Micro toxins

Question 1

Inactivates elongation factor 2 (EF2)

Answer 1

Diptheria toxin and exotoxin A (from pseudomonas)

Question 2

MOA of Shigella toxin and shiga-like toxin (EHEC)

Answer 2

Inactivate 60s ribosome by removing adenine from rRNA

Question 3

2 toxins from ETEC

Answer 3

Heat labile (LT) and heat-stable (ST) toxins

Question 4

MOA of heat-labile toxin (LT) from ETEC

Answer 4

overactivates adenylate cyclase to increase cAMP; leads to increase Cl- secretion in the gut and H2O efflux

Question 5

MOA of heat-stable (ST) from ETEC

Answer 5

Overactivate guanylate cyclase to increase cGMP levels; leads to decreased resorption of NaCl from the gut (and thus decreased H2) resorption

Question 6

Diptheria toxin and Toxin A from pseudomonas are what kind of toxin

Answer 6

A-B toxin; B is for Binding to the host cell, A is the Active component

Question 7

Bacillus anthracis toxin

Answer 7

Edema factor

Question 8

MOA of edema factor in anthrax

Answer 8

Mimics adenylate cyclase enzyme to increase cAMP

Question 9

Cholera toxin MOA

Answer 9

Overactivate adenylate cyclase to increase cAMP by permanently activating Gs

Leads to Cl- secretion in the gut and H2O efflux

Question 10

Pertussis toxin MOA

Answer 10

Overactivate adenylate cyclase to incease cAMP by disabling Gi

Question 11

Toxins that cleave the SNARE protein required for neurotransmitter release

Answer 11

Tetanospasmin and botulinum toxin

Question 12

If tetanus and botulinum toxins both have same MOA, why do the produced different effects

Answer 12

Tetanospasmin acts on inhibitory NTs (GABA and glycine) while botox prevents excitatory ACh release

Question 13

Clostridium perfringens toxin

Answer 13

Alpha toxin (aka lecithinase)

Question 14

MOA of alpha toxin from C. perfringens

Answer 14

Phospholipase that degrades tissues and cell membranes

Question 15

Streptolysin O MOA

Answer 15

Degrades cell membrane (responsible for the B-hemolysis of Strep pyogenes)

Question 16

Superantigen from S. aureus

Answer 16

Toxic shock syndrome Toxin (TSST-1)

Question 17

MOA of TSST-1

Answer 17

Bind MHC II and TCR outside of the binding site to cause non-specific release of IFN-gamma and IL-2. This leads to shock

Question 18

Superantigen in s. pyogenes

Answer 18

Bind MHC II and TCR outside of the binding site to cause non-specific release of IFN-gamma and IL-2. This leads to shock.

Question 19

C. dif toxin

Answer 19

Toxin A and B

Question 20

MOA of toxin A in C. dif

Answer 20

Binds to the brush border of the gut

Question 21

MOA of toxin B in C. dif

Answer 21

Destroys cytoskeletal structure of enterocytes; is what cause the pseudomembranous colits

Question 22

TB virulence factor

Answer 22

Cord factor

Question 23

MOA of cord factor

Answer 23

Inhibits macrophage release and induce release of TNF-alpha

Question 24

S. aureus virulence factor

Answer 24

Protein A

Question 25

MOA of protein A on S. aureus

Answer 25

Binds to IgG at the Fc region to prevent compliment fixation and phagocytosis