Clostridium tetani

Causative agent of tetanus (lockjaw). Tetanus results from trauma or a puncture wound leading to tissue contamination. Tetanus caused by the release of a single antigenic type of exotoxin by C. tetani. Tetanus exotoxin circulates in blood & adheres to neuronal receptors. Specifically, the toxin fixes to gangliosides thereby blocking the release of the neurotransmitters glycine and γ-amino butyric acid (GABA). Glycine normally prevents contraction of antagonistic muscles; therefore, muscle spasms and convulsions (lockjaw) may occur.