Lec 26 toxins Flashcards
What is the difference btw g neg and g pos cells?
G pos have a thicker layer of peptidoglycan, g neg has a thicker outer liposaccharide membrane
Endotoxin is recoignized by __ immunity
innate
Where do endotoxins come from?
they are fragments of g neg bacteria broken off
LPS disease symptoms
fever vomit tiredness
Excessive inflammatory response leads to what for LPS?
Septic shock because of host response
C tetani makes
tetanus toxin
C botulinum makes
botulism toxin
The 4 exotoxin groups are
poreforming, AB, superantigens, seconday metabolites
How are pore forming toxins formed?
They start off with a monomer binding to a host receptor, and then it oligomerizes
What disease is formed by listeriolysin O?
food brone systemic illness
S aureus alpha hemolysin targets include
monocytes, lymphocytes, erythrocytes, plateles, endothelial cells and more
What can we use in lab to detect hemolytic activity?
Blood agar plates. lighter zones mean lysis zone
Where does LLO (listeriolysin O) replicate and make pores?
Inside of the cell (cytosol)
What part of the AB exotoxin is active?
A is active and enzymatic; B does binding/attachment
What is the target for AB botulinism? how
neuronmuscularjunctions via interrupting acetyl coA signaling
The most potent AB toxin is
c botulism
Botulism causes what symptom?
flaccid paralysis (loose muscles)
BoNT can be used in which medical procedures?
botox
How does tetanus neurotoxin (TeNT) work?
Cleaves signaling protein in nerve cells
What is the symptom of TeNT?
spastic paralysis (flexed/clenched muscles)
What are the AB EXOtoxin diseases?
botulism, tetanus, diphtheria, anthrax,
Diptheria forms a membrane which causes __
host cell death and suffocation
What location in an area is anthrax common in? How else is it from?
agricultural areas, animals; inhaled, injected
How many subunits in anthrax toxin? Which binds? Which active
3; B binds; A active
What does cholera (CT) cause in our cells?
Massive water out of our cells
Antigen Presenting Cells activate which cell? what does this lead to?
T cells, leading to inflammatory response
What issues can super-antigens cause?
An overactive immune response: TSS, scalded skin , strep (scarlet fever), food poisonings
Alternative synthesis pathways are caused by
secondary metabolites
What type of protein is penicillin?
an NR protein
Polyketides are made of? They are made by?
2-4 Carbon molecules, PK synthase
Aflatoxin can cause __ via ___
liver and DNA damage; polyketide synthesis
Which vaccines use toxoids?
diptheria, tetanus, anthrax
Which vaccines use toxoids?
diphtheria, tetanus, anthrax
Anthrax vaccine is available to the general public, T/F?
FALSE- it is given to high exposure people (ie lab workers)
What is the only endotoxin we are expected to know?
Lipopolysaccharide (LPS)
Which exotoxin is cytolytic?
Pore forming exotoxin
What exotoxin is enzymatic?
AB exotoxin
Where do toxins come from?
Defense for plants, venom from animals, bacteria/fungi
A toxoid is a __based toxin used as an antigen in a vaccine.
protein
What toxin group is secreted soluble proteins?
Exotoxins
LPS is composed of?
lipids and sugars
By heat, chemicals, or recombination, you can ___ exotoxins.
detoxify
Exotoxins are only g pos, T/F?
FALSE, both g neg and g pos can be exo
Corynebacterium diptheriae can make
diphtheria toxin
The toxin can cause disease, not bacteria, T/F?
TRUE; presence of toxin increases virulence
Listeriolysin O LLO is present in?
Undercooked meat/contaminated foods
How do we internalize the AB exotoxin?
binding to cell receptors, endocytosis, release of chain = poison
How is food borne botulism treated?
anti toxin and supportive care
Spores germinate in what type of botulism?
Wound/injectons
What is infant botulism caused by usually?
honey and corn syrup
What do vibrio cholerae and e coli have in common?
They both permeate intestinal cells which causes diarrhea
