Part 1

Question 1

What are important characteristics of the genus Clostridium?

Answer 1

Gram positive rods
Anaerobic
Form spores
Commonly found in gastrointestinal tract

Question 2

How does Clostridium form endospores?

Answer 2

Under the presence of oxygen.

Spores are not sensitive to oxygen and allows them to survive.

Question 3

How does Clostridia cause disease?

Answer 3

produce potent protein toxins

Question 4

What are the neurotoxic Clostridia?

Answer 4

C.tetani

C.botulinum

Question 5

What does Clostridium tetani release?

Answer 5

tetanus, a neurotoxin

Question 6

Describe the pathogenesis of Clostridium tetani

Answer 6

entry of spore into deep wound
deep wound cuts off oxygen and it becomes anaerobic
bacteria produce toxin which is released when they die
toxin binds to nerve endings and is translocated into nerve cells
it inhibits the neurotransmitter release
blocks muscle relaxation pathway

Question 7

What does tetanus cause?

Answer 7

Uncontrolled stimulation of muscles

rigid paralysis

Question 8

How is Clostridium botulinum contracted?

Answer 8

contaminated canned food that have been inadequately heated

food-borne disease

Question 9

Describe the pathogenesis of Clostridium botulinum

Answer 9

spores germinate in food and toxin is produced
BoNT is ingested with food
toxin localises in neuromuscular junction
blocks the release of neurotransmitter

Question 10

What does botulinum cause?

Answer 10

uncontrolled relaxation of muscle
no vaccine available
flaccid paralysis

Question 11

What are the therapeutic uses of botulinum neurotoxins?

Answer 11

reversible effect on neuromuscular junction

treat spasms and removal of wrinkles

Question 12

Difference between tetanus and botulinum toxin

Answer 12

tetanus blocks the relaxation pathway

botulinum blocks the contraction pathway

Question 13

Features of clostridium perfringens

Answer 13

It is an aerotolerant anaerobe that forms spores.
It causes food poisoning (present in meat)
it produces an enterotoxin
it sporulates in the intestine

Question 14

What does clostridium perfringens cause

Answer 14

in humans, it causes food poisoning

in animals, enterotoxaemic diseases

Question 15

What are some predisposing factors of type D clostridium perfringens

Answer 15

sudden change in diet
bacterial contamination level
immune status

Question 16

Pathogenesis of type D clostridium perfringens

Answer 16

colonises the gut
activated by trypsin
increases intestinal permeability
absorbed systemic circulation
endothelial cells of brain

Question 17

How do enteric infections via clostridium perfringens occur

Answer 17

strain colonises and produce enteric toxin, which permeabilises the gut and absorbed
toxin acts on distant organs

Question 18

What does histotoxic clostridium perfringens cause

Answer 18

causes gas gangrene

injured tissue contaminated with spores

Question 19

Pathogenesis of clostridium perfringens histotoxic

Answer 19

produces alpha-toxin
symptoms are severe pain and muscle necrosis
blackened of skin
treatment include amputation of tissue