Host damage

Question 1

damage:

1. promotes
2. does what to host defenses
3. facilitates

Answer 1

1. promotes colonization in novel places
2. antagonizes host defenses
3. facilitates spread

Question 2

a protein that kills or alters the function of a host cell

Answer 2

TOXIN:

Question 3

a toxin that is secreted into the extracellular milieu or translocated into host cells

Answer 3

EXOTOXIN:

Question 4

lipopolysaccharide component of

Gram-negative outer membrane; NOT a true toxin

Answer 4

ENDOTOXIN:

Question 5

Exotoxins: two classes

Answer 5

A. Membrane-active toxins

B.  Effectors that alter host protein  			      activities

Question 6

membrane active exotoxins 2 types

Answer 6

1. pore formers

2. phosholipases- signaling

Question 7

Role of membrane active proteins in disease

Answer 7

1. hemolysisns- sequestration of iron
2. neutrophil attack “pneumolysin”- anti-phagocytic
3. destruction of phagosome membranes “listeriolysin”

Question 8

proteins that target host activites how do they get across host membranes?

Answer 8

1. AB toxins such as cholera toxin that has transferase activity
2. specialized secretion systems which is only found in gram negatives

Question 9

many exotoxins target

Answer 9

host GTPase cycle which is involved in translation, cell surface signaling, cytoskeleton activites sand secretion

Question 10

roles of toxins

1. promote bacterial growth by
2. facilitate dissemination by
3. interfere with host defenses by

Answer 10

1. promote bacterial growth by providing access to nutrients in damaged cells
2. facilitate dissemination by breaking down epithelial barriers
3. interfere with host defenses by inactivating phagocytic cells

Question 11

membrane active exotoxins that are pore formers are dependent on what?

Answer 11

concentration

Question 12

mechanisms of bacterial transferases

Answer 12

lock host proteins in one conformation

Question 13

AB toxins subunit

Answer 13

A- activity
B- binding

• both gram negative and positive

Question 14

example of a bacterial transferase that blocks host GTPase

Answer 14

cholera toxin

Question 15

tetanus neurotoxin intoxication leads to what type of paralysis

Answer 15

spastic

Question 16

botulinum neurotoxin action leads to what type of parakysis

Answer 16

flaccid

Question 17

1. spores enter through wound, germinate, make toxin
2. Due to action of toxin in CNS
3. Blocks release of INHIBITORY
   Neurotransmitters, e.g. GABA
4. A subunit is protease
5. Disease totally attributable to
   neurotoxin

Answer 17

clost. tetani

** spastic paralysis

Question 18

1. Ingestion of toxin “foodborne”
2. Due to action of toxin in PNS
3. Blocks release of STIMULATORY neurotransmitters, e.g. Acetylcholine
4. A subunit is protease
5. Disease totally attributable to
   neurotoxin

Answer 18

clost. botulinum

*** flaccid paralysis

Question 19

site of action of tetanus

Answer 19

retrograde axonal transit of TeNT

Question 20

site of action of botulinum

Answer 20

synaptic vesicles at neuromuscular junction

Question 21

what subunit is responsible for the neurotoxicity of tetatun and botulinum

Answer 21

metaloprotease in the A subunit

Question 22

what subunit explains the nature of paralysis of tetanus and botulinum neurotoxins

Answer 22

B subunit, binding to receptor