A novel toxin homologous to large clostridial cytotoxins found in culture supernatant of Clostridium perfringens type C

Abstract

An unknown cytotoxin was identified in the culture supernatant of Clostridium perfringens type C. The cytotoxin, named TpeL, which was purified using mAb-based affinity chromatography, had a lethal activity of 62 minimum lethal dose (MLD) mg "1 in mice and a cytotoxic activity of 6.2610 5 cytotoxic units (CU) mg "1 in Vero cells. The nucleotide sequence of TpeL was determined. The entire ORF had a length of 4953 bases, and the same nucleotide sequence was not recorded in the GenBank/EMBL/DDBJ databases. The molecular mass calculated from the deduced amino acid sequence was 191 kDa, and a signal peptide region was not found within the ORF. The deduced amino acid sequence exhibited 30-39 % homology to Clostridium difficile toxins A (TcdA) and B (TcdB), Clostridium sordellii lethal toxin (TcsL) and Clostridium novyi alpha-toxin (TcnA). The amino acid sequence of TpeL is shorter than these toxins, and the homologous region was located at the N-terminal site. Eighteen strains of C. perfringens types A, B and C were surveyed for the presence of the tpeL gene by PCR. The tpeL gene was detected in all type B (one strain) and C strains (five strains), but not in any type A strains (12 strains). TpeL was detected in culture filtrates of the five type C strains by dot-blot analysis, but not in the type B strain. It was concluded that TpeL is a novel toxin similar to the known large clostridial cytotoxins. Furthermore, the data indicated that TpeL is produced by many C. perfringens type C strains.

Host serum factor triggers germination of Clostridium perfringens spores lacking the cortex hydrolysis machinery

“…Clostridium perfringens is a Gram-positive, spore forming, anaerobic bacterium, which is highly associated with a wide array of gastrointestinal (GI) and histotoxic diseases in both humans and animals (Amimoto et al, 2007; Keyburn et al, 2008;McClane, 2007). However, the most common cause of C. perfringens-associated food poisoning in humans is the consumption of C. perfringens vegetative cells followed by sporulation in the gut (McClane, 2007;Paredes-Sabja & Sarker, 2009).…”

Caracterização molecular dos principais fatores de virulência e genótipos de Clostridium perfringens isolados de frangos com enterite necrótica.

“…Amimoto et al (2007) relataram a presença da toxina TpeL a qual foi classificada como pertencente a Família das Grandes Citotoxinas Clostridiais (LCT):…”

“…A toxina TpeL inicialmente detectada em sobrenadantes de C. perfringens tipo C de origem suína, foi relatada, mostrando-se letal em camundongos e produzindo alterações citotóxicas em células Vero (AMIMOTO et al, 2007;NAGAHAMA et al, 2011). Esta toxina também é produzida durante o processo de esporulação, da mesma forma que ocorre com a enterotoxina (PAREDES-SABJA; SARKER; SARKER, 2011).…”

“…Esta toxina também é produzida durante o processo de esporulação, da mesma forma que ocorre com a enterotoxina (PAREDES-SABJA; SARKER; SARKER, 2011). A toxina TpeL apresenta peso molecular de 191 KDa, com a conformação DXD e com triptofano em posições conservadas, essenciais para a atividade glicosil-transferase (AMIMOTO et al, 2007;GUTTENBERG et al, 2012;NAGAHAMA et al, 2011).…”

“…É sabido que, a toxina TpeL causa citotoxicidade e apoptose em células epiteliais; e tem sido incluída na Família Large Clostridial Citotoxin (LCT), produzidas também, por C. difficile, C. sordelli e C. novy (AMIMOTO et al, 2007;SONGER, 1996 Outras toxinas produzidas por C. perfringens são consideradas de importância na patogênese de diversos processos infecciosos em animais. Assim, as toxinas β e β2, apresentam similar mecanismo de ação e são estruturalmente diferentes.…”