Week 4 - Wed - Fri Flashcards
In which - UC or CD - do you get pseudopolyps
what are they
in UC
they are actually just left over segments of gut epithelial cells that are not ulcerated
crypt architectural distortion means what - acute or chronic IBD
chronic
antibody tests that can differentiate UC from CD
CD: ASCA positive
UC: pANCA positive
quiescent colitis
damaged crypt architecture without inflammation
patients with chronic watery diarrhea and a normal colonoscopic exam
microscopic colitits
if nothing on biopsy then irritable bowel syndrome
what are you thinking if you see intraepithelial lymphocytes
what other cells are you looking for
microscopic colitis - lymphocytic colitis type
also see increased plasma cells
what are you thinking if you see eosinophilic tissue right under the epithelium on colon biopsy
microscopic colitis - collagenous colitis type
it’s a collagen band
colonic cells with enlarged nuclei and with normal cytoplasm
radiation colitis
if there was less cytoplasm, higher chance of it being cancer
intestinal segments that are particularly susceptible to ischemic damage
splenic flexure (SMA and IMA watershed zone)
sigmoid colon and rectum (IMA, pudendal artery, and iliac arter watershed zone)
smudgy hyalinized appearance to LP and atrophic crypts
ischemic colitis
hematochezia in an older patient with tortuous dilation of vessels
what is it
where in the GI system
angiodysplasia
most often found in cecum, terminal ileum, and ascending colon
smooth muscle proliferation between the crypts
characteristic of a “solitary rectal ulcer”
the majority of foodborne illness outbreaks are caused by what
norovirus
gram positive rod that can produce biofilms and spores, and adheres to invasive medical devices
found in rice and can survive cooking
bacillus cereus
B. Cereus = Box Car appearance
gram pos bacilus non-fastiduous flagellated, motile non spore forming oxidase -
Listeria Monocytogenes
gram neg curved rod faculative anaerobe flagellated, motile oxidase pos
Vibrio spp
inc vibrio cholera
also grows in alkaline media (she didn’t mention it, but its in FA)
gram pos bacili spore-forming obligate anaerobe non-motile
clostridium perfringens
which bacteria produces an enterotoxin that binds to receptors in endothelial cell junctions and generates pores in the host mucosa cells
clostridium (perfringens, botulinum, difficile)
it’s called alpha toxin (lecithinase)
bacteria she wanted us to remember assc with cafeterias and will not normally cause fever or vom
c. perfringens
gram - bacili (spiral) microaerophilic motile cold sensitive
in what aninals?
what agar?
what possible complication
campylobacter jejuni
poultry
karmali agar - charcoal based
guillain-barre
karmali agar
used to culture campylobacter jejuni
has vanco for the gram positives, cefoperazone, and cyclohexamide
guillan-barre linked to what bacteria
campylobacter jejuni
what bacteria can generate H2S and cause an iron sulfide precipitate
salmonella enterica
salmonella found it what pets
turtles
i like turtles
what is more likely to cause bloody diarrhea - campylobacter, Staph a.
campyobacter
common food poisoning thing that causes projectile vom, low grade fever, diarrhea
noravirus
tests you can do to definitively diagnose noravirus
PCR assay on stool or vom samples
vibrio parahaemolyticus enterotoxin
TDH (thermostable direct hemolysin) and/or TRH
forms pores in RBCs, gut epithelial cells
foodborne
is cholera food borne?
no
leading cause of death with food borne illness
listeria
how to test for listeria
look for the bacteria in a normally sterile site like blood or CSF
don’t look in the stool because it can be there and not cause Sx
which bug can cause infection initiating in the GI tract but resulting in neurological symptoms including slurred speech and muscle weakness?
clostridium perfringens, gram pos, spore forming
this was one of her example questions
diarrhea (often bloody)
fever
stomach cramps
was passed through feces and not food
shigella spp.
most mild shigella spp
shegella sonnei
gram - bacillus faculative anaerobe nonmotile non sporeforming mainly lactose negative oxidase negative
shigella spp
what bacteria use actin in the cells to move around because they don’t have flagella
shigella spp
shigella toxin
shiga toxin
aka AB5 toxin
binds to Gb3 receptors on the colonic epithelial cells.
the A subunit is what enters the cell, inactivates the ribosome 60s by removing adenosine from rRNA
get dysentery, enhanced cytokine release, hemolytic uremic syndrome
STEC
VTEC
EHEC
what kind of toxin
shigalike
ETEC vs EHEC (STEC)
which has bacterial penetration
EHEC has penetration
EHEC (STEC) genes with toxins
stxA, stxB
they are italicized when genes
stx1 and stx2 are the toxins themselves
what bacterial infections of the gut do you not generally treat with antibiotics
EHEC (STEC)
because of bacterial lysis/aggravation leading to HUS`
examples of high inoculum organisms
v. cholerae, c. perfringens
as opposed to STEC which can be only 100 organisms
GI bacterial infecition that is gram variable
C. diff
pseudomembranous colitis
C. diff
Mech of nitazoxanide
used for what
interferes with pyruvate::ferredoxin oxidoreductase enzyme dependent electron transfer (not in mammals - we have NADH-producing pyruvate dehydrogenase), essential to anaerobic energy metabolism protein
primarly luminal
used for cryptosporidium
what antiparasite interferes with thyroid tests and causes loss of visual acuity
iodoquinol - a luminal amebicide
paromomycin
class?
tox?
aminoglycoside
tox - ototox, nephrotox
(it is a luminal antiparasitic and doesn’t have an many SE as other animoglycosides)
Tx for cyclospora (food borne outbreak)
bactrim
anal pruritis and intestinal infection symptoms.
a worm - name?
Dx?
Tx?
enterobius vermicularis (pinworm)
Dx - scotch tape test
Tx - bendazoles
barrel shaped appearance of eggs
Sx
trichuris trichiura
Sx - bloody diarrhea, anemia, finger clubbing the best indicator of severity
mech of pyrantel pamoate and levamisole
selectively opens a restricted subgroup of nematode acetylcholine receptor ion channels in nematode nerve and muscle. depolarization, entry of Ca, spastic contraction, worm can’t move and is swept away.
tape worm in:
pork
fish
dogs
pork - taenia solium - cysticercosis, neurocysticercosis - Tx is praziquantel, albendazole for neurocysticercosis
fish - diphyllobothrium latum - vit b12 deficiency - macrocytic anemia - Tx is praziquantel
dogs - echinococcus granulosus - hydatid cysts in liver, causing anaphylaxis if antigens released (surgeons preinject with ETOH to kill cysts before removal - Tx is albendazole
proglottids in stool
its a tape worm (not specific to which)
common treatment for flukes (and also tapeworms)
praziquantel
flukes are Schistosoma (in snails, cause liver and spleen granulomas, can lead to squamous cell of the bladder) and clonorchis sinensis (biliary tract inflammation –> pigmented gall stones, assc with cholangiocarcinoma)
we put up an immune response to what life cycle stage of schistosoma
egg
swimmers itch is causes by what type of organisms
flukes
3 parasites you are most likely to find in the us
giardia
crypto
pinworm (enterobius vermicularis)
