micro: exotoxins

Question 1

inactivate elongation factor EF-2

Answer 1

corynebacterium diphtheriae and pseudomonas aeruginosa

Question 2

corynebacterium diphteriae

Answer 2

diphtheria toxin - inactivates elongation factor EF-2

causes pharyngitis with pseudomembranes in throat and severe lymphadenopathy

Question 3

pseudomonas aeruginosa

Answer 3

exotoxin A = inactivates elongation factor EF-2

causes host cell death

Question 4

inactivate 60s ribosome by removing adenine from rRNA

Answer 4

shigella and EHEC (enterohemorrhagic e coli)

Question 5

shigella

Answer 5

shiga toxin - inactivates 60s ribosome by removing adenine from rRNA
GI mucosal damage causing dysentery and increased cytokine release (HUS)

Question 6

enterohemorrhagic e coli (EHEC)

Answer 6

shiga-like toxin - inactivates 60s ribosome by removing adenine from rRNA
enhances cytokine release cuasing HUS (0157:H7)
does not invade host cells

Question 7

increased cAMP causing increased Cl secretion and H2O efflux

Answer 7

heat labile enterotoxigenic Ecoli

Question 8

increased cGMP causing decreased resorption of NaCl and H2O in gut

Answer 8

heat stable toxin for enterotoxigenic e coli

Question 9

mimics the adenylate cyclase enzyme causing increased cAMP

Answer 9

edema toxin - bacillus anthracis

Question 10

increased cAMP by permanently activating G2 causing increased Cl secretion and H2O efflux

Answer 10

cholera toxin of vibrio cholerae (rice-water diarrhea)

Question 11

increased cAMP by disabling Gi; impairing phagocytosis to permit survival of microbe

Answer 11

pertussis toxin - bordetella pertussis (whopping cough)

Question 12

proteases that cleave SNARE

Answer 12

clostridium tetani and clostridium botulinum

Question 13

botulinum toxin

Answer 13

prevents release of stimulatory signals at neuromuscular junctions

Question 14

tetanospasmin

Answer 14

prevents release of inhibitory (GABA and glycine) neurotransmitters

Question 15

phospholipase (lecithinase) that degrades tissue and cell membranes

Answer 15

clostridium perfringens alpha toxin

Question 16

gas gangrene degradation of phospholipids

Answer 16

clostridium perfringens alpha toxin (phospholipase)

Question 17

protein that degrades cell membranes

Answer 17

streptolysin O of streptococcus pyogenes

Question 18

stroptococcus pyogenes

Answer 18

streptolysin O degrades cell membrane/lyses RBCs and contributes to beta-hemolysis - host antibodies (ASO) used to diagnose rheumatic fever

Question 19

binds to MHC II and TCR outside of antigen binding site to cause overwhelming release of IL-1, IL-2, IFN-gamme and TNF-alpha

Answer 19

staphylococcus aureus TSST-1 and streptococcus pyogenes exotoxin A

Question 20

staphylococcus aureus

Answer 20

toxic shock syndrome causing fever, rash, shock; also has exfoliative toxin causing scalded skin syndrome and enterotoxin causing food poisoning

Question 21

streptococcus pyogenes superantigen

Answer 21

exotoxin A - toxic shock syndrome of fever, rash, shock

Question 22

endotoxin effects

Answer 22

lipid A component causes

1. macrophage activation (TLR4) (IL-1,6 causing fever; TNF-a causing fever and hypotension; NO hypotension)
2. complement activation (C3a causing histamine release, hypotension and edema; C5a casuing neutrophil chemotaxis)
3. tissue factor activation (coagulation cascade -> DIC)