Bacterial toxins Flashcards
C dipth and pseudomas
Dipth = diphteria toxin, pseudo=exotoxin A
Both inactivate EF2
Shigella app and EHEC, including O157:H7
Shigella=ST. EHEC=SLT
Inactivate 60S ribosome by removing adenine from rRNA
Shigella= mucosal damage, cytokine, HUS
EHEC=cytokine,, HUS, but EHEC does NOT invade host cells.
ETEC
Heat labile increases cAMP: increase Cl excretion from the gut
Heat stable increases cGMP: decrease NaCl absorption
Watery diarrhea
Labile in the Air, stable on the ground
Bacillus anthracis
Edema factor
Mimics adenylate cyclase, so increase cAMP
This is responsible for characteristic edematous borders of black eschar in cutaneous anthrax
Vibrio cholerae
Cholera toxin
overactivestcAP by permanently activating Gs => increase Cl secretion in gut and H2O efflux
Volum rice water diarrhea
Bordetella pertussis
Pertussis toxin
Overactivate adenylyl cyclase by disabling Gi, imparing phagocytosis to permit the survival of microbe
Whooping cough: whoops on inspiration
C tetani and C botulism
Both proteases that cleave SNARE
Tetani: blocks inhibitory NTM (GABA and glycine) from Renshaw cells in spinal cord
Botulinum: blocks stimulatory NTM from NM junctions
C perfringe
alpha toxin
Phospholipase that degrades tissue and cell membrane
Gas gangrene, hemolysis (double zone of hemolysis on blood agar)
S. pyrogens
Streptolysin O
Protein that degrades cell membrane
Lyses RBCs, contributes to beta hemolysis,
Host antibodies against toxin (ASO) used to diagnosed rheumatic fever
S aureus and S pyrogen
Staphy: TSST1, strep pyrogen Exotoxin A
Bring MHCII and TCR in closer proximity
Endotoxins
Activates MP
- IL1= fever
- TNF=fever and hypotension
- NO=hypotension
Activates complements
- C3a=hypotension, edema
- C5a=neutrophil chemotaxis
Activates tissue factor
-DIC
ENDOTOXIN: edema, NO, DIC/death, TNF, outer membrane, O-antigen, eXtremely heat stable, IL1, neutrophil chemotaxis.
