Enterobacteriaceae Flashcards
1
Q
General biochemical characteristics of Enterobacteriaceae
A
Gram-negative rod reduce nitrates to nitrites Inability to produce oxidase Facultative anaerobic metabolism (prefers reduced oxygen environment) Fermentation of glucose
2
Q
Lactose positive Enterobacteriaceae
A
E. coli
K. pneumoniae
C. freundii
3
Q
Lactose negative Enterobacteriaceae
A
P. mirablis
Salmonella
Shigella
4
Q
Media to know
A
MacConkey Hektoen Enteric XLD MacSor Tetrathionate TCBS CIN
5
Q
O Antigens
A
associated with cell wall; are heat stable and allow for groupings (0157)
6
Q
K Antigens
A
associated with capsule around cell wall; responsible for inhibition of agglutination by specific antibody
7
Q
H Antigens
A
associated with flagella;
8
Q
EHEC Enterohemorrhagic E. Coli
A
produces a deadly bloody diarrhea often associated with Hemolytic Uremic Syndrome, caused by strain 0157:H7 from undercooked beef or raw milk
9
Q
IMVIC
A
Indole
Methyl red
Voges proskaur
Citrate
10
Q
Indole Principle
A
Determine the presence of the enzyme tryptophanase
11
Q
Indole Spot Test Result
A
Positive - blue color within 20 seconds
Negative - no color or slight pink
12
Q
Indole Results
A
Positive - pink to wine colored ring
Negative - no color change
13
Q
Methyl Red/Voges Proskaur Principle
A
determines ability of an organism to produce and maintain stable acid products from glucose fermentation
14
Q
MRVP Results
A
Positive - Red color
Negative - Yellow color
15
Q
Citrate Principle
A
To determine the ability to convert citrate to pyruvate
16
Q
Citrate Results
A
Positive - growth with or without color change
Negative - Absence of growth
17
Q
Oxidase Principle
A
To ID oxidase negative Enterobacteriaceae from other gram negative bacilli
18
Q
Oxidase Results
A
Positive - dark purple within 10 seconds
Negative - Absence of color
19
Q
TSI Results
A
Acid (A) - yellow
Alkaline (K) - red
H2S production - black
Gas: bubbles
20
Q
LIA Results
A
Acid (A) - yellow
Alkaline (K) - purple
H2S - black butt
Deaminase (R) - Red slant
21
Q
TSI A/A
A
glucose and lactose or sucrose fermented
22
Q
TSI K/A
A
only glucose fermented
23
Q
TSI K/K
A
no carbohydrates fermented
24
Q
LIA K/K/black
A
LDC pos/glucose neg/H2S positive
25
LIA K/A
LDC neg/glucose positive
26
LIA A/A
LDC neg/glucose positive
27
LIA R/A
LDA pos/glucose pos
28
E. coli
| biochemical features
Lactose +
Oxidase -
Indole +
H2S -
29
K. pneumoniae
| biochemical features
Lactose +
Oxidase -
Indole -
H2S -
30
C. freundii
| biochemical features
Lactose +
Oxidase -
Indole -
H2S +
31
P. mirablis
| biochemical features
Lactose -
Oxidase -
Indole -
H2S +
32
Salmonella
| biochemical features
Lactose -
Oxidase -
Indole -
H2S +
33
Shigella
| biochemical features
Lactose -
Oxidase-
Indole -
H2S -
34
Y. enterocolitica
| biochemical features
Lactose -
Oxidase -
Indole -
H2S -
35
P. aeruginosa
| biochemical features
Lactose -
Oxidase +
Indole -
H2S -
36
V. cholera
| biochemical features
Lactose +
Oxidase +
Indole +
H2S -
37
Acinetobacter
| biochemical features
Lactose -
Oxidase -
Indole -
H2S - -
38
S. maltophilia
| biochemical features
Lactose -
Oxidase -
Indole -
H2S -
39
E. corrodens
| biochemical features
Lactose +/-
Oxidase +
Indole -
H2S N/A
40
P. multocida
| biochemical features
Lactose -
Oxidase +
Indole +
H2S -
41
L. pneumophilia
| biochemical features
Lactose ?
Oxidase +
Indole ?
H2S ?
42
E. coli Habitat
Normal gut flora
43
E. coli special media and growth
MacSor to isolate 0157:H7, EMB green metallic sheen
44
E. coli diseases
UTI, neonatal meningitis, gastroenteritis & nosocomial infections
45
E. coli notes
Most common clinical isolate
46
K. pneumoniae habitat
Humans, animals, soil, sewage
47
K. pneumoniae diseases
Rarely pathogenic in healthy population, but severe pneumonia in compromised population
48
K. pneumoniae notes
Non motile
49
C. freundii habitat
Environment
50
C. freundii diseases
Associated with hospitalized and compromised patients, URI and RTI
51
C. freundii notes
Only lactose + H2S producer
52
P. mirablis habitat
Moist environments
53
P. mirablis diseases
Antibiotic resistant diarrhea, chronic UTIs, kidney stones
54
P. mirablis notes
Swarms on blood and chocolate (*vulgaris strain indole pos)
55
Salmonella habitat
Environment
56
Salmonella special media
SS agar, tetrathionate broth
57
Salmonella Diseases
Gastroenteritis/diarrhea, bacteremia/extraintestinal infections, typhoid fever
58
Salmonella Notes
Only lactose - H2S producer
59
Shigella habitat
Not normal flora
60
Shigella special media
SS agar, tetrathionate broth
61
Shigella diseases
Diarrhea, dysentery
62
Shigella notes
Non motile
63
Y. enterocolitica habitat
Domesticated animals, not normal human flora
64
Y. enterocolitica special media
CIN agar
65
Y. enterocolitica diseases
infections of wounds, joints, UTI
66
P. aeruginosa habitat
Environmental, not normal human flora
67
P. aeruginosa special media or growth
Cetrimide agar, growth at 42 degrees C
68
P. aeruginosa diseases
Opportunistic and nosocomial infections; folliculitis, otitis externa, cystic fibrosis, UTI, septicemia.
69
P. aeruginosa notes
Resistant to antimicrobials. Common in soil/water. Colonies blue-green, has grapelike odor
70
V. cholera habitat
Not normal flora
71
V. cholera special media or growth
Yellow colonies on TCBS
72
V. cholera diseases
Rice water stools
73
V. cholera notes
not normal flora, contaminates water
74
Acinetobacter habitat
Environment, may be normal in patients
75
Acinetobacter Diseases
Nosocomial, esp. during warm months, UTIs, respitory, wounds, soft tissue and bacteremia
76
Acinetobacter notes
Major outbreak during Iraq and Afghanistan wars
77
S. maltophilia habitat
Environment, may be normal in patients
78
S. maltophilia diseases
Opportunistic and nosocomial
79
S. maltophilia notes
Intrinsic resistance to antibacterials, ammonia odor
80
E. corrodens habitat
Normal flora of mouth and GI tract
81
E. corrodens Diseases
Bite wounds, head and neck infections, pneumonia aspirations, endocarditis (slow to develop)
82
E. corrodens notes
bleach like odor, pitting or corrosion of agar
83
P. multocida habitat
wild animals, nasopharynx and GI
84
P. multocida diseases
Bite or scratch or animal exposure leads to soft tissue infections, systemic; meningitis, endocarditis, septicemia
85
P. multocida notes
may have mushroom or musty odor
86
L. pneumophilia habitat
Community & nosocomial acquired
87
L. pneumophilia growth or media
serotyping required, growth on BYCE
88
L. pneumophilia diseases
Acute pneumonia w/non productive cough, myalgia, diarrhea, hyponatremia, elevated liver enzymes
89
E. coli media growth
Blood - growth
Mac - LF - flat dry pink colonies
XLD - yellow
HE - yellow
90
K. pneumoniae media growth
Blood - growth; mucoid
Mac - LF, mucoid
HE - Yellow
XLD - Yellow
91
C. freundii media growth
blood - growth
Mac - Late LF
HE - no color
XLD - Red or yellow with black center
92
P. mirablis media growth
blood - swarm growth
Mac - NLF, swarm
HE - no color
XLD - yellow or colorless with black center
93
Salmonella media growth
blood - growth
Mac - NLF
HE - green blk center
XLD - red w/blk center
94
Shigella media growth
blood - growth
Mac - NLF, flat w/jagged edges
HE - Green
XLD - colorless
95
Y. enterocolitica media growth
Mac - NLF; may be colorless to peach
HE - Salmon
XLD - yellow or colorless
96
P. aeruginosa media growth
Mac - NLF
HE - Colorless, media turns dark blue
XLD - pink, flat rough colonies
97
Which test in the IMViC will indicate glucose fermentation byproducts?
Methyl Red/Vioges Proskaur
98
Which organism appears to swarm on BAP?
P. mirabilis
99
Which organism may exhibit a red pigment on BAP, that differentiates it from other Enterobacteriaceae
S. marcescens
100
Which organisms in the Enterobacteriaceae family will be subject to serotyping to confirm their identity? Which antigens are involved?
Salmonella, O, H, and K
101
Which organisms exhibits slow lactose fermentation?
C. freundii
102
Which organism produces a characteristic mucoid colony?
K. pneumonia
103
Which biochemical reactions would you use to differentiate Proteus spp. from Salmonella spp.?
Urea test?
104
How would you differentiate Klebsiella spp. from Enterobacter spp?
Motility
105
Which test would differentiate P. mirabilis from P. vulgaris
Indole
106
Name the only lactose fermenting, H2S producer in the family of Enterobacteriaceae.
Citrobacter
107
Name special selective agars for E. coli 0157:H7, Y. enterocolitica, V. vulnificus, Salmonella and Shigella, B. cepacia
NEED ANSWER!!!
108
Which organism produces a distinctive purplish hue on MacConkey? Is this lactose fermentation
Acinetobacter spp. and no
109
How would you differentiate an organism like S. maltophilia from Acinetobacter spp. or Pseudomonas spp.
NEED ANSWER!!!
110
What are the pigments produced by P. aeruginosa?
NEED ANSWER!!!
111
How can P. aeruginosa be distinguished from fluorescent pseudomonads?
NEED ANSWER!!!
112
How would an LIA slant help you differentiate P. aeruginosa from V. parahemolyticus?
NEED ANSWER!!!
113
What odors are associated with P aeruginosa and S. maltophilia
P. aeruginosa - grapelike or corn-tortilla
| S. maltophilia - ammonia
114
What characteristic color may be associated with Acinetobacter on Mac?
Purple
115
How does salmonella spp. appear on HE and Mac plates?
HE - green w/black center
| Mac - NLF
116
How does E. coli appear on HE and Mac plates?
HE - orange
| Mac - fluorescent pink
