Characterization of six type A strains of Clostridium botulinum that contain type B toxin gene sequences

Six Clostridium botulinum isolates exhibiting type A toxicity as measured by the mouse bioassay were found to contain both type A and type B neurotoxin DNA sequences. The six strains were divided into three groups based on the DNA sequence of the type B neurotoxin gene. Members of each group exhibited 100% sequence identity over the 3876 by type B toxin open reading frame. The type B toxin sequence of all groups differed at more than 60 positions when compared to the BGB control strain. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.