Clostridium

Question 0

Laboratory characteristics of Clostridium?

Answer 0

Gram positive
Spore-forming
Anaerobic
Grow on blood agar

Question 1

Where are clostridial species normally found?

Answer 1

Soil
GIT
female genital tract

Question 2

Name four Clostridium species and what they cause.

Answer 2

C.difficile - pseudomembranous colitis
C. botulinum - botulism
C. tetani - tetanus
C. perfringens - gas gangrene + food poisoning

Question 3

How does one normally acquire C.botulinum?

Answer 3

Breakdown in sterility during canning or bottling.

Question 4

How does C.botulinum cause disease?

Answer 4

Produces botulinum toxin.

Question 5

What does botulism toxin do to the body? Comment on its passage through the stomach.

Answer 5

Is the most potent neurotoxin.
Prevents release of acetylcholine at peripheral cholinergic synapses > muscle paralysis
*is not destroyed by digestive enzymes, destroyed by heat

Question 6

What are signs of cholinergic blockade?

Answer 6

Dry mouth
Ileus (type of non-mechanical bowel obstruction)
Urinary retention

Question 7

How much time elapses before symptoms become apparent with regards to C.botulinum?

Answer 7

12-36 hours (sometimes days)

Question 8

Clinical manifestations of C.botulinum?

Answer 8

Weakness
dizziness
Diplopia (double vision) or blurred vision
Peripheral muscle weakness + respiratory paralysis
Fixed dilated pupils
Lassitude
Bulbar involvement - dysphagia, difficulty with speech

Question 9

What is lassitude?

Answer 9

State of mental/physical weakness

*lack of energy

Question 10

Does infection with C.botulinum result in fever?

Answer 10

No.

Question 11

How can one diagnose C.botulinum infection?

Answer 11

Via clinical grounds
Demonstrate organism in blood
Isolate organism from gut

Question 12

How to treat C.botulinum infection?

Answer 12

Mainly supportive.
Polyvalent antitoxin available (efficacy variable)
Penicillin (value uncertain)

Question 13

What does C.perfringens produce and what does it do?

Answer 13

Lecithinase > causes gas gangrene

Question 14

How can C.perfringens cause food poisoning?

Answer 14

Can produce an enterotoxin.

Question 15

What clinical manifestations of C.perfringens are there?

Answer 15

Simple contamination
Soft tissue infections
Anaerobic cellulitis
Gas gangrene
Uterine gas gangrene
Bacteriaemia

Question 16

What does one mean by simple contamination with regards to C.perfringens?

Answer 16

That it’s isolation from a would does no necessarily mean infection as this bacterium is often found on the skin.

Question 17

What is an example of a soft tissue infection involving C.perfringens?

Answer 17

Intra-abdominal infections < perforation

Question 18

What is anaerobic cellulitis?

Answer 18

Diffuse spreading of cellulitis and fasciitis.

Question 19

Signs of anaerobic fasciitis?

Answer 19

Toxaemia
Diffuse subcutaneous crepitus
Death > shock! renal failure, intravascular haemolysis

Question 20

What tissue is involved in gas gangrene?

Answer 20

Muscle tissue.

Question 21

What are bullae?

Answer 21

Fluid filled sacs/lesions that appear when fluid is trapped underneath a thin layer of skin

Question 22

Signs of gas gangrene?

Answer 22

Bullae
Pain
Crepitus
Renal failure 
Tachycardia 
Fever

Question 23

How can someone develop uterine has gangrene?

Answer 23

Septic abortion

Even normal delivery

Question 24

What tissue are involved in uterine gas gangrene?

Answer 24

Decidual (endometrium during pregnancy) | May involve uterus itself > mayo necrosis

Question 25

How does one diagnose a C.perfringens infection?

Answer 25

Biopsy > bullae fluid or necrotic tissue | Culture > Lecithinase production + grow in anaerobic conditions

Question 26

Treatment of C.perfringens infection?

Answer 26

Remove necrotic tissue Antibiotics Antitoxin? Hyperbolic oxygen?

Question 27

Which antibiotics are used to treat C.perfringens?

Answer 27

Metronidazole | Penicillin

Question 28

Where is C.difficile normally found?

Answer 28

GIT

Question 29

How is C.diffcile spread?

Answer 29

Via hands therefore infection control in hospital very important.

Question 30

When should one suspect C.difficile infection?

Answer 30

If someone develops Diarrhea within 48-72 hours of being admitted to hospital.

Question 31

What does C.difficile cause? How?

Answer 31

Colitis. | Produces a toxin.

Question 32

Clinical signs of C.difficile infection?

Answer 32

High fever Abdominal cramps Diarrhoea (normally watery, sometimes bloody) Pseudomembranous colitis

Question 33

What is pseudomembranous colitis?

Answer 33

Inflammation of the colon involving the development of a viscous collection of inflammatory cells, fibrin and necrotic cells

Question 34

How to diagnose C.difficle?

Answer 34

Toxin in stool. | Sigmoidoscopy - look for pseudomembrane

Question 35

How to treat C.difficile infection?

Answer 35

Rehydration therapy. | Antibiotics.

Question 36

Which antibiotics are used to treat C.difficile?

Answer 36

Oral metronidazole. | Vancomycin (severe disease).

Question 37

What is Bacillus cereus a known cause of?

Answer 37

Food poisoning.