Bacterial Toxins

Question 1

Diphtheria toxin - function?

Tissues hit?

Answer 1

Inhibits eukaryotic protein synthesis…
- ADP ribosylation of eEF-2

Heart, Nerves, Epithelium

Question 2

Pseudomonas toxin…name?

Function?

Tissue hit?

Answer 2

Exotoxin A

SAME AS DIPHTHERIA TOXIN

Liver

Question 3

Shigella (shiga) toxin…function?

Tissues hit?

Answer 3

Inhibits protein synthesis…
- Interferes w/ 60S ribosomal subunit

Enterics, nerves

Question 4

EHEC toxin…name?

Function?

Answer 4

Verotoxin

SAME AS SHIGA TOXIN

Question 5

Tetanus toxin…function?

Answer 5

Inhibits neurotransmission in inhibitory synapses…

- Blocks release of glycine and GABA (via SNARE cleavage in Renshaw cells of spinal cord)

Question 6

Botulinum toxin…function?

Answer 6

Inhibits cholinergic synapses…

- Blocks release of ACh (via SNARE cleavage)

Question 7

Toxic shock syndrome via coagulase positive organism…toxin?

Function?

Answer 7

TSST-1 superantigen

Binds to MHC II and T-cell receptor, causing widespread T-cell activation and cytokine release, causing fever, rash, shock, capillary leakage

Question 8

Toxin that increases susceptibility to LPS

Answer 8

TSST-1 (staph aureus)

Question 9

Toxic shock syndrome via coagulase negative organism…toxin?

Function?

Added

Answer 9

Exotoxin A (erythrogenic or pyogenic toxin) - strep. pyogenes

SAME AS TSST-1 superantigen

Question 10

Blanching sandpaper-like body rash, strawberry tongue, pale, sore throat…disease?

Cause?

Answer 10

Scarlet fever

Strep. pyogenes erythrogenic toxin (exotoxin A)

Question 11

ETEC toxin…name?

Function?

Answer 11

Heat labile toxin (LT)

Secretion of fluid and electrolytes from intestinal epithelium via…
- ADP ribosylation of GTP binding protein –> increased adenylate cyclase –> increased cAMP

Question 12

Cholera toxin…function?

Answer 12

SAME AS ETEC LT TOXIN

Question 13

Anthrax toxin…3 parts?

Functions?

Answer 13

Edema factor (EF) – increased cAMP via adenylate cyclase, causing edema and cell death

Lethal factor (LF) – causes macrophage apoptosis induction by inhibiting the MAPKK enzymes

Protective antigen (PA) - required for both EF and LF to work

Question 14

Pertussis toxin…function?

Answer 14

Histamine-sensitized LYMPHOCYTOSIS…

- ADP ribosylates the Gi, causing increased adenylate cyclase and cAMP

Question 15

Clostridium perfringens…toxin?

Function?

Answer 15

Alpha toxin

Lecithinase –> damages cell membranes, causing myonecrosis

Question 16

Staph aureus alpha toxin…function?

Answer 16

Intercalates into membranes, forming pores, causing leaky membranes