Molecular Mode of Action of the Large Clostridial Cytotoxins

  • I. Just
  • F. Hofmann
  • K. Aktories
Part of the Current Topics in Microbiology and Immunology book series (CT MICROBIOLOGY, volume 250)


The large clostridial cytotoxins are a family of functionally and structurally related toxins produced by clostridia comprising Clostridium difficile toxin A and toxin B, Clostridium sordellii lethal and haemorrhagic toxin and Clostridium novyi α-toxin (Table 1). These toxins are exotoxins which induce morphological changes of the cultured target cells based on the redistribution of the microfilament system. The cytotoxic activity on cultured cell lines led to their designation as cytotoxins. Despite their comparable in vitro effects, the cytotoxins — as major pathogenicity factors — are involved in different diseases and clinical outcomes. Clostridium difficile toxins A and B are of major clinical importance because both toxins are the causative agents in about 20% of antibiotic-associated diarrhoea and in almost all cases of pseudomembranous colitis (Kelly et al. 1994; Kelly and Lamont 1998; Bartlett 1994).


Nucleotide Sugar Lethal Toxin ToxinA Alpha Substrate Recognition Site Glucosyltransferase Activity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Aktories K, Just I (1995) Monoglucosylation of low-molecular-mass GTP-binding Rho proteins by clostridia) cytotoxins. Trends Cell Biol 5: 441–443PubMedCrossRefGoogle Scholar
  2. Aktories K, Koch G (1997) Clostridium hotulinum ADP-rihosyltransferase C3. In: Aktories K (ed) Bacterial toxins: tools in cell biology and pharmacology. Chapman 0000 Hall, Weinheim, pp 61 69Google Scholar
  3. Amano M, Fukata Y, Kaibuchi K (1998) Regulation of cytoskeleton and cell adhesions by the small GTPase Rho and its targets. TCM 8: 162 168Google Scholar
  4. Barroso LA, Monerief JS, Lyerly DM, Wilkins TD (1994) Mutagenesis of the Clostridium difficile toxin B gene and effect on cytotoxic activity. Microb Pathog 16: 297–303PubMedCrossRefGoogle Scholar
  5. Bartlett JG (1994) Clostridium difficile history of its role as an enteric pathogen and the current state of knowledge about the organism. Clin Infect Dis 18:265–272Google Scholar
  6. Bette P, Oksche A, Mauler F, Von Eichel-Streiber C, Popoff MR, Hahermann E (1991) A comparative biochemical, pharmacological and immunological study of Clostridium nory i a-toxin, C. difficile toxin B and C. sorde/lii lethal toxin. Toxicon 29: 877 887Google Scholar
  7. Busch C, Hofmann F, Selzer J, Munro J, Jeckel D, Aktories K (1998) A common motif of eukaryotic glycosyllransferases is essential for the enzyme activity of large clostridial cytotoxins. J Biol Chem 273: 19566–19572PubMedCrossRefGoogle Scholar
  8. Calderón GM, Torres-Lopez J, Lin T-J, Chavez B, Hernandez M, Munoz O, Befus AD, Enciso JA (1998) Effects of toxin A from Clostridium difficili’ on mast cell activation and survival. Infect Immun 66: 2755 2761Google Scholar
  9. Chaves-Olarte E, Florin I, Hoquet P, Popoff M, Von Eichel-Streiber C, Thelestam M (1996) UDP-glucose deficiency in a mutant cell line protects against glucosyltransferase toxins from Clostridium difficile and Clostridium sordellii. J Biol Chem 271: 6925 6932Google Scholar
  10. Chaves-Olarte E, Weidmann M, Von Eichel-Streiber C, Thelestam M (1997) Toxins A and B from Clostridium dijflcile diner with respect to enzymatic potencies, cellular substrate specificities, and surface binding to cultured cells. J Clin Invest 100: 1734–1741PubMedCrossRefGoogle Scholar
  11. Ciesielski-Treska J, Ulrich G, Rihn B, Aunis D (1989) Mechanism of action of Clostridium ((i//ci/e toxin B: role of external medium and cytoskeletal organization in intoxicated cells. Fur J (’ell Biol 48: 191–202Google Scholar
  12. Ciesielski-Treska J, Ulrich G, Baldacini O, Monteil II, Aunis D (1991) Phosphorylation of cellular proteins in response to treatment with Clostridium difficile toxin B and Clostridium.sordellii toxin I.. Eur J Cell Biol 56: 68–78PubMedGoogle Scholar
  13. Ciesla WP Jr, Bobak DA (1998) Clostridium difficile toxins A and B are cation-dependent UDP-glucose hydrolases with differing catalytic activities. J Biol (’hem 273: 16021–16026Google Scholar
  14. Couet J, Li S, Okamoto T, Ikezu T, Lisanti MP (1997) Identification of peptide and protein ligands for the caveolin-scaffolding domain..1 Biol Chen 272: 6525 6533Google Scholar
  15. Faust C, Ye B, Song K-P 11998) The enzymatic domain of Clostridium di/Jiile toxin A is located within its N-terminal region. Biochem Biophys Res Commun 251: 100–105Google Scholar
  16. Fiorentini C, Arancia (ì, Paradisi S, Donelli G, Giuliano M, Piemonto F, Mastrantonio P (1989) I (feels of Clostridium difficile toxins A and B on cytoskeleton organization in 1l1?p-2 cells: a comparative morphological study. Toxicon 27: 1209–1218Google Scholar
  17. Fiorentini C, Malorni W, Paradisi S, Giuliano M, Mastrantonio P. Donelli G (1990) Interaction of Clostridium difficile toxin A with cultured cells: cytoskeletal changes and nuclear polarization. Infect Immun 58: 2329 2336Google Scholar
  18. Fiorentini C, Donelli G, Nicotera P, Thelestam M (1993) Clostridium di//ui/c toxin A elicits Ca2 -independent cytotoxic effects in cultured normal rat intestinal crypt cells. Infect Immun 61: 3988 3993 Fiorentini C, Fabbri A, Falzano L, Fattorossi A. Matarrese P, Rivabene R, Donelli G (1998) Clostridium difficile toxin B induces apoptosis in intestinal cultured cells. Infect Immun 66:2660 2665Google Scholar
  19. Fiorentini C, Thelestam M (1991) Clostridium difficile toxin A and its effects on cells. Toxicon 29:543 567 Florin I, Thelestam M (1983) Internalization of Clostridium difficile cytotoxin into cultured human lung fibroblasts. Biochem Biophys Acta 763: 383–392Google Scholar
  20. Frey SM, Wilkins TD (1992) Localization of two epitopes recognized by monoclonal antibody PC(-4 on C’lo.shidium difficile toxin A. Infect Immun 60: 2488–2492PubMedGoogle Scholar
  21. Genth H, Hofmann h’, Selzer. J. Rex G, Aktories K, Just I (1996) Difference in protein substrate specificity between hemorrhagic toxin and lethal toxin from C’lostridiwn sordellii. Biochem Biophys Res Commun 229: 370–374Google Scholar
  22. Gomez.1, Martinez C, Gonzalez A, Rehollo A (1998) Dual role of Ras and Rho proteins at the cutting edge of life and death. Immunol Cell Biol 76: 125–134Google Scholar
  23. Guasch RM, Scambler P, Jones GE, Ridley AJ (1998) RhoF regulates actin cytoskeleton organization and cell migration. Mol Cell Biol 18: 4761 4771Google Scholar
  24. Hall A (1998) Rho (iTPases and the actin cytoskeleton. Science 279: 509 514Google Scholar
  25. Hannah A, Scott AM, Akhurst T, Berlangieri S, Bishop J, McKay WJ (1996) Abnormal colonic accumulation of fluorine-18-FDG in pseudomembranous colitis. J Nucl Med 37: 1683 1685Google Scholar
  26. Hecht G, Pothoulakis C, LaMont JT, Madam JL (1988) Clostridium difficile toxin A perturbs cytoskeletal structure and tight junction permeability of cultured human intestinal epithelial monolayers. J Clin Invest 82: 1516–1524Google Scholar
  27. Hecht G, Koutsouris A, Pothoulakis C, LaMont JT, Madam JL (1992) Clostridium difficile toxin B disrupts the barrier function of T84 monolayers. Gastroenterology 1(12:416–423Google Scholar
  28. Henriques B, Florin I, Thelestam M (1987) Cellular internalisation of Clostridium difficile toxin A. Microb Pathogen 2: 455–463CrossRefGoogle Scholar
  29. Herrmann C, Ahmadian MR, Hofmann F, Just I (1998) Functional consequences of monoglucosylation of H-Ras at effector domain amino acid threonine-35. J Biol Chem 273: 16134 16139Google Scholar
  30. Hofmann F, Rex G, Aktories K, Just 1 (1996) The Ras-related protein Ral is monoglucosylated by Closvridiunr sordellii lethal toxin. Biochem Biophys Res Commun 227: 77 81Google Scholar
  31. Hofmann F, Busch C, Prepens U, Just I, Aktories K (1997) Localization of the glucosyltransterase activity of Clostridium difficile toxin B to the N-terminal part of the holotoxin. J Biol Chem 272: 11074–11078PubMedCrossRefGoogle Scholar
  32. Hofmann F, Busch C, Aktories K (1998) Chimeric clostridial cytotoxins: identification of the N-terminal region involved in protein substrate recognition. Infect Immun 66: 1076–1081PubMedGoogle Scholar
  33. Jou T-S, Schnceberger FE, Nelson WJ (1998) Structural and functional regulation of tight junctions by RhoA and Racl small GTPases. J (’ell Biol 142: 101–115CrossRefGoogle Scholar
  34. Just I, Richter H-P, Prepens U, Von Eichel-Streiber C, Aktories K (1994) Probing the action of Clostridium difficile toxin B Xcnopus laeris oocytes. J Cell Science 107: 1653 1659Google Scholar
  35. Just I, Selzer J, Von Eichel-Streiber C, Aktories K (1995a) The low molecular mass GTP-binding protein Rho is affected by toxin A from Clostridium difficile. J Clin Invest 95: 1026 1031Google Scholar
  36. Just I, Selzer J, Wilm M, Von Eichel-Streiber C, Mann M, Aktories K 11995h) (;Iucosylation of Rho proteins by Clostridium difficile toxin B. Nature 375: 500–503Google Scholar
  37. Just I, Wilm M, Selzer J, Rex G, Von Eichel-Streiber C, Mann M, Aktories K (1995c) The enterotoxin from Clostridium difficile (ToxA) monoglucosylates the Rho proteins. J Biol Chem 270: 13932 13936Google Scholar
  38. Just I, Selzer J. Hofmann F, Green GA, Aktories K 11996) Inactivation of Ras by fiostridimn sordellii lethal toxin-catalyzed glucosylation. J Biol Chem 271:10149–11)153Google Scholar
  39. Karlsson KA (1995) Microbial recognition of target-cell glycoconjugates. Curr Opin Struct 13íol 5: 622–635CrossRefGoogle Scholar
  40. Kaul P, Silverman J, Shen WH, Blanke SR, Huynh PD, Finkelstein A, Collier RJ (1996) Roles of (ilu 349 and Asp 352 in membrane insertion and translocation by diphtheria toxin. Protein Sci 5: 687 692Google Scholar
  41. Kelly CP, Pothoulakis C, LaMont JT (1994) Clostridium difficile colitis. New England J Med 330(4): 257–262Google Scholar
  42. Kelly CP, LaMont JT (1998) Clostridium difficile infection. Annu Rev Med 49: 375–390Google Scholar
  43. Kink JA, Williams JA (1998) Antibodies to recombinant Clostridium difficile toxins A and B are an effective treatment and prevent relapse of C. difficile-associated disease in a hamster model of in-fection. Infect Immun 66: 2018 2025Google Scholar
  44. Krivan HC, Clark GF, Smith DF, Wilkins TD (1986) Cell surface binding site for Clostridium difficile enterotoxin: evidence for a glycoconjugate containing the sequence Galal-3Gal(l-4GIcNAc. Infect Immun 53: 573–581PubMedGoogle Scholar
  45. Kushnaryov VM, Sedmark JJ (1989) Effect of Clostridium diffcile enterotoxin A on ultrastructure of Chinese hamster ovary cells. infect Immun 57 (12): 3914–3921Google Scholar
  46. Larsen RD, Rivera-Marrero CA, Ernst LK, Cummings RD, Lowe JB (1990) Frameshift and nonsense mutations in a human genomic sequence homologous to a murine UDP-Gal:b-D-Gal(1,4)-D-GIcNAc a(1,3)-galactosyltransferase cDNA. J Biol Chem 265: 7055–7061PubMedGoogle Scholar
  47. Laughlin MR, Petit WA, Dizon JM, Shulman RG, Barrett EJ (1988) NMR measurements of in vivo myocardial glycogen metabolism. J Biol Chem 263: 2285–2291PubMedGoogle Scholar
  48. Lisanti MP, Scherer PE, Tang Z, Sargiacomo M (1994) Caveolae, caveolin and caveolin-rich membrane domains: a signalling hypothesis. Trends Cell Biol 4: 231–235PubMedCrossRefGoogle Scholar
  49. Lyerly DM, Lockwood DE, Richardson SH, Wilkins TD (1982) Biological activities of toxins A and B of Clostridium difficile. Infect immun 35: 1147–1150PubMedGoogle Scholar
  50. Lyerly DM, Saum KE, MacDonald DK, Wilkins TD (1985) Effects of Clostridium difficile toxins given intragastrically to animals. Infect Immun 47: 349–352PubMedGoogle Scholar
  51. Lyerly DM, Phelps CI, Toth J, Wilkins TD (1986) Characterization of toxins A and B of Clostridium dfficile with monoclonal antibodies. infect Immun 54: 70–76Google Scholar
  52. Lyerly DM, Wilkins TD (1995) Clostridium difficile. In: Blaser MJ, Smith PD, Ravdin JI infections of the Gastrointestinal Tract. Raven Press Ltd., New York, pp 867–891Google Scholar
  53. Machesky LM, Hall A (1996) Rho: a connection between membrane receptor signalling and the cytoskeleton. Trends Cell Biol 6: 304–310PubMedCrossRefGoogle Scholar
  54. Mackay DJG, Hall A (1998) Rho GTPases. J Biol Chem 273: 20685–20688CrossRefGoogle Scholar
  55. Mahida YR, Makh S, Hyde S, Gray T, Borriello SP (1996) Effect of Clostridium difficile toxin A on human intestinal epithelial cells: induction of interleukin 8 production and apoptosis after cell detachment. Gut 38: 337–347PubMedCrossRefGoogle Scholar
  56. Malorni W, Paradisi S, Dupuis ML, Fiorentini C, Ramoni C (1991) Enhancement of cell-mediated cytotoxicity by Clostridium difficile toxin A: an in vitro study. Toxicon 29 (4/5): 417–428PubMedCrossRefGoogle Scholar
  57. McEuen AR (1992) Manganese metalloproteins and manganese-activated enzymes. Inorganic Biochemistry 3: 314–343CrossRefGoogle Scholar
  58. Moore R, Pothoulakis C, LaMont JT, Carlson S, Madara JL (1990) C. difficile toxin A increases intestinal permeability and induces CI-. Am J Physiol 259: G165 - G172PubMedGoogle Scholar
  59. Narumiya S (1996) The small GTPase Rho: Cellular functions and signal transduction. J Biochem (Tokyo) 120: 215–228CrossRefGoogle Scholar
  60. Nobes CD, Lauritzen I, Mattel M-G, Paris S, Hall A (1998) A new member of the Rho family, Rnd1, promotes disassembly of actin filament structures and loss of cell adhesion.,I Cell Biol 141: 187–197Google Scholar
  61. Nusrat A, Giry M, Turner JR, Colgan SP, Parkos CA, Carnes D, Lemichez E, Boquet P, Madara JL (1995) Rho protein regulates tight junctions and perijunctional actin organization in polarized epithelia. Proc Natl Acad Sci USA 92: 10629–10633PubMedCrossRefGoogle Scholar
  62. Okamoto T, Schlegel A, Scherer PE, Lisanti MP (1998) Caveolins, a family of scaffolding proteins for organizing “preassembled signaling complexes” at the plasma membrane. J Biol Chem 273: 5419–5422PubMedCrossRefGoogle Scholar
  63. Oksche A, Nakov R, Habermann E (1992) Morphological and biochemical study of cytoskeletal changes in cultured cells after extracellular application of Clostridium tourd alpha-toxin. infect Immun 60: 3002–3006Google Scholar
  64. Pai EF, Kabsch W, Krengel U, Holmes KC, John J, Wittinghofer A (1989) Structure of the guaninenucleotide-binding domain of the Ha-ras oncogene product p21 in the triphosphate conformation. Nature 341: 209–214PubMedCrossRefGoogle Scholar
  65. Pai EF, Krengel U, Petsko GA, Goody RS, Kabsch W, Wittinghofer A (1990) Refined crystal structure of the triphosphate conformation of H-ras p21 at I.35A resolution: implications for the mechanism of GTP hydrolysis. EMBO J 9: 2351–2359PubMedGoogle Scholar
  66. Popoff MR (1987) Purification and characterization of Clostridium sordellii lethal toxin and cross-reactivity with Clostridium dii idle cytotoxin. Infect Immun 55: 35–43PubMedGoogle Scholar
  67. Popoff MR, Chaves OE, Lemichez. E, Von Iìichel-Streiter G, Thelestam M, Chardin P. Cussac D. (’havrier P, Flutau (ì, Giry M, (iunzburg J, Boquet P (1996) Ras, Rap, and Rac small (1.1I’-binding proteins are targets for Clostridium sordellii lethal toxin glucosylation. J Riot (’hem 271: 10217 10224Google Scholar
  68. Pothoulakis C, LaMont JT, Eglow R, Gao N, Rubins JB, Theoharides TC. Dickey BF (1991) Characterizing of rabbit Heal receptors for’iditun difficile toxin A..1 (’ in Invest 88:119 125Google Scholar
  69. Pothoulakis C, Gilbert 12.1, (’ladaras C. Gastiglisioto 1, Semenza G, Hitti Y. Montcricf.IS. Lineasks J. Kelly CP, Nikulasson S, Dessi I IP, Wilkins TD, LiMont IT (1990) Rabbit sucrose-isomaltase contain’, a functional intestinal receptor Ior C/ostriditon diffied(’ toxin A..I Clin Invest 98: 641 649Google Scholar
  70. Prepens U. Just I, Von Eiche!-Strciher C. Aktories K (1996) Inhibition of Fc)Rl-mediated activation of rat basophilic leukemia cells by (’lo.ctridùnn difficile toxin B (monoglucosyltransferase)..I Biol Chem 271: 7324 7329Google Scholar
  71. Price LS, Norman JC, Ridley A,I. Kother A (1995) The small GTPases Rac and Rho as regulators of secretion in mast cells. Curr Biol 5: 68 73Google Scholar
  72. Ridley AJ (1096) Rho: theme and variations. Carr Biol 6:1256 !264Google Scholar
  73. Riegler M, Sedivy R, Pothoulakis C, Hamilton G, lacheri J, Bischof G, Cosentini F. Feil W. Schicssel K. LaMont J’1. Weitz! E (1995) (’lustridiwm difficile toxin B is more potent than toxin A in damaging human colonic epithelium in vitro..J Clin Invest 95: 2004 2011Google Scholar
  74. Rolfe RD, Song W (1995) Irmnunoglobulin and non-immunoglobulin components of human milk inhibit Clostridium difficile toxin A-receptor binding..1 Med Microhiol 42: 10 19Google Scholar
  75. Ruoslahti E (1997) Stretching is good forr a cell. Science 276: 1345 1346Google Scholar
  76. Sasaki ‘F, Tekai Y (1998) The Rho small (3 protein family-Rho GDI system as a temporal Lind spatial determinant for cytoskeletal control. Biochcm Biophys Res Commun 245: 641 645Google Scholar
  77. Schmalzing (i, Richter IIP, Hansen A, Schwarz VV, Just I, Aktories K (1095) Ilsolvemcnt of the GTP binding protein Rho in constitutive endocytosis in.A’eiopus lu i ii,s oocytes. J Cell Biol 130: 1319–1332Google Scholar
  78. Schmidt M, Vo M, Thiel M, Bauer B, Grünnass A, Tapp It. Cool RI I. Dc Gunzburg.1. Von I[ichclStreiber C,.lakohs MI (1998) Specific inhibition of phor!ol ester-stimulated phospholipase D by Clostridium.sordellii lethal toxin and Clostridium difficile toxin B-1470 in 111,K-293 ce!ls..1 Biol Chem 273: 7413–7422Google Scholar
  79. Sehr P, Joseph G, Genth It Just I. Pick L. Aktories K (1998) Glucosylation and ADP-ribosylation of Rho proteins-effects on nucleotide binding. (ìTPase activity, and effector-coupling. Biochemistry 37: 5296–5304Google Scholar
  80. Selzer J, Hofmann F, Rex G, Wilm M. Mann M, Just I. Aktories K (1996) tIoslricliwi) mom incorporation of GIcNAc into Rho subfamily proteins. J Biol Chem 271: 25173 25177Google Scholar
  81. Shihata Y. Nakamura II, Kato S, Tomoike II (1996) Cellular detachment and deformation induce IL -8 gene expression in human bronchial epithelial cells. J Immunol 156: 772 777Google Scholar
  82. Siflert.I-C, Baldacini O. K uhry J-G, Wachsmann D, Benuhdelmoumene S, Faradji A, Monied II. Poindron P (1993) Effects of (’/osiridiwn difficile toxin It on human monocytes and macrophages: possible relationship with cytoskeletal rearrangement. Infect Immun 61: 1082 1090Google Scholar
  83. Smith JA, Cooke DI„ Ilyde S, Borriello SP, Long RG (1997) Clostridium difficile toxin A binding to human intestinal epithelial cells. J Med Microbio! 46: 953 958Google Scholar
  84. Tapon N, Hall A (1997) Rho, Rae and (’DC42 GTPases regulate the organization of the actin cytoskeleton. Curr ()pin Cell Biol 9: 86–92CrossRefGoogle Scholar
  85. Thompson JD, Higgins DG. Gibson TJ, (’Iustal W (1994) Improsmg the sensitivity of progressive multiple sequence alignment through sequence weighting, positions-specific gap penalties and weight matrix choice. Nucl Acids Res 22:4673–4680Google Scholar
  86. Triadafilopoulos G, Pothoulakis C, O’Brien M.4, LaMont JT (1987) Differential effects of C/ostridium difficilc toxins A and B on rabbit ileum. Gastroenterology 93(2): 273 279Google Scholar
  87. Tucker KD, Wilkins TD (1991) Toxin A of Clostridium di/furl-binds to the human carbohydrate antigens I, X, and Y. Infect lmmun 59: 73–78Google Scholar
  88. Van Aelst L, D’Souia-Schorey C (1997) Rho GTPases and signaling networks. Genes Dev 11:2295 2322 Von Fichel-Strciher C. Laufenberg-Feldmann R, Sartingen S. Schulte J. Sauerborn M (1992a) Com-parative sequence analysis of the Clostridium di/fici/e toxins A and B. Mol Gen Genet 233: 260 268Google Scholar
  89. Von Eichel-Strciher C. Sauerhorn M, Kuramitsu IIK (1992h) Evidence for a modular structure of the homologous repetitive C-terminal carbohydrate-binding sites of Clostridium difficile toxins and Streptococcus muffins gtucosyltransferases..1 Bacteriol 174: 6707 6710Google Scholar
  90. Von Eiehe!-Streiber C (1993) Molecular Biology of the Clnsiridìum diffici/e Eosins. In: Sebald M (ed) Genetics and Molecular Biology of Anaerobic Bacteria. Springer-Verlag. New York. pp 264 289Google Scholar
  91. Wiggins CAR, Munro S (1998) Activity of the yeast MNN I a-1,3-mannosyltransferase requires a motif conserved in many other families of glycosyltransferases. Proc Natl Acad Sci USA 95: 7945–7950PubMedCrossRefGoogle Scholar
  92. Wittinghofer A, Pai EF, Goody RS (1993) Structural and mechanistic aspects of the GTPase reaction of H-ras p21. In: Dickey F. Birnbaumer L (eds) GTPases in Biology I. Springer-Verlag, Berlin, Heidelberg, pp 195 211Google Scholar
  93. Wren BW (1991) A family of clostridia) and streptococcal ligand-binding proteins with conserved C-terminal repeat sequences. Mol Microbiol 5: 797 803Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • I. Just
    • 1
  • F. Hofmann
    • 1
  • K. Aktories
    • 1
  1. 1.Institut für Pharmakologie und ToxikologieUniversität FreiburgFreiburgGermany

Personalised recommendations