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33 Cards in this Set
- Front
- Back
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Inhibit protein synthesis |
1. Corynebacterium diphtheria
2. Pseudomonas aeruginosa 3. Shigella spp. 4. Enterohemorrhagic E. coli (EHEC) |
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Toxin in corynebacterium diphtheria |
Diphtheria toxin |
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Diphtheria toxin - Mechanism of Action? |
Inactivate elongation factor (EF-2) |
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Manifestation of the toxin with corynebacterium diphtheria infection? |
Pharyngitis with pseudomembranes in throat and severe lymphadenopathy (bull neck) |
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Toxin found in pseudomonas aeruginosa? |
Exotoxin A |
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Mechanism of Action of Exotoxin A? |
Inactivate elongation factor (EF-2) |
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Manifestation of the toxin with pseudomonas aeuriginosa infection? |
Host cell death |
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Toxin found in Shigella spp.? |
Shiga toxin (ST) |
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Mechanism of action of shiga toxin (ST)? |
Inactivate 60S ribosome by removing adenine from rRNA |
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Manifestation of the toxin in shigella spp. infection? |
GI mucosal damage - dysentery; ST also enhances cytokine release, causing hemolytic uremic syndrome |
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Which exotoxin in found in enterohemorrhagic E. coli (EHEC)? |
Shiga-like toxin (SLT)
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What is the mechanism of action of shiga-like toxin? |
Inactivate 60S ribosome by removing adenine from rRNA |
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What is the manifestation of the toxin in EHEC? |
SLT enhances cytokine release, causing HUS (prototypically in EHEC serotype O157:H7). Unlike shigella, EHEC does not invade host cell |
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What are the bugs with exotoxins that increase fluid secretion? |
1. Enterotoxigenic E. coli (ETEC) 2. Bacillus anthracis 3. Vibrio cholerae |
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What are the toxins found in enterotoxigenic e coli (EHEC)? |
Heat labile toxin (LT) and Heat-stable toxin (ST) |
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What is the mechanism of action of Heat-labile toxin (LT)? |
Overactivates adenylate cyclase (Increases cAMP) - Increases Cl- secretion in the gut and H2O efflux |
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What is the mechanism of action of Heat-Stable toxin (ST)? |
Over activates guanylate cyclase (increases cGMP) - decreases resorption of NaCl and H2O in gut |
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Manifestation of the toxin in ETEC? |
Watery diarrhea: labile in the Air (Adenylate cyclase), stable on the Ground (Guanylate cyclase) |
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What is the toxin found in bacillus anthracis? |
Edema toxin |
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What is the mechanism of action of edema toxin? |
Mimics adenylate cyclase enzyme (Increases cAMP) |
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What is the manifestation of the toxin (edema toxin) in Bacillus anthracis infection? |
Likely responsible for characteristic edematous borders of black eschar in cutaneous anthrax |
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What is the toxin found in Vibrio Cholerae infection? |
Cholera toxin |
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What is the mechanism of action of cholera toxin? |
Over activates adenylate cyclase (increases cAMP) by permanently activating Gs - Increases Cl- secretion in gut and H2O efflux |
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How does the cholera toxin manifests? |
Voluminous "rice water" diarrhea Bon Appétit |
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What is the toxin found in Bortadella Pertusis? |
Pertussis toxin |
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What is the mechanism of action of the pertussis toxin? |
Overactivates adenylate cyclase (increases cAMP) by disabling Gi, impairing phagocytosis to permit survival of microbe |
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How does the pertussis toxin manifest? |
Whopping cough - child coughs on expiration and "whoops" on inspiration (toxin may not actually be a cause of cough; can cause 100-day cough in adults) |
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Which buys have exotoxins that inhibit release of NTs? |
1. Clostridium tetani 2. Clostridium botulinum |
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Which exotoxin is found in Clostridium tetani? |
Tetanospasmin |
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Which exotoxin is found in Clostridium botulinum? |
Botulinum toxin |
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What is the mechanism of action of both tetanospasmin and botulinum toxin? |
Both are proteases that cleave SNARE (solute NSF attachment protein receptor), a set of proteins required for NT release via vesicular fusion |
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How does the tetanospasmin toxin manifest? |
Spastic paralysis, risus sardonic, and lockjaw; toxin prevents release of inhibitory (GABA and glycine) NTs from Renshaw cells in spinal cord |
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How does the Botulinum toxin manifest? |
Flaccid paralysis, floppy baby; toxin prevents release of stimulatory (ACh) signals at NMJ - flaccid paralysis |
