Question

Explain the effects of bacilli toxins on the nerves and the spinal cord. State the long term effects of certain bacilli species infections.

Answer 1

Botox (Clostridium botulinum toxin) is a neurotoxin isolated from the clostridium botulinum bacteria (can cause food poisoning). This is an anaerobic bacilli bacteria and it poisoning is called, “botulism.” It is not an infection of the nervous system, but it’s one of the key symptoms is, “paralysis.”

The botulinum toxin acts by inhibiting the release of acetylcholine (ACh) neurotransmitter from the presynaptic nerve terminal of the motor neurons. This results in the prevention of muscle depolarization and contraction process. The long term effect would be muscle atrophy as the muscles fail to generate tension.

Tetanus toxin:

It is a neurotoxin released by the Clostridium tetani. It is a gram-negative anaerobic bacilli. It causes muscle spam, convulsions and lock jaw disease in the affected people.

Pathogenesis:

Under normal conditions, muscle contraction occurs due to the release and binding of acetyl choline neurotransmitter to the nicotinic type of acetylcholine receptors, which causes depolarization and muscle contraction.

Tetanus toxin acts by inhibiting the release of acetylcholine (ACh) neurotransmitter from the presynaptic nerve terminal of the motor neurons, which prevents the muscle depolarization and contraction process. The SNAREs are the targets of neurotoxins such as botulinum toxin and tetanus.

The primary function of SNARE proteins is to allow the fusion of vesicles with their target membranes. Likewise they also facilitate the fusion of synaptic vesicles that store neurotransmitter with the presynaptic membranes in neurons. Thus, inhibition of SNAREs inhibits the vesicle fusion and release of neurotransmitter.