Pathogens / Toxins Flashcards
list 3 pathogens that are obligate intracellular
listeria
s. flexneri
s. typhi
what pathogen can be picked up from oysters / seafood?
V. parahaemolyticus
Exotoxin
extracellular diffusible proteins; most act at tissue sits remote from original point of invasion
Endotoxin
cell-associated structural components
Examples of endotoxins
LPS
LOS
LTA
What detects LPS?
TLR 4
What detects LTA?
TLR 2 and 6
proteases
enzymes that degrade connective tissue
list 2 superantigens
TSST
emetic / enterotoxin
*both superantigens come from S. aureus
What does emetic toxin cause?
food poisoning
4 exotoxins that are pore-forming
alpha-toxin (s. aureus)
steptolysins
listeriolysin
pneumolysin (s. pneumoniae)
Cholera toxin
AB5 toxin
targets Gs which leads to increase in cAMP
ADP-ribosylation of GTPase
Pertussis toxin
AB5 toxin
targets Gi
Gi becomes locked (GDP-bound) which results in increased levels of cAMP
Which toxins are AB5 toxins?
cholera
pertussis
shiga
shiga-like
(Can pat shack sam??)
Heat labile (ETEC)
increases cAMP
heat stable (ETEC)
increase cGMP
Shiga toxin
leads to hemolytic uremic syndrome
increases 38s rRNA
Diptheria toxin
AB toxin
ADP ribosylation
targets EF-2
What produces diptheria toxin?
clostridium diphtheriae
Which toxins are AB toxins?
diptheria
exotoxin A
botulinum toxin
tetanus toxin
(danny easily bothers tammy)
shiga-like toxin
EHEC
AB5 toxin
hemolytic uremic syndrom
inactivates 28S rRNA
Which 2 toxins inactivate 28S rRNA?
shiga-like toxin
shiga toxin
what should you remember about exotoxin A?
very similar to diptheria toxin
botulinum toxin
AB toxin
targets SNARE proteins to block acetylcholine release
leads to flaccid paralysis
tetanus toxin
AB toxin
binds to inhibitory transmitters (GABA and glycine)
results in spasm
TcdA
C. diff toxin A
glycosylation of GTP-binding proteins
TcdB
C. diff toxin B
glycosylation of GTP-binding proteins
targets CSPG4 and FZD
CDT
C. diff transferase toxin
ADP-ribosylation of G-actin
C. perfringens from notes
gram + bacteria
most common transmission is ingestion of contaminated food (ex. potato salad)
usually self-limiting within 24 hours
Which bacteria are obligate anaerobes?
bacteriobes
clostridium
What should you not do to treat E. coli?
do not treat with antibiotics or antidiarrheals (worsened outcomes)
Is listeria gram positive?
yes
What is the major concern of contracting listeria during pregnancy?
miscarriage and premature delivery
Is listeria an intracellular pathogen?
yes
intracellular, like Santa gets into your house
what is the most common cause of diarrhea in the US?
campylobacteria
non-typhoidal salmonella
iNTS
what does non-typhoidal salmonella normally present as?
diarrhea
compared to salmonella typhi which normally doesn’t have diarhea
serovars definition
antigenic phenotypes involving O-antigen of LPS combined with H-antigen of flagella
Which salmonella strand requires antibiotics?
typhi
not iNTS
Which pathogen is characterized by rapid onset of diarrhea?
staph aureus
Does staph aureus require a large or small amount to infect?
small since it is acid stable
What bacteria can come even from cured and cooked food?
staph aureus
How is vibriosis transmitted according to handout? (this doesn’t include cholera)
through undercooked / raw seafood
through open wound exposed to salt water
El Tor cholera
longer lasting
Toxin Co-Regulated Pilus
produced by V. cholera
helps the bacteria attach to gut epithelium
Which pathogen is a parasite?
giarda
Which pathogen isn’t gram positive or negative?
giarda
Which toxins can cause hemolytic uremic syndrome?
shigella
EHEC
