Systematic Veterinary Bacteriology and Mycology

TOXINS

• C.novyi possess several somatic and flagellar antigens, which are not of much importance.
• Based on toxin production C.novyi is classified into 4 types.
• C.novyi synthesizes five major toxins, α, β, γ, δ and ε.

	Alpha	Beta
C. novyi type A	+	-
Type B	+	+
Type C	-	-
Type D C. haemolyticum	-	+++

• Type A produces all toxins except beta. Type C isolates are non toxigenic.
• In addition to this type B also produce zeta, eta and theta toxin.
  • Alpha toxin produced by type A and B is lethal, necrotizing, causes increased capillary permeability, and is toxic to several tissues including muscle, heart and liver.
  • Beta toxin is a lecithinase and produced by type B and by C.haemolyticum in greater amounts.
  • This may account for the haemolytic crisis and death in bacillary haemoglobinuria.
  • Gamma toxin is a necrotising phospholipase D.
  • Delta toxin is an oxygen labile haemolysin.
  • Epsilon toxin is a lipolytic enzyme.
  • Zeta toxin is partly haemolytic.
  • Theta toxin is a lipase.
  • Eta toxin is a tropomyosinase, which degrades tropomyosin and myosin and may play a role in destruction of infected muscles.