Bacterial Spores

Question 1

What is an endospore?

Answer 1

Dormant, highly resistant body that survives adverse environmental conditions, produced by small percentage of bacteria

Question 2

What can endospores resist? How do we destroy them?

Answer 2

Can resist:
- Dessication
- Cold and freezing
- Boiling
- Radiation
- UV light
- Chemicals
Destroy by autoclaving

Question 3

Describe the clostridium bacterial species generally

Answer 3

• Anaerobic, spore-forming, gram-positive bacteria found in soil and faeces (normal GIT commensal) but can produce many toxins and enzymes and is frequently motile

Question 4

Give an example of an enteropathogenic (enterotoxaemic) species of clostridia and how it causes disease

Answer 4

C. Perfringens (Types A-E) - Produce clostridial enterotoxaemias causing histotoxic disease a.k.a. necrotic enteritis in pigs and poultry, enters wounds and causes infection

Question 5

What does Type A C.Perfringens cause?

Answer 5

Produces clostridial alpha toxin (necrotising toxin) which causes necrotic gastrointestinal diseases: Pig = Necrotising Entercolitis Poultry = Necrotic enteritis

Question 6

What does Type B C.Perfringens cause?

Answer 6

Lamb Dysentry:
Produces clostridial toxin alpha, beta and epsilon
Beta toxin is lethal but is inactivated by proteolytic enzymes (trypsin)
Causes damage to mucosa
caused by overdrinking of milk

Question 7

What does Type C C.Perfringens cause?

Answer 7

Produces clostridal toxin alpha and beta
causes infection in neonatal pigs (less than 3 days old)
and
Struck in adult sheep (death without previous clinical signs)
caused by overeating

Question 8

What does Type D C.Perfringens cause?

Answer 8

Produces alpha and epsilon clostridial toxins
Epsilon toxin is activated by trypsin
Causes sudden death in lambs and infects sheep of all ages
Also causes haemorrhagic enterotoxaemia in piglets, calves, lambs and foals
caused by poor to rich diets

Question 9

What does Type E C.Perfringens cause?

Answer 9

Very rare
Necrotic enteritis in calves australia

Question 10

What is Clostrdiodes Difficile? What does it cause?

Answer 10

Causes Enterocolitis in humans and is usually associated with previous antimicrobial therapy, also occurs in hamsters, rabbits and guinea pigs

Question 11

Give an example of a Histotoxic clostridial bacteria

Answer 11

C. chauvoei

Question 12

What does C.Chauvoei cause?

Answer 12

Blackleg in cattle
Caused by endospores being ingested and then passing into the lymphatics/blood

Question 13

How do we protect cattle against blackleg?

Answer 13

Vaccination = only means of protection
Toxoid vaccines - containing toxin that has been treated to remove the toxic effect but retain immunological properties

Question 14

Give 2 examples of Neurotropic clostridial bacteria

Answer 14

C.tetani and C.botulinum

Question 15

What does C.Tetani cause? Where is it found naturally?

Answer 15

Tetanus
Found in the soil or faeces

Question 16

How does C.Tetani cause disease?

Answer 16

Production of neurotoxin that localises in synaptic vesicles - blocks inhibitory neurotransmitters irreversibly
causes uncontrolled excitatory activity - Tensing, paralysis, death

Question 17

What species are affected by Tetanus?

Answer 17

• Almost all mammals especially horses (this is a core vaccine in horses)

Question 18

How do we treat Tetanus?

Answer 18

Antitoxin when animals are infected with C.Tetani or immunoglobulin is also used

Question 19

What does C.Botulinum cause and where is it found naturally?

Answer 19

Botulism
found in soil, water and faeces

Question 20

How does C.Botulinum cause disease? What does this cause?

Answer 20

Produces a neurotoxin that blocks vesicles that release acetylcholine causing flaccid paralysis and death

Question 21

Describe Bacillus species generally

Answer 21

Aerobic, spore forming, gram-positive bacilli that are found in soil and faeces (normal GIT commensals) with most not being pathogens

Question 22

Give some examples of pathogenic bacillus and what they cause

Answer 22

B.Anthracis - Anthrax (Notifiable disease)
B.Cereus - Food Poisoning
B.Licheniformis - Bovine Abortion

Question 23

What species do B.Anthracis affect?

Answer 23

Sheep, cattle, horses and other animals

Question 24

How do we test for anthrax?

Answer 24

• McFadyean’s reaction on blood smear
• Polychrome methylene blue can detect capsule of B.Antracis