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Siqueira FDF, Silva ROS, do Carmo AO, de Oliveira-Mendes BBR, Horta CCR, Lobato FCF, Kalapothakis E. Immunization with a nontoxic naturally occurring Clostridium perfringens alpha toxin induces neutralizing antibodies in rabbits. Anaerobe 2017; 49:48-52. [PMID: 29246841 DOI: 10.1016/j.anaerobe.2017.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 12/09/2017] [Accepted: 12/11/2017] [Indexed: 01/08/2023]
Abstract
Clostridium perfringens alpha toxin, encoded by plc gene, has been implicated in gas gangrene, a life threatening infection. Vaccination is considered one of the best solutions against Clostridium infections. Although studies have identified many low quality clostridial vaccines, the use of recombinant proteins has been considered a promising alternative. Previously, a naturally occurring alpha toxin isoform (αAV1b) was identified with a mutation at residue 11 (His/Tyr), which can affect its enzymatic activity. The aim of the present study was to evaluate whether the mutation in the αAV1b isoform could result in an inactive toxin and was able to induce protection against the native alpha toxin. We used recombinant protein techniques to determine whether this mutation in αAV1b could result in an inactive toxin compared to the active isoform, αZ23. Rabbits were immunized with the recombinant toxins (αAV1b and αZ23) and with native alpha toxin. αAV1b showed no enzymatic and hemolytic activities. ELISA titration assays showed a high titer of both anti-recombinant toxin (anti-rec-αAV1b and anti-rec-αZ23) antibodies against the native alpha toxin. The alpha antitoxin titer detected in the rabbits' serum pool was 24.0 IU/mL for both recombinant toxins. These results demonstrate that the inactive naturally mutated αAV1b is able to induce an immune response, and suggest it can be considered as a target for the development of a commercial vaccine against C. perfringens alpha toxin.
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Affiliation(s)
- Flávia de Faria Siqueira
- Instituto Federal de Minas Gerais, Campus Betim, Betim, 32656-840, Minas Gerais, Brazil; Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Minas Gerais, Brazil
| | - Rodrigo Otávio Silveira Silva
- Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Minas Gerais, Brazil
| | - Anderson Oliveira do Carmo
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Minas Gerais, Brazil
| | | | - Carolina Campolina Rebello Horta
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Minas Gerais, Brazil; Mestrado Profissional em Biotecnologia e Gestão da Inovação, Centro Universitário de Sete Lagoas, Sete Lagoas, 32701-242, Minas Gerais, Brazil
| | - Francisco Carlos Faria Lobato
- Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Minas Gerais, Brazil
| | - Evanguedes Kalapothakis
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Minas Gerais, Brazil.
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Effect of Clostridium perfringens β-Toxin on Platelets. Toxins (Basel) 2017; 9:toxins9100336. [PMID: 29064418 PMCID: PMC5666382 DOI: 10.3390/toxins9100336] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 10/19/2017] [Accepted: 10/20/2017] [Indexed: 02/07/2023] Open
Abstract
Clostridium perfringensβ-toxin (CPB) is the major virulence factor of C.perfringens type C causing a hemorrhagic enteritis in animals and humans. In experimentally infected pigs, endothelial binding of CPB was shown to be associated with early vascular lesions and hemorrhage but without obvious thrombosis of affected vessels, suggesting altered hemostasis in the early phase of the disease. The objective of the present study was to investigate the effect of CPB on platelets, with respect to primary hemostasis. Our results demonstrate that CPB binds to porcine and human platelets and forms oligomers resulting in a time- and dose-dependent cell death. Platelets showed rapid ultrastructural changes, significantly decreased aggregation and could no longer be activated by thrombin. This indicates that CPB affects the physiological function of platelets and counteracts primary hemostasis. Our results add platelets to the list of target cells of CPB and extend the current hypothesis of its role in the pathogenesis of C. perfringens type C enteritis.
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Seike S, Takehara M, Takagishi T, Miyamoto K, Kobayashi K, Nagahama M. Delta-toxin from Clostridium perfringens perturbs intestinal epithelial barrier function in Caco-2 cell monolayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:428-433. [PMID: 28988777 DOI: 10.1016/j.bbamem.2017.10.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/26/2017] [Accepted: 10/03/2017] [Indexed: 01/02/2023]
Abstract
Clostridium perfringens delta-toxin is a β-barrel-pore-forming toxin (β-PFT) and a presumptive virulence factor of type B and C strains, which are causative organisms of fatal intestinal diseases in animals. We showed previously that delta-toxin causes cytotoxicity via necrosis in sensitive cells. Here, we examined the effect of delta-toxin on intestinal membrane integrity. Delta-toxin led to a reduction in transepithelial electrical resistance (TEER) and increased the permeability of fluorescence isothiocyanate-conjugated dextran in human intestinal epithelial Caco-2 cells without changing the tight junction proteins, such as zonula occludens-1 (ZO-1), occludin, and claudin-1. On the other hand, delta-toxin reduced the cellular levels of adherence junction protein E-cadherin before cell injury. A disintegrin and metalloprotease (ADAM) 10 facilitates E-cadherin cleavage and was identified as the cellular receptor for alpha-toxin, a β-PFT produced by Staphylococcus aureus. ADAM10 inhibitor (GI254023X) blocked the toxin-induced decrease in TEER and cleavage of E-cadherin. Delta-toxin enhanced ADAM10 activity in a dose- and time-dependent manner. Furthermore, delta-toxin colocalized with ADAM10. These results indicated that ADAM10 plays a key role in delta-toxin-induced intestinal injury.
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Affiliation(s)
- Soshi Seike
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Teruhisa Takagishi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Kazuaki Miyamoto
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
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Schönauer E, Kany AM, Haupenthal J, Hüsecken K, Hoppe IJ, Voos K, Yahiaoui S, Elsässer B, Ducho C, Brandstetter H, Hartmann RW. Discovery of a Potent Inhibitor Class with High Selectivity toward Clostridial Collagenases. J Am Chem Soc 2017; 139:12696-12703. [PMID: 28820255 PMCID: PMC5607459 DOI: 10.1021/jacs.7b06935] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Secreted virulence
factors like bacterial collagenases are conceptually
attractive targets for fighting microbial infections. However, previous
attempts to develop potent compounds against these metalloproteases
failed to achieve selectivity against human matrix metalloproteinases
(MMPs). Using a surface plasmon resonance-based screening complemented
with enzyme inhibition assays, we discovered an N-aryl mercaptoacetamide-based inhibitor scaffold that showed
sub-micromolar affinities toward collagenase H (ColH) from the human
pathogen Clostridium histolyticum. Moreover, these
inhibitors also efficiently blocked the homologous bacterial collagenases,
ColG from C. histolyticum, ColT from C. tetani, and ColQ1 from the Bacillus cereus strain Q1,
while showing negligible activity toward human MMPs-1, -2, -3, -7,
-8, and -14. The most active compound displayed a more than 1000-fold
selectivity over human MMPs. This selectivity can be rationalized
by the crystal structure of ColH with this compound, revealing a distinct
non-primed binding mode to the active site. The non-primed binding
mode presented here paves the way for the development of selective
broad-spectrum bacterial collagenase inhibitors with potential therapeutic
application in humans.
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Affiliation(s)
- Esther Schönauer
- Division of Structural Biology, Department of Molecular Biology, University of Salzburg , Billrothstrasse 11, 5020 Salzburg, Austria
| | - Andreas M Kany
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Campus E8.1, 66123 Saarbrücken, Germany
| | - Jörg Haupenthal
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Campus E8.1, 66123 Saarbrücken, Germany
| | - Kristina Hüsecken
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Campus E8.1, 66123 Saarbrücken, Germany
| | - Isabel J Hoppe
- Division of Structural Biology, Department of Molecular Biology, University of Salzburg , Billrothstrasse 11, 5020 Salzburg, Austria
| | - Katrin Voos
- Department of Pharmacy, Pharmaceutical and Medicinal Chemistry, Saarland University , Campus C2.3, 66123 Saarbrücken, Germany
| | - Samir Yahiaoui
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Campus E8.1, 66123 Saarbrücken, Germany
| | - Brigitta Elsässer
- Division of Structural Biology, Department of Molecular Biology, University of Salzburg , Billrothstrasse 11, 5020 Salzburg, Austria
| | - Christian Ducho
- Department of Pharmacy, Pharmaceutical and Medicinal Chemistry, Saarland University , Campus C2.3, 66123 Saarbrücken, Germany
| | - Hans Brandstetter
- Division of Structural Biology, Department of Molecular Biology, University of Salzburg , Billrothstrasse 11, 5020 Salzburg, Austria
| | - Rolf W Hartmann
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) , Campus E8.1, 66123 Saarbrücken, Germany.,Department of Pharmacy, Pharmaceutical and Medicinal Chemistry, Saarland University , Campus C2.3, 66123 Saarbrücken, Germany
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Takehara M, Takagishi T, Seike S, Oda M, Sakaguchi Y, Hisatsune J, Ochi S, Kobayashi K, Nagahama M. Cellular Entry of Clostridium perfringens Iota-Toxin and Clostridium botulinum C2 Toxin. Toxins (Basel) 2017; 9:toxins9080247. [PMID: 28800062 PMCID: PMC5577581 DOI: 10.3390/toxins9080247] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 07/31/2017] [Accepted: 08/09/2017] [Indexed: 12/05/2022] Open
Abstract
Clostridium perfringens iota-toxin and Clostridium botulinum C2 toxin are composed of two non-linked proteins, one being the enzymatic component and the other being the binding/translocation component. These latter components recognize specific receptors and oligomerize in plasma membrane lipid-rafts, mediating the uptake of the enzymatic component into the cytosol. Enzymatic components induce actin cytoskeleton disorganization through the ADP-ribosylation of actin and are responsible for cell rounding and death. This review focuses upon the recent advances in cellular internalization of clostridial binary toxins.
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Affiliation(s)
- Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Teruhisa Takagishi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Soshi Seike
- Laboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Kure, Hiroshima 737-0112, Japan.
| | - Masataka Oda
- Department of Microbiology and Infection Control Science, Kyoto Pharmaceutical University, Yamashina, Kyoto 607-8414, Japan.
| | - Yoshihiko Sakaguchi
- Department of Microbiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.
| | - Junzo Hisatsune
- Department of Bacteriology, Graduate school of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
| | - Sadayuki Ochi
- Faculty of Pharmacy, Yokohama University of Pharmacy, 601 Matano-cho, Totsuka-ku, Yokohama-shi, Kanagawa 245-0066, Japan.
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
| | - Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
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56
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Uno M, Phansroy N, Aso Y, Ohara H. Starch-fueled microbial fuel cells by two-step and parallel fermentation using Shewanella oneidensis MR-1 and Streptococcus bovis 148. J Biosci Bioeng 2017; 124:189-194. [DOI: 10.1016/j.jbiosc.2017.03.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/27/2017] [Indexed: 12/31/2022]
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Vázquez-Iglesias L, Estefanell-Ucha B, Barcia-Castro L, Páez de la Cadena M, Álvarez-Chaver P, Ayude-Vázquez D, Rodríguez-Berrocal FJ. A simple electroelution method for rapid protein purification: isolation and antibody production of alpha toxin from Clostridium septicum. PeerJ 2017; 5:e3407. [PMID: 28652930 PMCID: PMC5483040 DOI: 10.7717/peerj.3407] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 05/11/2017] [Indexed: 12/16/2022] Open
Abstract
Clostridium septicum produces a number of diseases in human and farm animals which, in most of the cases, are fatal without clinical intervention. Alpha toxin is an important agent and the unique lethal virulent factor produced by Clostridium septicum. This toxin is haemolytic, highly lethal and necrotizing activities but is being used as an antigen to develop animal vaccines. The aim of this study was to isolate the alpha toxin of Clostridium septicum and produce highly specific antibodies against it. In this work, we have developed a simple and efficient method for alpha toxin purification, based on electroelution that can be used as a time-saving method for purifying proteins. This technique avoids contamination by other proteins that could appear during other protein purification techniques such chromatography. The highly purified toxin was used to produce polyclonal antibodies. The specificity of the antibodies was tested by western blot and these antibodies can be applied to the quantitative determination of alpha toxin by slot blot.
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Affiliation(s)
- Lorena Vázquez-Iglesias
- Department of Biochemistry, Genetics and Immunology, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - Borja Estefanell-Ucha
- Department of Biochemistry, Genetics and Immunology, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - Leticia Barcia-Castro
- Department of Biochemistry, Genetics and Immunology, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - María Páez de la Cadena
- Department of Biochemistry, Genetics and Immunology, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - Paula Álvarez-Chaver
- Unidad de Proteómica, Servicio de Determinación Estructural, Proteómica y Genómica, CACTI, Universidad de Vigo, Spain
| | - Daniel Ayude-Vázquez
- Department of Biochemistry, Genetics and Immunology, Facultad de Biología, Universidad de Vigo, Vigo, Spain
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The Contribution of Bacteriophages to the Biology and Virulence of Pathogenic Clostridia. ADVANCES IN APPLIED MICROBIOLOGY 2017; 101:169-200. [PMID: 29050666 DOI: 10.1016/bs.aambs.2017.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bacteriophages are key players in the evolution of most bacteria. Temperate phages have been associated with virulence of some of the deadliest pathogenic bacteria. Among the most notorious cases, the genes encoding the botulinum neurotoxin produced by Clostridium botulinum types C and D and the α-toxin (TcnA) produced by Clostridium novyi are both encoded within prophage genomes. Clostridium difficile is another important human pathogen and the recent identification of a complete binary toxin locus (CdtLoc) carried on a C. difficile prophage raises the potential for horizontal transfer of toxin genes by mobile genetic elements. Although the TcdA and TcdB toxins produced by C. difficile have never been found outside the pathogenicity locus (PaLoc), some prophages can still influence their production. Prophages can alter the expression of several metabolic and regulatory genes in C. difficile, as well as cell surface proteins such as CwpV, which confers phage resistance. Homologs of an Agr-like quorum sensing system have been identified in a C. difficile prophage, suggesting that it could possibly participate in cell-cell communication. Yet, other C. difficile prophages contain riboswitches predicted to recognize the secondary messenger molecule c-di-GMP involved in bacterial multicellular behaviors. Altogether, recent findings on clostridial phages underline the diversity of mechanisms and intricate relationship linking phages with their host. Here, milestone discoveries linking phages and virulence of some of the most pathogenic clostridial species will be retraced, with a focus on C. botulinum, C. novyi, C. difficile, and Clostridium perfringens phages, for which evidences are mostly available.
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Wisniewski JA, Rood JI. The Tcp conjugation system of Clostridium perfringens. Plasmid 2017; 91:28-36. [PMID: 28286218 DOI: 10.1016/j.plasmid.2017.03.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 02/24/2017] [Accepted: 03/06/2017] [Indexed: 11/18/2022]
Abstract
The Gram-positive pathogen Clostridium perfringens possesses a family of large conjugative plasmids that is typified by the tetracycline resistance plasmid pCW3. Since these plasmids may carry antibiotic resistance genes or genes encoding extracellular or sporulation-associated toxins, the conjugative transfer of these plasmids appears to be important for the epidemiology of C. perfringens-mediated diseases. Sequence analysis of members of this plasmid family identified a highly conserved 35kb region that encodes proteins with various functions, including plasmid replication and partitioning. The tcp conjugation locus also was identified in this region, initially based on low-level amino acid sequence identity to conjugation proteins from the integrative conjugative element Tn916. Genetic studies confirmed that the tcp locus is required for conjugative transfer and combined with biochemical and structural analyses have led to the development of a functional model of the Tcp conjugation apparatus. This review summarises our current understanding of the Tcp conjugation system, which is now one of the best-characterized conjugation systems in Gram-positive bacteria.
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Affiliation(s)
- Jessica A Wisniewski
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Victoria 3800, Australia.
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Riedel T, Wittmann J, Bunk B, Schober I, Spröer C, Gronow S, Overmann J. A Clostridioides difficile bacteriophage genome encodes functional binary toxin-associated genes. J Biotechnol 2017; 250:23-28. [PMID: 28216103 DOI: 10.1016/j.jbiotec.2017.02.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/10/2017] [Accepted: 02/15/2017] [Indexed: 12/29/2022]
Abstract
Pathogenic clostridia typically produce toxins as virulence factors which cause severe diseases in both humans and animals. Whereas many clostridia like e.g., Clostridium perfringens, Clostridium botulinum or Clostridium tetani were shown to contain toxin-encoding plasmids, only toxin genes located on the chromosome were detected in Clostridioides difficile so far. In this study, we determined, annotated, and analyzed the complete genome of the bacteriophage phiSemix9P1 using single-molecule real-time sequencing technology (SMRT). To our knowledge, this represents the first C. difficile-associated bacteriophage genome that carries a complete functional binary toxin locus in its genome.
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Affiliation(s)
- Thomas Riedel
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7B, Braunschweig, Germany; North German Center of Microbial Genomics, Germany.
| | - Johannes Wittmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7B, Braunschweig, Germany
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7B, Braunschweig, Germany; North German Center of Microbial Genomics, Germany; German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
| | - Isabel Schober
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7B, Braunschweig, Germany
| | - Cathrin Spröer
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7B, Braunschweig, Germany; North German Center of Microbial Genomics, Germany; German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
| | - Sabine Gronow
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7B, Braunschweig, Germany; North German Center of Microbial Genomics, Germany; German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
| | - Jörg Overmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Inhoffenstraße 7B, Braunschweig, Germany; North German Center of Microbial Genomics, Germany; German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
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Effect of tcdR Mutation on Sporulation in the Epidemic Clostridium difficile Strain R20291. mSphere 2017; 2:mSphere00383-16. [PMID: 28217744 PMCID: PMC5311115 DOI: 10.1128/msphere.00383-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/29/2017] [Indexed: 12/19/2022] Open
Abstract
C. difficile infects thousands of hospitalized patients every year, causing significant morbidity and mortality. C. difficile spores play a pivotal role in the transmission of the pathogen in the hospital environment. During infection, the spores germinate, and the vegetative bacterial cells produce toxins that damage host tissue. Thus, sporulation and toxin production are two important traits of C. difficile. In this study, we showed that a mutation in tcdR, the toxin gene regulator, affects both toxin production and sporulation in epidemic-type C. difficile strain R20291. Clostridium difficile is an important nosocomial pathogen and the leading cause of hospital-acquired diarrhea. Antibiotic use is the primary risk factor for the development of C. difficile-associated disease because it disrupts normally protective gut flora and enables C. difficile to colonize the colon. C. difficile damages host tissue by secreting toxins and disseminates by forming spores. The toxin-encoding genes, tcdA and tcdB, are part of a pathogenicity locus, which also includes the tcdR gene that codes for TcdR, an alternate sigma factor that initiates transcription of tcdA and tcdB genes. We created a tcdR mutant in epidemic-type C. difficile strain R20291 in an attempt to identify the global role of tcdR. A site-directed mutation in tcdR affected both toxin production and sporulation in C. difficile R20291. Spores of the tcdR mutant were more heat sensitive than the wild type (WT). Nearly 3-fold more taurocholate was needed to germinate spores from the tcdR mutant than to germinate the spores prepared from the WT strain. Transmission electron microscopic analysis of the spores also revealed a weakly assembled exosporium on the tcdR mutant spores. Accordingly, comparative transcriptome analysis showed many differentially expressed sporulation genes in the tcdR mutant compared to the WT strain. These data suggest that regulatory networks of toxin production and sporulation in C. difficile strain R20291 are linked with each other. IMPORTANCEC. difficile infects thousands of hospitalized patients every year, causing significant morbidity and mortality. C. difficile spores play a pivotal role in the transmission of the pathogen in the hospital environment. During infection, the spores germinate, and the vegetative bacterial cells produce toxins that damage host tissue. Thus, sporulation and toxin production are two important traits of C. difficile. In this study, we showed that a mutation in tcdR, the toxin gene regulator, affects both toxin production and sporulation in epidemic-type C. difficile strain R20291.
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Lugli GA, Milani C, Mancabelli L, Turroni F, Ferrario C, Duranti S, van Sinderen D, Ventura M. Ancient bacteria of the Ötzi's microbiome: a genomic tale from the Copper Age. MICROBIOME 2017; 5:5. [PMID: 28095919 PMCID: PMC5240250 DOI: 10.1186/s40168-016-0221-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 12/13/2016] [Indexed: 05/19/2023]
Abstract
BACKGROUND Ancient microbiota information represents an important resource to evaluate bacterial evolution and to explore the biological spread of infectious diseases in history. The soft tissue of frozen mummified humans, such as the Tyrolean Iceman, has been shown to contain bacterial DNA that is suitable for population profiling of the prehistoric bacteria that colonized such ancient human hosts. RESULTS Here, we performed a microbial cataloging of the distal gut microbiota of the Tyrolean Iceman, which highlights a predominant abundance of Clostridium and Pseudomonas species. Furthermore, in silico analyses allowed the reconstruction of the genome sequences of five ancient bacterial genomes, including apparent pathogenic ancestor strains of Clostridium perfringens and Pseudomonas veronii species present in the gut of the Tyrolean Iceman. CONCLUSIONS Genomic analyses of the reconstructed C. perfringens chromosome clearly support the occurrence of a pathogenic profile consisting of virulence genes already existing in the ancient strain, thereby reinforcing the notion of a very early speciation of this taxon towards a pathogenic phenotype. In contrast, the evolutionary development of P. veronii appears to be characterized by the acquisition of antibiotic resistance genes in more recent times as well as an evolution towards an ecological niche outside of the (human) gastrointestinal tract.
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Affiliation(s)
- Gabriele Andrea Lugli
- Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parco Area delle Scienze 11a, 43124, Parma, Italy
| | - Christian Milani
- Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parco Area delle Scienze 11a, 43124, Parma, Italy
| | - Leonardo Mancabelli
- Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parco Area delle Scienze 11a, 43124, Parma, Italy
| | - Francesca Turroni
- Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parco Area delle Scienze 11a, 43124, Parma, Italy
| | - Chiara Ferrario
- Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parco Area delle Scienze 11a, 43124, Parma, Italy
| | - Sabrina Duranti
- Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parco Area delle Scienze 11a, 43124, Parma, Italy
| | - Douwe van Sinderen
- APC Microbiome Institute and School of Microbiology, National University of Ireland, Cork, Ireland
| | - Marco Ventura
- Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parco Area delle Scienze 11a, 43124, Parma, Italy.
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Vagin O, Beenhouwer DO. Septins: Regulators of Protein Stability. Front Cell Dev Biol 2016; 4:143. [PMID: 28066764 PMCID: PMC5168428 DOI: 10.3389/fcell.2016.00143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/02/2016] [Indexed: 12/31/2022] Open
Abstract
Septins are small GTPases that play a role in several important cellular processes. In this review, we focus on the roles of septins in protein stabilization. Septins may regulate protein stability by: (1) interacting with proteins involved in degradation pathways, (2) regulating the interaction between transmembrane proteins and cytoskeletal proteins, (3) affecting the mobility of transmembrane proteins in lipid bilayers, and (4) modulating the interaction of proteins with their adaptor or signaling proteins. In this context, we discuss the role of septins in protecting four different proteins from degradation. First we consider botulinum neurotoxin serotype A (BoNT/A) and the contribution of septins to its extraordinarily long intracellular persistence. Next, we discuss the role of septins in stabilizing the receptor tyrosine kinases EGFR and ErbB2. Finally, we consider the contribution of septins in protecting hypoxia-inducible factor 1α (HIF-1α) from degradation.
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Affiliation(s)
- Olga Vagin
- Department of Physiology, Geffen School of Medicine at UCLALos Angeles, CA, USA; VA Greater Los Angeles Healthcare SystemLos Angeles, CA, USA
| | - David O Beenhouwer
- Department of Medicine, Geffen School of Medicine at UCLALos Angeles, CA, USA; Division of Infectious Diseases, VA Greater Los Angeles Health Care SystemLos Angeles, CA, USA
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64
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Chukwu EE, Nwaokorie FO, Coker AO, Avila-Campos MJ, Solis RL, Llanco LA, Ogunsola FT. Detection of toxigenic Clostridium perfringens and Clostridium botulinum from food sold in Lagos, Nigeria. Anaerobe 2016; 42:176-181. [DOI: 10.1016/j.anaerobe.2016.10.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/21/2016] [Accepted: 10/23/2016] [Indexed: 12/23/2022]
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Pires PS, Santos RL, da Paixão TA, de Oliveira Bernardes LC, de Macêdo AA, Gonçalves LA, de Oliveira Júnior CA, Silva ROS, Lobato FCF. Intracellular survival of Clostridium chauvoei in bovine macrophages. Vet Microbiol 2016; 199:1-7. [PMID: 28110774 DOI: 10.1016/j.vetmic.2016.11.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 11/08/2016] [Accepted: 11/27/2016] [Indexed: 12/27/2022]
Abstract
Clostridium chauvoei is the etiological agent of blackleg, a severe disease of domestic ruminants, causing myonecrosis and serious toxemia with high mortality. Despite the known importance of this agent, studies evaluating its pathogenesis of blackleg are scarce, and many are based on an unproven hypothesis that states that macrophages are responsible for carrying C. chauvoei spores from the intestines to muscles in the early stages of blackleg. Therefore, the present study aimed to investigate the survival of C. chauvoei vegetative cells or spores after phagocytosis by a murine macrophage cell line (RAW 264.7) and bovine monocyte-derived macrophages and to profile inflammatory and anti-inflammatory cytokine transcripts of bovine macrophages infected with C. chauvoei vegetative cells or spores. Both vegetative cells and spores of C. chauvoei remain viable after internalization by murine and bovine macrophages. Bovine macrophages infected with vegetative cells showed a pro-inflammatory profile, while those infected with spores displayed an anti-inflammatory profile. Together, these results corroborate the classical hypothesis that macrophages may play a role in the early pathogenesis of blackleg. Moreover, this is the first study to evaluate the infection kinetics and cytokine profile of bovine monocyte-derived macrophages infected with a Clostridium species.
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Affiliation(s)
- Prhiscylla Sadanã Pires
- Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Renato Lima Santos
- Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Tatiane Alves da Paixão
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Laura Cristina de Oliveira Bernardes
- Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Auricélio Alves de Macêdo
- Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Luciana Aramuni Gonçalves
- Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Carlos Augusto de Oliveira Júnior
- Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
| | - Rodrigo Otávio Silveira Silva
- Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
| | - Francisco Carlos Faria Lobato
- Escola de Veterinária, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, 31270-901, Brazil
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66
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Crystal structure of the ADP-ribosylating component of BEC, the binary enterotoxin of Clostridium perfringens. Biochem Biophys Res Commun 2016; 480:261-267. [PMID: 27751850 DOI: 10.1016/j.bbrc.2016.10.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 10/14/2016] [Indexed: 11/20/2022]
Abstract
Binary enterotoxin of Clostridium perfringens (BEC), consisting of the components BECa and BECb, was recently identified as a novel enterotoxin produced by C. perfringens that causes acute gastroenteritis in humans. Although the detailed mechanism of cell intoxication by BEC remains to be defined, BECa shows both NAD+-glycohydrolase and actin ADP-ribosyltransferase activities in the presence of NAD+. In this study, we determined the first crystal structure of BECa in its apo-state and in complex with NADH. The structure of BECa shows striking resemblance with other binary actin ADP-ribosylating toxins (ADPRTs), especially in terms of its overall protein fold and mechanisms of substrate recognition. We present a detailed picture of interactions between BECa and NADH, including bound water molecules located near the C1'-N glycosidic bond of NADH and the catalytically important ADP-ribosylating turn-turn (ARTT) loop. We observed that the conformational rearrangement of the ARTT loop, possibly triggered by a conformational change involving a conserved tyrosine residue coupled with substrate binding, plays a crucial role in catalysis by properly positioning a catalytic glutamate residue in the E-X-E motif of the ARTT loop in contact with the nucleophile. Our results for BECa provide insight into the common catalytic mechanism of the family of binary actin ADPRTs.
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67
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Hosny M, Benamar S, Durand G, Armstrong N, Michelle C, Cadoret F, La Scola B, Cassir N. Description of Clostridium phoceensis sp. nov., a new species within the genus Clostridium. New Microbes New Infect 2016; 14:85-92. [PMID: 27818774 PMCID: PMC5078575 DOI: 10.1016/j.nmni.2016.09.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/09/2016] [Accepted: 09/16/2016] [Indexed: 01/15/2023] Open
Abstract
Clostridium phoceensis sp. nov., strain GD3T (= CSUR P1929 = DSM 100334) is the type strain of C. phoceensis sp. nov., a new species within the genus Clostridium. This strain was isolated from the gut microbiota of a 28-year-old healthy French man. C. phoceensis is a Gram-negative, spore-forming, nonmotile, strictly anaerobic bacterium. We describe its complete genome sequence and annotation, together with its phenotypic characteristics.
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Affiliation(s)
- M Hosny
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1095, IHU Méditerranée Infection, Pôle des Maladies Infectieuses, Assistance Publique-Hôpitaux de Marseille, Faculté de Médecine, Marseille, France
| | - S Benamar
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1095, IHU Méditerranée Infection, Pôle des Maladies Infectieuses, Assistance Publique-Hôpitaux de Marseille, Faculté de Médecine, Marseille, France
| | - G Durand
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1095, IHU Méditerranée Infection, Pôle des Maladies Infectieuses, Assistance Publique-Hôpitaux de Marseille, Faculté de Médecine, Marseille, France
| | - N Armstrong
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1095, IHU Méditerranée Infection, Pôle des Maladies Infectieuses, Assistance Publique-Hôpitaux de Marseille, Faculté de Médecine, Marseille, France
| | - C Michelle
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1095, IHU Méditerranée Infection, Pôle des Maladies Infectieuses, Assistance Publique-Hôpitaux de Marseille, Faculté de Médecine, Marseille, France
| | - F Cadoret
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1095, IHU Méditerranée Infection, Pôle des Maladies Infectieuses, Assistance Publique-Hôpitaux de Marseille, Faculté de Médecine, Marseille, France
| | - B La Scola
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1095, IHU Méditerranée Infection, Pôle des Maladies Infectieuses, Assistance Publique-Hôpitaux de Marseille, Faculté de Médecine, Marseille, France
| | - N Cassir
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63 CNRS 7278 IRD 198 INSERM U1095, IHU Méditerranée Infection, Pôle des Maladies Infectieuses, Assistance Publique-Hôpitaux de Marseille, Faculté de Médecine, Marseille, France
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68
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Kronhardt A, Beitzinger C, Barth H, Benz R. Chloroquine Analog Interaction with C2- and Iota-Toxin in Vitro and in Living Cells. Toxins (Basel) 2016; 8:toxins8080237. [PMID: 27517960 PMCID: PMC4999853 DOI: 10.3390/toxins8080237] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/28/2016] [Indexed: 12/22/2022] Open
Abstract
C2-toxin from Clostridium botulinum and Iota-toxin from Clostridium perfringens belong both to the binary A-B-type of toxins consisting of two separately secreted components, an enzymatic subunit A and a binding component B that facilitates the entry of the corresponding enzymatic subunit into the target cells. The enzymatic subunits are in both cases actin ADP-ribosyltransferases that modify R177 of globular actin finally leading to cell death. Following their binding to host cells’ receptors and internalization, the two binding components form heptameric channels in endosomal membranes which mediate the translocation of the enzymatic components Iota a and C2I from endosomes into the cytosol of the target cells. The binding components form ion-permeable channels in artificial and biological membranes. Chloroquine and related 4-aminoquinolines were able to block channel formation in vitro and intoxication of living cells. In this study, we extended our previous work to the use of different chloroquine analogs and demonstrate that positively charged aminoquinolinium salts are able to block channels formed in lipid bilayer membranes by the binding components of C2- and Iota-toxin. Similarly, these molecules protect cultured mammalian cells from intoxication with C2- and Iota-toxin. The aminoquinolinium salts did presumably not interfere with actin ADP-ribosylation or receptor binding but blocked the pores formed by C2IIa and Iota b in living cells and in vitro. The blocking efficiency of pores formed by Iota b and C2IIa by the chloroquine analogs showed interesting differences indicating structural variations between the types of protein-conducting nanochannels formed by Iota b and C2IIa.
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Affiliation(s)
- Angelika Kronhardt
- Rudolf Virchow Center, Research Center for Experimental Biomedicine, University of Würzburg, Versbacher Straße 9, 97078 Würzburg, Germany.
| | - Christoph Beitzinger
- Rudolf Virchow Center, Research Center for Experimental Biomedicine, University of Würzburg, Versbacher Straße 9, 97078 Würzburg, Germany.
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | - Roland Benz
- Department of Life Sciences and Chemistry, Jacobs-University Bremen, Campus-Ring 1, 28759 Bremen, Germany.
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69
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Takagishi T, Oda M, Takehara M, Kobayashi K, Nagahama M. Oligomer formation of Clostridium perfringens epsilon-toxin is induced by activation of neutral sphingomyelinase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2681-2688. [PMID: 27453200 DOI: 10.1016/j.bbamem.2016.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 07/14/2016] [Accepted: 07/19/2016] [Indexed: 11/24/2022]
Abstract
BACKGROUND Clostridium perfringens epsilon-toxin is responsible for fatal enterotoxemia in ungulates. The toxin forms a heptamer in the lipid rafts of Madin-Darby Canine Kidney (MDCK) cells, leading to cell death. Here, we showed that epsilon-toxin requires neutral sphingomyelinase (nSMase) activity during oligomerization. METHODS We tested the role of nSMase in the oligomerization of epsilon-toxin using specific inhibitors, knockdown of nSMase, formation of ceramide, and localization of epsilon-toxin and ceramide by immunofluorescence staining. RESULTS Epsilon-toxin induced the production of ceramide is a dose- and time-dependent manner in ACHN cells. GW4869, an inhibitor of nSMase, inhibited ceramide production induced by the toxin. GW4869 and knockdown of nSMase blocked toxin-induced cell death and oligomer formation of epsilon-toxin. Confocal microscopy images showed that the toxin induced ceramide clustering and colocalized with ceramide. CONCLUSIONS These results demonstrated that oligomer formation of epsilon-toxin is facilitated by the production of ceramide through activation of nSMase caused by the toxin. GENERAL SIGNIFICANCE Inhibitors of nSMase may confer protection against infection.
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Affiliation(s)
- Teruhisa Takagishi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima 770-8514, Japan
| | - Masataka Oda
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan
| | - Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima 770-8514, Japan
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima 770-8514, Japan
| | - Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 180, Tokushima 770-8514, Japan.
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70
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Goossens E, Verherstraeten S, Valgaeren BR, Pardon B, Timbermont L, Schauvliege S, Rodrigo-Mocholí D, Haesebrouck F, Ducatelle R, Deprez PR, Van Immerseel F. The C-terminal domain of Clostridium perfringens alpha toxin as a vaccine candidate against bovine necrohemorrhagic enteritis. Vet Res 2016; 47:52. [PMID: 27121298 PMCID: PMC4847199 DOI: 10.1186/s13567-016-0336-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 04/12/2016] [Indexed: 01/01/2023] Open
Abstract
Bovine necrohemorrhagic enteritis is caused by Clostridium perfringens and leads to sudden death. Alpha toxin, together with perfringolysin O, has been identified as the principal toxin involved in the pathogenesis. We assessed the potential of alpha toxin as a vaccine antigen. Using an intestinal loop model in calves, we investigated the protection afforded by antisera raised against native alpha toxin or its non-toxic C-terminal fragment against C. perfringens-induced intestinal necrosis. Immunization of calves with either of the vaccine preparations induced a strong antibody response. The resulting antisera were able to neutralize the alpha toxin activity and the C. perfringens-induced endothelial cytotoxicity in vitro. The antisera raised against the native toxin had a stronger neutralizing activity than those against the C-terminal fragment. However, antibodies against alpha toxin alone were not sufficient to completely neutralize the C. perfringens-induced necrosis in the intestinal loop model. The development of a multivalent vaccine combining the C-terminal fragment of alpha toxin with other C. perfringens virulence factors might be necessary for complete protection against bovine necrohemorrhagic enteritis.
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Affiliation(s)
- Evy Goossens
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Stefanie Verherstraeten
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Bonnie R Valgaeren
- Department of Internal Medicine and Clinical Biology of Large Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Bart Pardon
- Department of Internal Medicine and Clinical Biology of Large Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Leen Timbermont
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Stijn Schauvliege
- Department of Surgery and Anesthesia of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Diego Rodrigo-Mocholí
- Department of Surgery and Anesthesia of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Richard Ducatelle
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Piet R Deprez
- Department of Internal Medicine and Clinical Biology of Large Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium
| | - Filip Van Immerseel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium.
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71
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Nava P, Vidal JE. The CpAL system regulates changes of the trans-epithelial resistance of human enterocytes during Clostridium perfringens type C infection. Anaerobe 2016; 39:143-9. [PMID: 27063897 DOI: 10.1016/j.anaerobe.2016.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 03/21/2016] [Accepted: 04/04/2016] [Indexed: 01/17/2023]
Abstract
Clostridium perfringens type C strains produce severe disease in humans and animals including enterotoxaemia and hemorrhagic diarrhea. Type C disease is mediated by production of toxins that damage the site of infection inducing loss of bloody fluids. Production of type C toxins, such as CPA, PFO, and, CPB is regulated by the C. perfringens Agr-like (CpAL) quorum sensing (QS) system. The CpAL system is also required to recapitulate, in vivo, intestinal signs of C. perfringens type C-induced disease, including hemorrhagic diarrhea and accumulation of fluids. The intestinal epithelium forms a physical barrier, made up of a series of intercellular junctions including tight junctions (TJs), adherens junctions (AJs) and desmosomes (DMs). This selective barrier regulates important physiological processes, including paracellular movement of ions and solutes, which, if altered, results in loss of fluids into the intestinal lumen. In this work, the effects of C. perfringens infection on the barrier function of intestinal epithelial cells was evaluated by measuring trans-epithelial resistance (TEER). Our studies demonstrate that infection of human enterocytes with C. perfringens type C strain CN3685 induced a significant drop on TEER. Changes in TEER were mediated by the CpAL system as a CN3685ΔagrB mutant did not induce such a drop. Physical contact between bacteria and enterocytes produced more pronounced changes in TEER and this phenomenon appeared also to be mediated by the CpAL system. Finally, immunofluorescence studies demonstrate that C. perfringens type C infection redistribute TJs protein occludin, and Claudin-3, and DMs protein desmoglein-2, but did not affect the AJs protein E-cadherin.
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Affiliation(s)
- Porfirio Nava
- Department of Physiology, Biophysics and Neurosciences, Cinvestav, Mexico City, Mexico
| | - Jorge E Vidal
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
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72
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Bezrukov SM, Nestorovich EM. Inhibiting bacterial toxins by channel blockage. Pathog Dis 2016; 74:ftv113. [PMID: 26656888 PMCID: PMC4830228 DOI: 10.1093/femspd/ftv113] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/15/2015] [Accepted: 11/24/2015] [Indexed: 01/01/2023] Open
Abstract
Emergent rational drug design techniques explore individual properties of target biomolecules, small and macromolecule drug candidates, and the physical forces governing their interactions. In this minireview, we focus on the single-molecule biophysical studies of channel-forming bacterial toxins that suggest new approaches for their inhibition. We discuss several examples of blockage of bacterial pore-forming and AB-type toxins by the tailor-made compounds. In the concluding remarks, the most effective rationally designed pore-blocking antitoxins are compared with the small-molecule inhibitors of ion-selective channels of neurophysiology.
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Affiliation(s)
- Sergey M Bezrukov
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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73
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Clostridium perfringens Delta-Toxin Induces Rapid Cell Necrosis. PLoS One 2016; 11:e0147957. [PMID: 26807591 PMCID: PMC4726729 DOI: 10.1371/journal.pone.0147957] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 01/10/2016] [Indexed: 12/26/2022] Open
Abstract
Clostridium perfringens delta-toxin is a β-pore-forming toxin and a putative pathogenic agent of C. perfringens types B and C. However, the mechanism of cytotoxicity of delta-toxin remains unclear. Here, we investigated the mechanisms of cell death induced by delta-toxin in five cell lines (A549, A431, MDCK, Vero, and Caco-2). All cell lines were susceptible to delta-toxin. The toxin caused rapid ATP depletion and swelling of the cells. Delta-toxin bound and formed oligomers predominantly in plasma membrane lipid rafts. Destruction of the lipid rafts with methyl β-cyclodextrin inhibited delta-toxin-induced cytotoxicity and ATP depletion. Delta-toxin caused the release of carboxyfluorescein from sphingomyelin-cholesterol liposomes and formed oligomers; toxin binding to the liposomes declined with decreasing cholesterol content in the liposomes. Flow cytometric assays with annexin V and propidium iodide revealed that delta-toxin treatment induced an elevation in the population of annexin V-negative and propidium iodide-positive cells. Delta-toxin did not cause the fragmentation of DNA or caspase-3 activation. Furthermore, delta-toxin caused damage to mitochondrial membrane permeability and cytochrome c release. In the present study, we demonstrate that delta-toxin produces cytotoxic activity through necrosis.
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74
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Beta Lactamase Producing Clostridium perfringens Bacteremia in an Elderly Man with Acute Pancreatitis. Case Rep Crit Care 2016; 2016:7078180. [PMID: 26904307 PMCID: PMC4745868 DOI: 10.1155/2016/7078180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/04/2016] [Indexed: 11/18/2022] Open
Abstract
Clostridium perfringens bacteremia is associated with adverse outcomes. Known risk factors include chronic kidney disease, malignancy, diabetes mellitus, and gastrointestinal disease. We present a 74-year-old man admitted with confusion, vomiting, and abdominal pain. Exam revealed tachycardia, hypotension, lethargy, distended abdomen, and cold extremities. He required intubation and aggressive resuscitation for septic shock. Laboratory data showed leukocytosis, metabolic acidosis, acute kidney injury, and elevated lipase. CT scan of abdomen revealed acute pancreatitis and small bowel ileus. He was started on vancomycin and piperacillin-tazobactam. Initial blood cultures were positive for C. perfringens on day five. Metronidazole and clindamycin were added to the regimen. Repeat CT (day 7) revealed pancreatic necrosis. The patient developed profound circulatory shock requiring multiple vasopressors, renal failure requiring dialysis, and bacteremia with vancomycin-resistant enterococci. Hemodynamic instability precluded surgical intervention and he succumbed to multiorgan failure. Interestingly, our isolate was beta lactamase producing. We review the epidemiology, risk factors, presentation, and management of C. perfringens bacteremia. This case indicates a need for high clinical suspicion for clostridial sepsis and that extended spectrum beta lactam antibiotic coverage may be inadequate and should be supplemented with use of clindamycin or metronidazole if culture is positive, until sensitivities are known.
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75
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Cassir N, Benamar S, La Scola B. Clostridium butyricum : from beneficial to a new emerging pathogen. Clin Microbiol Infect 2016; 22:37-45. [DOI: 10.1016/j.cmi.2015.10.014] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/09/2015] [Accepted: 10/09/2015] [Indexed: 02/07/2023]
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76
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Schönauer E, Brandstetter H. Inhibition and Activity Regulation of Bacterial Collagenases. TOPICS IN MEDICINAL CHEMISTRY 2016. [DOI: 10.1007/7355_2016_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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77
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Lacasta D, Ferrer L, Ramos J, González J, Ortín A, Fthenakis G. Vaccination schedules in small ruminant farms. Vet Microbiol 2015. [DOI: 10.1016/j.vetmic.2015.07.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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78
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Worbs S, Fiebig U, Zeleny R, Schimmel H, Rummel A, Luginbühl W, Dorner BG. Qualitative and Quantitative Detection of Botulinum Neurotoxins from Complex Matrices: Results of the First International Proficiency Test. Toxins (Basel) 2015; 7:4935-66. [PMID: 26703724 PMCID: PMC4690107 DOI: 10.3390/toxins7124857] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 11/03/2015] [Accepted: 11/05/2015] [Indexed: 11/16/2022] Open
Abstract
In the framework of the EU project EQuATox, a first international proficiency test (PT) on the detection and quantification of botulinum neurotoxins (BoNT) was conducted. Sample materials included BoNT serotypes A, B and E spiked into buffer, milk, meat extract and serum. Different methods were applied by the participants combining different principles of detection, identification and quantification. Based on qualitative assays, 95% of all results reported were correct. Successful strategies for BoNT detection were based on a combination of complementary immunological, MS-based and functional methods or on suitable functional in vivo/in vitro approaches (mouse bioassay, hemidiaphragm assay and Endopep-MS assay). Quantification of BoNT/A, BoNT/B and BoNT/E was performed by 48% of participating laboratories. It turned out that precise quantification of BoNT was difficult, resulting in a substantial scatter of quantitative data. This was especially true for results obtained by the mouse bioassay which is currently considered as "gold standard" for BoNT detection. The results clearly demonstrate the urgent need for certified BoNT reference materials and the development of methods replacing animal testing. In this context, the BoNT PT provided the valuable information that both the Endopep-MS assay and the hemidiaphragm assay delivered quantitative results superior to the mouse bioassay.
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Affiliation(s)
- Sylvia Worbs
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany.
| | - Uwe Fiebig
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany.
| | - Reinhard Zeleny
- European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel, Belgium.
| | - Heinz Schimmel
- European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel, Belgium.
| | - Andreas Rummel
- toxogen GmbH, Feodor-Lynen-Strasse 35, 30625 Hannover, Germany.
| | | | - Brigitte G Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany.
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79
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Gil C, Dorca-Arévalo J, Blasi J. Clostridium Perfringens Epsilon Toxin Binds to Membrane Lipids and Its Cytotoxic Action Depends on Sulfatide. PLoS One 2015; 10:e0140321. [PMID: 26452234 PMCID: PMC4599917 DOI: 10.1371/journal.pone.0140321] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 09/24/2015] [Indexed: 12/23/2022] Open
Abstract
Epsilon toxin (Etx) is one of the major lethal toxins produced by Clostridium perfringens types B and D, being the causal agent of fatal enterotoxemia in animals, mainly sheep and goats. Etx is synthesized as a non-active prototoxin form (proEtx) that becomes active upon proteolytic activation. Etx exhibits a cytotoxic effect through the formation of a pore in the plasma membrane of selected cell targets where Etx specifically binds due to the presence of specific receptors. However, the identity and nature of host receptors of Etx remain a matter of controversy. In the present study, the interactions between Etx and membrane lipids from the synaptosome-enriched fraction from rat brain (P2 fraction) and MDCK cell plasma membrane preparations were analyzed. Our findings show that both Etx and proEtx bind to lipids extracted from lipid rafts from the two different models as assessed by protein-lipid overlay assay. Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids. Binding of proEtx to sulfatide, phosphatidylserine, phosphatidylinositol (3)-phosphate and phosphatidylinositol (5)-phosphate was detected. Removal of the sulphate groups via sulfatase treatment led to a dramatic decrease in Etx-induced cytotoxicity, but not in proEtx-GFP binding to MDCK cells or a significant shift in oligomer formation, pointing to a role of sulfatide in pore formation in rafts but not in toxin binding to the target cell membrane. These results show for the first time the interaction between Etx and membrane lipids from host tissue and point to a major role for sulfatides in C. perfringens epsilon toxin pathophysiology.
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Affiliation(s)
- Carles Gil
- Departament de Bioquímica i Biologia Molecular and Institut de Neurociències, Universitat Autònoma de Barcelona, Bellaterra, Catalunya, Spain
- * E-mail: (JB); (CG)
| | - Jonatan Dorca-Arévalo
- Laboratory of Cellular and Molecular Neuroscience, Department of Pathology and Experimental Therapeutics, School of Medicine, Universitat de Barcelona, L’Hospitalet de Llobregat, Barcelona, Spain
- IDIBELL-Bellvitge Biomedical Research Institute, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Juan Blasi
- Laboratory of Cellular and Molecular Neuroscience, Department of Pathology and Experimental Therapeutics, School of Medicine, Universitat de Barcelona, L’Hospitalet de Llobregat, Barcelona, Spain
- IDIBELL-Bellvitge Biomedical Research Institute, L’Hospitalet de Llobregat, Barcelona, Spain
- * E-mail: (JB); (CG)
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80
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Pore-forming activity of clostridial binary toxins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:512-25. [PMID: 26278641 DOI: 10.1016/j.bbamem.2015.08.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/13/2015] [Accepted: 08/11/2015] [Indexed: 11/24/2022]
Abstract
Clostridial binary toxins (Clostridium perfringens Iota toxin, Clostridium difficile transferase, Clostridium spiroforme toxin, Clostridium botulinum C2 toxin) as Bacillus binary toxins, including Bacillus anthracis toxins consist of two independent proteins, one being the binding component which mediates the internalization into cell of the intracellularly active component. Clostridial binary toxins induce actin cytoskeleton disorganization through mono-ADP-ribosylation of globular actin and are responsible for enteric diseases. Clostridial and Bacillus binary toxins share structurally and functionally related binding components which recognize specific cell receptors, oligomerize, form pores in endocytic vesicle membrane, and mediate the transport of the enzymatic component into the cytosol. Binding components retain the global structure of pore-forming toxins (PFTs) from the cholesterol-dependent cytotoxin family such as perfringolysin. However, their pore-forming activity notably that of clostridial binding components is more related to that of heptameric PFT family including aerolysin and C. perfringens epsilon toxin. This review focuses upon pore-forming activity of clostridial binary toxins compared to other related PFTs. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale.
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81
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Upadhyay A, Mooyottu S, Yin H, Nair MS, Bhattaram V, Venkitanarayanan K. Inhibiting Microbial Toxins Using Plant-Derived Compounds and Plant Extracts. MEDICINES (BASEL, SWITZERLAND) 2015; 2:186-211. [PMID: 28930207 PMCID: PMC5456214 DOI: 10.3390/medicines2030186] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 06/07/2023]
Abstract
Many pathogenic bacteria and fungi produce potentially lethal toxins that cause cytotoxicity or impaired cellular function either at the site of colonization or other locations in the body through receptor-mediated interactions. Various factors, including biotic and abiotic environments, competing microbes, and chemical cues affect toxin expression in these pathogens. Recent work suggests that several natural compounds can modulate toxin production in pathogenic microbes. However, studies explaining the mechanistic basis for their effect are scanty. This review discusses the potential of various plant-derived compounds for reducing toxin production in foodborne and other microbes. In addition, studies highlighting their anti-toxigenic mechanism(s) are discussed.
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Affiliation(s)
- Abhinav Upadhyay
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
| | - Shankumar Mooyottu
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
| | - Hsinbai Yin
- Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
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82
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Diversity, Structures, and Collagen-Degrading Mechanisms of Bacterial Collagenolytic Proteases. Appl Environ Microbiol 2015; 81:6098-107. [PMID: 26150451 DOI: 10.1128/aem.00883-15] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Bacterial collagenolytic proteases are important because of their essential role in global collagen degradation and because of their virulence in some human bacterial infections. Bacterial collagenolytic proteases include some metalloproteases of the M9 family from Clostridium or Vibrio strains, some serine proteases distributed in the S1, S8, and S53 families, and members of the U32 family. In recent years, there has been remarkable progress in discovering new bacterial collagenolytic proteases and in investigating the collagen-degrading mechanisms of bacterial collagenolytic proteases. This review provides comprehensive insight into bacterial collagenolytic proteases, especially focusing on the structures and collagen-degrading mechanisms of representative bacterial collagenolytic proteases in each family. The roles of bacterial collagenolytic proteases in human diseases and global nitrogen cycling, together with the biotechnological and medical applications for these proteases, are also briefly discussed.
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83
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Kim IH, Kim IJ, Wen Y, Park NY, Park J, Lee KW, Koh A, Lee JH, Koo SH, Kim KS. Vibrio vulnificus Secretes an Insulin-degrading Enzyme That Promotes Bacterial Proliferation in Vivo. J Biol Chem 2015; 290:18708-20. [PMID: 26041774 DOI: 10.1074/jbc.m115.656306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 12/23/2022] Open
Abstract
We describe a novel insulin-degrading enzyme, SidC, that contributes to the proliferation of the human bacterial pathogen Vibrio vulnificus in a mouse model. SidC is phylogenetically distinct from other known insulin-degrading enzymes and is expressed and secreted specifically during host infection. Purified SidC causes a significant decrease in serum insulin levels and an increase in blood glucose levels in mice. A comparison of mice infected with wild type V. vulnificus or an isogenic sidC-deletion strain showed that wild type bacteria proliferated to higher levels. Additionally, hyperglycemia leads to increased proliferation of V. vulnificus in diabetic mice. Consistent with these observations, the sid operon was up-regulated in response to low glucose levels through binding of the cAMP-receptor protein (CRP) complex to a region upstream of the operon. We conclude that glucose levels are important for the survival of V. vulnificus in the host, and that this pathogen uses SidC to actively manipulate host endocrine signals, making the host environment more favorable for bacterial survival and growth.
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Affiliation(s)
- In Hwang Kim
- From the Department of Life Science, Sogang University, Seoul 121-742, Korea
| | - Ik-Jung Kim
- From the Department of Life Science, Sogang University, Seoul 121-742, Korea
| | - Yancheng Wen
- From the Department of Life Science, Sogang University, Seoul 121-742, Korea
| | - Na-Young Park
- From the Department of Life Science, Sogang University, Seoul 121-742, Korea
| | - Jinyoung Park
- the Division of Life Science, Korea University, Seoul 136-701, Korea
| | - Keun-Woo Lee
- From the Department of Life Science, Sogang University, Seoul 121-742, Korea
| | - Ara Koh
- From the Department of Life Science, Sogang University, Seoul 121-742, Korea
| | - Ji-Hyun Lee
- the Division of Life Science, Korea University, Seoul 136-701, Korea
| | - Seung-Hoi Koo
- the Division of Life Science, Korea University, Seoul 136-701, Korea
| | - Kun-Soo Kim
- From the Department of Life Science, Sogang University, Seoul 121-742, Korea,
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84
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Observations on the Role of TcdE Isoforms in Clostridium difficile Toxin Secretion. J Bacteriol 2015; 197:2600-9. [PMID: 26013487 DOI: 10.1128/jb.00224-15] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/19/2015] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED Clostridium difficile is a major nosocomial pathogen and the principal causative agent of antibiotic-associated diarrhea. The toxigenic C. difficile strains that cause disease secrete virulence factors, toxin A and toxin B, that cause colonic injury and inflammation. C. difficile toxins have no export signature and are secreted by an unusual mechanism that involves TcdE, a holin-like protein. We isolated a TcdE mutant of the epidemic R20291 strain with impaired toxin secretion, which was restored by complementation with functional TcdE. In the TcdE open reading frame (ORF), we identified three possible translation start sites; each translated isoform may play a specific role in TcdE-controlled toxin release. We created plasmid constructs that express only one of the three TcdE isoforms and complemented the TcdE mutant with these isoforms. Western blot analysis of the complemented strains demonstrated that TcdE is translated efficiently from the start codon at the 25th and 27th positions in the predicted ORF, producing proteins with 142 amino acids (TcdE142) and 140 amino acids (TcdE140), respectively. TcdE166 was not detected when expressed from its own ribosomal binding site (RBS). The effects of all three TcdE isoforms on C. difficile cell viability and toxin release were determined. Among the three isoforms, overexpression of TcdE166 and TcdE142 had a profound effect on cell viability compared to the TcdE140 isoform. Similarly, TcdE166 and TcdE142 facilitated toxin release more efficiently than did TcdE140. The importance of these variations among TcdE isoforms and their role in toxin release are discussed. IMPORTANCE C. difficile is a nosocomial pathogen that has become the most prevalent cause of antibiotic-associated diarrhea in North America and in several countries in Europe. Most strains of C. difficile produce two high-molecular-weight toxins that are regarded as the primary virulence factors. The mechanism by which these large toxins are secreted from bacterial cells is not yet clear but involves TcdE, a holin-like protein. In this work, we show that TcdE could be translated from three different start codons, resulting in the production of three TcdE isoforms. Furthermore, we investigated the role of these isoforms in toxin release and cell lysis in C. difficile. An understanding of TcdE-dependent toxin secretion may be helpful for the development of strategies for preventing and treating C. difficile infections.
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85
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Varela Chavez C, Hoos S, Haustant GM, Chenal A, England P, Blondel A, Pauillac S, Lacy DB, Popoff MR. The catalytic domains of Clostridium sordellii lethal toxin and related large clostridial glucosylating toxins specifically recognize the negatively charged phospholipids phosphatidylserine and phosphatidic acid. Cell Microbiol 2015; 17:1477-93. [PMID: 25882477 DOI: 10.1111/cmi.12449] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/15/2015] [Indexed: 12/23/2022]
Abstract
Clostridium sordellii lethal toxin (TcsL) is a potent virulence factor belonging to the large clostridial glucosylating toxin family. TcsL enters target cells via receptor-mediated endocytosis and delivers the N-terminal catalytic domain (TcsL-cat) into the cytosol upon an autoproteolytic process. TcsL-cat inactivates small GTPases including Rac and Ras by glucosylation with uridine-diphosphate (UDP)-glucose as cofactor leading to drastic changes in cytoskeleton and cell viability. TcsL-cat was found to preferentially bind to phosphatidylserine (PS)-containing membranes and to increase the glucosylation of Rac anchored to lipid membrane. We here report binding affinity measurements of TcsL-cat for brain PS-containing membranes by surface plasmon resonance and enzyme-linked immunosorbent assay (ELISA). In addition, TcsL-cat bound to phosphatidic acid (PA) and, to a lesser extent, to other anionic lipids, but not to neutral lipids, sphingolipids or sterol. We further show that the lipid unsaturation status influenced TcsL-cat binding to phospholipids, PS with unsaturated acyl chains and PA with saturated acyl chains being the preferred bindingsubstrates. Phospholipid binding site is localized at the N-terminal four helical bundle structure (1-93 domain). However, TcsL-1-93 bound to a broad range of substrates, whereas TcsL-cat, which is the active domain physiologically delivered into the cytosol, selectively bound to PS and PA. Similar findings were observed with the other large clostridial glucosylating toxins from C. difficile, C. novyi and C. perfringens.
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Affiliation(s)
| | - Sylviane Hoos
- Plateforme de Biophysique Moléculaire, Institut Pasteur, Paris, France
| | | | - Alexandre Chenal
- Unité de Biochimie des Interactions Macromoléculaires, Institut Pasteur, Paris, France
| | - Patrick England
- Plateforme de Biophysique Moléculaire, Institut Pasteur, Paris, France
| | - Arnaud Blondel
- Unité de Bioinformatique Structurale, Institut Pasteur, Paris, France
| | - Serge Pauillac
- Unité des Bactéries anaérobies et Toxines, Institut Pasteur, Paris, France
| | - D Borden Lacy
- Unité de Bioinformatique Structurale, Institut Pasteur, Paris, France.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
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86
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Roos S, Wyder M, Candi A, Regenscheit N, Nathues C, van Immerseel F, Posthaus H. Binding studies on isolated porcine small intestinal mucosa and in vitro toxicity studies reveal lack of effect of C. perfringens beta-toxin on the porcine intestinal epithelium. Toxins (Basel) 2015; 7:1235-52. [PMID: 25860161 PMCID: PMC4417965 DOI: 10.3390/toxins7041235] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/18/2015] [Accepted: 03/31/2015] [Indexed: 12/14/2022] Open
Abstract
Beta-toxin (CPB) is the essential virulence factor of C. perfringens type C causing necrotizing enteritis (NE) in different hosts. Using a pig infection model, we showed that CPB targets small intestinal endothelial cells. Its effect on the porcine intestinal epithelium, however, could not be adequately investigated by this approach. Using porcine neonatal jejunal explants and cryosections, we performed in situ binding studies with CPB. We confirmed binding of CPB to endothelial but could not detect binding to epithelial cells. In contrast, the intact epithelial layer inhibited CPB penetration into deeper intestinal layers. CPB failed to induce cytopathic effects in cultured polarized porcine intestinal epithelial cells (IPEC-J2) and primary jejunal epithelial cells. C. perfringens type C culture supernatants were toxic for cell cultures. This, however, was not inhibited by CPB neutralization. Our results show that, in the porcine small intestine, CPB primarily targets endothelial cells and does not bind to epithelial cells. An intact intestinal epithelial layer prevents CPB diffusion into underlying tissue and CPB alone does not cause direct damage to intestinal epithelial cells. Additional factors might be involved in the early epithelial damage which is needed for CPB diffusion towards its endothelial targets in the small intestine.
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Affiliation(s)
- Simone Roos
- Department of Infectious Diseases and Pathobiology, Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern 3012, Switzerland.
| | - Marianne Wyder
- Department of Infectious Diseases and Pathobiology, Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern 3012, Switzerland.
| | - Ahmet Candi
- Department of Infectious Diseases and Pathobiology, Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern 3012, Switzerland.
| | - Nadine Regenscheit
- Department of Infectious Diseases and Pathobiology, Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern 3012, Switzerland.
| | - Christina Nathues
- Veterinary Public Health Institute, Vetsuisse Faculty, University of Bern, Bern 3012, Switzerland.
| | - Filip van Immerseel
- Department of Pathology, Bacteriology and Avian Medicine, Ghent University, Ghent 9000, Belgium.
| | - Horst Posthaus
- Department of Infectious Diseases and Pathobiology, Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern 3012, Switzerland.
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87
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The CpAL quorum sensing system regulates production of hemolysins CPA and PFO to build Clostridium perfringens biofilms. Infect Immun 2015; 83:2430-42. [PMID: 25824838 DOI: 10.1128/iai.00240-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/23/2015] [Indexed: 11/20/2022] Open
Abstract
Clostridium perfringens strains produce severe diseases, including myonecrosis and enteritis necroticans, in humans and animals. Diseases are mediated by the production of potent toxins that often damage the site of infection, e.g., skin epithelium during myonecrosis. In planktonic cultures, the regulation of important toxins, such as CPA, CPB, and PFO, is controlled by the C. perfringens Agr-like (CpAL) quorum sensing (QS) system. Strains also encode a functional LuxS/AI-2 system. Although C. perfringens strains form biofilm-like structures, the regulation of biofilm formation is poorly understood. Therefore, our studies investigated the role of CpAL and LuxS/AI-2 QS systems and of QS-regulated factors in controlling the formation of biofilms. We first demonstrate that biofilm production by reference strains differs depending on the culture medium. Increased biomass correlated with the presence of extracellular DNA in the supernatant, which was released by lysis of a fraction of the biofilm population and planktonic cells. Whereas ΔagrB mutant strains were not able to produce biofilms, a ΔluxS mutant produced wild-type levels. The transcript levels of CpAL-regulated cpa and pfoA genes, but not cpb, were upregulated in biofilms compared to planktonic cultures. Accordingly, Δcpa and ΔpfoA mutants, in type A (S13) or type C (CN3685) backgrounds, were unable to produce biofilms, whereas CN3685Δcpb made wild-type levels. Biofilm formation was restored in complemented Δcpa/cpa and ΔpfoA/pfoA strains. Confocal microscopy studies further detected CPA partially colocalizing with eDNA on the biofilm structure. Thus, CpAL regulates biofilm formation in C. perfringens by increasing levels of certain toxins required to build biofilms.
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88
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Characterization of Clostridium perfringens TpeL toxin gene carriage, production, cytotoxic contributions, and trypsin sensitivity. Infect Immun 2015; 83:2369-81. [PMID: 25824828 DOI: 10.1128/iai.03136-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/20/2015] [Indexed: 12/14/2022] Open
Abstract
Large clostridial toxins (LCTs) are produced by at least four pathogenic clostridial species, and several LCTs are proven pivotal virulence factors for both human and veterinary diseases. TpeL is a recently identified LCT produced by Clostridium perfringens that has received relatively limited study. In response, the current study surveyed carriage of the tpeL gene among different C. perfringens strains, detecting this toxin gene in some type A, B, and C strains but not in any type D or E strains. This study also determined that all tested strains maximally produce, and extracellularly release, TpeL at the late-log or early-stationary growth stage during in vitro culture, which is different from the maximal late-stationary-phase production reported previously for other LCTs and for TpeL production by C. perfringens strain JIR12688. In addition, the present study found that TpeL levels in culture supernatants can be repressed by either glucose or sucrose. It was also shown that, at natural production levels, TpeL is a significant contributor to the cytotoxic activity of supernatants from cultures of tpeL-positive strain CN3685. Lastly, this study identified TpeL, which presumably is produced in the intestines during diseases caused by TpeL-positive type B and C strains, as a toxin whose cytotoxicity decreases after treatment with trypsin; this finding may have pathophysiologic relevance by suggesting that, like beta toxin, TpeL contributes to type B and C infections in hosts with decreased trypsin levels due to disease, diet, or age.
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89
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Kull S, Schulz KM, Strotmeier JWN, Kirchner S, Schreiber T, Bollenbach A, Dabrowski PW, Nitsche A, Kalb SR, Dorner MB, Barr JR, Rummel A, Dorner BG. Isolation and functional characterization of the novel Clostridium botulinum neurotoxin A8 subtype. PLoS One 2015; 10:e0116381. [PMID: 25658638 PMCID: PMC4320087 DOI: 10.1371/journal.pone.0116381] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/06/2014] [Indexed: 12/31/2022] Open
Abstract
Botulism is a severe neurological disease caused by the complex family of botulinum neurotoxins (BoNT). Based on the different serotypes known today, a classification of serotype variants termed subtypes has been proposed according to sequence diversity and immunological properties. However, the relevance of BoNT subtypes is currently not well understood. Here we describe the isolation of a novel Clostridium botulinum strain from a food-borne botulism outbreak near Chemnitz, Germany. Comparison of its botulinum neurotoxin gene sequence with published sequences identified it to be a novel subtype within the BoNT/A serotype designated BoNT/A8. The neurotoxin gene is located within an ha-orfX+ cluster and showed highest homology to BoNT/A1, A2, A5, and A6. Unexpectedly, we found an arginine insertion located in the HC domain of the heavy chain, which is unique compared to all other BoNT/A subtypes known so far. Functional characterization revealed that the binding characteristics to its main neuronal protein receptor SV2C seemed unaffected, whereas binding to membrane-incorporated gangliosides was reduced in comparison to BoNT/A1. Moreover, we found significantly lower enzymatic activity of the natural, full-length neurotoxin and the recombinant light chain of BoNT/A8 compared to BoNT/A1 in different endopeptidase assays. Both reduced ganglioside binding and enzymatic activity may contribute to the considerably lower biological activity of BoNT/A8 as measured in a mouse phrenic nerve hemidiaphragm assay. Despite its reduced activity the novel BoNT/A8 subtype caused severe botulism in a 63-year-old male. To our knowledge, this is the first description and a comprehensive characterization of a novel BoNT/A subtype which combines genetic information on the neurotoxin gene cluster with an in-depth functional analysis using different technical approaches. Our results show that subtyping of BoNT is highly relevant and that understanding of the detailed toxin function might pave the way for the development of novel therapeutics and tailor-made antitoxins.
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Affiliation(s)
- Skadi Kull
- Biological Toxins (ZBS3), Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
| | - K. Melanie Schulz
- Biological Toxins (ZBS3), Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
| | | | - Sebastian Kirchner
- Biological Toxins (ZBS3), Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
| | - Tanja Schreiber
- Biological Toxins (ZBS3), Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
| | | | - P. Wojtek Dabrowski
- Highly Pathogenic Viruses (ZBS1), Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
| | - Andreas Nitsche
- Highly Pathogenic Viruses (ZBS1), Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
| | - Suzanne R. Kalb
- Centers for Disease Control and Prevention, National Center for Environmental Health, Division of Laboratory Sciences, Atlanta, Georgia, United States of America
| | - Martin B. Dorner
- Biological Toxins (ZBS3), Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
| | - John R. Barr
- Centers for Disease Control and Prevention, National Center for Environmental Health, Division of Laboratory Sciences, Atlanta, Georgia, United States of America
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Brigitte G. Dorner
- Biological Toxins (ZBS3), Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
- * E-mail:
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90
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Nagahama M, Ochi S, Oda M, Miyamoto K, Takehara M, Kobayashi K. Recent insights into Clostridium perfringens beta-toxin. Toxins (Basel) 2015; 7:396-406. [PMID: 25654787 PMCID: PMC4344631 DOI: 10.3390/toxins7020396] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 01/15/2015] [Accepted: 01/29/2015] [Indexed: 01/06/2023] Open
Abstract
Clostridium perfringens beta-toxin is a key mediator of necrotizing enterocolitis and enterotoxemia. It is a pore-forming toxin (PFT) that exerts cytotoxic effect. Experimental investigation using piglet and rabbit intestinal loop models and a mouse infection model apparently showed that beta-toxin is the important pathogenic factor of the organisms. The toxin caused the swelling and disruption of HL-60 cells and formed a functional pore in the lipid raft microdomains of sensitive cells. These findings represent significant progress in the characterization of the toxin with knowledge on its biological features, mechanism of action and structure-function having been accumulated. Our aims here are to review the current progresses in our comprehension of the virulence of C. perfringens type C and the character, biological feature and structure-function of beta-toxin.
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Affiliation(s)
- Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 770-8514, Tokushima, Japan.
| | - Sadayuki Ochi
- Department of Microbiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan.
| | - Masataka Oda
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Gakkocho-dori, Chuo-ku 951-8514, Niigata, Japan.
| | - Kazuaki Miyamoto
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 770-8514, Tokushima, Japan.
| | - Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 770-8514, Tokushima, Japan.
| | - Keiko Kobayashi
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho 770-8514, Tokushima, Japan.
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91
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Foot infection by Clostridium sordellii: case report and review of 15 cases in France. J Clin Microbiol 2015; 53:1423-7. [PMID: 25609723 DOI: 10.1128/jcm.03414-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We report a case of foot infection by Clostridium sordellii and review 15 human infections registered at a Reference Center in France during the period 1998 to 2011. All strains were found nontoxigenic, lacking the lethal toxin gene coding for TcsL. Like Clostridium septicum, several C. sordellii infections were associated with intestinal neoplasms.
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92
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Abstract
Clostridial vaccines are commonly used in most countries where farming of cattle, sheep, goats and horses occurs on a commercial scale. Vaccines to protect against clostridial diseases make up the second largest group of ruminant vaccines sold globally. In Australia the sales value of these vaccines makes up $46m of the $96m sheep and cattle vaccine market (Baron market data). This group of vaccines has become so ubiquitous, and competition between competitors so fierce, that they have been reduced to the status of commodities where they can sell for less than 20c/dose. However, this definition does not do justice to the enormous value they have generated for many decades ‘behind the farm gate'.
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93
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Clostridial pore-forming toxins: Powerful virulence factors. Anaerobe 2014; 30:220-38. [DOI: 10.1016/j.anaerobe.2014.05.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/16/2014] [Accepted: 05/25/2014] [Indexed: 01/05/2023]
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94
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Abstract
Plasmid-encoded virulence factors are important in the pathogenesis of diseases caused by spore-forming bacteria. Unlike many other bacteria, the most common virulence factors encoded by plasmids in Clostridium and Bacillus species are protein toxins. Clostridium perfringens causes several histotoxic and enterotoxin diseases in both humans and animals and produces a broad range of toxins, including many pore-forming toxins such as C. perfringens enterotoxin, epsilon-toxin, beta-toxin, and NetB. Genetic studies have led to the determination of the role of these toxins in disease pathogenesis. The genes for these toxins are generally carried on large conjugative plasmids that have common core replication, maintenance, and conjugation regions. There is considerable functional information available about the unique tcp conjugation locus carried by these plasmids, but less is known about plasmid maintenance. The latter is intriguing because many C. perfringens isolates stably maintain up to four different, but closely related, toxin plasmids. Toxin genes may also be plasmid-encoded in the neurotoxic clostridia. The tetanus toxin gene is located on a plasmid in Clostridium tetani, but the botulinum toxin genes may be chromosomal, plasmid-determined, or located on bacteriophages in Clostridium botulinum. In Bacillus anthracis it is well established that virulence is plasmid determined, with anthrax toxin genes located on pXO1 and capsule genes on a separate plasmid, pXO2. Orthologs of these plasmids are also found in other members of the Bacillus cereus group such as B. cereus and Bacillus thuringiensis. In B. thuringiensis these plasmids may carry genes encoding one or more insecticidal toxins.
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95
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Genth H, Pauillac S, Schelle I, Bouvet P, Bouchier C, Varela-Chavez C, Just I, Popoff MR. Haemorrhagic toxin and lethal toxin from Clostridium sordellii strain vpi9048: molecular characterization and comparative analysis of substrate specificity of the large clostridial glucosylating toxins. Cell Microbiol 2014; 16:1706-21. [PMID: 24905543 DOI: 10.1111/cmi.12321] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 05/12/2014] [Accepted: 05/29/2014] [Indexed: 12/16/2022]
Abstract
Large clostridial glucosylating toxins (LCGTs) are produced by toxigenic strains of Clostridium difficile, Clostridium perfringens, Clostridium novyi and Clostridium sordellii. While most C. sordellii strains solely produce lethal toxin (TcsL), C. sordellii strain VPI9048 co-produces both hemorrhagic toxin (TcsH) and TcsL. Here, the sequences of TcsH-9048 and TcsL-9048 are provided, showing that both toxins retain conserved LCGT features and that TcsL and TcsH are highly related to Toxin A (TcdA) and Toxin B (TcdB) from C. difficile strain VPI10463. The substrate profile of the toxins was investigated with recombinant LCGT transferase domains (rN) and a wide panel of small GTPases. rN-TcsH-9048 and rN-TcdA-10463 glucosylated preferably Rho-GTPases but also Ras-GTPases to some extent. In this respect, rN-TcsH-9048 and rN-TcdA-10463 differ from the respective full-length TcsH-9048 and TcdA-10463, which exclusively glucosylate Rho-GTPases. rN-TcsL-9048 and full length TcsL-9048 glucosylate both Rho- and Ras-GTPases, whereas rN-TcdB-10463 and full length TcdB-10463 exclusively glucosylate Rho-GTPases. Vero cells treated with full length TcsH-9048 or TcdA-10463 also showed glucosylation of Ras, albeit to a lower extent than of Rho-GTPases. Thus, in vitro analysis of substrate spectra using recombinant transferase domains corresponding to the auto-proteolytically cleaved domains, predicts more precisely the in vivo substrates than the full length toxins. Except for TcdB-1470, all LCGTs evoked increased expression of the small GTPase RhoB, which exhibited cytoprotective activity in cells treated with TcsL isoforms, but pro-apoptotic activity in cells treated with TcdA, TcdB, and TcsH. All LCGTs induced a rapid dephosphorylation of pY118-paxillin and of pS144/141-PAK1/2 prior to actin filament depolymerization indicating that disassembly of focal adhesions is an early event leading to the disorganization of the actin cytoskeleton.
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Affiliation(s)
- Harald Genth
- Institute of Toxicology, Medical School Hannover, Hannover, Germany
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96
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Vagin O, Tokhtaeva E, Garay PE, Souda P, Bassilian S, Whitelegge JP, Lewis R, Sachs G, Wheeler L, Aoki R, Fernandez-Salas E. Recruitment of septin cytoskeletal proteins by botulinum toxin A protease determines its remarkable stability. J Cell Sci 2014; 127:3294-308. [PMID: 24928902 DOI: 10.1242/jcs.146324] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Proteolytic cleavage of synaptosomal-associated protein 25 by the light chain of botulinum neurotoxin type A (LCA) results in a blockade of neurotransmitter release that persists for several months in motor neurons. The L428A/L429A mutation in LCA is known to significantly shorten both the proteolytic and neuroparalytic effects of the neurotoxin in mice. To elucidate the cellular mechanism for LCA longevity, we studied the effects of L428A/L429A mutation on the interactome, localization and stability of LCA expressed in cultured neuronal cells. Mass spectrometry analysis of the LCA interactome showed that the mutation prevented the interaction of LCA with septins. The wild-type LCA was concentrated in plasma-membrane-associated clusters, colocalizing with septins-2 and septin-7, which accumulated in these clusters only in the presence of LCA. The L428A/L429A mutation decreased co-clustering of LCA and septins and accelerated proteasomal and non-proteasomal degradation of LCA. Similarly, the impairment of septin oligomerization by forchlorfenuron or silencing of septin-2 prevented LCA interaction and clustering with septins and increased LCA degradation. Therefore, the dileucine-mediated LCA-septin co-clustering is crucial for the long-lasting stabilization of LCA-related proteolytic and presumably neuroparalytic activity.
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Affiliation(s)
- Olga Vagin
- Department of Physiology, School of Medicine, UCLA and Veterans Administration Greater Los Angeles Health Care System, Los Angeles, CA 91343, USA
| | - Elmira Tokhtaeva
- Department of Physiology, School of Medicine, UCLA and Veterans Administration Greater Los Angeles Health Care System, Los Angeles, CA 91343, USA
| | - Patton E Garay
- Department of Biological Sciences, Allergan Inc., Irvine, CA 92612, USA
| | - Puneet Souda
- The NPI-Semel Institute, Pasarow Mass Spectrometry Laboratory, UCLA, Los Angeles, CA 90095, USA
| | - Sara Bassilian
- Department of Physiology, School of Medicine, UCLA and Veterans Administration Greater Los Angeles Health Care System, Los Angeles, CA 91343, USA
| | - Julian P Whitelegge
- The NPI-Semel Institute, Pasarow Mass Spectrometry Laboratory, UCLA, Los Angeles, CA 90095, USA
| | - Ramilla Lewis
- Department of Biological Sciences, Allergan Inc., Irvine, CA 92612, USA
| | - George Sachs
- Department of Physiology, School of Medicine, UCLA and Veterans Administration Greater Los Angeles Health Care System, Los Angeles, CA 91343, USA
| | - Larry Wheeler
- Department of Biological Sciences, Allergan Inc., Irvine, CA 92612, USA
| | - Roger Aoki
- Department of Biological Sciences, Allergan Inc., Irvine, CA 92612, USA
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97
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Popoff MR. Bacterial factors exploit eukaryotic Rho GTPase signaling cascades to promote invasion and proliferation within their host. Small GTPases 2014; 5:28209. [PMID: 25203748 DOI: 10.4161/sgtp.28209] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Actin cytoskeleton is a main target of many bacterial pathogens. Among the multiple regulation steps of the actin cytoskeleton, bacterial factors interact preferentially with RhoGTPases. Pathogens secrete either toxins which diffuse in the surrounding environment, or directly inject virulence factors into target cells. Bacterial toxins, which interfere with RhoGTPases, and to some extent with RasGTPases, catalyze a covalent modification (ADPribosylation, glucosylation, deamidation, adenylation, proteolysis) blocking these molecules in their active or inactive state, resulting in alteration of epithelial and/or endothelial barriers, which contributes to dissemination of bacteria in the host. Injected bacterial virulence factors preferentially manipulate the RhoGTPase signaling cascade by mimicry of eukaryotic regulatory proteins leading to local actin cytoskeleton rearrangement, which mediates bacterial entry into host cells or in contrast escape to phagocytosis and immune defense. Invasive bacteria can also manipulate RhoGTPase signaling through recognition and stimulation of cell surface receptor(s). Changes in RhoGTPase activation state is sensed by the innate immunity pathways and allows the host cell to adapt an appropriate defense response.
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Affiliation(s)
- Michel R Popoff
- Unité des Bactéries anaérobies et Toxines; Institut Pasteur; Paris, France
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98
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Abstract
Bacterial collagenases are metalloproteinases involved in the degradation of the extracellular matrices of animal cells, due to their ability to digest native collagen. These enzymes are important virulence factors in a variety of pathogenic bacteria. Nonetheless, there is a lack of scientific consensus for a proper and well-defined classification of these enzymes and a vast controversy regarding the correct identification of collagenases. Clostridial collagenases were the first ones to be identified and characterized and are the reference enzymes for comparison of newly discovered collagenolytic enzymes. In this review we present the most recent data regarding bacterial collagenases and overview the functional and structural diversity of bacterial collagenases. An overall picture of the molecular diversity and distribution of these proteins in nature will also be given. Particular aspects of the different proteolytic activities will be contextualized within relevant areas of application, mainly biotechnological processes and therapeutic uses. At last, we will present a new classification guide for bacterial collagenases that will allow the correct and straightforward classification of these enzymes.
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Affiliation(s)
- Ana Sofia Duarte
- a Department of Biology and Cesam , University of Aveiro, Campus Universitario de Santiago , Aveiro , Portugal
| | - Antonio Correia
- a Department of Biology and Cesam , University of Aveiro, Campus Universitario de Santiago , Aveiro , Portugal
| | - Ana Cristina Esteves
- a Department of Biology and Cesam , University of Aveiro, Campus Universitario de Santiago , Aveiro , Portugal
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99
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BEC, a novel enterotoxin of Clostridium perfringens found in human clinical isolates from acute gastroenteritis outbreaks. Infect Immun 2014; 82:2390-9. [PMID: 24664508 DOI: 10.1128/iai.01759-14] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Clostridium perfringens is a causative agent of food-borne gastroenteritis for which C. perfringens enterotoxin (CPE) has been considered an essential factor. Recently, we experienced two outbreaks of food-borne gastroenteritis in which non-CPE producers of C. perfringens were strongly suspected to be the cause. Here, we report a novel enterotoxin produced by C. perfringens isolates, BEC (binary enterotoxin of C. perfringens). Culture supernatants of the C. perfringens strains showed fluid-accumulating activity in rabbit ileal loop and suckling mouse assays. Purification of the enterotoxic substance in the supernatants and high-throughput sequencing of genomic DNA of the strains revealed BEC, composed of BECa and BECb. BECa and BECb displayed limited amino acid sequence similarity to other binary toxin family members, such as the C. perfringens iota toxin. The becAB genes were located on 54.5-kb pCP13-like plasmids. Recombinant BECb (rBECb) alone had fluid-accumulating activity in the suckling mouse assay. Although rBECa alone did not show enterotoxic activity, rBECa enhanced the enterotoxicity of rBECb when simultaneously administered in suckling mice. The entertoxicity of the mutant in which the becB gene was disrupted was dramatically decreased compared to that of the parental strain. rBECa showed an ADP-ribosylating activity on purified actin. Although we have not directly evaluated whether BECb delivers BECa into cells, rounding of Vero cells occurred only when cells were treated with both rBECa and rBECb. These results suggest that BEC is a novel enterotoxin of C. perfringens distinct from CPE, and that BEC-producing C. perfringens strains can be causative agents of acute gastroenteritis in humans. Additionally, the presence of becAB on nearly identical plasmids in distinct lineages of C. perfringens isolates suggests the involvement of horizontal gene transfer in the acquisition of the toxin genes.
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100
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Popoff MR, Bouvet P. Genetic characteristics of toxigenic Clostridia and toxin gene evolution. Toxicon 2013; 75:63-89. [DOI: 10.1016/j.toxicon.2013.05.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 04/30/2013] [Accepted: 05/08/2013] [Indexed: 12/14/2022]
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