Spore-Formers Flashcards
Why form Endospores?
Resistance to dessication, freezing, heating, Radiation, UV light, and chemicals.
What are the important spore formers? What is their classification?
Both Gram positive rods.
Clostridium - Anaerobic
Bacillus - Aerobic
Important Clostridium species (3)
C. perfringens, C. botulinum, C. tetani
What diseases are the Clostridia related to? (3)
Enterotoxaemias, Intoxication, Histotoxic affects.
C. Perfringens: How many types?
Five types (A-E) based on toxin production.
C. perfringens mainly related to which diseases (3)…
Enterotoxaemias in sheep, Blackleg (in ruminants) and Necrotic Enteritis in Pigs and Poultry.
C. perfringens Type A: which toxins?, causes…
Alpha toxin, Enteritis in Pigs and Chickens.
C. perfringens Type B: which toxins?, causes…
Mainly Beta toxin, but also Epsilon. Enterotoxaemia in Sheep (Lamb Dysentery)
C. perfringens Type C: which toxins?, causes…
Mainly Beta toxin.
Enterotoxaemia in Sheep (Struck), Necrotic Enteritis in Lambs and Piglets.
C. perfringens Type D: which toxins?, causes…
Mainly Epsilon toxin.
Enterotoxaemia in Sheep (Pulpy Kidney)
C. perfringens: What are it’s histotoxic effects?
Wound contamination. Spores contaminate traumatised tissue from the soil or faeces.
C. chauvoei causes…
Blackleg in Ruminants. - Latent spores in muscle and liver, may be activated by trauma.
C. novyi toxins causes…
Histotoxic wound infections in Rams (Big Head), and Black Disease following Fasciola Hepatica infestatio.
C. botulinum: Why is it important?
Preventable by careful canning and treatment, Spores germinate in Anaerobic feed stuff. Ingestion of very poisonous Toxin.
C. botulinum: How does the toxin work, what is the final outcome?
Botox blocks release of ACh at NMJ. This leads to Flaccid paralysis and Death.
C. tetani: Where it it found, what does it cause?
‘Drumstick’ shaped Spores found in Soil or Faeces. Inoculated into Tissue. Causes Tetanus.
C. tetani: How does the toxin work, what is the final outcome?
Release of Tetanospasmin. It blocks release of NT from inhibitory synapse, uncontrolled synapse. Tensing of muscles, Paralysis.
Bacillus: Which species is important and why?
Bacillus anthracis - cause of Anthrax.
Why is B. anthracis so important?
Produces a highly toxic exotoxin - Holotoxin. This causes death by causing systemic shock.
B. anthracis: Holotoxin components (3)
(1) Oedema factor, (2) Protective factor (binding to receptor), (3) Lethal Factor
Anthrax: Species, Route of Infection?
Affects mainly Sheep, Cattle and Horses. Spores enter usually via GIT (esp with spiny vegetation), gain entry to Blood.
