Bowel Path II Flashcards
most common cause of severe diarrhea in infants and young children
rotavirus
rotavirus
dsRNA virus
-reoviridae family
five species - A, B, C, D, E
A - most common - >90% of infections
fecal-oral transmission
-often stomach flu
rotavirus infection
easily managed
-but causes lots of death worldwide - developing countries
oral rehydration therapy and vaccines
malabsorption
-toxic protein NSP4
may also see lactose intolerance - for weeks
rotarix
vaccine for rotavirus
attenuated live virus
oral admin
ingestion of preformed toxins
rapid onset
staph food poisoning
vibrio
c perfringens
c botulinum
infection by toxigenic organisms
incubation - then diarrhea
travelers diarrhea
e coli
v cholerae
campylobacter
infection by enteroinvasive organisms
invade destroy mucosa
shigella
salmonella
campylobacter
enteroinvasive e coli
E. coli
gram negative bacilli
-colonize GI tract
ETEC
enterotoxic e coli
travelers diarrhea
food or water spread
heat labile toxin and heat stable toxin
induce chloride and water secretion
secretory diarrhea, dehydration
EHEC
E. coli 0157:H7
undercooked beef
shiga-like toxins
bloody diarrhea and HUS
EIEC
food, water, person to person
no toxins
-invade epithelial cells
EAEC
enteroaggregative e coli
adhere to epithelial
cause of diarrhea
adhere with adherence fimbrae
damage due to adherence
nonblood diarrhea - prolonged in AIDS patients
campylobacter
water or bloody diarrhea
arthritis
guillan barre syndrome
salmonella
gram negative bacilli
typhi - typhoid fever
nontyphi - enteritidis
raw or undercooked meat
few organisms required for infection
bacteria grown in phagosomes
Th17 limits to colon
diagnosis of salmonella
stool culture
typhoid fever
salmonella typhi
travel to india, mexico, phillipines, etc.
enlarged peyers patches in terminal ileum
oval ulcers - oriented along axis of ileum - may perforate**
liver - typhoid nodules
abdomen pain, bloating, nausea, vomiting, bloody diarrhea - fever and flu-like sx
blood cultures positive - more than 90% during febrile phase
rose spots - chest and abdomen
cholera
gram negative bacteria
contaminated drinking water
cholera toxin - causes disease
- five B subunits and single A subunit
- B goes retrograde transport to ER - A then reduced
- A released to cytosol
- interacts with ARF to activate and increase cAMP
- causes chloride release to lumen
- massive diarrhea
flagella for colonization
rice water stool
cholera
with fishy odor
dehydration, hypotension, shock
campylobacter jejuni
gram negative motile
most common enteric pathogen developed countries
-travelers diarrhea
improper cooked chickens
four virulence properties
-motility, adherence, toxin, invasion
flagella - motlie
see arthritis, erythema nodosum, guillan barre syndrome
most common bacterial enteritis in the world
campylobacter
shigella
gram negative bacilli
unencapsulated, nonmotile facultative anaerobes
watery diarrhea progres to bloody diarrhea - dysentery
resistant to acidic stomach
taken up by M cells
to left colon
diagnosis - stool culture
reiter syndrome
complication of shigella
arthritis, urethritis, conjuntivitis
HLA-B27 positive men
pseudomembranous colitis
antibiotic associated
-3rd gen cephalosporins
c. difficile overgrowth and toxin production - A and B toxins
in adults - acut ediarrhea
diagnosis - C. dif in stool
eruption reminiscent of volcano
diagnosis of c dif infection
presence of toxin
volcanic eruptions
c dif - pseudomembranous colitis
whipple disease
relapsing multisystem illness of GI tract and distant sites
weight loss, diarrhea, polyarthritis
tropheryma whipplei
40-50yo, males
tx - antibiotics
trophermya whipplei
whipple disease
gram positive actinomycete
foamy macrophages with argyrophilic rods in lymph nodes
path of whipple disease
malabsorptive diarrhea - impaired lymph transport
organism clogs up nodes and lymph tracts
distended foamy macrophages
whipple disease
PAS positive rod shaped bacilli
and NO acid-fast staining
t. whippelii
diarrhea, weight loss, and malabsorption
triad of whipple disease
cryptosporidium
contaminated drinking water
travelers diarrhea
terminal ileum and right colon
intracellular at brush border
H and E stain and Ag stain
appears to sit on top of epithelial apical membrane
diagnosis - oocysts in stool
AIDS and diarrhea
50% patients
cryptosporidium
CMV
MAI
pinworms
enterobius vermicularis
-live in intestinal lumen - rarely cause illness
eggs deposited at night at perirectal mucosa- irritation
-itchy
diagnosis - tape to anus
ascaris
small intestine roundworm
-a. lumbricoides
compromised nutritional status
SOB, fever, abdomen pain, diarrhea, malnutrition, mental changes
eggs hatch in intestines - go to lungs - coughed up and swallowed
amebiasis
entamoeba histolytica
-ingestion of mature cysts
trophozites invade intestinal mucosa
cecum and ascending colon
abdomen pain, diarrhea, weight loss
acute necrotizing colitis and megacolon possible
obligate fermenters of glucose
most common parasite infection
giardia
giardia
g. duodenalis and g. intestinalis
asymptomatic, acute diarrhea, or chronic GI disease
malabsorption, diarrhea, abdominal pain/discomfort
giardia morph
flagellated protozoans
cause decreased expression of brush border enzymes
pear shape with two nulei and line down middle
steatorrhea
bulky, frothy, greasy, yellow, gray stool - with malabsorption
ADEK
fat soluble vits - with malabsorption
most common causes of malabsorption
celiac
pancreatic insufficiency
crohn disease
abetalipoproteinemia
only see transepithelial transport defect
altered lymph transport
whipple disease
celiac disease
inflammatory disease
-gluten ingestion
genetic predisposition, inciting agent exposure, T cell repsonse
gliadin
disease producing component of gluten
induce IL-15 expression stimulates T8 Cells
enters and stimulates T4 cells - to create B cells - make Abs
path - is CD8 cells
class II HLA DQ2 and DQ8
carried by those with celiac
celiac clinical
steattorhea, weight loss, abdominal pain cramping bloating, mouth ulcers, lactose intolerance, IBS
increased risk of adenocarcinoma and lymphoma
malaborption vits A, D, E, K
anemia, fatigue, megaloblastic anemia, hyperparathyroid, osteopenia, osteoporosis
celiac disease
adults 30-60yo and children
diarrhea with steatorrhea
dermatitis herpetiformis
dermatitis herpetiformis
extremely itchy blisters extensor surfaces of body
IgA deposition at dermal/epidermal junction
with celiac disease**
celiac tx
remove from diet
diagnosis of celiac
1 clinical malabsorption
2 small bowel bx - gold standard
3 response to gluten free diet
also serologic testing and HLA testing
-if IgA deficient - sero tests won’t work
gold standard celiac diagnosis
small bowel biopsy
-distal duodenum/jejunum
-villous atrophy
celiac sero tests
IgA tTG antibodies
also anti-endomysial antibodies - IgA EMA
cracked mud mucosa
in celiac on endoscope
