Escherichia Coli gastroenteritis

Question 1

shape

Answer 1

gram (-) bacilli

Question 2

ferements

Answer 2

lactose (coliform)

Question 3

eneterpathogenic E. coli (EPEC)

Answer 3

noninvasive
* changes the microvilli of the small intestines –> formation of attaching and effacing lesion
* prevents reabsorption of water into the cell

Question 4

enterotoxgenic E. coli (ETEC)

Answer 4

• reservoir: humans
• high infectious dose
• at-risk groups: children < 5 yrs and travelers from non-endemic countries
• watery diarrhea

Question 5

ETEC is mediated by

Answer 5

heat-labile enterotoxin

Question 6

heat-labile enterotoxin (LT)

Answer 6

• A-B exotoxin
• A subunit ADP ribosylates and activates stimulatory G protein to increase adenylate cycle

Question 7

increased cAMP (ETEC) distrupts the normal ion balacne, causing

Answer 7

cells to secrete excessive amount of fluid and electrolytes into the lumen of the intestinal tract

Question 8

Enteroinvasive E. coli (EIEC)

Answer 8

• 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

Question 9

Enterohemmorhagic E. coli (EHEC)

Answer 9

• invasive pathovar
• reservoir : ruminant animals (especially cattle)
• typically associated with consumption of undercooked ground beerf and raw green leafy vegetables contaminated with cattle feces

Question 10

shiga toxin in E. coli

Answer 10

• A subunit inhibits protein synthesis by acting on the rRNA of large ribosome –> lysis –> inflammation
• may travel by blood to the kidney

Question 11

EHEC signs and symptoms

Answer 11

• bloody diarrhea, faatl hemorrhagic colitis
• possible complication: hemolytic uremic syndrome (HUS)