Enterobacteriaceae Flashcards
1
Q
Shigella motility
A
100% neg
2
Q
Kleb pneumo motility
A
100% neg
3
Q
Proteus spp phenylalanine deaminase
A
positive
4
Q
Providencia phenylalanine deaminase
A
positive
5
Q
Principle of serological typing of Salmonella & Shigella species
A
Somatic O antigens & flagella H antigens for Salmonella
O antigens for Shigella
6
Q
Escherichieae tribe
A
Escherichia, Shigella
7
Q
Edwardsielleae tribe
A
Edwardsiella
8
Q
Salmonelleae tribe
A
Salmonella
9
Q
Citrobacteriaceae tribe
A
Citrobacter
10
Q
Klebsielleae tribe
A
Klebsiella, Enterobacter, Hafnia, Serratia
11
Q
Proteae tribe
A
Proteus, Morganella, Providencia
12
Q
Yersinieae tribe
A
Yersinia
13
Q
IMVIC reactions for E. coli
A
Indole +
MR +
VP =
Citrate +
14
Q
IMVIC reactions for Klebsiella pneumoniae
A
Indole =
MR =
VP +
Citrate +
15
Q
IMVIC reactions for Klebsiella oxytoca
A
Indole +
MR =
MP +
Citrate +
16
Q
IMVIC reactions for Enterobacter aerogenes
A
Indole =
MR =
VP +
Citrate +
17
Q
IMVIC reactions for Enterobacter intermedius
A
Indole =
MR +
VP +
Citrate +
18
Q
4 characteristics shared by members of Enterobacteriacea
A
Gram neg rod/bacilli
Oxidase =
Convert nitrate to nitrites
Ferment glucose
19
Q
K antigen of Enterobacteriaceae
A
Capsular antigen
20
Q
O antigen of Enterobacteriaceae
A
somatic antigen
21
Q
H antigen of Enterobacteriaceae
A
Flagellar antigen
22
Q
TSI
-K/A
A
Utilizes glucose only
23
Q
TSI
-K/K
A
Non fermenter
24
Q
TSI
-A/A
A
Utilize glucose and/or lactose and/or sucrose
25
TSI
| -No gas production
Nonaerogenic
26
TSI
| Gas production
Aerogenic, H2S production
27
LIA
| -K/A
Utilize glucose only
28
LIA
| -K/K
Decarboxylated lysine
29
LIA
| -R/Y
Phenylalanine deaminase
30
Indole
If organism has enzyme tryptophanase, it will deaminate tryptophan & make product indole
31
Methyl red
Glucose is metabolized by mixed acid fermentation & produces an acidic end product, which decreases the pH & gives a color change
32
Voges-Proskauer
Acids formed are metabolized to 2,3-butanediol through acetoin, alpha napthol & 40% KOH are added, resulting in a red complex
33
Citrate
Uses citrate as sole source of carbon
34
Urea
If organism an hydrolyze urea to ammonia
35
Amino acid degradation
| -Lysine
--> cadaverine
36
Amino acid degradation
| -Arginine
--> putrescine (production of ammonia causes color change)
37
Amino acid degradation
| -Ornithine
--> putrescine (production of ammonia causes color change)
38
ONPG
If organism ahs B-galactosidase, it acts on ONPG to produce galactose & orthonitrophenol - a neg reaction will occur if the org is a non-lactose fermenter
39
PYR
The organism can hydrolyze the substrate PYR
- L-prolidonyl-B naphthylamide
- L-pyroglutamic acid-B naphthylamide
40
Hippurate
If organism has enzyme hippicurase, will hydrolyze sodium hippurate
41
Hydrogen sulfide
Organism's ability to produce H2S
42
Tryptophan deaminase (TDA)
Produces indole pyruvic acid which reacts with ferric ammonium citrate in the medium after addition of ferric chloride to produce a brown color
43
Nitrate
Conversion of nitrate to nitrite
44
Esculin
If organism hydrolyzes esculin, the product will react with ferric salt to form a black precipitate
45
Why suspected Salmonella species isolates boiled for 20 if no reaction with O typing sera
Vi antigen may block the O antigen & may give a false negative.
If Vi antigen is heated, it will be removed & allow access to the O antigen
46
Sorbitol MacConkey agar isolation pathogen
E.coli O157:H7
Causes hemorrhagic diarrhea & hemolytic uremic syndrome.
Appears as a clear/colorless colony on SMAC
47
Indole positive Proteus
Proteus vulgaris
48
3 sources Salmonella typhi can be isolated from during typhoid fever
Blood, gallbladder, GI tract
49
Carrier state
Carriers shed organisms continuously or intermittently & feces may contaminate food or water sources
50
Treatment of Salmonella gastroenteritis
If treated by antibiotics, patient may have a higher risk for developing carrier state
If treatment is necessary, use trimethoprim-sulfamethoxazole
51
Purpose of MacConkey & eosin Methylene Blue agar
Selective: isolate gram neg rods, inhibit gram pos
differential: lactose positive & negative
52
E. coli on EMB agar
Forms blue-black colonies with metallic-greenish sheen
53
GN broth purpose
Selective enrichment media that inhibits gram pos bacteria & has high % of mannitol, which temporarily favors mannitol-fermenting gram neg rods
54
Zinc dust use in nitrate test
If neg color reaction, zinc dust added to the nitrate test will show a color if nitrate is still present, which shows a true negative
If true neg color reaction, the nitrate has been reduced to nitrite then further reduced to gaseous products or a true pos reaction
55
Non-lactose & lactose fermenters on EMB
Non-lactose: translucent, amber color
| Lactose: pink
56
Non-lactose & lactose fermenters on MAC
Non-lactose fermenters: colorless of transparent
| Lactose: pink/red
57
Non-lactose & lactose fermenters on HE
non-lactose: green/blue green. black H2s
| Lactose: orange/salmon-pink
58
Non-lactose & lactose fermenters on XLD
Non-lactose: red/colorless. black H2S
| Lactose: yellow
59
Non-lactose & lactose fermenters on TERGITOL-7
Non-lactose: red
| lactose: green/blue
60
Coliforms
Organisms commonly seen in GI tract (neg rods) as normal for a
-E. coli, Klebsiella, Enterobacter, Proteus, Pseudomonas
61
Tribe with strong positive urea reaction
Proteeae tribe
62
Vitek system
Inoculum size is small & is an enclosed walk-away system
63
Microscan system
Fluorescent color change. If the microbe begins to se the substance in the well, it breaks a quenching bond for fl. and the well will fluoresce.
64
Klebsiella pneumoniae reactions
```
TSI: K/A + G
MIO: ===
CIT: +
LIA: K/K
UREA +
```
65
Klebsiella oxytoca
```
TSI: K/A + G
MIO: =+=
CIT +
LIA: K/K
Urea: +
```
66
Enterobacter aerogenes
```
TSI: A/A +G
MIO: +=+
CIT: +
LIA: K/K
Urea: =
```
67
E. coli
```
TSI: K or A/A +G
MIO: +++
CIT: =
LIA: K/K or A
Urea: =
```
68
Salmonella
```
TSI: K/A +H2S
MIO: +=+
CIT: =
LIA: K/K +H2S
Urea: =
```
69
Citrobacter fruendii
```
TSI: K/A +H2S
MIO: +==
CIT: +
LIA: K/A +H2S
Urea: +
```
70
Proteus vulgaris
```
TSI: A/A +G +H2S
MIO: ++=
CIT: =
LIA: R/A
Urea: +
```
71
Proteus mirabilis
```
TSI: K/A +G +H2S
MIO: +=+
CIT: +
LIA: R/A
Urea: +
```
72
Shigella
```
TSI: K/A
MIO: ===
CIT: =
LIA: K/A
Urea: =
```
73
Chemicals used in the oxidase test
C tetra methyl-p-phynylene-diamine-dihydrochloride
74
Chemicals used in the indole test
C paradimethylamnobenzaldehyde
75
Kleb pneumoniae colony morphology
pink mucoid colonies
76
Proteus morphology
swarm on non-selective media
77
E. coli morphology
Usually dryer pink with surrounding pink precipitated bile salt
78
Yersinia optimal temperature and atmosphere
Grows best at 25-30 degrees Celcuis, ambient atmosphere, but will also grow at 37 degree
