Exotoxins Flashcards
Which exotoxins inactivate elongation factor 2?
diptheria toxin
exotoxin A of pseudomonas
Where does shiga toxin act on?
inactivate 60S ribosome
How is shiga like toxin different from actual shiga toxin
EHEC doesnt invade host cells
ETEC secretes two toxins what are they and their MOAs
heat labile - inc cAMP - inc Cl secretion
heat stable - inc cGMP - dec absorption of NaCl
“labile in the Air - adenylate cyclase, stable on the ground”
What is the toxin of anthrax
edema toxin - inc cAMP
how does cholera toxin inc cAMP vs pertussis toxin
cholera: permanently activates Gs
pertussis: diables Gi
What is the toxin of C perfringens
alpha toxin - lecthinase that degrades tissue and cell membranes
What are the toxins of strep pyogenes?
strep O - degrades cell membrane - antibodies used to diagnose RF
exotoxin A - superantigen causes TSS
What is the toxin of staph aureus
TSST1 - superantigen
exfoliative toxin - scalded skin syndrome
enterotoxin - immediate food poisoning
Superantigens cause overwhelming release of which cytokines? how do they do this?
binds to MHC II and TCR
IL1, 2, IFN gamma, TNF alpha
What is the active factor of LPS? what does it cause??
Lipid A
IL1 - fever
TNF alpha - fever and hypotension
NO - hypotension
activates complement
c3a - hypotension, edema
c5a - neutrophil chemotaxis
tissue factor –> coag cascade –> DIC
How do the the ADP ribosylating AB toxins work?
B - binding component
A - attaches ADP ribosyl to disrupt cell proteins
Name some ADP ribosylating AB toxins
Diptheria toxin exotoxin A shiga toxin heat labile toxin edema toxin cholera toxin pertussis toxin tetanospasmin toxin botulinum toxin