Bugs With Exotoxines

Q1: Patient develops an infection in the legs after a car accident. Physical exam shows crepitus of the tissue of the legs. Which Clostridium toxin produce these findings?

A1: Alpha toxin.

A-B TOXINS (ADP RIBOSILATYNG)

• A = Active ADP ribosyl / B = Binding receptor
•  Bugs:
1. Corynebacterium diphteriae (inactive EF-2) = Pseudomona exotoxin A
2. Bordetella pertusis (disables Gi -> increases AMPc).
3. Escherichia coli (heat labil & heat stable toxins) = Stimulator
4. Vibrio cholerae (actives Gs -> stimulates Adenylate cyclase)

SUPERANTIGENS

Binds to MHC-II & T-cell receptors, stimulates IFN-Y, and IL-2

• Staphylococcus aureus, TSST-1
• Streptococcus pyogenes

OTHERS

• Clostridium:
1. DIfficile (DIarrhea), citotoxin kills enterocytes
2. PERfringens (PERforate), Alpha toxin (lecithinase) ->gangrene
3. tetani, block release GABA and Glycine
4. BOTulinum, (BOTtle), block release Ach - floppy baby
• Bacillus anthracis, edema factor (adenylate cyclase) - inhibit phagocytosis
• Shigella, shiga toxin (inactive 60s ribosome) causes HUS

Q2: Patient to begins to experience bloody diarrhea a few days after eating at a fast food restaurant. Patient is treated with plasmapheresis and eventually recovers from acute renal failure. Which mechanisms is used by the toxin?

A2: Inactivation ribosome unit 60S.