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

• Published in: Microbiology (Society for General Microbiology) 2007-04, Vol.153 (4), p.1198-1206
• Main Authors: Amimoto, Katsuhiko, Noro, Taichi, Oishi, Eiji, Shimizu, Mitsugu
• Format: Article
• Language: English
• Subjects: Animals; Bacterial Toxins - chemistry; Bacterial Toxins - genetics; Bacterial Toxins - isolation & purification; Bacterial Toxins - toxicity; Bacteriology; Biological and medical sciences; Cattle; Chlorocebus aethiops; Clostridium difficile; Clostridium novyi; Clostridium perfringens; Clostridium perfringens - chemistry; Clostridium perfringens - genetics; Clostridium perfringens - isolation & purification; Clostridium sordellii; Cytotoxins - chemistry; Cytotoxins - genetics; Cytotoxins - isolation & purification; Cytotoxins - toxicity; Fundamental and applied biological sciences. Psychology; Mice; Microbiology; Molecular Sequence Data; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Phylogeny; Swine; Vero Cells
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.2006/002287-0

Kyoto Biken Laboratories, Inc., 24-16 Makishima-cho, Uji, Kyoto 611-0041, Japan Correspondence Katsuhiko Amimoto por{at}kyotobiken.co.jp 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 6.2 x 10 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. Abbreviations: CBB, Coomassie brilliant blue; CU, cytotoxic units; LCT, large clostridial cytotoxin; MLD, minimum lethal dose The GenBank/EMBL/DDBJ accession number for the tpeL sequence reported in this paper is AB262081. Multiple sequence alignment data of this toxin and large clostridial cytotoxins are available as a supplementary figure with the online version of this paper.