Clostridium botulinum Ba4 str. 657

Clostridium botulinum produces botulinum neurotoxin, one of deadliest toxins known. It inhibits acetylcholine release in neuromuscular junctions, causing paralysis by inhibiting muscle contraction. In most cases the affected person dies of asphyxiation or heart failure. Strains of C. botulinum are physiologically heterogeneous, and four distinct phenotypic groups (I to IV) are recognized. These four metabolically distinct groups do not, however, necessarily correlate with the serological specificities of the botulinum neurotoxin produced, which are classified into 7 serotypes, A-F. The type A toxin is used in minute doses to treat both painful muscle spasms and as a cosmetic treatment to temporarily remove frown lines between eyebrows. Strain Hall, ATCC 3502, is a representative of the Group I (proteolytic) botulinum toxin producing bacteria. Group I strains produce one or two toxins of type A, B or F; strain Hall produces type A1 neurotoxin. Food-borne, infant and wound botulism can all be caused by Group I strains. Strain Hall, the most widely studied of the C.botulinum strains, has been found to have an active chitinolytic system, enabling it to colonize environments where chitin-containing organism such as fungi, insects and crustaceans are abundant. Additionally it produces several extracellular proteases, presumably helping it to soften and destroy rotting or decaying tissues to support its saprophytic lifestyle. Two representatives of this strain have been sequenced, one of which contains a plasmid that encodes a bacteriocin boticin-like synthetic and transport system which may enable the bacteria to compete against other microbes. (EBI Integr8)