Pathogens and the Host

Question 1

Describe some of the more important virulence factors involved in bacterial pathogenesis.

Answer 1

- Invasiveness
	-Necrotising fasciitis
	-Cellulitis
	-Connective tissue breakdown
	F-ibrinolysis
- Toxins
	-Exotoxins 
	-Enterotoxins 
	-Endotoxins

Question 2

What are the virus pathogenic mechanisms?

Answer 2

o Cell destruction following infection
 - Death of T4+ cells by HIV
o Virus-induced changes to cellular gene expression
 - Cellular transformation by tumour viruses
o Immunopathogenic Disease
 - Influenza A virus

Question 3

What is a commensal?

Answer 3

An organism that is part of the normal flora

Question 4

What are exotoxins ?

Answer 4

Released extracellularly by the micro-organism (tetanus)

Question 5

What are enterotoxins?

Answer 5

Exotoxins which act on the GI tract

Question 6

What is endotoxin ?

Answer 6

Part of the gram negative cell wall

Question 7

What factors affect infectivity?

Answer 7

Attachment Acid resistance

Question 8

What factors affect virulence?

Answer 8

Invasiveness
Toxin production
Evasion of immune system