The toxin responsible for spastic paralysis is produced by which organism?

• A. Clostridium botulinum
• B. Staphylococcus aureus
• C. Bacillus cereus
• D. Clostridium tetani

Answer: (D)

Tetanus toxin causes spastic paralysis by blocking inhibitory signals in the spinal cord. The toxin produced by Clostridium tetani travels from the wound to the central nervous system and prevents the release of inhibitory neurotransmitters GABA and glycine from interneurons. Without this inhibition, motor neurons fire unchecked, leading to sustained muscle contractions and rigidity seen in tetanus. This organism is an anaerobic, spore-forming gram-positive rod commonly found in soil and contaminated wounds. In contrast, botulinum toxin from Clostridium botulinum causes flaccid paralysis by blocking acetylcholine release at the neuromuscular junction, while toxins from Staphylococcus aureus and Bacillus cereus produce different disease syndromes rather than spastic paralysis.