Session 9- Gastrointestinal Infection Flashcards
what is the benefit of the bacteria in the colon
SCFAs
acetate- involved in cholesterol metabolism
proprionate- regulates satiety
butyrate- energy source for colonocytes
what is FMT
faecal microbiota transplant
how do salmonella cause disease
gain access to enterocytes
move to submucosa where encoutner macrophages
macrophages transfer salmonella to RES where they multiply inside cells
causing lymphoid hyperplasia
reenter gut from the liver
how is salmonella spread
ingesting infected food or waterv
how is campybacter spreas
faecal oral
how does campylobacter cause disease
release a cytotoxin similar to cholera causing diarrhoea
treatment of infection with campylobacter
fluid/ electrolyte replacement
consider antibiotics if blood diarrhoea
how is shigella spread
spread from infected stools - flies
how does shigella cause disease
kills colonocytes and forms abcesses in the mucosa
of all the gram negative rods that cause gastroenteritis which one is likely to produce symptoms hat lasts weeks
campylobacter
which one of the gram negative rods is most likley to cause blood diarrhoea
shigella- produces colonic abcesses
what is pseudomembranous colitis
inflammatory condition where elevated yellow plaues join to orma pseudomembrane
swelling or inflammation of the large intestine (colon) due to an overgrowth of Clostridioides difficile (C difficile) bacteria.
treatment of c diff
remove offending antibiotic
fluid resuscitation
vancomycin
probiotics
what precipotates c diff proliferaion
most antibiotics
what causes viral gastroentertis in under 5s
rotavirus- double stranded RNA virus
how does rotavirus cause diarrhoea
Cl- secretion
SGLT1 disruption
- reduced movement of Na/glucose into emyrocyte
- higher osmotic load in gut lumen
- water follows
brush border dysfunction
-general malabsorption
what is the most common cause of viral gastroenteritis
norovirus
what can cause parasitic gastroenterotis
cryptospotidium
giardia lamblia
entamoeba
how does cryptosporidium cause disease
ingestion of oocyst= cyst containing parasite
- reproduces inside the cells of the distal small intestine
- oocysts are excreted in faeces to continue cycle
prouces watery diarrhoes
how does giardia cause disease
cyst is ingested
- stomach acid/ pancreatic enzymes release parasite wihch multiplies
- damaes proximal SI
prasite then gors back into cyst stage in colon
what is the most common cause pf travellers diarrhoea
ETEC
what parasitic infection is most likely to be a cause for persistent infection
giardia