BACTERIAL PATHOGENESIS 2

Question 1

what do virulence factors improve

Answer 1

confer an increased ability to cause disease

Question 2

what are koch’s postulates to define virulence factors

Answer 2

Question 3

how are bacterial virulence factors acquired?

Answer 3

through horizontal gene transfer

Question 4

what are some examples of virulence factors

Answer 4

Question 5

what are adhesins

Answer 5

present on bacteria, interact with the receptors on the target cells

Question 6

how are receptor decoys used as anti virulence drugs

Answer 6

used to treat chronic UTIs

Question 7

how do nutrient acquisition systems work

Answer 7

iron is really limited and is really important
hosts developed ways to sequester iron and keep it away from pathogens

Question 8

how is the capsule a virulence factor

Answer 8

no capsule: your immune system can clear the infection naturally

Question 9

what are virulence associated secretion systems

Answer 9

several types exist
we focus on type III secretion system (T3SS)
complex molecular machines
span bacterial and host membranes
allow for delivery of effector proteins (bacterial weapons) which are transported through hollow channel inside the syringe
powered by ATP

Question 10

what are characteristics of T3SS

Answer 10

Question 11

what do T3SS ressemble?

Answer 11

ressemble the flagellar basal body

Question 12

how do different bacteria use T3SS differently?

Answer 12

Question 13

what are the two categories of toxins?

Answer 13

Question 14

what is LPS of gram negative bacteria?

Answer 14

endotoxin

Question 15

how does LPS cause its effects?

Answer 15

sepsis=body’s reaction to LPS

Question 16

what is an example of an exotoxin

Answer 16

causes botulism

Question 17

what are the effects of botulinum toxin?

Answer 17

used in botox in very small quantities
you can get botulism from improperly processed canned food

Question 18

what are characteristics of exotoxins

Answer 18

Question 19

what are categories of exotoxins?

Answer 19

Question 20

characteristics of AB toxins

Answer 20

A= toxic activity
B= binding to target on host cell

Question 21

how do membrane disrupting exotoxins work

Answer 21

Question 22

key differences between exo and endotoxins

Answer 22

Question 23

what are intoxications

Answer 23

Question 24

what is an example of intoxication

Answer 24

Question 25

characteristics of enterohemorrhagic e.coli (EHEC)

Answer 25

enterohemorrhagic e.coli

Question 26

what is EHEC illness

Answer 26

Question 27

how does EHEC’s T3SS work

Answer 27

EHEC remains extracellular
T3SS is the main interference with the host cell
injects Tir, which becomes a receptor for EHEC inside the host cell
also injects ~30 other proteins which dissociate tight junctions between intestinal epithelial cells, block host phagocytic pathways and interfere with host immune response
EHEC is very tightly associated with the host cell now

Question 28

what is Shiga toxin

Answer 28

Question 29

what does shiga toxin cause when it is present in different parts of the body?

Answer 29

why cattle carry EHEC asymptomatically

Question 30

how is EHEC treated?

Answer 30

Question 31

how can EHEC be prevented?

Answer 31