Molecular basis of toxicity of Clostridium perfringens epsilon toxin

FEBS Journal

Volumn 278, Issue 23, 2011, Pages 4589-4601

  Bokori Brown, Monika ^a   Savva, Christos G ^b   Fernandes Da Costa, Sérgio P ^a   Naylor, Claire E ^b   Basak, Ajit K ^b   Titball, Richard W ^a  

^a UNIVERSITY OF EXETER   (United Kingdom)

^b UNIVERSITY OF LONDON   (United Kingdom)

Author keywords

Clostridium perfringens; crystal structure; enterotoxaemia; epsilon toxin; pore forming

Indexed keywords

BACTERIAL TOXIN; BACTERIAL VACCINE; CLOSTRIDIUM PERFRINGENS EPSILON TOXIN; EPSILON TOXOID VACCINE; UNCLASSIFIED DRUG;

CELL CULTURE; CHANNEL GATING; CLOSTRIDIUM PERFRINGENS; CRYSTAL STRUCTURE; CYTOTOXICITY; ENTEROTOXEMIA; HUMAN; INFECTION PREVENTION; MOLECULAR BIOLOGY; NEUROTOXICITY; NONHUMAN; PRIORITY JOURNAL; RECEPTOR BINDING; REVIEW; TISSUE INJURY; TOXIN STRUCTURE; VACCINATION;

ANIMALS; BACTERIAL TOXINS; CLOSTRIDIUM PERFRINGENS; HUMANS; MODELS, MOLECULAR; PROTEIN CONFORMATION; RATS; SYNAPTOSOMES;

AEROMONAS HYDROPHILA; BACILLUS THURINGIENSIS; CAPRA HIRCUS; CLOSTRIDIUM; CLOSTRIDIUM PERFRINGENS; LAETIPORUS; LAETIPORUS SULPHUREUS; OVIS ARIES; RATTUS;

EID: 81555216783     PISSN: 1742464X     EISSN: 17424658     Source Type: Journal    
DOI: 10.1111/j.1742-4658.2011.08140.x     Document Type: Review

References (95)

1. Alouf JE, (2006) A 116-year story of bacterial protein toxins (1888-2004): from "diphteric poison" to molecular toxinology. In The Comprehensive Sourcebook of Bacterial Protein Toxins (, Alouf JE, &, Popoff MR, eds), pp. 3-21. Academic Press, London, UK.
2. Loesche WJ, (1969) Oxygen sensitivity of various anaerobic bacteria. Appl Microbiol 18, 723-727.
3. Fredette V, Plante C, &, Roy A, (1967) Numerical data concerning the sensitivity of anaerobic bacteria to oxygen. J Bacteriol 94, 2012-2017.
4. Rood JI, McClane BA, Songer JG, &, Titball RW, (1997) The Clostridia: Molecular Biology and Pathogenesis. Academic Press, London, UK.
5. Songer JG, (1996) Clostridial enteric diseases of domestic animals. Clin Microbiol Rev 9, 216-234. (Pubitemid 26124457)
6. McDonel JL, (1980) Clostridium perfringens toxins (type A, B, C, D, E). Pharmacol Ther 10, 617-655. (Pubitemid 11233584)
7. Petit L, Gibert M, &, Popoff MR, (1999) Clostridium perfringens: toxinotype and genotype. Trends Microbiol 7, 104-110. (Pubitemid 29271996)
8. Rood JI, (1998) Virulence genes of Clostridium perfringens. Annu Rev Microbiol 52, 333-360. (Pubitemid 28481195)
9. Rood JI, &, Cole ST, (1991) Molecular genetics and pathogenesis of Clostridium perfringens. Microbiol Rev 55, 621-648. (Pubitemid 21895169)
10. Songer JG, (1997) Clostridial Diseases of Animals. Academic Press, London, UK.
11. Finnie JW, (2003) Pathogenesis of brain damage produced in sheep by Clostridium perfringens type D epsilon toxin: a review. Aust Vet J 81, 219-221. (Pubitemid 43934479)
12. CDC Strategic Planning Workgroup (2000) Biological and chemical terrorism: strategic plan for preparedness and response. Recommendations of the CDC Strategic Planning Workgroup. MMWR Recomm Rep 49, 1-14.
13. Hoffman B, (2006) Inside Terrorism. Columbia University Press, New York, NY.
14. Minami J, Katayama S, Matsushita O, Matsushita C, &, Okabe A, (1997) Lambda-toxin of Clostridium perfringens activates the precursor of epsilon-toxin by releasing its N- and C-terminal peptides. Microbiol Immunol 41, 527-535. (Pubitemid 27318089)
15. Canard B, Saint-Joanis B, &, Cole ST, (1992) Genomic diversity and organization of virulence genes in the pathogenic anaerobe Clostridium perfringens. Mol Microbiol 6, 1421-1429.
16. Miyamoto K, Li J, Sayeed S, Akimoto S, &, McClane BA, (2008) Sequencing and diversity analyses reveal extensive similarities between some epsilon-toxin-encoding plasmids and the pCPF5603 Clostridium perfringens enterotoxin plasmid. J Bacteriol 190, 7178-7188.
17. Sayeed S, Li J, &, McClane BA, (2010) Characterization of virulence plasmid diversity among Clostridium perfringens type B isolates. Infect Immun 78, 495-504.
18. Sayeed S, Li J, &, McClane BA, (2007) Virulence plasmid diversity in Clostridium perfringens type D isolates. Infect Immun 75, 2391-2398. (Pubitemid 46744329)
19. Bannam TL, Teng WL, Bulach D, Lyras D, &, Rood JI, (2006) Functional identification of conjugation and replication regions of the tetracycline resistance plasmid pCW3 from Clostridium perfringens. J Bacteriol 188, 4942-4951. (Pubitemid 43956091)
20. Hughes ML, Poon R, Adams V, Sayeed S, Saputo J, Uzal FA, McClane BA, &, Rood JI, (2007) Epsilon-toxin plasmids of Clostridium perfringens type D are conjugative. J Bacteriol 189, 7531-7538. (Pubitemid 350035061)
21. McDonel JL, (1986) Toxins of Clostridium perfringens types A, B, C, D and E. In Pharmacology of Bacterial Toxins (, Dorner F, &, Drews J, eds), pp. 477-517. Pergamon Press, Oxford, UK.
22. Havard HL, Hunter SE, &, Titball RW, (1992) Comparison of the nucleotide sequence and development of a PCR test for the epsilon toxin gene of Clostridium perfringens type B and type D. FEMS Microbiol Lett 76, 77-81.
23. Bhown AS, &, Habeerb AF, (1977) Structural studies on epsilon-prototoxin of Clostridium perfringens type D. Localization of the site of tryptic scission necessary for activation to epsilon-toxin. Biochem Biophys Res Commun 78, 889-896. (Pubitemid 8209820)
24. Jin F, Matsushita O, Katayama S, Jin S, Matsushita C, Minami J, &, Okabe A, (1996) Purification, characterization, and primary structure of Clostridium perfringens lambda-toxin, a thermolysin-like metalloprotease. Infect Immun 64, 230-237. (Pubitemid 26009362)
25. Hunter SEC, Clarke IN, Kelly DC, &, Titball RW, (1992) Cloning and nucleotide sequencing of the Clostridium perfringens epsilon-toxin gene and its expression in Escherichia coli. Infect Immun 60, 102-110.
26. Worthington RW, &, Mulders MS, (1977) Physical changes in the epsilon prototoxin molecule of Clostridium perfringens during enzymatic activation. Infect Immun 18, 549-551. (Pubitemid 8231936)
27. Miyata S, Matsushita O, Minami J, Katayama S, Shimamoto S, &, Okabe A, (2001) Cleavage of a C-terminal peptide is essential for heptamerization of Clostridium perfringens epsilon-toxin in the synaptosomal membrane. J Biol Chem 276, 13778-13783.
28. Liu JW, Porter AG, Wee BY, &, Thanabalu T, (1996) New gene from nine Bacillus sphaericus strains encoding highly conserved 35.8-kilodalton mosquitocidal toxins. Appl Environ Microbiol 62, 2174-2176. (Pubitemid 26169019)
29. Thanabalu T, &, Porter AG, (1996) A Bacillus sphaericus gene encoding a novel type of mosquitocidal toxin of 31.8 kDa. Gene 170, 85-89. (Pubitemid 26130800)
30. Knight PA, Queminet J, Blanchard JH, &, Tilleray JH, (1990) In vitro tests for the measurement of clostridial toxins, toxoids and antisera. II. Titration of Clostridium perfringens toxins and antitoxins in cell culture. Biologicals 18, 263-270.
31. Payne DW, Williamson ED, Havard H, Modi N, &, Brown J, (1994) Evaluation of a new cytotoxicity assay for Clostridium perfringens type D epsilon toxin. FEMS Microbiol Lett 116, 161-167. (Pubitemid 124011993)
32. Shortt SJ, Titball RW, &, Lindsay CD, (2000) An assessment of the in vitro toxicology of Clostridium perfringens type D epsilon-toxin in human and animal cells. Hum Exp Toxicol 19, 108-116. (Pubitemid 30189872)
33. Petit L, Gibert M, Gillet D, Laurent-Winter C, Boquet P, &, Popoff MR, (1997) Clostridium perfringens epsilon-toxin acts on MDCK cells by forming a large membrane complex. J Bacteriol 179, 6480-6487. (Pubitemid 27443933)
34. Donelli G, Fiorentini C, Matarrese P, Falzano L, Cardines R, Mastrantonio P, Payne DW, &, Titball RW, (2003) Evidence for cytoskeletal changes secondary to plasma membrane functional alterations in the in vitro cell response to Clostridium perfringens epsilon-toxin. Comp Immunol Microbiol Infect Dis 26, 145-156. (Pubitemid 36372265)
35. Petit L, Maier E, Gibert M, Popoff MR, &, Benz R, (2001) Clostridium perfringens epsilon toxin induces a rapid change of cell membrane permeability to ions and forms channels in artificial lipid bilayers. J Biol Chem 276, 15736-15740.
36. Lindsay CD, (1996) Assessment of aspects of the toxicity of Clostridium perfringens epsilon-toxin using the MDCK cell line. Hum Exp Toxicol 15, 904-908. (Pubitemid 26392109)
37. Lindsay CD, Hambrook JL, &, Upshall DG, (1995) Examination of toxicity of Clostridium perfringens -toxin in the MDCK cell line. Toxicol In Vitro 9, 213-218.
38. Chassin C, Bens M, de Barry J, Courjaret R, Bossu JL, Cluzeaud F, Ben Mkaddem S, Gibert M, Poulain B, Popoff MR, et al. (2007) Pore-forming epsilon toxin causes membrane permeabilization and rapid ATP depletion-mediated cell death in renal collecting duct cells. Am J Physiol Renal Physiol 293, F927-F937. (Pubitemid 47403365)
39. Buxton D, (1978) In-vitro effects of Clostridium welchii type-D epsilon toxin on guinea-pig, mouse, rabbit and sheep cells. J Med Microbiol 11, 299-302. (Pubitemid 9001181)
40. Soler-Jover A, Dorca J, Popoff MR, Gibert M, Saura J, Tusell JM, Serratosa J, Blasi J, &, Martin-Satue M, (2007) Distribution of Clostridium perfringens epsilon toxin in the brains of acutely intoxicated mice and its effect upon glial cells. Toxicon 50, 530-540. (Pubitemid 47368587)
41. Lonchamp E, Dupont JL, Wioland L, Courjaret R, Mbebi-Liegeois C, Jover E, Doussau F, Popoff MR, Bossu JL, de Barry J, et al. (2010) Clostridium perfringens epsilon toxin targets granule cells in the mouse cerebellum and stimulates glutamate release. PLoS ONE 5, e13046.
42. Fernandez Miyakawa ME, Zabal O, &, Silberstein C, (2010) Clostridium perfringens epsilon toxin is cytotoxic for human renal tubular epithelial cells. Hum Exp Toxicol 30, 275-282.
43. Fernandez Miyakawa ME, &, Uzal FA, (2003) The early effects of Clostridium perfringens type D epsilon toxin in ligated intestinal loops of goats and sheep. Vet Res Commun 27, 231-241. (Pubitemid 36582642)
44. Goldstein J, Morris WE, Loidl CF, Tironi-Farinatti C, McClane BA, Uzal FA, &, Fernandez Miyakawa ME, (2009) Clostridium perfringens epsilon toxin increases the small intestinal permeability in mice and rats. PLoS ONE 4, e7065.
45. Uzal FA, &, Kelly WR, (1997) Effects of the intravenous administration of Clostridium perfringens type D epsilon toxin on young goats and lambs. J Comp Pathol 116, 63-71. (Pubitemid 27110526)
46. Morgan KT, Kelly BG, &, Buxton D, (1975) Vascular leakage produced in the brains of mice by Clostridium welchii type D toxin. J Comp Pathol 85, 461-466.
47. Griner LA, &, Carlson WD, (1961) Enterotoxemia of sheep. II. Distribution of I-131 radioiodinated serum albumin in brains of Clostridium perfringens type D intoxicated lambs. Am J Vet Res 22, 443-446.
48. Adamson RH, Ly JC, Fernandez-Miyakawa M, Ochi S, Sakurai J, Uzal F, &, Curry FE, (2005) Clostridium perfringens epsilon-toxin increases permeability of single perfused microvessels of rat mesentery. Infect Immun 73, 4879-4887. (Pubitemid 41105644)
49. Soler-Jover A, Blasi J, Gomez de Aranda I, Navarro P, Gibert M, Popoff MR, &, Martin-Satue M, (2004) Effect of epsilon toxin-GFP on MDCK cells and renal tubules in vivo. J Histochem Cytochem 52, 931-942. (Pubitemid 38857158)
50. Dorca-Arevalo J, Soler-Jover A, Gibert M, Popoff MR, Martin-Satue M, &, Blasi J, (2008) Binding of epsilon-toxin from Clostridium perfringens in the nervous system. Vet Microbiol 131, 14-25.
51. Finnie JW, (2004) Neurological disorders produced by Clostridium perfringens type D epsilon toxin. Anaerobe 10, 145-150. (Pubitemid 38519815)
52. Finnie JW, (1984) Histopathological changes in the brain of mice given Clostridium perfringens type D epsilon toxin. J Comp Pathol 94, 363-370. (Pubitemid 15070105)
53. Miyamoto O, Minami J, Toyoshima T, Nakamura T, Masada T, Nagao S, Negi T, Itano T, &, Okabe A, (1998) Neurotoxicity of Clostridium perfringens epsilon-toxin for the rat hippocampus via the glutamatergic system. Infect Immun 66, 2501-2508. (Pubitemid 28261744)
54. Finnie JW, Blumbergs PC, &, Manavis J, (1999) Neuronal damage produced in rat brains by Clostridium perfringens type D epsilon toxin. J Comp Pathol 120, 415-420. (Pubitemid 29204494)
55. Nagahama M, &, Sakurai J, (1991) Distribution of labeled Clostridium perfringens epsilon toxin in mice. Toxicon 29, 211-217.
56. Nagahama M, &, Sakurai J, (1992) High-affinity binding of Clostridium perfringens epsilon-toxin to rat brain. Infect Immun 60, 1237-1240.
57. Nagahama M, &, Sakurai J, (1993) Effect of drugs acting on the central nervous system on the lethality in mice of Clostridium perfringens epsilon toxin. Toxicon 31, 427-435.
58. Miyamoto O, Sumitani K, Nakamura T, Yamagami S, Miyata S, Itano T, Negi T, &, Okabe A, (2000) Clostridium perfringens epsilon toxin causes excessive release of glutamate in the mouse hippocampus. FEMS Microbiol Lett 189, 109-113. (Pubitemid 30456256)
59. Miyata S, Minami J, Tamai E, Matsushita O, Shimamoto S, &, Okabe A, (2002) Clostridium perfringens epsilon-toxin forms a heptameric pore within the detergent-insoluble microdomains of MDCK cells and rat synaptosomes. J Biol Chem 277, 39463-39468. (Pubitemid 35190922)
60. Cole AR, Gibert M, Popoff M, Moss DS, Titball RW, &, Basak AK, (2004) Clostridium perfringens epsilon-toxin shows structural similarity to the pore-forming toxin aerolysin. Nat Struct Mol Biol 11, 797-798. (Pubitemid 39014507)
61. Parker MW, Buckley JT, Postma JPM, Tucker AD, Leonard K, Pattus F, &, Tsernoglou D, (1994) Structure of the Aeromonas toxin proaerolysin in its water-soluble and membrane-channel states. Nature 367, 292-295. (Pubitemid 24051148)
62. Akiba T, Abe Y, Kitada S, Kusaka Y, Ito A, Ichimatsu T, Katayama H, Akao T, Higuchi K, Mizuki E, et al. (2009) Crystal structure of the parasporin-2 Bacillus thuringiensis toxin that recognizes cancer cells. J Mol Biol 386, 121-133.
63. Mancheno JM, Tateno H, Goldstein IJ, Martinez-Ripoll M, &, Hermoso JA, (2005) Structural analysis of the Laetiporus sulphureus hemolytic pore-forming lectin in complex with sugars. J Biol Chem 280, 17251-17259. (Pubitemid 41389193)
64. Moniatte M, van der Goot FG, Buckley JT, Pattus F, &, Van Dorselaer A, (1996) Characterization of the heptameric pore-forming complex of the Aeromonas toxin aerolysin using MALDI-TOFF mass spectrometry. FEBS Lett 384, 269-272. (Pubitemid 26126088)
65. Abe Y, Shimada H, &, Kitada S, (2008) Raft-targeting and oligomerization of parasporin-2, a Bacillus thuringiensis crystal protein with anti-tumour activity. J Biochem 143, 269-275. (Pubitemid 351238172)
66. MacKenzie CR, Hirama T, &, Buckley JT, (1999) Analysis of receptor binding by the channel-forming toxin aerolysin using surface plasmon resonance. J Biol Chem 274, 22604-22609.
67. Knapp O, Maier E, Benz R, Geny B, &, Popoff MR, (2009) Identification of the channel-forming domain of Clostridium perfringens epsilon-toxin (ETX). Biochim Biophys Acta 1788, 2584-2593.
68. Pelish TM, &, McClain MS, (2009) Dominant-negative inhibitors of the Clostridium perfringens epsilon-toxin. J Biol Chem 284, 29446-29453.
69. Iacovache I, Paumard P, Scheib H, Lesieur C, Sakai N, Matile S, Parker MW, &, van der Goot FG, (2006) A rivet model for channel formation by aerolysin-like pore-forming toxins. EMBO J 25, 457-466. (Pubitemid 43237653)
70. Melton JA, Parker MW, Rossjohn J, Buckley JT, &, Tweten RK, (2004) The identification and structure of the membrane-spanning domain of the Clostridium septicum alpha toxin. J Biol Chem 279, 14315-14322. (Pubitemid 38468972)
71. Tsitrin Y, Morton CJ, el-Bez C, Paumard P, Velluz MC, Adrian M, Dubochet J, Parker MW, Lanzavecchia S, &, van der Goot FG, (2002) Conversion of a transmembrane to a water-soluble protein complex by a single point mutation. Nat Struct Biol 9, 729-733.
72. Nagahama M, Ochi S, &, Sakurai J, (1998) Assembly of Clostridium perfringens epsilon-toxin on MDCK cell membrane. J Nat Toxins 7, 291-302. (Pubitemid 28456463)
73. Wilmsen HU, Leonard KR, Tichelaar W, Buckley JT, &, Pattus F, (1992) The aerolysin membrane channel is formed by heptamerization of the monomer. EMBO J 11, 2457-2463.
74. Nagahama M, Hara H, Fernandez-Miyakawa M, Itohayashi Y, &, Sakurai J, (2006) Oligomerization of Clostridium perfringens epsilon-toxin is dependent upon membrane fluidity in liposomes. Biochemistry 45, 296-302. (Pubitemid 43054107)
75. Abrami L, &, van Der Goot FG, (1999) Plasma membrane microdomains act as concentration platforms to facilitate intoxication by aerolysin. J Cell Biol 147, 175-184. (Pubitemid 30211805)
76. Shimamoto S, Tamai E, Matsushita O, Minami J, Okabe A, &, Miyata S, (2005) Changes in ganglioside content affect the binding of Clostridium perfringens epsilon-toxin to detergent-resistant membranes of Madin-Darby canine kidney cells. Microbiol Immunol 49, 245-253.
77. Kitada S, Abe Y, Maeda T, &, Shimada H, (2009) Parasporin-2 requires GPI-anchored proteins for the efficient cytocidal action to human hepatoma cells. Toxicology 264, 80-88.
78. Nestorovich EM, Karginov VA, &, Bezrukov SM, (2010) Polymer partitioning and ion selectivity suggest asymmetrical shape for the membrane pore formed by epsilon toxin. Biophys J 99, 782-789.
79. Lewis M, Weaver CD, &, McClain MS, (2010) Identification of small molecule inhibitors of Clostridium perfringens epsilon-toxin cytotoxicity using a cell-based high-throughput screen. Toxins (Basel) 2, 1825-1847.
80. Tilley SJ, Orlova EV, Gilbert RJ, Andrew PW, &, Saibil HR, (2005) Structural basis of pore formation by the bacterial toxin pneumolysin. Cell 121, 247-256. (Pubitemid 40546392)
81. Flanagan JJ, Tweten RK, Johnson AE, &, Heuck AP, (2009) Cholesterol exposure at the membrane surface is necessary and sufficient to trigger perfringolysin O binding. Biochemistry 48, 3977-3987.
82. Walker B, Braha O, Cheley S, &, Bayley H, (1995) An intermediate in the assembly of a pore-forming protein trapped with a genetically-engineered switch. Chem Biol 2, 99-105.
83. Uzal FA, Wong JP, Kelly WR, &, Priest J, (1999) Antibody response in goats vaccinated with liposome-adjuvanted Clostridium perfringens type D epsilon toxoid. Vet Res Commun 23, 143-150. (Pubitemid 29266190)
84. Rosskopf-Streicher U, Volkers P, Noeske K, &, Werner E, (2004) Quality assurance of C. perfringens epsilon toxoid vaccines-ELISA versus mouse neutralisation test. Altex 21 (Suppl 3), 65-69. (Pubitemid 38979459)
85. Lobato FC, Lima CG, Assis RA, Pires PS, Silva RO, Salvarani FM, Carmo AO, Contigli C, &, Kalapothakis E, (2010) Potency against enterotoxemia of a recombinant Clostridium perfringens type D epsilon toxoid in ruminants. Vaccine 28, 6125-6127.
86. Stokka GL, Edwards AJ, Spire MF, Brandt RT Jr, and, Smith JE, (1994) Inflammatory response to clostridial vaccines in feedlot cattle. J Am Vet Med Assoc 204, 415-419. (Pubitemid 24062235)
87. Mathur DD, Deshmukh S, Kaushik H, &, Garg LC, (2011) Functional and structural characterization of soluble recombinant epsilon toxin of Clostridium perfringens D, causative agent of enterotoxaemia. Appl Microbiol Biotechnol 88, 877-884.
88. Chandran D, Naidu SS, Sugumar P, Rani GS, Vijayan SP, Mathur D, Garg LC, &, Srinivasan VA, (2010) Development of a recombinant epsilon toxoid vaccine against enterotoxemia and its use as a combination vaccine with live attenuated sheep pox virus against enterotoxemia and sheep pox. Clin Vaccine Immunol 17, 1013-1016.
89. Oyston PCF, Payne DW, Havard HL, Williamson ED, &, Titball RW, (1998) Production of a non-toxic site-directed mutant of Clostridium perfringens epsilon-toxin which induces protective immunity in mice. Microbiology-UK 144, 333-341. (Pubitemid 28067738)
90. Sakurai J, &, Nagahama M, (1987) Histidine residues in Clostridium perfringens epsilon toxin. FEMS Microbiol Lett 41, 317-319. (Pubitemid 17103443)
91. Percival DA, Shuttleworth AD, Williamson ED, &, Kelly DC, (1990) Anti-idiotypic antibody-induced protection against Clostridium perfringens type D. Infect Immun 58, 2487-2492. (Pubitemid 20228229)
92. Odendaal MW, Visser JJ, Bergh N, &, Botha WJ, (1989) The effect of passive immunization on active immunity against Clostridium perfringens type D in lambs. Onderstepoort J Vet Res 56, 251-255.
93. Clarkson MJ, Faull WB, &, Kerry JB, (1985) Vaccination of cows with clostridial antigens and passive transfer of clostridial antibodies from bovine colostrum to lambs. Vet Rec 116, 467-469.
94. El-Enbaawy MI, Abdalla YA, Hussein AZ, Osman RM, &, Selim SA, (2003) Production and evaluation of a monoclonal antibody to Clostridium perfringens type D epsilon toxin. Egypt J Immunol 10, 77-81.
95. McClain MS, &, Cover TL, (2007) Functional analysis of neutralizing antibodies against Clostridium perfringens epsilon-toxin. Infect Immun 75, 1785-1793. (Pubitemid 46559446)