Microbiology General 8145ecd8 Clostridium botulinum toxin mode of action is by: March 2012 A Presynaptic block B Postsvnaptic block C Competitive inhibition of acetylcholine D Destruction of acetylcholine High-Yield Explanation Ans: A i.e. Presynaptic block Cl. Botulinum toxin acts by blocking the production/ release of acetylcholine at the synapses & neuromuscular junctions