Exotoxins Flashcards
Bordatella pertussis
Category: inhibit phagocytosis
Toxin: pertussis toxin
Mechanism: overactivates adenylate cyclase
Manifestation: whooping cough, 100 day cough
Enterohemorrhagic E Coli
Category: Inhibit protein synthesis
Toxin: Shiga-like Toxin
Mechanism: Inactivate 60S ribosom by removing adenine from rRNA
Manifestations: HUS without host cell invasion
Bacillus anthracis
Category: Increase fluid secretion
Toxin: Edema toxin
Mechanism: mimics adenylate cyclase (increase cAMP)
Manifestation: edematous border of black eschar in antrax
C. tetani
Category: inhibit neurotransmitter release
Toxin: tetanospasmin
Mechanism: cleave SNARE protein required for neurotransmitter release
Manifestation: Spasticity, lockjaw, smile, prevents inhibitory NT release from Renshaw cells
Administering diphtheria antitoxin is what kind of immunization
Passive
Strep pyogenes
First
Category: lyse cell membranes
Toxin: Streptolysin O
Mechanism: Protein degrades cell membrane
Manifestation: Lyse RBC, contributes to beta-hemolysis
Second
Category: superantigens causing shock
Toxin: Exotoxin A
Mechanism: Same as Staph aureus
Manifestation: Toxic shock syndrome
C diptheriae
Category: Inhibit protein synthesis
Toxin: Diptheria toxin
Mechanism: Inactivate EF-2
Manifestations: Pharyngitis with pseudomembranes and Bull Neck
Vibrio cholerae
Category: Increase fluid secretion
Toxin: Cholera toxin
Mechanism: activates adenylate cyclase leading to Cl- secretion in gut
Manifestation: rice-water diarrhea
Enterotoxigenic E Coli
Category: Increase fluid secretion
Toxin: heat labile and heat stable
Mechanism: labile –> cAMP, stable –> cGMP (labile in the air, stable on the ground)
Manifestation: watery diarrhea
C perfringens
Category: lyse cell membranes
Toxin: alpha toxin
Mechanism: phospholipase (lecithinase)
Manifestation: gas gangrene and hemolysis (double zone)
C. botulinum
Category: inhibit neurotransmitter release
Toxin: botulinum toxin
Mechanism: cleave SNARE protein required for neurotransmitter release
Manifestation: flaccid paralysis, floppy baby, prevents release of stimulatory NT
Pseudomonas
Category: Inhibit protein synthesis
Toxin: Exotoxin A
Mechanism: Inactivate EF-2
Manifestations: Host cell death
Endotoxin acronym
Edema
Nitric Oxide
DIC/Death
Outer membrane
TNF-alpha
O-antigen
eXtremely heat stable
IL1
Neutrophil chemotaxis
Staph aureus
Category: superantigen causing shock
Toxin: Toxin shock syndrome toxin
Mechanism: binds to MHC II and TCR causing release of IL1, IL2, IFN-gamma
Manifestation: toxic shock syndrome (fever, rash, shock)
Lysogenic phage toxins
ShigA-like toxin
Botulinum toxin
Cholera toxin
Diphtheria toxin
Erythrogenic toxin
