Part 2

Question 0

What are endospores resistant to?

Answer 0

Desiccation
Cold and freezing
Boiling
Radiation
UV 
Chemicals

Question 1

What classifications of bacteria are spore formers?

Answer 1

Gram positive rods. Clostridia sp. and bacillus sp.

Question 2

Give the group of anaerobic spore formers

Answer 2

Clostridium

Question 3

Give the group of aerobic spore formers

Answer 3

Bacillus

Question 4

Give 3 manifestations of chlostridial disease

Answer 4

Enterotoxaemias- eg pulpy kidney (toxin produced in gut and absorbed into kidney)

Intoxication - ingestion of preformed toxin e.g. Botulinum toxin

Histotoxic infection- e.g. Gas gangrene. Bacteria grow in necrosis and tissue damage (anaerobes). Wet gangrene, black leg in cattle, necrotic enteritis in pigs and poultry

Question 5

What is alpha toxin that all groups of clostridium perfringens produce?

Answer 5

Phospholipase C

Question 6

C. Perfringens type A produces which toxin and causes what?

Answer 6

Alpha (phospolipase C) . Causes Human disease, enteritis in pigs and poultry

Question 7

What toxins does C. Perfringens type B produce and what is its disease manifestation?

Answer 7

Alpha, beta and epsilon. Causes lamb dysentery.
As young lambs suckle milk it causes overgrowth of commensals which feed on the milk. Toxins rapidly secreted and absorbed.

Question 8

C. Perfringens type C?

Answer 8

Alpha and beta toxins. Causes struck. Occurs in over-eating as beta toxin not inactivated by trypsin as it normally would be. Damages mucosa and is absorbed. Pancreatic insufficiency?

Question 9

C. Perfringens type D

Answer 9

Alpha and epsilon toxins. Pulpy kidney in lambs - quick diet change from poor to rich food. Overgrowth of CP in small intestine. Epsilon toxin activated by enzymes. Absorption causes enterotoxaemia.
Affects brain and kidney - increased capillary permeability.
Autolytic changes.

Question 10

C. Perfringens type E

Answer 10

Alpha and iota toxins. Necrotic enteritis in calves in Australia

Question 11

How does chlostridium chauvoei cause blackleg?

Answer 11

Histotoxic infection- spores lie dormant in muscle until activated by trauma which lowers the redox of tissues - anaerobic spores germinate

Question 12

How is chlostridium tetani spread?

Answer 12

Spores in soil or faeces- inoculated deep into tissue. Wound necrotic or anaerobic and spores germinate. Tetanospasmin released

Question 13

How does tetanospasmin affect host?

Answer 13

Localised in synaptic vesicles.
Blocks release of neurotransmitter for inhibitory synapses (GABA and glycine)
Uncontrolled excitatory synaptic activity
Constant tensing of muscle.
Spastic paralysis

Question 14

What sort of vaccine could protect against chlostridium tetani?

Answer 14

Toxoid

Question 15

Where is chlostridium botulinum found in environment?

Answer 15

Soil, water, faeces

Question 16

Where do C. Botulinum spores germinate?

Answer 16

Anaerobic feedstuffs

Question 17

What causes botulism disease?

Answer 17

Production of toxins A-H which go to circulation and peripheral nerves. Blocks release of ACh at synapse - flaccid paralysis and death

Question 18

What bacteria causes anthrax?

Answer 18

Bacillus anthracis

Question 19

Describe epidemiology of anthrax

Answer 19

Affects sheep, cattle, horses and other animals. Spores ingested from contaminates soil, phagocytosed and germinate in lymphatics. Spread to blood and multiply- septicaemia.

Question 20

Describe capsule of B. anthracis

Answer 20

Poly D-glutamic acid.

Antiphagocytic- prevents C3b binding to surface.

Question 21

What are the 3 components to B. anthracis toxin?

Answer 21

Factor 1 (oedema factor - adenylate Cyclase - raised cAMP inhibits PMNL phagocytosis)

Factor 2 (protective factor)

Factor 3 (lethal factor - toxic to macrophages. Alters membrane permeability- pulmonary oedema)

Together make holotoxin.