Toxins
Slackers Facts by Mike Ori
Disclaimer
The information represents my understanding only so errors and omissions are
probably rampant. It has not been vetted or reviewed by faculty. The source is our
class notes.
The document can mostly be used forward and backward. I tried to mark
questionable stuff with (?).
If you want it to look pretty, steal some crayons and go to town.
Finally…
If you’re a gunner, buck up and do your own work.
List the staph aureus toxins
Alpha toxin
Exfolatin
Pyrogenic Toxin Superantigens (PTSAgs)
Enterotoxin
Toxic Shock Syndrome Toxin (TSST)
Alpha toxin effects
Pore forming exotoxin
Exfolatin symptoms
Exfoliation at epidermal stratum spinosum and
stratum granulosum
PTSags action
Activates T cells via MHC-II interaction with APC
regardless of TCR fit
Staph food poisoning toxin
Staph Enterotoxins
(PTSags)
Enterotoxin effect
Vomiting by direct action on nerves.
TSST effects
Superantigen based shock
M protein producer
Group A strep (pyogenes)
M protein effect
Surface antigen
Fixes serum factor H which inactivates
complement
Group A Strep (GAS) toxins
Streptolysin O
Streptococcal Pryogenic Exotoxin (Spe)
Streptolysin O function
Pore forming exotoxin
Streptolysin O serum sign
Anti Strep O antibodies (ASO)
Toxin similar to Strep Pyrogenic Exotoxin (Spe)
PTSAgs
Spe effects
Systemic effects like fever, rash
Strep agalactiae surface antigen
Polysaccharide capsule
Strep pneumoniae pore forming exotoxin
Pneumolysin
Pneumolysin function
Pore forming exotoxin
Pneumolysin target cells
Respiratory epithelium
Strep pneumoniae antigen
Polysaccharide capsule
Corynebacterium diphtheriae toxin
Diphtheria toxin (DT)
DT function
A-B toxin that ADP-ribosylates ribosome EF-2 to
halt protein synthesis.
Internalin producer
Listeria
Interalin function
Facilitates Listeria entry into cell
Listerlysin O function
Pore forming exotoxin
Bacillis anthracis capsule characteristic
D-glutamic acid capsule with antiphagocytic
properties
Anthrax exotoxin description
Three component exotoxin composed of lethal
factor, protective antigen, and edema factor.
Not well described in notes. I think we only
need to know it has one.
Clostridium perfringens toxin
Alpha toxin
Alpha toxin function
Kills muscle cells.
Not well described in notes.
Toxin produced by Clostridium difficile
Toxin A – enterotoxin
Toxin B – cytotoxin
Toxin A effects
Hemorrhagic necrosis
Toxin B effects
Disrupts microfilaments and decreases protein
synthesis
Name the other two Clostridia toxins
Tetanospasmin toxin
Botulism toxin
Tetanospasmin toxin function
Inhibits the action of inhibitory neurons in the
anterior horn of the spinal cord to produce
rigid paralysis
Botulism toxin effects
Blocks the release of Ach at the neuromuscular
junction to produce flaccid paralysis.
Removes wrinkles in foreheads.
Bacteriodes fragilis capsule characteristics
Polysaccharide capsule that confers resistance to
phagocytosis
Gram negative endemic toxin
Lipopolysaccharide (LPS)
AKA endotoxin
Common to all Gram-negatives
Neisseria menigitidis toxin
LPS blebs
Neisseria gonorrhea toxin
LPS
Cholera toxin characteristics
An A-B toxin that inhibits GTPase activity of Gas
to cause overproduction of cAMP thus causing
Cl-, K, HCO3, Na to exit the cell drawing water
with them resulting in watery diarrhea.
Cholera toxin systemic effects
None to speak of as cholera are not invasive.
Helicobacter pylori toxin
Vacuolating cytotoxin
Vacuolating cytotoxin function
Causes apoptosis that results in large
cytoplasmic vaculoles
Cag secretor
H pylori
Cag entry mechanism
Direct injection
Cag function
Alters cellular proteins and has a strong
association with virulence
Antecedant cause of gastritis and gastric
adenocarcinoma
Cag+ strains of H pylori
Alpha hemolysin secretor
E. Coli
Alpha hemolysin function
Pore forming exotoxin
Shiga toxin secretor
EHEC
Shigella dysenteriae type 1
Shiga toxin effects
A-B toxin that binds to the 60s ribosome on the
28s subunit to block the tRNA binding site
thus disabling protein synthesis.
Labile toxin and stabile toxin secretor
ETEC
EPEC (?)
(Others ??)
LT function
Increase cAMP
LT stability
Breaks down at low temp
Stabile toxin function
Increase cGMP
ST stability
Breaks down at higher temp and thus is more
stabile than LT.
Salmonella typhi toxin
LPS
Hib capsule characteristics
Ribose, ribitol, and phosphate (polyribitol
phosphate) capsule that is associated with
virulence
Bordetella pertussis toxin characteristics
An A-B toxin that ADP-ribosylates a Gai thus
leading to prolonged activation of adenylyl
cyclase and a concomitant in cAMP. This
interferes with immune cell function,
Soluble adenylate cyclase producer
B pertussis
AC characteristics
Increases cAMP production when activated by
Ca/calmodulin.
Tracheal toxin producer
B pertussis
Tracheal toxin characteristics
A cytotoxic compound that is a fragment of the
cell wall of B pertussis. It has direct cytotoxic
effects on ciliated respiratory epithelium.
Name the Psuedomonas aeruginosa toxins
Exotoxin A
Elastase
Exoenzyme S
Exotoxin A function
Enters cells to interfere with ribosomal EF-2 to
shut down protein synthesis. It is analogous
to but not homologous to DT.
Elastase function
Degrades elastase
Exoenzyme S function
ADP-ribosylates intracellular proteins including
cytoskeleton filament vimentin
P aeruginosa capsule description
A thick alginate that forms a protective biofilm
that is particularly troublesome in CF patients.