microbio exotoxins and endotoxins

Question 1

Corynebacterium diphtheria exotoxin:

Answer 1

diphtheria toxin

Question 2

diphtheria toxin mechanism

Answer 2

inactivates EF-2

Question 3

diphtheria toxin manifestations

Answer 3

pharyngitis

pseudomembranes in throat and severe lymphadenopathy

Question 4

pseudomonas aeruginosa exotoxin:

Answer 4

exotoxin A

Question 5

pseudomonas exotoxin A mechanism

Answer 5

inactivates EF-2

Question 6

pseudomonas exotoxin A manifestations

Answer 6

host cell death

Question 7

shigella and enterohemorrhagic EC extoxins

Answer 7

shiga toxin and shiga like toxin respectively

Question 8

ST and SLT mechanism

Answer 8

inactivate 60S ribosome by removing adenine from rRNA

Question 9

ST and SLT manifestations

Answer 9

• both enhance cytokine release and cause HUS

- ST does direct cellular damage to GI mucosa while SLT does not

Question 10

what are the two exotoxins of enterotoxigenic EC?

Answer 10

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

Question 11

mechanisms of LT and ST

Answer 11

LT - adenylate cyclase (cAMP) up, Cl secretion up
ST - guanylate cyclase (cGMP) up, NaCl resorption down
both cause watery diarrhea

Question 12

exotoxin of bacillus anthracis

Answer 12

edema factor

Question 13

edema factor mechanism

Answer 13

mimics cAMP

Question 14

vibrio cholera exotoxin

Answer 14

cholera toxin

Question 15

cholera toxin mechanism

Answer 15

over activation of cAMP by permanently activating G subunit. Cl secretion, rice water diarrhea

Question 16

bordetella pertussis toxin:

Answer 16

pertussis toxin

Question 17

pertussis toxin mechanism

Answer 17

over activates cAMP by disabling Gi, impairing phagocytosis

Question 18

pertussis toxin manifestations

Answer 18

pediatric whooping cough

Question 19

clostridium tetani exotoxin

Answer 19

tetanospasmin

Question 20

tetanospasmin mechanism

Answer 20

protease that cleaves SNARE proteins required for neurotransmitter release (no GABA or glycine)

Question 21

tetanospasmin manifestations

Answer 21

lockjaw
spasticity
risus sardonicus

Question 22

clostridium botulinum exotoxin

Answer 22

botulinum toxin

Question 23

botulinum toxin mechanism

Answer 23

protease, cleaves SNARE proteins, no ACh

Question 24

botulinum toxin manifestations

Answer 24

flaccid paralysis, floppy baby

Question 25

clostridium perfringens exotoxin

Answer 25

alpha toxin

Question 26

alpha toxin mechanism

Answer 26

phospholipase that degrades tissue and cell membranes

Question 27

alpha toxin manifestations

Answer 27

myonecrosis (gas gangrene)

hemolysis

Question 28

strep pyogenes exotoxin

Answer 28

streptolysin O

exotoxin A

Question 29

streptolysin O mechanism

Answer 29

degrades cell membrane

Question 30

streptolysin O manifestations

Answer 30

B-hemolysis

rheumatic fever

Question 31

staph aureus exotoxin

Answer 31

toxic shock syndrom toxin (TSST-1)

Question 32

TSST-1 mechanism

Answer 32

overwhelming release of IFN-gamma and IL-2

Question 33

TSST-1 manifestations

Answer 33

toxic shock syndrome
scalded skin syndrome
food poisoning

Question 34

S. pyogenes exotoxin A mechanism

Answer 34

overwhelming release of IFN-gamma and IL-2

Question 35

S. pyogenes exotoxin A manifestations

Answer 35

toxic shock syndrome

Question 36

what is an endotoxin?

Answer 36

lipopolysaccharide found in outer membrane of gram-negative bacteria

Question 37

important manifestations of endotoxins

Answer 37

ENDOTOXIN

Edema
Nitric oxide
DIC/Death
Outer membrane
TNF-a
O-antigen
Xtremely heat sensitive
IL-1
Neutrophil chemotaxis