [PMID: 17678428 DOI: 10.1586/14787210.5.4.653] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Over a quarter century after the discovery of verocytotoxin and the first report by Karmali and colleagues of cases of postdiarrheal hemolytic uremic syndrome (HUS) caused by verotoxigenic Escherichia coli (VTEC), otherwise known as Shiga-toxigenic E. coli (STEC), successful treatment of these infections has remained elusive. This is because the pathological insult producing the clinical picture of HUS occurs early in the disease process and curtails quickly, making treatment intervention a largely vain hope. Nevertheless, understanding of the pathogenesis of HUS has expanded and, as a result, we can expect a future breakthrough in the treatment of this life-threatening condition. This review examines the pathogenesis of HUS and explores targets for treatment, including the reasons why certain therapies have failed and why future therapies could be successful. This review also examines the status of vaccine development in prevention of VTEC/STEC disease.
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Affiliation(s)
- Paul N Goldwater
- The Women's & Children's Hospital, North Adelaide, South Australia, Australia.
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23
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Beceiro A, Tomás M, Bou G. Antimicrobial resistance and virulence: a successful or deleterious association in the bacterial world? Clin Microbiol Rev 2013; 26:185-230. [PMID: 23554414 PMCID: PMC3623377 DOI: 10.1128/cmr.00059-12] [Citation(s) in RCA: 602] [Impact Index Per Article: 54.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Hosts and bacteria have coevolved over millions of years, during which pathogenic bacteria have modified their virulence mechanisms to adapt to host defense systems. Although the spread of pathogens has been hindered by the discovery and widespread use of antimicrobial agents, antimicrobial resistance has increased globally. The emergence of resistant bacteria has accelerated in recent years, mainly as a result of increased selective pressure. However, although antimicrobial resistance and bacterial virulence have developed on different timescales, they share some common characteristics. This review considers how bacterial virulence and fitness are affected by antibiotic resistance and also how the relationship between virulence and resistance is affected by different genetic mechanisms (e.g., coselection and compensatory mutations) and by the most prevalent global responses. The interplay between these factors and the associated biological costs depend on four main factors: the bacterial species involved, virulence and resistance mechanisms, the ecological niche, and the host. The development of new strategies involving new antimicrobials or nonantimicrobial compounds and of novel diagnostic methods that focus on high-risk clones and rapid tests to detect virulence markers may help to resolve the increasing problem of the association between virulence and resistance, which is becoming more beneficial for pathogenic bacteria.
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24
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Fahnoe KC, Flanagan ME, Gibson G, Shanmugasundaram V, Che Y, Tomaras AP. Non-traditional antibacterial screening approaches for the identification of novel inhibitors of the glyoxylate shunt in gram-negative pathogens. PLoS One 2012; 7:e51732. [PMID: 23240059 PMCID: PMC3519852 DOI: 10.1371/journal.pone.0051732] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 11/08/2012] [Indexed: 01/06/2023] Open
Abstract
Antibacterial compounds that affect bacterial viability have traditionally been identified, confirmed, and characterized in standard laboratory media. The historical success of identifying new antibiotics via this route has justifiably established a traditional means of screening for new antimicrobials. The emergence of multi-drug-resistant (MDR) bacterial pathogens has expedited the need for new antibiotics, though many in the industry have questioned the source(s) of these new compounds. As many pharmaceutical companies' chemical libraries have been exhaustively screened via the traditional route, we have concluded that all compounds with any antibacterial potential have been identified. While new compound libraries and platforms are being pursued, it also seems prudent to screen the libraries we currently have in hand using alternative screening approaches. One strategy involves screening under conditions that better reflect the environment pathogens experience during an infection, and identifying in vivo essential targets and pathways that are dispensable for growth in standard laboratory media in vitro. Here we describe a novel screening strategy for identifying compounds that inhibit the glyoxylate shunt in Pseudomonas aeruginosa, a pathway that is required for bacterial survival in the pulmonary environment. We demonstrate that these compounds, which were not previously identified using traditional screening approaches, have broad-spectrum antibacterial activity when they are tested under in vivo-relevant conditions. We also show that these compounds have potent activity on both enzymes that comprise the glyoxylate shunt, a feature that was supported by computational homology modeling. By dual-targeting both enzymes in this pathway, we would expect to see a reduced propensity for resistance development to these compounds. Taken together, these data suggest that understanding the in vivo environment that bacterial pathogens must tolerate, and adjusting the antibacterial screening paradigm to reflect those conditions, could identify novel antibiotics for the treatment of serious MDR pathogens.
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Affiliation(s)
- Kelly C. Fahnoe
- Antibacterials Research Unit, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
| | - Mark E. Flanagan
- Antibacterials Research Unit, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
| | - Glenn Gibson
- Antibacterials Research Unit, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
| | - Veerabahu Shanmugasundaram
- Antibacterials Research Unit, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
| | - Ye Che
- Antibacterials Research Unit, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
| | - Andrew P. Tomaras
- Antibacterials Research Unit, Pfizer Worldwide Research & Development, Groton, Connecticut, United States of America
- * E-mail:
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25
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Watts RE, Tan CK, Ulett GC, Carey AJ, Totsika M, Idris A, Paton AW, Morona R, Paton JC, Schembri MA. Escherichia coli 83972 Expressing a P fimbriae Oligosaccharide Receptor Mimic Impairs Adhesion of Uropathogenic E. coli. J Infect Dis 2012; 206:1242-9. [DOI: 10.1093/infdis/jis493] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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26
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Loirat C, Saland J, Bitzan M. Management of hemolytic uremic syndrome. Presse Med 2012; 41:e115-35. [PMID: 22284541 DOI: 10.1016/j.lpm.2011.11.013] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 11/16/2011] [Indexed: 12/19/2022] Open
Abstract
2011 has been a special year for hemolytic uremic syndrome (HUS): on the one hand, the dramatic epidemic of Shiga toxin producing E. coli -associated HUS in Germany brought the disease to the attention of the general population, on the other hand it has been the year when eculizumab, the first complement blocker available for clinical practice, was demonstrated as the potential new standard of care for atypical HUS. Here we review the therapeutic options presently available for the various forms of hemolytic uremic syndrome and show how recent knowledge has changed the therapeutic approach and prognosis of atypical HUS.
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Affiliation(s)
- Chantal Loirat
- Assistance publique-Hôpitaux de Paris, Hôpital Robert-Debré, Nephrology Department, 75019 Paris, France.
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27
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Abstract
Antibiotic resistance is one of the greatest challenges of the twenty-first century. However, the increasing understanding of bacterial pathogenesis and intercellular communication has revealed many potential strategies to develop novel drugs to treat bacteria-mediated disease. Interference with bacterial virulence and/or cell-to-cell signalling pathways is an especially compelling approach, as it is thought to apply less selective pressure for the development of bacterial resistance than traditional strategies, which are aimed at killing bacteria or preventing their growth. Here, we discuss the mechanisms of bacterial virulence and present promising anti-virulence strategies and compounds for the future treatment of bacterial infections.
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Yamamoto T, Satomura K, Okada S, Ozono K. Risk factors for neurological complications in complete hemolytic uremic syndrome caused by Escherichia coli O157. Pediatr Int 2009; 51:216-9. [PMID: 19405919 DOI: 10.1111/j.1442-200x.2008.02690.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The aim of the present study was to investigate the predictive parameters for encephalopathy in complete hemolytic uremic syndrome (HUS) in a large outbreak of O157: H7 infection in 1996. METHODS A total of 182 inpatients, 71 of whom had complete HUS, including 12 patients with neurological complications, and 46 colitis patients were studied. Presenting signs and symptoms (n = 115) and laboratory data (n = 69) were analyzed using monovariate and multivariate analysis. RESULTS After adjusting for age and gender, logistic regression showed that presenting symptoms such as bloody diarrhea (odds ratio [OR] = 7.39), proteinuria (OR = 6.16), hematuria (OR = 8.31), oliguria (OR = 17.4) and a pale face (OR = 10.7) were useful for predicting complete HUS. Also, increased white blood cell counts >12,000 microL/mL (OR = 10.0) and C-reactive protein >1.5 mg/dL (OR = 7.39) at the onset of infection, were useful as predictive laboratory parameters. To predict neurological complications in complete HUS patients, the average daily increase of lactate dehydrase >1200 IU/L per day (OR = 26.3) and creatinine >0.5 mg/dL per day (OR = 12) were found to be useful on multivariate logistic regression. CONCLUSION There are useful predictive clinical factors for neurological complications in complete HUS.
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Abstract
Experiences with childhood hemolytic uremic syndrome (HUS) in Canada will focus on the development of the Canadian Pediatric Kidney Disease Research Centre (CPKDRC) and the results of our collaborative research over a 13-year period (1985-1998).
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31
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In vivo supramolecular templating enhances the activity of multivalent ligands: a potential therapeutic against the Escherichia coli O157 AB5 toxins. Proc Natl Acad Sci U S A 2008; 105:16837-42. [PMID: 18955695 DOI: 10.1073/pnas.0804919105] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We demonstrate that interactions between multimeric receptors and multivalent ligands are dramatically enhanced by recruiting a complementary templating receptor such as an endogenous multimeric protein but only when individual ligands are attached to a polymer as preorganized, covalent, heterobifunctional pairs. This effect cannot be replicated by a multivalent ligand if the same recognition elements are independently arrayed on the scaffold. Application of this principle offers an approach to create high-avidity inhibitors for multimeric receptors. Judicious selection of the ligand that engages the templating protein allows appropriate effector function to be incorporated in the polymeric construct, thereby providing an opportunity for therapeutic applications. The power of this approach is exemplified by the design of exceptionally potent Escherichia coli Shiga toxin antagonists that protect transgenic mice that constitutively express a human pentraxin, serum amyloid P component.
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32
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Affiliation(s)
- Hye Won Park
- Department of Pediatrics, Pochon CHA University, Sungnam, Korea
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Kuribayashi T, Seita T, Fukuyama M, Furuhata K, Honda M, Matsumoto M, Seguchi H, Yamamoto S. Neutralizing activity of bovine colostral antibody against verotoxin derived from enterohemorrhagic Escherichia coli O157:H7 in mice. J Infect Chemother 2006; 12:251-6. [PMID: 17109087 DOI: 10.1007/s10156-006-0470-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Accepted: 07/31/2006] [Indexed: 01/08/2023]
Abstract
The neutralization efficacy of bovine colostral antibody against verotoxin (VT) 1 and 2 was investigated. Cows were immunized with VT1 or VT2 fourteen times at 7-day intervals. A colostral antibody exhibiting high titers was obtained from immunized cows. Survival rates were evaluated in mice administered VT1 or VT2, and those infected with Escherichia coli (E. coli) O157:H7 producing VT1 or VT2. Survival rates after VT1 administration were 100% in the single-administration group, 90% in the repeat-administration group, and 78.6% in the control group. Survival rates after VT2 were 75.0% in the single-administration group, and 100% in the repeat-administration group. All mice in the control group died. Colostral antibody and fosfomycin (FOM) in the colostral antibody group and FOM and skim milk in the control group were administered three times per day for 5 days to mice infected with E. coli O157:H7 producing VT1 or VT2. Survival rates after inoculation with E. coli O157:H7 producing VT1 were 80.0% in the colostral antibody group, and 63.6% in the control group. Survival rates after inoculation with E. coli O157:H7 producing VT2 were 83.3% in the colostral antibody group, and 20.0% in the control group. The survival rate in mice without treatment following inoculation with E. coli O157:H7 producing VT2 was 88.2%. The survival rates in mice infected with E. coli O157:H7 strains producing VT1 or VT2 improved after administration of this colostral antibody, which exhibited neutralization efficacy against VT.
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Affiliation(s)
- Takashi Kuribayashi
- Laboratory of Immunology, College of Environmental and Health Sciences, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa, 229-8501, Japan
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Matsuoka K, Terabatake M, Umino A, Esumi Y, Hatano K, Terunuma D, Kuzuhara H. Carbosilane Dendrimers Bearing Globotriaoses: Syntheses of Globotrioasyl Derivative and Introduction into Carbosilane Dendrimers†. Biomacromolecules 2006; 7:2274-83. [PMID: 16903671 DOI: 10.1021/bm060368+] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As an application of a one-pot reaction involving Birch reduction and subsequent S(N)2 reaction in liquid ammonia, synthetic assembly of trisaccharidic moieties of globotriaosyl ceramide onto carbosilane dendrimers was accomplished using tris(3-bromopropyl)phenylsilane and tris[tris(3-bromopropyl)silylpropyl]phenylsilane as the core scaffolds. The common globotriaosyl derivative having benzylsulfide functionality at the terminal of the aglycon was efficiently prepared from d-galactose and d-lactose as starting materials. The glycosyl donor derived from galactose and the glycosyl acceptor derived from lactose were condensed in the presence of silver triflate as the best promoter to provide corresponding trisaccharide with newly formed alpha-1-4 linkages in 90% yield. Fully benzylated protection of the trisaccharide was deprotected under the Birch reduction condition followed by acetylation to give an acetate in which alkene was converted into benzyl sulfide by radical addition of alpha-toluenethiol in high yields. On the other hand, carbosilane dendrimers were prepared from appropriate chlorosilanes as starting materials by a combination of hydrosylation followed by alkenylation. The terminal C=C double bonds of the carbosilanes were converted into corresponding alcohols by means of the usual hydroboration reaction, and the alcohols underwent further chemical manipulation to give carbosilane dendrimers with peripheral bromine atoms.
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Affiliation(s)
- Koji Matsuoka
- Department of Functional Materials Science, Faculty of Engineering, Saitama University, Sakura, Saitama 338-8570, Japan.
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Matsuoka K, Terabatake M, Esumi Y, Hatano K, Terunuma D, Kuzuhara H. Carbosilane Dendrimers Bearing Globotriaoses: Construction of a Series of Carbosilane Dendrimers Bearing Globotriaoses. Biomacromolecules 2006; 7:2284-90. [PMID: 16903672 DOI: 10.1021/bm0603692] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To enhance biological activities on the basis of the sugar cluster effect, a series of carbosilane dendrimers as core scaffolds for the construction of glycodendrimers was systematically synthesized from appropriate chlorosilanes by a combination of alkenylation and hydrosylation reactions. Those carbosilane dendrimers having terminal C=C double bonds underwent general hydroboration reactions to give corresponding primary polyols. Further transformations of the alcohols were then performed by mesylation followed by a displacement with NaBr to provide corresponding dendrimers with 4 to 36 bromine atoms at each terminal end. Assembly of trisaccharide moieties of globotriaosyl ceramide using alkyl halide-type carbosilane dendrimers as the core frame was conducted in liquid ammonia by a one-pot reaction involving selective removal of a benzyl group under the Birch reduction condition and subsequent S(N)2 reaction to yield a series of carbosilane dendrimers having appropriate numbers of trisaccharide moieties. These dendrimers have unique shapes and adequate numbers of terminal trisaccharide moieties. Some of the dendrimers showed unique biological activity against Stxs, which were produced by pathogenic Escherichia coli O157:H7.
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Affiliation(s)
- Koji Matsuoka
- Department of Functional Materials Science, Faculty of Engineering, Saitama University, Sakura, Saitama 338-8570, Japan.
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Murinda SE, Oliver SP. Physiologic and molecular markers for detection of shiga toxin-producing Escherichia coli serotype O26 strains. Foodborne Pathog Dis 2006; 3:163-77. [PMID: 16761942 DOI: 10.1089/fpd.2006.3.163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Knowledge of physiologic/phenotypic and genetic variation of Escherichia coli O157 and its tight clonality was the basis for development of successful detection protocols for Shiga toxin-producing E. coli (STEC) O157:H7/H. Phenotypic and genetic characteristics of diarrheagenic E. coli O26 isolates from different geographical regions may differ as indicated by representative reports from all continents. In this review, we summarize current knowledge on STEC O26, a pathogen whose emergence predates that of other STEC, including O157:H7/H-. The overall objectives are to integrate information available from peer-reviewed literature on the clinical and public health significance of STEC O26 worldwide, and to highlight phenotypic and genetic markers that could be used for routine detection of this pathogen. Our ultimate goal is to render information that will allow quick, accurate, and specific detection of STEC O26 genotypic variants worldwide, so as to aid with control of this pathogen. The information herein will be invaluable to a variety of scientists that include epidemiologists and microbiologists (medical, veterinary, food, and environmental) with interest in STEC O26--a zoonotic and emerging foodborne pathogen.
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Affiliation(s)
- Shelton E Murinda
- Department of Animal and Veterinary Sciences, California State Polytechnic University, 3801West Temple Ave., Pomona, California 91768, USA.
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Agin TS, Zhu C, Johnson LA, Thate TE, Yang Z, Boedeker EC. Protection against hemorrhagic colitis in an animal model by oral immunization with isogeneic rabbit enteropathogenic Escherichia coli attenuated by truncating intimin. Infect Immun 2005; 73:6608-19. [PMID: 16177337 PMCID: PMC1230981 DOI: 10.1128/iai.73.10.6608-6619.2005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Strains of Shiga toxin (Stx)-producing Escherichia coli, also called enterohemorrhagic E. coli (EHEC), are important food-borne pathogens for humans. Most EHEC strains intimately adhere to the intestinal mucosa in a characteristic attaching and effacing (A/E) pattern, which is mediated by the bacterial adhesin intimin. Subsequent release of Stx1 and/or Stx2 leads to the frequent development of hemorrhagic colitis and, less commonly, to hemolytic-uremic syndrome. The aim of the present study was to develop an attenuated A/E E. coli strain for use as a vaccine against EHEC infection encoding a truncated intimin lacking adhesive capacity, but which would still express somatic antigens, other products of the locus of enterocyte effacement pathogenicity island, and an immunogenic remnant of the intimin molecule. A single-nucleotide deletion was generated in the eae gene in the prototype rabbit A/E E. coli strain RDEC-1 (O15:H-), which resulted in truncation of intimin by 81 C-terminal residues (860 to 939 amino acids) containing a disulfide loop. Inoculation of rabbits with large doses of the truncated intimin mutant (RDEC-1Deltaeae(860-939)) was well tolerated, as observed by the absence of clinical signs of disease or evidence of intestinal A/E lesions. The efficacy of RDEC-1Deltaeae(860-939) as a vaccine was evaluated by orogastric inoculation of rabbits with RDEC-1Deltaeae(860-939) followed by challenge with the virulent strain RDEC-H19A, an Stx1-producing derivative of wild-type RDEC-1 capable of inducing hemorrhagic colitis in rabbits. Following RDEC-H19A challenge, nonimmunized control rabbits exhibited characteristic weight loss with watery to bloody diarrhea and demonstrated intimate bacterial attachment, effacement of microvilli, submucosal edema, mucosal heterophile infiltrates, and Shiga toxin-induced vascular lesions. In contrast, the RDEC-1Deltaeae(860-939)-immunized rabbits showed no clinical signs of disease, maintained normal weight gain, had reduced fecal shedding of challenge organisms, and showed an absence of gross or microscopic lesions in the intestinal mucosa. Serum antibodies specific to intimin were detected among rabbits immunized with RDEC-1Deltaeae(860-939), indicating that truncation of the intimin functional domain not only attenuated bacterial virulence, but also retained at least some of the immunogenicity of native intimin. Although it is not possible to gauge the exact contribution of residual intimin immunity to protection, this attenuation strategy for A/E E. coli strains shows promise for the development of effective vaccines to prevent EHEC infection in humans and animals.
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Affiliation(s)
- Tonia S Agin
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, 21201, USA
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Akiyoshi DE, Rich CM, O'Sullivan-Murphy S, Richard L, Dilo J, Donohue-Rolfe A, Sheoran AS, Chapman-Bonofiglio S, Tzipori S. Characterization of a human monoclonal antibody against Shiga toxin 2 expressed in Chinese hamster ovary cells. Infect Immun 2005; 73:4054-61. [PMID: 15972493 PMCID: PMC1168570 DOI: 10.1128/iai.73.7.4054-4061.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Revised: 10/26/2004] [Accepted: 03/02/2005] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin-producing Escherichia coli infections can often lead to the development of hemolytic-uremic syndrome (HUS) in a small percentage of infected humans. Patients with HUS receive only supportive treatment as the benefit of antibiotic therapy remains uncertain. We have previously reported the generation and preclinical evaluation of neutralizing human monoclonal antibodies (HuMAbs) against the Shiga toxins (Stx). In this paper, we describe the expression in Chinese hamster ovary (CHO) cells of 5C12 HuMAb, which is directed against the A subunit of Stx2. The cDNAs of the light and heavy chain immunoglobulin (Ig) variable regions of 5C12 HuMAb were isolated and cloned into an expression vector containing human IgG1 constant regions. The vector was transfected into CHO cells, and transfectants secreting Stx2-specific antibody were screened by an Stx2-specific enzyme-linked immunosorbent assay. The CHO-produced recombinant 5C12 (r5C12) showed similar specificity and binding affinity to Stx2 as the parent hybridoma-produced 5C12. More significantly, the r5C12 displayed the same neutralizing activity as the parent 5C12 in vitro and in vivo. In the mouse toxicity model, both antibodies significantly and equally prolonged survival at a dose of 0.312 microg/mouse. The data showed that since r5C12, produced in CHO cells, was equally effective as the parent 5C12, it is our choice candidate as a potential prophylactic or therapeutic agent against hemolytic-uremic syndrome.
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Affiliation(s)
- D E Akiyoshi
- Division of Infectious Diseases, Tufts University School of Veterinary Medicine, 200 Westboro Road, Building 20, North Grafton, Massachusetts 01536, USA
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Gamage SD, McGannon CM, Weiss AA. Escherichia coli serogroup O107/O117 lipopolysaccharide binds and neutralizes Shiga toxin 2. J Bacteriol 2004; 186:5506-12. [PMID: 15292153 PMCID: PMC490921 DOI: 10.1128/jb.186.16.5506-5512.2004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The AB(5) toxin Shiga toxin 2 (Stx2) has been implicated as a major virulence factor of Escherichia coli O157:H7 and other Shiga toxin-producing E. coli strains in the progression of intestinal disease to more severe systemic complications. Here, we demonstrate that supernatant from a normal E. coli isolate, FI-29, neutralizes the effect of Stx2, but not the related Stx1, on Vero cells. Biochemical characterization of the neutralizing activity identified the lipopolysaccharide (LPS) of FI-29, a serogroup O107/O117 strain, as the toxin-neutralizing component. LPSs from FI-29 as well as from type strains E. coli O107 and E. coli O117 were able bind Stx2 but not Stx1, indicating that the mechanism of toxin neutralization may involve inhibition of the interaction between Stx2 and the Gb(3) receptor on Vero cells.
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Affiliation(s)
- Shantini D Gamage
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, OH 45267-0524 USA
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Gavin PJ, Peterson LR, Pasquariello AC, Blackburn J, Hamming MG, Kuo KJ, Thomson RB. Evaluation of performance and potential clinical impact of ProSpecT Shiga toxin Escherichia coli microplate assay for detection of Shiga Toxin-producing E. coli in stool samples. J Clin Microbiol 2004; 42:1652-6. [PMID: 15071021 PMCID: PMC387566 DOI: 10.1128/jcm.42.4.1652-1656.2004] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Shiga toxin-producing Escherichia coli bacteria (STEC) are emerging pathogens capable of producing sporadic and epidemic diarrhea, hemorrhagic colitis, and potentially life-threatening hemolytic-uremic syndrome. Although the presence of E. coli O157 can be readily detected in stool by sorbitol-MacConkey agar culture (SMAC), STEC non-O157 serotypes cannot. In contrast to culture, testing for the presence of Shiga toxins 1 and 2 in stool detects both O157 and non-O157 STEC serotypes capable of causing disease. Over two consecutive summers, we evaluated the performance of the ProSpecT Shiga toxin E. coli Microplate assay (Alexon-Trend, Ramsey, Minn.), an enzyme immunoassay for the detection of Shiga toxins 1 and 2, on all stools submitted for culture of enteric pathogens, and the potential clinical impact of Shiga toxin detection. Twenty-nine stool specimens were STEC positive by ProSpecT assay. Twenty-seven of 29 STEC-positive isolates were confirmed by SMAC and serotyping or by a second enzyme immunoassay and PCR (positive predictive value, 93%). Thirteen of 27 confirmed Shiga toxin-producing strains were serotype O157. The remaining 14 strains represented 8 other serotypes. The ProSpecT assay was 100% sensitive and specific for detection of E. coli O157 in stool (7 of 7) compared to SMAC. In addition, the ProSpecT assay detected twice as many STEC as SMAC. Fifty-two percent of confirmed STEC-positive stools were nonbloody. Thus, in our population, screening strategies that test only visibly bloody stools for STEC would miss a majority of cases. Eleven (41%) STEC-positive patients were hospitalized, and eight (30%) developed severe disease (two developed hemolytic-uremic syndrome, and six developed hemorrhagic colitis). Prior to detection of STEC infection, seven (26%) and eight patients (30%) underwent unnecessary diagnostic procedures or received potentially deleterious empirical treatment, respectively. We propose that establishing a specific diagnosis of STEC may have prevented these potentially harmful interventions. We conclude that the ProSpecT assay is sensitive and specific for the detection of Shiga toxins 1 and 2 in stool and has potentially significant clinical impact for the individual patient and public health. Shiga toxin assays should be considered for routine use in settings where prevalence of STEC disease warrants testing.
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Affiliation(s)
- Patrick J Gavin
- Department of Pathology and Laboratory Medicine, Evanston Northwestern Healthcare, Evanston. Northwestern University Feinberg School of Medicine. Enteric Laboratory, Illinois Department of Public Health, Chicago, Illinois
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Zhang J, Kowal P, Chen X, Wang PG. Large-scale synthesis of globotriose derivatives through recombinant E. coli. Org Biomol Chem 2004; 1:3048-53. [PMID: 14518127 DOI: 10.1039/b304911f] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The carbohydrate chains decorating cell membranes and secreted proteins participate in a range of important biological processes. However, their ultimate significance and possible therapeutic potential have not been fully explored due to the lack of economical methods for their production. This study is an example of the use of a genetically engineered bacterial strain in the preparation of diverse oligosaccharides. Based on an ex vivo biosynthetic pathway, an artificial gene cluster was constructed by linking the genes of five associated enzymes on a plasmid vector. This plasmid was inserted into the E. coli NM522 strain to form globotriose-producing cells ('superbug' pLDR20-CKTUF). The specific strain was conveniently applied to the synthesis of globotriose trisaccharide and its derivatives, as potential neutralizers for Shiga toxin. This work demonstrates a novel and economical method for generating ligand diversity for carbohydrate drug development.
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Affiliation(s)
- Jianbo Zhang
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
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Sheoran AS, Chapman S, Singh P, Donohue-Rolfe A, Tzipori S. Stx2-specific human monoclonal antibodies protect mice against lethal infection with Escherichia coli expressing Stx2 variants. Infect Immun 2003; 71:3125-30. [PMID: 12761090 PMCID: PMC155773 DOI: 10.1128/iai.71.6.3125-3130.2003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) strains are responsible for causing hemolytic-uremic syndrome (HUS), and systemic administration of Shiga toxin (Stx)-specific human monoclonal antibodies (HuMAbs) is considered a promising approach for prevention or treatment of the disease in children. The goal of the present study was to investigate the ability of Stx2-specific HuMAbs to protect against infections with STEC strains that produce Stx2 variants. Dose-response studies on five HuMAbs, using the mouse toxicity model, revealed that only the three directed against the A subunit were protective against Stx2 variants, and 5C12 was the most effective among the three tested. Two HuMAbs directed against the B subunit, while highly effective against Stx2, were ineffective against Stx2 variants. In a streptomycin-treated mouse model, parenteral administration of 5C12 significantly protected mice up to 48 h after oral bacterial challenge. We conclude that 5C12, reactive against the Stx2 A subunit, is an excellent candidate for immunotherapy against HUS and that antibodies directed against the A subunit of Stx2 have broad-spectrum activity that includes Stx2 variants, compared with those directed against the B subunit.
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Affiliation(s)
- Abhineet S Sheoran
- Division of Infectious Diseases, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA
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Allford SL, Hunt BJ, Rose P, Machin SJ. Guidelines on the diagnosis and management of the thrombotic microangiopathic haemolytic anaemias. Br J Haematol 2003; 120:556-73. [PMID: 12588343 DOI: 10.1046/j.1365-2141.2003.04049.x] [Citation(s) in RCA: 244] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Sarah L Allford
- Department of Haematology, University College London Hospitals, London, UK
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Olano-Martin E, Williams MR, Gibson GR, Rastall RA. Pectins and pectic-oligosaccharides inhibit Escherichia coli O157:H7 Shiga toxin as directed towards the human colonic cell line HT29. FEMS Microbiol Lett 2003; 218:101-5. [PMID: 12583904 DOI: 10.1111/j.1574-6968.2003.tb11504.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Pectins and pectic-oligosaccharides, as derived by controlled enzymatic hydrolysis, were evaluated for their ability to interfere with the toxicity of Shiga-like toxins from Escherichia coli O157:H7. Both types of material resulted in some degree of protection but this was significantly higher (P>0.01) with the oligosaccharide fractions (giving 90-100% cell survival, compared to 70-80% with the polymer). An effect of methylation on the protective effect was detected with lower degrees being more active. The pectic-oligosaccharides and galabiose, the minimum toxin receptor analogue, were shown to inhibit toxicity and were both protective at 10 mg x ml(-1), but not at lower concentrations.
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Affiliation(s)
- Estibaliz Olano-Martin
- School of Food Biosciences, The University of Reading, PO Box 226, Whiteknights, Reading RG6 6AP, UK
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Abstract
This article describes the birth of the Canadian Pediatric Kidney Disease Research Centre (CPKDRC) in 1985 and the activities that have transpired as a result of collaborative research at paediatric centres across Canada. These include the National Retrospective Study of Childhood Hemolytic Uremic Syndrome (HUS), National Prospective Study of Risk Factors for Developing Escherichia coli O157:H7 Infection, and Intervention Studies for the Prevention of HUS. A look to the future describes possible studies to determine potential factors (surrogate markers) to identify children who are at risk for developing HUS following verotoxin-producing E coli gastroenteritis, other intervention studies and a more accurate understanding of permanent renal insufficiency in children who have had HUS.
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Affiliation(s)
- Peter N McLaine
- Department of Pediatrics, University of Ottawa; Children's Hospital of Eastern Ontario; Canadian Pediatric Kidney Disease Research Centre, Ottawa, Ontario
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Fan HN, Liu MZ, Lee YC. Large-scale preparation of α-D-(14)-oligogalacturonic acids from pectic acid. CAN J CHEM 2002. [DOI: 10.1139/v02-055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An efficient and inexpensive method for large-scale preparation of α-D-(1[Formula: see text]4)-oligogalacturonic acids (oligo-GalA), up to DP 5, from pectic acid is described. Pectic acid was digested with a commercially available pectinase to yield a mixture of oligo-GalA, which was effectively separated by a combination of low-pressure size-exclusion chromatography based on ion-exchange chromatography to obtain pure oligo-GalA of DP 2-5. Key words: pectic acid, galacturonic acid, galabiose, galatriose, pectinase.
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Mulvey G, Rafter DJ, Armstrong GD. Potential for using antibiotics combined with a Shiga toxin-absorbing agent for treating 0157:H7 Escherichia coli infections. CAN J CHEM 2002. [DOI: 10.1139/v02-028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Antibiotics are not recommended for treating O157:H7 Escherichia coli infections because they may promote Shiga toxin (Stx) release from these bacteria. This could increase the risk of Stx-mediated complications in patients suffering from such infections. Here, we observed increased cell-free Stx in E. coli O157:H7 cultures exposed to sub-inhibitory concentrations of several antibiotics. Synsorb-Pk, an agent with a high affinity for Stx, absorbed Stx activity from the antibiotic-treated cultures. These data suggest certain antibiotics, given in combination with an orally administered Stx-binding agent, may be useful in treating O157:H7 E. coli infections.Key words: Shiga toxin, Synsorb, Escherichia coli, O157:H7, antibiotics, therapy.
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Richards A, Goodship JA, Goodship THJ. The genetics and pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura. Curr Opin Nephrol Hypertens 2002; 11:431-5. [PMID: 12105394 DOI: 10.1097/00041552-200207000-00010] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE OF REVIEW In recent years there has been a substantial increase in the understanding of the genetics and pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura. RECENT FINDINGS In diarrhoeal associated haemolytic uraemic syndrome it has been established that the virulence of Escherichia coli O157 is related to intimin adhesion and the transport of verocytotoxin on polymorphonuclear cells. It has been shown that early changes in the coagulation pathway predate the onset of diarrhoeal haemolytic uraemic syndrome. Mutations in factor H, a fluid-phase regulator of the alternative complement pathway, have been identified in 10-20% of patients with both familial and sporadic (non-diarrhoeal-associated) haemolytic uraemic syndrome. The mutations mainly cluster in the C terminal part of factor H, a region that is important for both binding to C3b and also polyanionic structures on cell surfaces. The identification of antibodies against a plasma metalloproteinase responsible for cleaving ultralarge von Willebrand factor multimers in thrombotic thrombocytopenic purpura has been followed by the elucidation of the identity of the proteinase. It has been shown to be a member of the ADAMTS family, and mutations have been identified in the gene in families with inherited thrombotic thrombocytopenic purpura. SUMMARY The molecular pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura is an exciting and rapidly evolving field. These recent advances will lead to logical, targetted changes in the management of these conditions.
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Affiliation(s)
- Anna Richards
- The Institute of Human Genetics and School of Clinical Medical Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 4LP, UK
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