Day 2: Interpretation Flashcards
1
Q
What is a positive DN’ase test
A
Zone of clearance around colonies
2
Q
What is a negative DN’ase test
A
No zone of clearance around the colonies
3
Q
What organisms produce a positive DN’ase result
A
S. aureus
M. Catarrhalis
4
Q
What organisms produce a negative DN’ase result
A
S. epidermidis, S. saprophyticus
N. species e.g. N. meningitidis,
5
Q
What is a positive mannitol salt agar test
A
Yellow colonies on mannitol agar indicate mannitol fermenter and salt tolerant
6
Q
What is a negative mannitol salt agar test
A
Red colonies on mannitol salt agar indicate non mannitol fermenter but salt tolerant
7
Q
What species are positive on mannitol salt - yellow/pink and growth?
A
S. aureus
8
Q
What species are negative on mannitol salt - red/pink but growth
A
S. epidermidis or S. saprophyticus
9
Q
What does it mean if an organism doesn’t grow on mannitol agar
A
It is not salt tolerant i.e. its a staphylococcus
10
Q
What does pink colonies on SAIDE agar indicate
A
Staphylococcus aureus
11
Q
What is a negative Staphaurex plus result
A
No agglutination
12
Q
What is a positive Staphaurex plus result
A
Agglutination
13
Q
What species will give a positive Staphaurex plus result
A
Only S. aureus
14
Q
What species of staphylococcus give a negative staphaurex plus result?
A
Coag negative staph e.g. S. epidermidis or S. saprophyticus
15
Q
What is a positive result for optochin susceptibility?
A
Susceptibility -> zone of no growth around optochin disk
16
Q
What is a negative result for optochin susceptibilty?
A
Resistance -> growth around optochin disk
17
Q
What species will give a positive optochin result?
A
S. pneumonia (susceptible)
18
Q
What species will give a negative optochin result?
A
S. viridans (resistant)
19
Q
What is a positive Lancefield test?
A
Agglutination
20
Q
What is a negative Lancefield test?
A
No agglutination
21
Q
What does a Lancefield group A indicate?
A
Streptococcus pyogenes
22
Q
What does a Lancefield group B indicate?
A
Streptococcus agalactiae
23
Q
What does Lancefield group C indicate?
A
Streptococcus equi (most probable)
Streptococcus epidemicus
Streptococcus equisimilis
24
Q
What does Lancefield group D indicate?
A
Streptococcus bovis
Or the more probable Enterococcus -> E. faecalis
25
What does Lancefield group F indicate?
Streptococcus anginosus
26
What does Lancefield group G indicate?
Streptococcus canis
Streptococcus dysgalactiae
27
What is a positive bacitracin test?
Susceptible to bacitracin
28
What is a negative bacitracin test?
Resistant to bacitracin
29
What species give a positive bacitracin test?
Streptococcus pyogenes (susceptible)
30
What species give a negative bacitracin test?
Enterococcus species
31
What is a positive result for MacConkey agar?
Pink colonies
32
What is a negative result for MacConkey agar?
Yellow colonies
33
What species will give a positive result on MacConkey?
Enterococci
34
What species will give a negative result on MacConkey?
Streptococci
35
What is a positive bile aesculin test?
Blackening of the medium
36
What is a negative bile aesculin result
No blackening of the medium
37
What species will give a positive result on bile aesculin agar?
Enterococci
38
What species will give a negative result on bile aesculin agar?
Streptococci
39
What TAXO sugars does N. Meningitidis utilise?
Glucose
Maltose
40
What TAXO sugars does N. Gonorrhoeae utilise?
Glucose
41
What TAXO sugars does N. flavescens utilise?
None
42
What TAXO sugars does N. lactamica utilise?
Glucose
Maltose
Lactose
43
What TAXO sugars does N. sicca utilise?
Glucose
Maltose
Sucrose
44
What Neisseria species ferments glucose only?
Gonorrhoeae
45
What Neisseria species ferments none of the TAXO sugars ?
N. flavescens
46
What Neisseria species ferments glucose and maltose?
N. meningitidis
47
What Neisseria species ferments glucose, maltose and lactose?
N. lactamica
48
What Neisseria species ferments glucose, maltose and sucrose?
N. sicca
49
What is a positive result for the TAXO sugar test?
Yellow colour -> colour change from red to yellow upon addition of the phenol red indicator
50
What is a negative result for the TAXO sugar test
Red colour -> no colour change upon addition of the phenol red indicator
51
What is a positive catarrhalis disc test?
Blue-green colour development
52
What is a negative catarrhalis disc test?
No colour development within 2 minutes
53
What species will give a positive catarrhalis disc test?
M. catarrhalise
54
What species will give a negative catarrhalis disc test?
Neisseria species
55
What is a positive lecithinase reaction on PEMBA agar?
Zone of clearance around colonies
56
What is a negative lecitihinase reaction on PEMBA agar?
No zone of clearance around colonies
57
What is a positive mannitol fermentation reaction on PEMBA agar?
Yellow colonies
58
What is a negative mannitol fermentation reaction on PEMBA agar?
Blue colonies
59
What bacillus species will grow on PEMBA agar as blue colonies with a zone of clearance?
B. cereus or B. thuringenesis
60
What bacillus species will grow on PEMBA agar as blue colonies with a variable narrow zone of clearance?
B. anthracis
61
What bacillus species will grow on PEMBA agar as yellow colonies with no zone of clearance?
B. subtilis
62
How does B. cerues and B. thuringensis look on PEMBA agar?
Blue colonies with a zone of clearance
63
How does B. anthracis look on PEMBA agar?
Blue colonies with a narrow zone of clearance
64
How does B. subtilis look on PEMBA agar?
Yellow colonies with no zone of clearance
65
What exactly does motility look like?
Movement in a definite direction
66
What species of bacillus are motile
B. cerues
B. thuringenesis
B. subtilis
67
What species of bacillus are non motile
B. anthracis
68
What is a positive trehalose test
Yellow colour change
69
What is a negative trehalose test
No colour change = pink colour
70
What is a positive urease test
Pink colour change
71
What is a negative urease test
No colour change = yello
72
What species of Corynebacteria will give a positive trehalose and positive urease test?
C. ulcerans
73
What species of Corynebacteria will give a negative trehalose and a negative urease test?
C. diptheria
74
What species of Corynebacteria will give a negative trehalose and positive urease
C. pseudotuberculosis
Diptheroids
75
How will C. ulcerans look in the trehalose and urease tests?
Trehalose = yellow = positive
Urease = pink = positive
76
How will C. diptheria look in the trehalose and urease tests?
Trehalose = pink = negative
Urease = yellow = negative
77
How will C. pseudotuberculosis and the diptheroids look on the trehalose and urease tests?
Trehalose = pink = negative
Urease = pink = positive
78
What species will grow on Tinsdale agar?
Only Corynebacteria will grow on Tinsdale
79
How does C. diptheriae/C. ulcerans appear on Tinsdale medium?
Black colonies with brown halos
80
How do the diptheroids look on Tinsdale medium
Dark brown colonies without halos
81
What species grows on Tinsdale medium with black colonies and no discoloration of the medium?
Diptheroids such as haemophilus, klebsiella, neisseria, staphylococcus and streptococccus
82
What species of Corynebacteria grows on Tinsdale medium with black colonies and brown halos/discoloration of medium?
C. diptheria
C. ulcerans
83
What is a positive result for lactose fermentation in the lactose-gelatin tubes?
Yellow colour
84
What is a negative result for lactose fermentation in the lacctose-gelatin tubes?
Red colour
85
What is a positive result for gelatinase in the lactose-gelatin tubes?
Liquid formation
86
What is a negative result for gelatinase in the lactose-gelatin tubes?
Gel formation
87
How does C. perfringens appear in the lactose-gelatin tubes
Yellow liquid
Lactose fermentation - positive = yellow
Gelatinase - positive = liquid
88
How does C. tetani/ C. difficile appear in the lactose-gelatin tubes?
Red gel
Lactose fermentation - negative = red
Gelatinase - negative = gel
89
How does C. botulinum/ C. sporogenes appear in the lactose-gelatin tubes?
Red liquid
Lactose fermentation - negative = red
Gelatinase - positive = liquid
90
Which species will appear as a yellow gel in the lactose-gelatin tubes?
E. coli
91
Which species will appear as a yellow liquid in the lactose-gelatin tubes?
C. perfringens
92
Which species will appear as a red gel in the lactose gelatin tubes
C. tetani
C. difficile
93
Which species will appear as a red liquid in the lactose gelatin tubes?
C. botulinum and C. sporogenes
94
What is a positive lecithinase result for the egg yolk agar
opaque diffuse zone
95
What is a negative lecithinase result for the egg yolk agar
No opaque diffuse zone
96
What is a positive lipase result for the egg yolk agar?
Pearly/shiny layer
97
What is a negative lipase result for the egg yolk agar?
Absence of pearly/shiny layer
98
Which species will give a positive lecithinase but a negative lipase result on egg yolk agar?
C. perfringens
99
Which species will give a negative lecithinase and negative lipase result on egg yolk agar?
C. tetani
C. difficile
100
Which species will give a variable amount of lecithinase activity and a positive lipase result on egg yolk agar?
C. botulinum
101
Which species will give a negative lecithinase and a positive lipase result on egg yolk agar?
C. sporogenes
102
What is a positive Naglar test result
Disappearance of opacity
103
What is a negative Naglar test result
No disappearance of opacity
104
How does B. fragilis appear on the MID8 mastring test?
Erythromycin = Occassionally susceptible
Rifampicin = Susceptible
Colistin sulphate = Ocassionally resistant
Penicillin = Resistant
Kanamycin = Resistant
Vancomycin = Resistant
105
What growth factors does H. influenzae need?
X factor and V factor
106
What growth factors does H. parainfluenzae need?
V factor only
107
What growth factors does H.ducreyi need?
X factor only
108
What growth factors does H. aegyptius need?
X factor and V factor
109
What growth factors does H. aphrophilus need?
Variable growth with X only
110
What haemophilus species need both X and V factors to grow
H. influenzae
H. aegyptius
111
What haemophilus species need V factor only to grow
H. parainfluenzae
112
What haemophilus species need X factor only to grow
H. ducreyi
H. aphrophilus (variable growth with X only)
113
What is a positive result for King's A Medium
P. aeruginosa grows at 37 degrees with green fluorescence
114
What is a negative result for King's A Medium
P. fluorescence will grow but won't be fluorescent green
E.Coli will not grow at all
115
What does pink/red on Brilliance chromagar suggest?
E. Coli
116
What does turquoise/blue-green indicate on brilliance chromagar?
Enterococcus species
117
What does dark blue/purple indicate on brilliance chromagar
Colliforms -> enterobacteroides
118
What does brown halos indicate on brilliance chromagar
Proteus
Morganella
Providencia
119
What does brown/green translucent indicate on brilliance chromagar
Pseudomonas
120
What does non pigmented indicate on brilliance chromagar
Staphylococci
Streptococci
121
What does pink indicate on brilliance chromagar
S. saprophyticus
122
What is a positive citrate test
Colour change from green to blue
123
What is a negative citrate test
No colour change - green colour
124
What is a positive indole test?
Cherry red colour development after addition of 8 drops kovaks reagent
125
What is a negative indole test?
No colour development after addition of Kovaks reagent
126
What is a positive MR test?
Maintenance of red colour following addition of MR solution
127
What is a negative MR test?
A yellow colour persists following addition of MR solution
128
What is a positive VP test?
Red colour development after addition of the VP reagent 1 and 2
129
What is a negative VP test?
No red colour development after addition of the VP reagents 1 and 2
130
What is a positive dulcitol test?
Colour change from pink to yellow
131
What is a negative dulcitol test?
No colour change -> pink colour
132
What is a positive decarboxylase test?
Purple colour
133
What is a negative decarboxylase test?
Yellow colour
