- Ubiquitous organism
- Oval, subterminal endospores; spores survive boiling for hours
- Causes botulism, a potentially fatal intoxication
- Germination of endospores, growth of bacterial cells and toxin production in anaerobic conditions e.g. decaying carcasses and vegetation
- Disease in animals consuming rotting carcasses and in herbivores through contamination of feed
- Pathogenesis:
- Intoxication on ingestion and absorbtion of toxin from GIT into the blood
- Occasionally germination of spores in wounds or GIT
- Neurotoxin carried to peripheral nervous system
- Toxin binds gangliosides irreversibly at the neuromuscular junction
- Blocks release of acetylcholine
- Clinical signs:
- Dilated pupils, dry mucus membranes, decreased salivation, tongue flacidity, dysphagia in farm animals
- Incoordination and knuckling followed by flacid paralysis and recumbency
- Paralysis of respiratory muscles leads to death
- Flacid paralysis of legs and wings in birds
- Diagnosis:
- Mouse inoculation with infected serum
- Toxin detection by PCR, ELISA
- Toxin neutralisation tests in mice
- Treatment: polyvalent antiserum neutralises unbound toxin
- Toxoid vaccine used in endemic regions
- Implicated in equine grass sickness