Gram-⊕, spore-forming, obligate anaerobic rods.- Produces tetanospasmin- Ubiquitous (especially animal feces and soil)

- Wounds with compromising blood supply create anaerobic conditions that are ideal for the multiplication and germination of C tetani, eg, penetrating wounds (gunshot, animal bites), open fractures, surgical procedures, burns, umbilical stump infections.

- Tetanus toxin: protease that cleaves SNARE proteins for neurotransmitters. Blocks release of inhibitory neurotransmitters (GABA and glycine) from Renshaw cells in spinal cord.

Causes:- Initially headache and flu-like symptoms - Spastic paralysis that begin in face muscles and descend: trismus (lockjaw), risus sardinocus (raised eyebrows and open grin), opisthotonus (spasms of spinal extensors).- Laryngospasm → respiratory failure- Autonomic dysfunction → circulatory arrest and shock

- Tetanus is a clinical diagnosis.

- Prevent with tetanus vaccine.- Treat with antitoxin +/- vaccine booster, antibiotics (metronidazole), diazepam (for muscle spasms), and wound debridement.