micro lab final Flashcards
(124 cards)
1
Q
stain reagent Crystal Violet
A
primary stain
2
Q
stain reagent Iodine
A
mordant
3
Q
stain reagent Alcohol/Acetone
A
decolorizer
4
Q
stain reagent Safranin
A
counter stain `
5
Q
When are bacteria considered no longer infectious during the Gram Stain procedure?
A
Non-infectious After: Fixation (heat or alcohol).
6
Q
What Shapes are Bacilli?
A
Rod shaped
7
Q
what shape are cocci?
A
spheres(round)
8
Q
what shape are diplococci?
A
ovoid pairs
9
Q
what shapes are spirochetes?
A
spiral
10
Q
what shape are coccobacilli
A
short rods
11
Q
What shapes/orientations are in Staph?
A
GPC in clusters
12
Q
What shapes/orientations are in strep?
A
GPC in chains
13
Q
What shapes/orientations are in micrococcus?
A
GPC in tetrads
14
Q
What shapes/orientations are in yeast?
A
GPC-like, large ovals
15
Q
What is a Direct Gram Stain? Why do physicians order them?
A
From specimen (shows infection); ordered for quick diagnosis.
16
Q
what does selective mean in media?
A
Grows specific group (e.g., MAC for GNs)
17
Q
what does nutrient mean in media?
A
general growth
18
Q
what does differential mean in media?
A
Distinguishes based on traits (e.g., MAC – lactose fermenters)
19
Q
what is MAC selective for?
A
GN bacteria
20
Q
what is CNA selective for?
A
GP bacteria
21
Q
what is MSA selective for?
A
staph spp. (high salt)
22
Q
what is BAP differential for?
A
Hemolysis
23
Q
hemolysis with a clear yellow zone
A
beta
24
Q
hemolysis with a green background
A
alpha
25
no hemolysis on BAP
gamma
26
what is MAC differential for? what color does it turn?
differential for lactose fermentors (pink)
27
what is CNA differential for?
hemolysis of GP
28
what is MSA differential for?
mannital fermentation(yellow)
29
CHOC media is a nutrient for what 2 bacteria species?
Nutrient-rich; grows Haemophilus & Neisseria
30
Microaerophilic
Low O₂ (micro)
31
Capnophilic
High CO₂
32
what special media goes with N. gonorrhoeae
MTM
33
enrichment broth to grow anaerobic or aerobic
THIO
34
nutrient broth to grow GBS
LIM broth
35
selective and differential medium used to identify Enterococcus and Group D Streptococcus species
BE=Bile esculin
36
oculars is what magnification
10x
37
low magnification is what
10x
38
high magnification is what
40x
39
oil immersion is what
100x
40
total magnification for low is what?
100x
41
total magnification for high is what?
400x
42
total magnification for oil is what?
1000x
43
What is the definition of microscopic working distance?
Space between lens and slide.
44
When do we use Course adjustment knob?
Only for 10x;
45
When can you NOT use the course adjustment knob?
never use at 40x or 100x
46
What is Quadrant streaking good for? how do you quantitate bacterial growth?
Isolates colonies; quantifies as 1+ to 4+.
47
How do you Streak a Urine?
Draw the sample into a vertical or horizontal streak (primary streak) at the center of the plate. Using the same loop spread the inoculum by continuously moving the loop in back and forth (zigzag) motion crossing the primary streak
48
What are the sizes of the 2 common urine loops used?
1 μL (0.001 mL), 10 μL (0.01 mL)
49
when using 1 uL loop how much do you multiply by?
1000
50
when using a 10 uL loop how much to multiply by?
100
51
0.001mL is calibrated for which loop?
1uL
52
0.01 mL is calibrated for which loop?
10uL
53
What are the 2 Quality Control organisms used for Catalase controls?
pos (staph aureus) : neg (strep pyogenes)
54
What are the 2 Quality Control organisms used for Coagulase controls?
pos (staph aureus) : neg (staph epi)
55
what does a positive catalase test look like?
bubbles
56
what does a positive tube coagulase test look like?
a clot in the tube
57
what does a positive coagulase slide test look like?
clumping
58
coagulase slide test; extracellular or cell bound?
cell bound
59
coagulase tube test; extracellular or cell bound?
extracellular
60
What does positive Bile Esculin look like?
Black = Positive
61
Which Streps did we learn were positive for BE?
group D enterococcus
62
What does positive 6.5% NaCL test look like?
turbidity or cloudiness
63
Which Streps did we learn were positive for 6.5%NaCL?
enterococcus
64
What does positive PYR test look like?
Pink/cherry red = Positive
65
hich Streps are PYR positive?
S. pyogenes, Enterococcus
66
What is a 0.04 Bacitracin disk? What organisms are sensitive/resistant to it?
disk with 0.04 bacitracin in it S. pyogenes = Sensitive
GBS= resistant
67
What is a “P” disk? What is the chemical name for it? What organisms are sensitive/resistant to it?
(Optochin):
S. pneumoniae = Sensitive
viridans group= resistant
68
What is the CAMP test? what does it stand for?
micro test used to identify GBS
Christie, Atkinson, Munch, Peterson
69
What does positive Oxidase look like? Know how to perform this test.
purple =pos
70
What does sensitive / resistant look like on a plate.
Clear = Sensitive
Growth to disk = Resistant
71
What is Novobiocin disc used for? How would you read this test?
to differentiate Staph sapro from other clinically significant coagulase-negative. look for zone of inhibition
S. saprophyticus = Resistant
72
β-hemolytic, A disk sensitive,
Strep pyogenes
73
β-hemolytic, CAMP +, Hippurate +, part of normal vaginal flora.
Strep agalactiae (GBS)
74
Gram stain morphology and catalase reaction of Streptococcus
GPC in chains / catalase negative
75
Hemolysis of Streptococcus
beta, alpha, gamma
76
a small, grayish-white, dome-shaped appearance with smooth or moist surfaces and clear margins, surrounded by a zone of beta-hemolysis
colony characteristics of Strep pyogenes
77
Group A strep virulence factors
streptolysin O, hyaluronidase
78
stab agar to check for certain hemolysis (streptolysin O) main pathogen in throat cultures
Strep pyogenes
79
3-4 mm in diameter, gray-white, flat, and mucoid, beta hemolysis
GBS colony characteristics
80
alpha hemolytic, mucoid, and silvery colonies, sometimes having umbilicate colonies due to autolysis (self digestion) after a certain stage of development
Strep pneumoniae
81
bile soluble + (pos test is clear tube)
strep pneumo
82
beta alpha or gamma hemolysis, small circular colonies 1-2 mm in diameter, can appear mucoid or smooth. Some strains may be elevated, especially if they are heavily encapsulated.
group D strep colony characteristics
83
how to differentiate group D from enterococcus?
NaCl growth, enterococcus grows in 6.5% NaCl
84
small (1-3 mm diameter), moist, convex, and semitranslucent colonies on blood agar, alpha beta or gamma Hemolysis, 6.5 NaCl pos
Enterococcus
85
VRE can cause what type of reactions?
pseudo catalase reaction (false positive)
86
gram stain morphology and catalase reaction of staphylococcus
GPC in clusters/ catalase pos
87
beta hemolytic staph that is coagulase positive
Staph aureus
88
similar to staph aureus, slide coagulase test pos but tube test negative
staph lugdunesis
89
On mannitol salt agar these colonies appear yellow (ferment mannitol)
staph aureus
90
large, circular, golden-yellow, and convex, beta hemolytic
staph aureus
91
small, white, and opaque; 1-2 mm in diameter. round, raised, and have complete edges. they tend to stick together. gamma hemolysis; CoNS
staph epi
92
zone of inhibition to
Novobiocin >17 mm
CoNS; Staph epi
93
Color: creamy white to pale yellow.
Shape: Round or slightly irregular.
Size: 1-3 mm in diameter.
Texture: smooth, glistening
colonies can appear slightly raised or convex; gamma hemolysis
CoNS; Staph sapro
94
resistant to novobiocin
Staph sapro
95
GPC in tetrads, oxidase +, Bacitracin sensitive
micrococcus
96
circular, yellow, convex and smooth colonies with gamma hemolysis; colonies could reach up to 4mm
micrococcus
97
how to differentiate micrococcus from staph
bacitracin susceptability or oxidase
micrococcus-S
staph-R
98
micrococcus is commonly known as what?
contaminent except for immunocompromised patients
99
What does yeast look like on a gram stain?
GPC-like; budding or pseudohyphae
100
what does yeast look like on BAP?
white
101
Quick test to differentiate from colonies of Staph from yeast ?
germ tube
102
What are X and V factors? What media are they found in?
X Factor = Heme
V Factor = NAD
CHOC = Both factors
103
Where does satellitism show up and with what 2 organisms?
H. influenzae colonies "satellite" to S. aureus on BAP because they can access the released growth factors from the lysed rbcs
104
what are in each quadrant in a quad plate
quadrant 1: x factor (hemin)
quadrent 2: v factor (NAD)
quadrant 3: x and v
quadrant 4: x, v, and SBA
105
GNCB or GNB; special media or growth requirements (Quad plates); X & V
factor; no hemolysis
H. influenzae
106
GNCB or GNB; Quad plate growth; V factor only required, no hemolysis
H. parainfluenzae
107
GNCB or GNB that resemble school of fish or train tracks on gram stain
H. ducreyi
108
GNDC, Ox +, Cat +, needs MTM, ferments glucose
N. gonorrhoeae
109
GNDC, Ox +, Cat +, ferments glucose & maltose
N. meningitidis
110
Differentiate N. lactamica and N. sicca from the other Neisseria based on CTA fermentation tests
N. lactamica ferments lactose and N. sicca does not; N. sicca ferments sucrose and N. lactamica does not
111
GNDC; DNAase+; Hockey Puck’ colonies
Moraxella catarrhalis
112
differentiate Neisseria from moraxella cat. with CTA
fermentation test;
moraxella neg for all sugars; neisseria spp ferments some sugars
113
Acceptable Aerobic vs. Anaerobic culture specimen types
aerobic=pretty much anything
anaerobic= tissues; aspirates
114
How long are AFB/Fungal cultures incubated for?
up to 6 weeks
115
How long can urine cultures be held at room temp before being processed?
2 hours
116
Instrument that provides Moist heat Sterilization of Biological Waste using pressurized
Steam; 121⁰C, 15lbs pressure for 15 minutes
autoclave
117
provides classification (nature) of a chemical, General characteristics, precautions to take while using; emergency information, cleanup
procedure; disposal recommendations.
MSDS/SDS
118
Biologic Safety Level 1
harmless
119
Biologic Safety Level 2
moderate risk
120
Biologic Safety Level 3
aerosal pathogens
121
Biologic Safety Level 4
lethal high risk
122
Hazardous Materials Classification color blue is for what?
Health
123
Hazardous Materials Classification color red is for what?
fire
124
Hazardous Materials Classification color yellow is for what?
reactivity
