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Flashcards in Clostridium Deck (38):
0

Where are clostridial species normally found?

Soil
GIT
female genital tract

1

Laboratory characteristics of Clostridium?

Gram positive
Spore-forming
Anaerobic
Grow on blood agar

2

Name four Clostridium species and what they cause.

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

3

How does one normally acquire C.botulinum?

Breakdown in sterility during canning or bottling.

4

How does C.botulinum cause disease?

Produces botulinum toxin.

5

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

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

6

What are signs of cholinergic blockade?

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

7

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

12-36 hours (sometimes days)

8

Clinical manifestations of C.botulinum?

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

9

What is lassitude?

State of mental/physical weakness
*lack of energy

10

Does infection with C.botulinum result in fever?

No.

11

How can one diagnose C.botulinum infection?

Via clinical grounds
Demonstrate organism in blood
Isolate organism from gut

12

How to treat C.botulinum infection?

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

13

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

Lecithinase > causes gas gangrene

14

How can C.perfringens cause food poisoning?

Can produce an enterotoxin.

15

What clinical manifestations of C.perfringens are there?

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

16

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

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

17

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

Intra-abdominal infections < perforation

18

What is anaerobic cellulitis?

Diffuse spreading of cellulitis and fasciitis.

19

Signs of anaerobic fasciitis?

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

20

What tissue is involved in gas gangrene?

Muscle tissue.

21

What are bullae?

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

22

Signs of gas gangrene?

Bullae
Pain
Crepitus
Renal failure
Tachycardia
Fever

23

How can someone develop uterine has gangrene?

Septic abortion
Even normal delivery

24

What tissue are involved in uterine gas gangrene?

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

25

How does one diagnose a C.perfringens infection?

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

26

Treatment of C.perfringens infection?

Remove necrotic tissue
Antibiotics
Antitoxin?
Hyperbolic oxygen?

27

Which antibiotics are used to treat C.perfringens?

Metronidazole
Penicillin

28

Where is C.difficile normally found?

GIT

29

How is C.diffcile spread?

Via hands therefore infection control in hospital very important.

30

When should one suspect C.difficile infection?

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

31

What does C.difficile cause? How?

Colitis.
Produces a toxin.

32

Clinical signs of C.difficile infection?

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

33

What is pseudomembranous colitis?

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

34

How to diagnose C.difficle?

Toxin in stool.
Sigmoidoscopy - look for pseudomembrane

35

How to treat C.difficile infection?

Rehydration therapy.
Antibiotics.

36

Which antibiotics are used to treat C.difficile?

Oral metronidazole.
Vancomycin (severe disease).

37

What is Bacillus cereus a known cause of?

Food poisoning.