Nelson - Ch. 200 E. coli

Question 1

E.coli ?aerobic ?gram ?lactose

Answer 1

Facultative anaerobic, G-, lactose fermenter

Question 2

T/F Most fecal E.coli cause diarrhea

Answer 2

F, do not cause

Question 3

Most diarrheagenic E.coli except ___ require a large inoculum of organisms to induce disease

Answer 3

STEC

Question 4

MCC of traveler’s diarrhea

Answer 4

ETEC

Question 5

Accounts for 10-30% of dehydrating infantile diarrhea

Answer 5

ETEC

Question 6

Enterotoxin produced by ETEC associated with increased risk of death

Answer 6

ST-ETEC or heat stable enterotoxin

Question 7

ETEC diarrhea is self-limited and resolves in

Answer 7

3-5 days, occasionally longer than 1 week

Question 8

ETEC enterotoxin that is structurally, functionally, and immunologically related to cholera toxin produced by V. cholerae

Answer 8

LT or heat labile toxin

Question 9

ETEC enterotoxin: Large molecule

Answer 9

LT

Question 10

ETEC enterotoxin: Small molecule

Answer 10

ST

Question 11

ETEC enterotoxin: Stimulates adenylate cyclase –> increased CAMP

Answer 11

LT

Question 12

ETEC enterotoxin: Stimulates guanylate cyclase –> increased CGMP

Answer 12

ST

Question 13

Genes for ST and LT of ETEC are encoded on

Answer 13

Plasmids

Question 14

E. coli: Explosive, nonmucoid, nonbloody diarrhea, little or no fever

Answer 14

ETEC

Question 15

E. coli: Resembles bacillary dysentery since it shares virulence genes with Shigella spp

Answer 15

EIEC

Question 16

E. coli: Cause colonic ulcerations, hemorrhage, mucosal and submucosal edema, and infiltration by PMNs

Answer 16

EIEC

Question 17

E. coli: Nonmotile and usually non lactose fermenting

Answer 17

EIEC

Question 18

E. coli: Acute, prolonged (>7d), and persistent diarrhea (>14) in children less than 2

Answer 18

EPEC

Question 19

E. coli: Outbreaks in daycare centers

Answer 19

EPEC

Question 20

E. coli: Studies show that breastfeeding is protective against diarrhea caused by

Answer 20

EPEC

Question 21

E. coli: Duodenum through colon

Answer 21

EPEC

Question 22

E. coli: Colonization causes blunting of villi, inflammatory changes, and sloughing of superficial mucosal cells

Answer 22

EPEC

Question 23

E. coli: Characteristic attaching and effacing histopathologic lesion

Answer 23

EPEC

Question 24

E. coli: Abdominal pain with diarrhea that is initially watery but within a few days become blood-streaked or grossly bloody

Answer 24

STEC

Question 25

Associated with HUS

Answer 25

STEC

Question 26

Severe illness with STEC occurs in what age-group

Answer 26

6m-10yrs

Question 27

STEC-positive young children with ___ early in the course of diarrhea are at high risk for HUS progression

Answer 27

Bloody diarrhea and neutrophilic leukocytosis

Question 28

Poorly cooked hamburger, apple cider, mayonnaise, spinach, dry fermented sausage, unpasteurized dairy

Answer 28

STEC

Question 29

STEC affects the ___ most severely

Answer 29

Colon

Question 30

Attaching-effacing lesions like those seen in EPEC but with production of toxins that kill cells

Answer 30

STEC

Question 31

Key virulence factors of STEC

Answer 31

Shiga toxins aka VEro toxins aka Shiga like toxins

Question 32

The ___ family of toxins produced by STEC is associated with a higher risk of causing HUS

Answer 32

Stx2

Question 33

MC STEC serotype

Answer 33

O157:H7, O111:NM and O26:H11

Question 34

Most virulent STEC serotype

Answer 34

O157:H7

Question 35

E coli most frequently associated with HUS

Answer 35

O157:H7

Question 36

2nd MCC of traveler's diarrhea

Answer 36

EAEC

Question 37

Acute and persistent diarrhea in HIV-infected adults and children

Answer 37

EAEC

Question 38

Associated with growth retardation and malnutrition in infants

Answer 38

EAEC

Question 39

Form a characteristic biofilm on the intestinal mucosa and induce shortening of the villi

Answer 39

EAEC

Question 40

Secretory mucoid diarrhea

Answer 40

EAEC

Question 41

AA fimbriae

Answer 41

EAEC