Virulence factors

Question 1

Toxigenicity

Answer 1

P produce a wide range of biological poisons used to damage tissues, facillitate invasion and damage host’s defence mechanisms

Question 2

Exotoxins

Answer 2

Produced by living P

Question 3

Endotoxins

Answer 3

Lipopolysaccharides, componets of the cell wall of gram negative that are released from dead B or those undergoing division

Question 4

Exo vs endo

Answer 4

insert

Question 5

Exotoxin catrgories

Answer 5

• A-B toxins: specific cellular targets
• Cytolytic toxins- membrane disrupting
  -Superantigens: cause immune overactivation

Question 6

A-B exotoxins

Answer 6

-B component, like a viral receptor, is responsible for cellular specificty of toxin and mediates initial attachment to cell surface receptors
-Once A-B toxins binds to host cell, it is brought into cell by endocytosis and entrapped in a vacuole
-A and B subunits separate as vacuole acidifies after fusion with lysosome. The A subunit enters the cell cytoplasm and interferes with specific internal cell function that it targets

Question 7

diptheria toxin

Answer 7

-An ACleavagB toxin produced by cells of Corynebacterium diphtheria which binds to the host cytoplasmic membrane by way of its B subunit
-Cleavage of toxin allows A subunit to calayse ADP-ribosylation of elongation factor (EF2) which prevents it from binding to ribisome
-Prevents prtotein synthesis and results in cell death
-B has to be infected by phage to be harmful