Exotoxins

Question 1

increases cAMP via disabling Gi - impairs phagocytosis - microbe can survive
whooping cough results

Answer 1

Bordatella pertussis toxin

Question 2

increases cAMP via permanent Gs activation - Cl- secretion in gut + H20 efflux - rice water diarrhea

Answer 2

Vibrio cholera toxin

Question 3

mimics cAMP - edema + black eschar (cutaneous anthrax)

Answer 3

Bacillus anthracis edema toxin

Question 4

increases cGMP = less resorption of NaCl & H20 in gut - watery diarrhea

Answer 4

ETEC heat stable toxin

Question 5

increases cAMP = increased Cl- secretion in gut with H20 efflux - watery diarrhea

Answer 5

ETEC heat labile toxin

Question 6

inactivates 60S ribosome via removal of adenine from rRNA - enhances CK release - HUS
no invasion of host cells

Answer 6

EHEC shiga-like toxin

esp. 0157:h7 strains

Question 7

inactivates 60S ribosome via removal of adenine from rRNA - GI mucosal damage - dysentery
also enhances CK release - HUS

Answer 7

Shigella shiga toxin

Question 8

inactivates EF-2 - host cell death

Answer 8

Pseudomonas aeruginosa: Exotoxin A

Question 9

inactivates EF-2 - pharyngitis, pseudomembrane in throat, severe LAD (bull neck)

Answer 9

Corynebacterium diphtheria toxin

Question 10

binds MHC II & TCR outside Ag binding site - IL-1, IL-2, IFN gamma, TNFa release - toxic shock

Answer 10

Strep pyogenes exotoxin A

Question 11

degrades cell membrane - lyses RBCs (beta hemolysis)

host ASO Ab used to diagnose Rheumatic fever

Answer 11

Strep pyogenes streptolysin O

Question 12

food poisoning

Answer 12

S. aureus enterotoxin

Question 13

scalded skin syndrome

Answer 13

S. aureus exfoliative toxin A/B

Question 14

binds MHC II & TCR outside Ag binding site - huge release of IL-1, IL-2, IFNgamma, TNFa - toxic shock

Answer 14

S. aureus toxic shock syndrome toxin 1 (superAg)

Question 15

phospholipase degrades cell membrane - myonecrosis gas gangrene + hemolysis (double zone on blood agar)

Answer 15

Clostridium perfringens alpha toxin

Question 16

cleaves SNARE - prevents release of ACh at Nm - flaccid paralysis, floppy baby

Answer 16

Clostridium botulinum toxin

Question 17

cleaves SNARE - prevents release of inhibitory GABA from Renshaw cells @ spinal cord - spasticity, risus sardonicus, lockjaw

Answer 17

Clostridium tetani tetanospasmin