Bacterial toxins

Question 1

inactivates EF-2 (via ribosylation); inhibits host cell protein synthesis

Answer 1

diphtheria toxin (corynebacterium diphtheriae)
exotoxin A (Pseudomonas aeruginosa)

Question 2

superantigen that acts locally in the GI tract, causing vomiting

Answer 2

enterotoxin (Staph aureus)

Question 4

superantigen that stimulates T cells, leading to widespread cytokine release and shock

Answer 4

Toxic shock toxin (Staph aureus)

Question 5

induces actin depolymerization (mucosal death and pseudomembrane formation)

Answer 5

cytotoxin B (C. diff)

Question 6

blocks presynaptic release of Ach (flaccid paralysis)

Answer 6

botulinum toxin (Clostridium botulinum)

Question 7

disinhibits adenylate cyclase (vi Gi ADP ribosylation); increasing cAMP—–> causes increased histamine sensitivity and phagocyte dysfunction

Answer 7

pertussis toxin (Bordetella pertussis)

Question 8

activates adenylate cyclase (via Gs ADP ribosylation); increasing cAMP——-> secretory diarrhea, dehydration and electrolyte imbalance

Answer 8

cholera toxin (vibrio cholerae)

Question 9

can cross react after strep infection and lead to rheumatic carditis (resists phagocytosis)

Answer 9

Group A strep

Question 10

edema factor: increases cAMP, causing edema and phagocyte dysfunction

Answer 10

anthrax toxin (bacillus anthracis)

Question 11

lethal factor: zinc dependent protease that inhibits mitogen-activated protein kinase signaling, causing apoptosis

Answer 11

anthrax toxin (bacillus anthracis)

Question 12

halts protein synthesis by disabling the 60S ribosomal subunit, leading to intestinal epithelial cell death and diarrhea

Answer 12

shiga toxin (shigella dysenteriae)

Question 13

acts as superantigen, inducing fever and shock; associated with scarlet fever and strep toxic shock syndrome

Answer 13

pyrogenic exotoxin (group A strep)

Question 14

damages erythrocytes membranes, causing beta hemolysis

Answer 14

streptolysin O and S (group A strep)