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Principles of Disease > Pathogens and Hosts > Flashcards

Flashcards in Pathogens and Hosts Deck (27)
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1
Q

In what 7 ways can clinical infections be characterised?

A
Inflammation
Pain
Pyrexia
Tachycardia
Rigors
Increased white cell count
Increased C Reactive Protein
2
Q

What are the 2 types of clinical infection?

A

Latent

Sub-clinical

3
Q

Define a pathogen.

A

Organism which can cause disease.

4
Q

Define commenal.

A

Organism which is part of the normal flora.

5
Q

What are Koch’s postulates?

A

Four criteria that were established by Robert Koch to identify the causative agent of a particular disease.

6
Q

What are the 4 Koch’s postulates?

A

Organism must be found in all cases of the disease
Be cultured outside the body
Reproudce the disease on inoculation

7
Q

Define pathogenicity.

A

Capacity of a micro-organism to cause an infection.

8
Q

Define infectivity.

A

Ability to become established.

9
Q

Define virulence.

A

Ability to cause harmful effects once established.

10
Q

Name the pathogen which would attach for infectivity.

A

E.Coli

11
Q

Name the pathogen which would be acid resistant for infectivity.

A

Helicobacter pylori

12
Q

What is virulence conferred by?

A

Virulence factors.

13
Q

How do streptococcus pyogenes invade?

A

Necrotising fasciitis
Cellulitis
Connective tissue breakdown
Fibrinolysis

14
Q

Define exotoxins.

A

Released extracellularly by the microorganism.

15
Q

Define enterotoxins.

A

Exotoxins which act on the GI tract.

16
Q

Define endotoxin.

A

Structurally part of the gram negative cell wall.

17
Q

Name an exotoxin disease.

A

Clostridium Tetani

18
Q

How does clostridium tetani cause death?

A

Respiratory paralysis.

19
Q

How is clostridium tetani treated?

A

Debridement
Antibiotics
Antitoxin

20
Q

Name an enterotoxin disease.

A

Cholera

21
Q

How does cholera cause death?

A

Dehydration.

22
Q

How is cholera treated?

A

Rehydration.

23
Q

What are superantigens?

A

Certain exotoxins of strep pyogenes and staph aureus.

24
Q

What do superantigens do?

A

Stimulate division of T cells in the absence of specific antigen, causing toxic shock from overwhelming cytokine production.

25
Q

What part of the lipopolysaccharide is an endotoxin?

A

Lipid A

26
Q

Name two types of endotoxin.

A

E.Coli

Neisseria meningitidis

27
Q

What host responses are induced by endotoxins?

A
Cytokine production
Fever
Rigors
Hypotension
Tachycardia
Collapse