Escherichia Coli gastroenteritis Flashcards
1
Q
shape
A
gram (-) bacilli
2
Q
ferements
A
lactose (coliform)
3
Q
eneterpathogenic E. coli (EPEC)
A
noninvasive
* changes the microvilli of the small intestines –> formation of attaching and effacing lesion
* prevents reabsorption of water into the cell
4
Q
enterotoxgenic E. coli (ETEC)
A
- reservoir: humans
- high infectious dose
- at-risk groups: children < 5 yrs and travelers from non-endemic countries
- watery diarrhea
5
Q
ETEC is mediated by
A
heat-labile enterotoxin
6
Q
heat-labile enterotoxin (LT)
A
- A-B exotoxin
- A subunit ADP ribosylates and activates stimulatory G protein to increase adenylate cycle
7
Q
increased cAMP (ETEC) distrupts the normal ion balacne, causing
A
cells to secrete excessive amount of fluid and electrolytes into the lumen of the intestinal tract
8
Q
Enteroinvasive E. coli (EIEC)
A
- invades and replicates within the mucosa of the large intestine
- moves from clel to cell via nucleating actin filaments
- eleicits inflammatory response
- neutrophils damage and ulcerates the intestinal lining
- dysentery
9
Q
Enterohemmorhagic E. coli (EHEC)
A
- invasive pathovar
- reservoir : ruminant animals (especially cattle)
- typically associated with consumption of undercooked ground beerf and raw green leafy vegetables contaminated with cattle feces
10
Q
shiga toxin in E. coli
A
- A subunit inhibits protein synthesis by acting on the rRNA of large ribosome –> lysis –> inflammation
- may travel by blood to the kidney
11
Q
EHEC signs and symptoms
A
- bloody diarrhea, faatl hemorrhagic colitis
- possible complication: hemolytic uremic syndrome (HUS)