Abstract
Clostridium botulinum types C and D toxin production is governed by the specific bacteriophages. A type C phage, c-st, was isolated from a toxigenic strain of C-Stockholm, and its whole genome sequence was determined. The genome was a linear double-stranded 185, 681 by DNA with a G+C content of 26.2%, and identical 403-bp sequences were found at each end of the genome. From the DNA research, 198 potential protein-coding regions (ORFs) were identified. The genes for type C progenitor toxin and C3 exoenzyme were identified, but no type D toxin gene was found.A number of genes were homologous to those of a Bacillus subtilis bacteriophage, SPβ. On Southern blot analysis between type C and D cell DNAs and the specific probes for H and L chains of C and D neurotoxins, it became clear that type C and D strains posses only one type of toxin gene. From these findings, it is concluded that cross-neutralization observed between toxins (types C and D) and their antiserums can be caused by the common-antigens in C and D toxins.
