title: Evaluation of a new cytotoxicity assay for Clostridium perfringens type D epsilon toxin.
abstract: A new cytotoxicity assay for determining the activity of epsilon toxin produced by Clostridium perfringens type D has been developed. Viability of cultured cells was determined by the ability of only live cells to convert 5-(3-carboxymethoxyphenyl)-2-(4,5-dimethylthiazolyl)-3-(4- sulfophenyl)tetrazolium to the coloured product formazan in the presence of phenazine methosulfate. Of the 12 cell lines tested, only the MDCK cell line was susceptible to epsilon toxin. Specificity was confirmed by the ability of only specific monoclonal antibodies to inhibit cytotoxicity. Good correlation was obtained with the mouse lethality assay (r = 0.991) and over a wide range of viability (15-75%) as determined by ethidium bromide/acridine orange staining (r = 0.995).
authors.affiliation: Chemical and Biological Defence Establishment, Porton Down, Nr. Salisbury, Wiltshire, UK.
authors.forename: D W
authors.initials: DW
authors.lastname: Payne
authors.forename: E D
authors.initials: ED
authors.lastname: Williamson
authors.forename: H
authors.initials: H
authors.lastname: Havard
authors.forename: N
authors.initials: N
authors.lastname: Modi
authors.forename: J
authors.initials: J
authors.lastname: Brown
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001427:Bacterial Toxins / Q000302:isolation & purification / Q000633:toxicity*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D003016:Clostridium perfringens / Q000737:chemistry*; D007928:Lethal Dose 50; D008773:Methylphenazonium Methosulfate; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D013194:Staining and Labeling; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D000911:Antibodies, Monoclonal; D001427:Bacterial Toxins; C039811:Clostridium perfringens epsilon-toxin; D013778:Tetrazolium Salts; D013844:Thiazoles; C070380:3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium; D008773:Methylphenazonium Methosulfate