GI 2 Flashcards
1
Q
macconkey agar
A
lactose fermentation
positive=red
negative = white
2
Q
e.coli on macconkey agar
A
positive red
3
Q
salmonella or shigella on macconkey agar
A
negative white
4
Q
positive indole test
A
red color change (indole production)
5
Q
negative indole test
A
no color change (no indole production)
6
Q
e.coli or vibrio spp. on indole test
A
positive red color change
7
Q
salmonella on indole test
A
negative no color change
8
Q
black precipitate
A
hydrogen sulfite production
9
Q
salmonella v. shigella
A
salmonella= black precipitate
shigella = no precipitate
10
Q
- gram negative faculative anaerobe
- moderately invasive
- watery diarrhea
- pediatric diarrhea in developing countries
A
EPEC
11
Q
virulence of EPEC
A
- no toxins
- BfpA bundle forming pilus
- Type III secretion system
12
Q
pathogenesis of EPEC
A
- bac injects Type III secretion
“attaching and effacing”
system prtns directly into host cells - bac produced intimin binds to Tir and creates tight interaction
- F actin polymerization causes a loss of brush border ( less absorption of liquid –> diarrhea)
13
Q
lactose positive indole positive
A
e. coli, use PCR to determine which type
14
Q
- gram negative
- faculative anaerobe
- non-invasice
- travelers’s diarrhea
- diarrhea in children in developing world
A
ETEC
“t for travelers”
15
Q
virulence factors for ETEC
A
- fimbriae
- LT heat liable toxin
- ST heat stable toxin
- plasmid encoded
