Type of Media Flashcards
(131 cards)
1
Q
differentiate Staphylococcus from Streptococcus
A
CATALASE TEST
2
Q
differentiate Micrococcus from Streptococcus
A
OXIDASE TEST; BACITRACIN ST
3
Q
differentiate S. aureus from CONS
A
COAGULASE TEST
4
Q
identification test for S. aureus
A
DNAse TEST
5
Q
differentiate the CONS
A
NOVOBIOCIN ST
6
Q
Check the presence the bacteria in patient sample
A
PRIMARY OR DIRECT GRAMSTAIN
7
Q
Lookout for inflammatory or pus cells
A
PRIMARY OR DIRECT GRAMSTAIN
8
Q
Used as basis for the
secondary gram staining
A
PRIMARY OR DIRECT GRAMSTAIN
9
Q
Presence of complete hemolysis ( β-hemolytic) on BAM
A
may suggest S. aureus or β-hemolytic streptococci
10
Q
degrades the red cells in the agar; hence, the clearing on BAM
A
HEMOLYSIN
11
Q
Absence of hemolysis on BAM
A
γ-hemolytic
12
Q
makes MSA selective for HALOPHILES
A
High salt concentration (7.5%NaCl)
13
Q
differentiates MF and MNF on MSA
A
Mannitol fermentation
14
Q
Fermentation on MSA
A
produces acids = change in pH =
change in color
15
Q
pH indicator of MSA
A
phenol red = turns red in alkaline pH
and turns yellow in acidic pH
16
Q
MFs of MSA
A
S. aureus and S. saprophyticus
17
Q
MNFs of MSA
A
S. epidermidis and S. lugdunensis
18
Q
allows growth of gram positive cocci, while inhibiting most gram negative microbes on PEA
A
Selective agar
19
Q
inhibits or markedly reduces the growth of Gram-negative organisms by interfering with DNA synthesis
A
phenylethyl alcohol
20
Q
used for the selective growth of Staphylococcus and Streptococcus in mixed cultures
A
PHENYLETHYL ALCOHOL AGAR (PEA)
21
Q
used to isolate most gram-positive and gram-negative anaerobes from enteric samples
A
PEA with sheep’s blood (ENRICHED-SELECTIVE)
22
Q
inhibits facultative gram-negative rods
A
PEA with sheep’s blood (ENRICHED-SELECTIVE)
23
Q
COLUMBIA (CNA) AGAR: type of media
A
Enriched/differential/selective medium
24
Q
supports growth of fastidious organisms on CNA
A
Addition of 5% defibrinated sheep’s blood =
25
Hemolytic patterns
COLUMBIA (CNA) AGAR
26
binds to LPSs and phospholipids in the outer cell membrane of Gram-negative bacteria
Colistin (10mg)
27
blocks DNA replication in susceptible bacteria (Gram neg) by inhibiting a subunit of DNA gyrase
Nalidixic acid (10mg)
28
Vogel-Johnson (VJ) Agar: type of media
Selective medium; Differential medium
29
toxic to gram negative bacteria
potassium tellurite
30
favors growth of Staphylococcus spp
Lithium chloride and Glycine
31
Blackish colonies
tellurite (colorless) reduction to metallic tellurium (black) = S. aureus
32
No blackening/ transparent colonies
other Staphylococcus
33
Color change from red to yellow
mannitol fermenter
34
Ph indicator
phenol red
35
color remains red
color remains red
36
Chapman Stone Agar: type of media
Selective medium (5.5% NaCl); Differential
37
Chapman Stone Agar: fermentation
mannitol fermentation
38
turns yellow in acidic pH on CSA
bromcresol purple
39
substrate in Gelatin hydrolysis
Gelatin
40
allows visualization of gelatin liquefaction in Gelatin hydrolysis
Ammonium sulfate
41
Yellow colonies surrounded by clear halo (gelatinase +), MF
S. aureus
42
White nonpigmented colonies with or without clear halo
S. epidermidis
43
Small yellow colonies, MF
Enterococcus, Group D strep
44
Baird-Parker Agar: type of media
Enriched medium
Selective medium
Differential medium
45
enhances growth of Staphylococcus on BPA
Sodium pyruvate and glycine
46
toxic to most microbes esp gram negative bacteria on BPA
Tellurite
47
used for observance of proteolysis (lecithinase-clearing around the colony) and lipolysis (lipase-opaque zone around the colony upon 24H incubation) on BPA
Egg yolk
48
Black, shiny, convex colonies 1-5 mm in diameter with a narrow, white edge, lecithinase and lipase +
S. aureus
49
Black, shiny, irregular shape, Lecithinase –, lipase +
S. epidermidis
50
“staphyle”
“staphyle”
51
Grapelike clustering of gram + cocci
STAPHYLOCOCCUS
52
are commonly seen from broth of STAPHYLOCOCCUS
Singles, pairs, tetrads and chains
53
Resembles Staphylococcus
MICROCOCCUS
54
MICROCOCCUS Also produces [?] but shorter
clusters
55
MICROCOCCUS are Usually in packets of
four or eight
56
Test used to detect the presence of enzyme catalase
CATALASE TEST
57
CATALASE TEST: reagent
Uses 3% H2O2
58
an enzyme that degrades H2O2 into water and oxygen
CATALASE
59
CATALASE Allows the bacteria to survive
peroxides
60
CATALASE + result & control
effervescence or vigorous bubbling = MICROCOCCACEAE
61
CATALASE - result & control
no effervescence or weak to few bubbles = STREPTOCOCCACEAE
62
Determines the presence of cytochrome oxidase
OXIDASE TEST; MODIFIED OXIDASE TEST (MICRODASE)
63
used in aerobic respiration -> transfer electron (H) to Oxygen to form water
Cytochromes
64
OXIDASE TEST: reagent
p-phenylenediamine dihydrochloride
65
Substitute to oxygen
p-phenylenediamine dihydrochloride
66
OXIDASE TEST: Reduced state
colorless, oxidized = indophenol blue
67
OXIDASE TEST: Positive result
formation of BLUE color = Micrococcus
68
OXIDASE TEST: Negative result
no change in color = Staphylococcus
69
MODIFIED OXIDASE TEST (MICRODASE)
| Uses filter paper disks impregnated with
1% tetramethyl-p-phenylenediamine in dimethyl sulfoxide (DMSO)
70
aids in the permeability of cells to the reagent (allows interaction of oxidase and cytochrome C) and stability against auto-oxidation (decreases false positive result)
DMSO
71
MODIFIED OXIDASE TEST (MICRODASE): Positive result
blue-purple color within 30 seconds = Micrococcus
72
Used to reduce false positive result from metal inoculating loop
wooden applicator stick
73
MODIFIED OXIDASE TEST (MICRODASE): Negative result
no color change in 30seconds = Staphylococcus
74
(+) atmospheric oxygen
oxidase enzyme + oxidase reagent & cytochrome C = indophenol
When exposed to atmospheric oxygen, the oxidase enzyme reacts with the oxidase reagent and cytochrome C to yield the colored compound, indophenol indicated as [?] on the disc after the bacterial colony is introduced on the disc.
blue or purplish blue coloration
75
Medium used in O/F TEST
HUGH and LEIFSON’S MEDIUM
76
the only carbohydrate included in the medium
GLUCOSE
77
non-glucose utilizer
Asaccharolytic/nonsaccharolytic
78
glucose utilizer
Saccharolytic
79
turns yellow in acidic pH in O/F test
Bromothymol blue/green
80
(pH indicator) for O/F TEST
Bromothymol blue/green
81
O/F TEST detects ability of the bacteria to utilize glucose through oxidative process (?), both fermentative and oxidative () or not at all (?)
AEROBE
FACULTATIVE ANAEROBE
Asaccharolytic
82
O/F TEST uses two tubes
with mineral oil = ?
without mineral oil = ?
(anerobic environment)
| aerobic
83
Both tubes turned yellow suggest use of glucose with and without oxygen
Facultative anaerobe = Staphylococcus
84
Aerobic tube turns yellow, the anerobic tube remains blue/green suggest use of glucose in presence of oxygen only
Obligate aerobe = Micrococcus
85
do not USE glucose, but may utilize other carbohydrate
Both remains green/blue
86
One tube for unknown (with Lysostaphin), another tube for negative control (without Lysostaphin)
TUBE METHOD
87
10ug of lysostaphin
AGAR DISK SENSITIVITY TEST
88
TUBE METHOD: Positive result
bacteria is lysed by lysostaphin resulting to clearing (clearing means no growth or death of bacteria) of the sample tube = Staphylococcus
89
TUBE METHOD: Negative result
bacteria resist lysis so sample remains turbid = Micrococcus
90
AGAR DISK SENSITIVITY TEST: RESISTANT
SUSCEPTIBLE
91
AGAR DISK SENSITIVITY TEST: SUSCEPTIBLE
10 to 16 mm = Staphylococcus
92
is one of the synthetic antimicrobial nitrofurans with antiprotozoal and antibacterial activity.
Furoxone (furazolidone)
93
Furazolidone binds bacterial DNA which leads to the gradual inhibition of
monoamine oxidase
94
FURAZOLIDONE ST: Resistant
Zone of inhibition ≤ 9 mm = Micrococcus spp
95
FURAZOLIDONE ST: Sensitive
Zone of inhibition > 15 mm = Staphylococcus spp
96
Must be tested for catalase test first; To rule out Streptococcus species
BACITRACIN ST
97
BACITRACIN ST is known as
TAXO A
98
Due to sensitivity of [?] strep to this antibiotic
Group A
99
Uses [?] of Bacitracin
0.04U
100
BACITRACIN ST: RESISTANT
<10 mm ZOI = Staphylococcus
101
BACITRACIN ST: SUSCEPTIBLE
10-20 mm ZOI = Micrococcus
102
Test for bound catalase / “clumping factor”
SLIDE COAGULASE TEST
103
clumping will occur because the clumping factor is an [?] which causes cells to bind fibrinogen in plasma
adhesin
104
SLIDE COAGULASE TEST
| is not a definitive test for
S. aureus
105
Negative result still needs to undergo
tube coagulase test
106
presence of [?] in negative control invalidates the test
autoagglutination
107
possible due to dirty glass slides
autoagglutination
108
SLIDE COAGULASE TEST: Positive result
clumping within 10s = S. aureus, S. lugdunensis, S. schleiferi
109
SLIDE COAGULASE TEST: Negative result
homogenous/ no clumping
110
Around [?] of S. aureus strains test negative
15%
111
Test for free coagulase
TUBE COAGULASE TEST
112
May act to coat the bacterial cells with fibrin making them resistant to
opsonisation and phagocytosis
113
Uses lyophilized EDTA rabbit plasma
↑CRF = better clotting
114
Breaks fibrin clot and allow the spread of infection to contiguous tissues
Staphylokinase
115
TUBE COAGULASE TEST: Positive result
clot/gel formation = S. aureus
116
False positive: TUBE COAGULASE TEST
citrate-using organisms such as Pseudomonas species, Serratia marcescens, Enterococcus faecalis, and some strains of Streptococcus will coagulate citrated plasma (EDTA plasma is preferred over citrated plasma)
117
Negative result: TUBE COAGULASE TEST
no clot formation = Coagulase negative staphylococcus (CONS)
118
a hydrolytic enzyme that depolymerizes and degrades DNA
Deoxyribonuclease
119
Dyes used in DNAse test
Methyl green or
| Toluidine blue O
120
Positive result: DNAse test
clearing around colony = S. aureus
121
Negative result: DNAse test
no clearing = CONS
122
allows better visualization of the clearing if no dye is included in the agar
HCl
123
inhibitor of DNA gyrase
Novobiocin disk (5ug)
124
usually performed on urine isolates (isolated from women of reproductive age group) that are coagulase-negative
Novobiocin sensitivity test
125
usually performed on urine isolates (isolated from women of reproductive age group) that are
coagulase-negative
126
is second only to E. coli as the most frequent causative organism of uncomplicated urinary tract infections (UTIs)
S. saprophyticus
127
RESISTANT: Novobiocin sensitivity test
<12mm ZOI = S. saprophyticus
128
SUSCEPTIBLE: Novobiocin sensitivity test
>16mm ZOI S. aureus, S. epidermidis
129
diagnostic to S. saprophyticus with [?], coagulase negative result
γ-hemolytic
130
Encapsulated (mucoid colonies)
Staphylococcus epidermidis
131
may be positive in the tube test
S. Intermedius (dogs) and S. hyicus (pigs)
