C.
perfringens Virulence Factors
Approximately 12 toxins have been described
 Alpha
toxin = lecithinase = phospholipase C:
Damages cell membrane --> cell lysis
Specific mutants of £\-toxin--> unable to
cause disease.
Theta
toxin: lethal, hemolytic, increases capillary permeability
Collagenase:
breaks down collagen (extracellular matrix in muscle)
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Alpha-toxin is actually
a phospholipase C. It is dependent on two to three zinc atoms
and possibly calcium. It is haemolytic,
necrotic and
lethal. Its
main activity is believed to be cleavage
of phospholipids in the cell membrane,
and its toxic effects are thought to be primarily the
result of its rapid action, which destroys the membrane. However, one
of the products of the reaction, diacyl glycerol, also interacts with
and disrupts the cell's second messenger systems.
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