title: Epsilon-toxin is required for most Clostridium perfringens type D vegetative culture supernatants to cause lethality in the mouse intravenous injection model.
abstract: Clostridium perfringens type D enterotoxemias have significant economic impact by causing rapid death of several domestic animal species. Consequently, domestic animals are commonly vaccinated, at varying efficacy, with inactivated type D vegetative supernatants. Improved type D vaccines might become possible if the lethal toxins produced by type D isolates were characterized and the contributions of those toxins to supernatant-induced lethality were established. Therefore, the current study evaluated the presence of lethal toxins in supernatants prepared from late-log-phase vegetative cultures of a large collection of genotype D isolates. Under this growth condition, most genotype D isolates produced variable levels of at least three different lethal toxins, including epsilon-toxin (ETX). To model the rapid lethality of type D enterotoxemias, studies were conducted involving intravenous (i.v.) injection of genotype D vegetative supernatants into mice, which were then observed for neurotoxic distress. Those experiments demonstrated a correlation between ETX (but not alpha-toxin or perfringolysin O) levels in late-log-phase genotype D supernatants and lethality. Consistent with the known proteolytic activation requirement for ETX toxicity, trypsin pretreatment was required for, or substantially increased, the lethality of nearly all of the tested genotype D vegetative supernatants. Finally, the lethality of these trypsin-pretreated genotype D supernatants could be completely neutralized by an ETX-specific monoclonal antibody but not by an alpha-toxin-specific monoclonal antibody. Collectively, these results indicate that, under the experimental conditions used in the present study, ETX is necessary for the lethal properties of most genotype D vegetative supernatants in the mouse i.v. injection model.
authors.affiliation: E1240 BSTWR, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA.
authors.forename: Sameera
authors.initials: S
authors.lastname: Sayeed
authors.forename: M E
authors.initials: ME
authors.lastname: Fernandez-Miyakawa
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Fisher
authors.forename: Vicki
authors.initials: V
authors.lastname: Adams
authors.forename: Rachael
authors.initials: R
authors.lastname: Poon
authors.forename: Julian I
authors.initials: JI
authors.lastname: Rood
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Uzal
authors.forename: Bruce A
authors.initials: BA
authors.lastname: McClane
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001427:Bacterial Toxins / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology / Q000633:toxicity*; D003016:Clostridium perfringens / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D017077:Culture Media, Conditioned / Q000737:chemistry* / Q000633:toxicity*; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005838:Genotype; D007275:Injections, Intravenous; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D009500:Neutralization Tests
chemical_list: D000911:Antibodies, Monoclonal; D001427:Bacterial Toxins; C039811:Clostridium perfringens epsilon-toxin; D017077:Culture Media, Conditioned