Exotoxins & Endotoxins Flashcards
Corynebacterium diphtheriae
(X) DIPHTHERIA TOXIN: inactivates EF-2
pharyngitis with pseudomembranes in throat and severe LAD (bull neck)
Pseudomonas aeruginosa
(X) EXOTOXIN A: inactivates EF-2
host cell death
Shigella
(X) SHIGA TOXIN: inactivates 60S ribosome by removing adenine from rRNA
GI mucosal damage = dysentery
enhances cytokine release = HUS
EHEC
(X) SHIGA-LIKE TOXIN: inactivates 60S ribosome by removing adenine from rRNA
enhances cytokine release = HUS
DOES NOT invade host cells
name 4 that inhibit protein synthesis with exotoxin
Corynebacterium diphtheriae
Pseudomonas aeruginosa
Shigella
EHEC
name 3 that increase fluid secretion with exotoxin
ETEC
Bacillus anthracis
Vibrio cholerae
ETEC
(X)
1. HEAT-LABILE TOXIN (aka cholera-like toxin): overactivates AC, increasing cAMP = increase Cl secretion in gut and H2O efflux
- HEAT-STABILE TOXIN: overactivates GC, increasing cGMP = decrease resorption of NaCl and H2O in gut
watery diarrhea
Bacillus anthracis
(X) EDEMA FACTOR: mimics adenylate cyclase = increase cAMP
edematous borders of black eschar in cutaneous anthrax
Vibrio cholera
(X) CHOLERA TOXIN: overactivates AC by permanently activating Gs = increase Cl secretion in gut and H2O efflux
voluminous rice-water diarrhea
name 1 that inhibits phagocytic ability with exotoxin
Bordetella pertussis
Bordetella pertussis
(X) PERTUSSIS TOXIN: overactivates AC by disabling Gi = impairs phagocytosis of microbe
whooping cough
name 2 that inhibit release of neurotransmitter with exotoxin
Clostridium tetani
Clostridium botulinum
Clostridium tetani
(X) TETANOSPASMIN: cleave SNARE protein, which is required for NT release
muscle rigidity and lock jaw
toxin prevents release of inhibitory NTs in spinal cord (GABA, glycine)
Clostridium botulinum
(X) BOTULINUM TOXIN: cleave SNARE protein, which is required for NT release
flaccid paralysis, floppy baby
toxin prevents release of stimulatory NTs at NMJ (ACh)
name 2 that lyse cell membranes with exotoxin
Clostridium perfringens
Streptococcus pyogenes
Clostridium perfringens
(X) ALPHA TOXIN: phospholipase that degrades tissue and cell membranes
degradation of phospholipid C = myonecrosis (gas gangrene) and hemolysis (double zone of hemolysis on blood agar)
Streptococcus pyogenes
(X) STREPTOLYSIN O: protein that degrades cell membrane
lyses RBCs
contributes to B-hemolysis
ASO used to diagnose rheumatic fever
name 2 that act as superantigens causing shock with exotoxin
Staphylococcus aureus
Streptococcus pyogenes
Staphylococcus aureus
(X) bring MHC II and TCR in proximity to outside of Ag binding site, resulting in polyclonal T cell activation and overwhelming release of IFN-y and IL2 => shock
- TOXIN SHOCK SYNDROME TOXIN (TSST-1): TSS: fever, rash, vomiting, desquamation, shock, end-organ failure
- EXFOLIATIVE TOXIN: scalded skin syndrome
- ENTEROTOXIN: food poisoning
Streptococcus pyogenes
(X) EXOTOXIN A: bring MHC II and TCR in proximity to outside of Ag binding site to cause overwhelming release of IFN-y and IL2 => shock
TSS
ENDOTOXIN
LPS in outer membrane of Gr(-)
(LIPID A especially)
Edema Nitric oxide DIC/Death Outer membrane TNF-a O-antigen eXtremely heat stable IL-1 Neutrophil chemotaxis
endotoxin - name 3 that activates macrophages
- NITRIC OXIDE = hypotension
- IL-1 = fever
- TNF-a = fever, hypotension
endotoxin - name 2 that activate complement
- C3a = hypotension, edema
2. C5a = neutrophil chemotaxis
endotoxin - name 1 that activates tissue factor
coagulation cascade = DIC
