What is the causative agent of tetanus?

What is the causative agent of tetanus?

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

Answer: (A)

Tetanus is caused by a toxin produced by Clostridium tetani, an anaerobic, spore-forming bacterium commonly found in soil and animal feces. When a wound provides a low-oxygen environment, the bacteria can germinate and release tetanospasmin, a powerful neurotoxin that travels to the central nervous system and blocks the release of inhibitory neurotransmitters like GABA and glycine. With these brakes removed, motor neurons fire excessively, leading to the hallmark signs of tetanus: painful muscle rigidity and spasms, often starting with lockjaw. This mechanism explains why tetanus presents with stiff, sustained muscle contractions rather than flaccid weakness. Other organisms listed don’t cause tetanus. Staphylococcus aureus can cause a range of infections but does not produce tetanospasmin. Clostridium botulinum produces botulinum toxin, which causes a flaccid paralysis rather than the rigidity seen in tetanus. Bacillus cereus is associated with food poisoning and not tetanus toxin.

Tetanus is caused by a toxin produced by Clostridium tetani, an anaerobic, spore-forming bacterium commonly found in soil and animal feces. When a wound provides a low-oxygen environment, the bacteria can germinate and release tetanospasmin, a powerful neurotoxin that travels to the central nervous system and blocks the release of inhibitory neurotransmitters like GABA and glycine. With these brakes removed, motor neurons fire excessively, leading to the hallmark signs of tetanus: painful muscle rigidity and spasms, often starting with lockjaw. This mechanism explains why tetanus presents with stiff, sustained muscle contractions rather than flaccid weakness.

Other organisms listed don’t cause tetanus. Staphylococcus aureus can cause a range of infections but does not produce tetanospasmin. Clostridium botulinum produces botulinum toxin, which causes a flaccid paralysis rather than the rigidity seen in tetanus. Bacillus cereus is associated with food poisoning and not tetanus toxin.