CHAPTER 2 Flashcards
(149 cards)
1
Q
five i’s of microbology
A
inoculation
incubation
isolation
inspection
identification
2
Q
to culture something means
A
to grow organisms
3
Q
medium
A
nutrients for the growth of microbes
4
Q
inoculum
A
a small sample of microbes
5
Q
inoculation
A
the introduction of an inoculum into media to culture microbes
6
Q
where are clinical specimens obtained form
A
bodily fluids, discharges, diseased tissues, anatomical sites
7
Q
whats an incubator?
A
a temperature controlled chamber to encourage the multiplication of microbes
8
Q
what temperatures are used in lab propagation of micro organisms
A
20-45 c or 68-113 F
9
Q
atmospheric gases such as ___ or ____ may be required for the growth of certain microbes
A
oxygen or carbon dioxide
10
Q
t/f after incubation you still can macroscopically see any growth
A
FALSE you can see with plain eye
11
Q
3 states of media are
A
physical state ( solid, liquid)
Chemical Composition (Defined/Synthetic, Complex)
Functional Type
12
Q
what are the three physical states of media
A
liquid
semi solid
solid (soil that can be converted to liquid + solid that can not)
13
Q
agar is made from
A
a complex polysaccharide isolated from Gelidium
14
Q
t/f agar is solid at room temperature
A
true
15
Q
what temperature does agar liquidify
A
100 C or 212F
16
Q
what temperature does it solidify
A
42c (107.6F)
17
Q
___ medium is flexible and moldible
A
agar
18
Q
t/f agar is digestible for most microorganisms
A
false
19
Q
whats a defined/synthetic media
A
composition is precisely chemically defined
contains pure organic and inorganic compounds that vary little
molecular content is exact, exact formula
20
Q
what is complex media
A
one or more components is not chemically defined
contains extracts of animals, plants or yeasts
ex. blood, serum, meat extracts or infusion, milk yeast peptone
21
Q
whts teh opposite of complex media
A
defined/synthetic
22
Q
a media to grow a broat spectrum of microbes is a _____
A
broad spectrum media
23
Q
t/f broad spectrum media are synthetic/defined
A
false. complex
24
Q
enriched media is an example of _____ media
A
complex
25
enriched media contains complex organic substances (blood, serum, hemoglobin) or special growth factors for the growth of ______ microbes
fastidious
26
what type of media is used in the laboratory to encourage growth of pathogens present in low numbers
enriched media
27
_____ contains one or more agents that inhibit the growth of a certain microbe of microbes and favoring the growth of desired ones
selective media
28
a ____ media is important in isolation of a specific type of microorganism from a sample containing dozens of different species
selective
29
is MacConkey Agar a selective or differential media
BOTH
Selective:
MacConkey Agar selects for Gram negative enterics (bacteria in intestinal track) (E.coli)
Differential: The medium provides lactose and a pH indicator, allowing for differentiation; lactose fermenters produce acid, resulting in phenol red turning pink colonies, while non-fermenters remain colorless.
30
how is SIM Sulfur Indole Motility (SIM) a differential media
Sulfur Indole Motility (SIM) medium is differential because it allows for the identification of bacteria based on three characteristics:
Sulfur Reduction: Some bacteria can reduce sulfur to hydrogen sulfide (H₂S), which reacts with iron salts in the medium to form a black precipitate. This indicates sulfur reduction.
Indole Production: After incubation, the addition of Kovac's reagent reveals indole production. If the organism can convert tryptophan to indole, a red ring forms at the top of the medium.
Motility: SIM medium is semi-solid, allowing motile bacteria to spread from the stab line, resulting in turbidity throughout the medium. Non-motile bacteria will only grow along the stab line.
30
is Blood agar selective or differential
Blood agar is a differential medium because it can distinguish between different types of bacteria based on their ability to lyse red blood cells and degrade hemoglobin. It contains intact red blood cells, and bacteria that produce hemolysins can break down these cells, resulting in visible changes in the aga
31
CNA Agar is differential of selective
selective for Gram positive cocci
32
Mannitol Salt Agar (MSA) is selectie or differential
BOTH
Selective for Staphylococcus species because high salt content adn many cant grow (halophile species can )
Differential - mannitol fermenters vs non. Fermenters = acidic red to yellow ph indicator (phenol red)
33
Sabouraud's Agar is selective or differential
Selective for Fungi
34
_______ media allow multiple organisms to grow but display the visible differences in how they grow
differential
35
Media color changes is an example of ___ media
differential
36
t/f production of gas bubbles is an example of selective media
differential
37
reducing medium
contains a substance that absorbs oxygen or slows the penetration fo oxygen
38
Thioglycolic acid broth is good for growing ______
anaerobs
39
reducing medias are important for growing
anaerobic bacter
40
what is transport media used for
maintain and preserve specimens that have to be held for a long time before clinical analysis (chemicals in it maintain species for longer)
41
what is the red showing
red is the lactose fermentors,
whitish are not
differential media- MacConkey Agar
phenol red
42
43
Carbohydrate Fermentation Media is esentially a ____ broth
nutrient broth
44
what is carbohydrate fermentation media
liquid that contains sugars that can be fermented with a pH indicator to show reaction (sucrose and manitol)
with fermentation, color change red - yellow as well as air space to show if organism produces gas (o2) (DIFFERENTIAL MEDIA)
45
what is the pH indicator in carbohyrate fermentation media
phenol red ... turns red to yellow
45
assay media is used for
testing the effectiveness of antimicrobial drugs
46
what si enumeration media used for
industrial and enviornmental microbologists to count the numbers of organisms in milk, water, food soil
47
Whats a colony forming unit
a term used to more appropriately describe that a colony might have been formed by more than one cell of the same species
48
t/f only sterilize loop after first inoculation
what is this called
false after each step
streak plate
49
what is this called
pour plate/loop dilution
50
what is this called
spread plate
51
microbes can be identified through
- Microscopic appearance
- characterization of cellular metabolism (methobolic pathways - do they produce enzymes or not)
- determination of nutrient requirements, products given off during growth
- presence of enzymes and mechanisms for deriving energy
genetic adn immonological chatacteristcs
52
dimentionals of microscopic organisms range from
mm, um and nm
(cm, m = macro)
53
1um = 1000 nm
1um = .001 mm
54
protozoa and algae are on average what size
3-4 mm
55
yeasts are generally what size
3-4 um
56
the smallest bacteria are ___ and largest are ____
200nm - 750 um
57
t/f viruses are larger than bacteria
FALSE - much much smaller with very few exceptions
58
how big are viruses
20nm and 400nm (MOST)
some as big as 800 - 1500 nm
59
real image is formed by the ____
objective lens
60
virtual image is formed _____
when the image is projected up through teh microscope body to the plane of the eye piece the occular lens forms a second image
61
resolving power also known as
resolution
62
resolving power of human eye
.2mm
63
resolving power or the light microscope using oil immersion
.2um
64
t/f with oil immersion 90% of light rays pass up through objective lens
false - 100%
65
refractive index
degree of bend that light undergoes as it passes from one medium to the next
66
t/f the HIGHER the difference in the refractive indexes (more bending of light) the sharper the contrast registered by the microscope
TRUE
67
t/f too much light can reduce contrast and burn out the image.
how do you control this
true
iris diaphphragm
68
Use the ______ to control the amount of light coming into the _____.
iris diaphragm, condensor
69
type of microscope that forms an image when light is transmitted through the specimen
bright field microscope
70
a brihgt field microscope can be adapted as a dark field microscope by adding a disc called a ____ to the condensor
stop
71
what does a stop do?
blocks all light from entering the objective lens, except the peripheral light that is reflexted off the sides of the specimen itself. creates a beautiful illuminated specimen around a dark field
72
when to use a dark field microscope
to visualize living cells that would be distorted by drying or heat or that cannot be stained with the usual methods
73
what microscope is this image from
bright field scope
74
versitile microscope, live dead, unstained, stained
bright field
75
what microscope is this from
darkfield scope
76
what microscope
phase contrast
77
what does the phase contrast microscope take advantage of
the fact that cell structures differ in density
78
________ microscope contains devices that transform the subtle changes in light waves passing though the specimen into differences in light intensity
phase contrast
79
the detail visable by this method of miscropy is greater than that of bright or dark field
phase contrast
80
what is phase contrast most useful for observing
intracellular structures (ornganelles, granules, bacterial endospores
81
_____ overcomes the problem of cells or structures being too thick by using a laser beam of light to scan various depths inteh specimen and deliver a sharp image
confocal
82
what microscope is able to capture highly focused view at any level of the cell
confocal
83
the _____ microscope is a specially modified compound microscope furnished with an UV radiation source
fluorescnece
84
for an image to be formed in fluorescence microscope must be coated in ____ and UV lights it up
fluorescence
85
most useful applications in fluorescence microscopy is diagnosing _______ and pinpointing ________
infections, particular cellular structures (pathogy labs, diagnostics)
86
what microscope
fluorescence
87
what microscope
confocal
88
for viewing the detailed structure of the cells and viruses use the ______ microscope
Transmission electron microscope
89
how does the TEM microscope work
by transmitting electrons through the specimen
90
t/f because they are electrons, the TEM microcscope can easily penetrate thick preparations
FALSE - must be sectioned into extremely thin slices (20-100nm) and stained or coated with metals that increase image contrast
91
what microscope
Transmission electron microscope
92
what are the dark adn light parts
dark = dense part of cell and light = more transparents, less dense
93
94
what microscope creates the most dramatic and realistic image
scanning electron microscope ( SEM)
95
what microscope creates this
SEM scanning electron microscope
96
consists of a drop or two of culture placed on a slide and overlaid with a cover slip
wet mount
97
a drop of culture is placed in a concave (depression) slide. vasaline adhesive or sealant and a cover slip are used to suspend the sample
hanging drop
98
two fresh living preparation techniques
hanging drop, and wet mount
99
t/f unstained cells in a fixed smear are difficult to see regardless of magnification and resolving power
true
100
basic dyes have a ____ charge
positive (cationic)
101
acidic dyes have a ___ charge
negative (anionic)
102
only SOME bacteria have a negative charge
FASE ( all bacteria)
103
_______ stain dye sticks to the specimen and gives it color
positive
104
when dye does not stick to the specimen but settles some distance from its outer boundary (forms silhouette) we call this a
negative stain
105
in a negative stain we ALWAYS heat fix
FALSE ( not heat fixed so the distoration adn shrinkage of cells is reduced)
106
t/f negative stain keep accurate shape of cell
TRUE - no heat fixing
107
____ stains are used to accentuate a capsule
negative stains
108
t/f simple stains require two dyes
false - single dye
109
_____ stains cause all the cells in the smear to appear the same color regardless of type,
simple
110
_____ stains reveal shape, size, arrangement
simple
111
_____ stains use two differently colored dyes the primary dye and counter stain
differential stain
112
what type of stain is used to distinguish cell types or parts
differential
113
what is a capsule mad from
thick polysaccharide coating
114
when were differential stains developed
1884 Hans christian Gram
115
what two stains are used for negative stain?
Nigrosin and India ink
116
what is the primary stain in gram staining
Crystal violet
117
what is the mordant in gram staning
Gram's iodine, allows primary stain to form insoluble complex in peptidoglycan so to not leak out
118
what is the decolorizer in gram staining
alcohol
119
what is the counter stain in gram staining
ex. Safranin
120
t/f ALL bacteria can be categorized as gram + or gram -
false - most bacteria
121
t/f gram staining has everything to do with the charge of the cell
false - has to do with the cell wall
122
_____ stain remains the universal basis for bacterial classification and identification
gram staining
123
what does acid fast mean
acid resistant
124
what type of stain is acid- fast
differential
125
what does acid-fast stain do
differentiates acid fast (acid resistant) bacteria vs not
126
how did acid fast stain originate?
as a method to detect Mycobacterium tuberculosis
127
what does Mycobacterium tuberculosis do when acid-fast stained?
their cell wall holds fast (tightly) to the dye carbolfuchsin) when washed with an acid decolorizer (acid resistant)
128
what bacteria is acid fast
Mico (genus), and Norcardia both are pathogens
129
what dye is used in acid-fast staining
carbolfuchsin
130
endospore is a _____ stain
differential
131
both acid-fast staining and endospore staining dye is forced by _____ into resistant bodies
heat
132
what does endospore stain do
stain distinguishes between endospores and vegetative cells
133
t/f a vegetative cell contains an inner spore
fa;lse
134
endospore stain is significant in identifying GRAM +, spore forming members of genus ________ and ___________
Bacillus and clostridium
135
shape of gram - cells
shape of gram + cells
rods , the red
cocci, purple
136
what stain is this and what does blue and purple represent
acid fast,
blue = not acid fast (not acid resistant)
purple = acid fast (holds dye in cell wall even w acidic decolorer)
137
what are special stains
used to emphasize cell parts that are not revealed by conventional staining methods
138
two examples of special stains
capsular staining and flagellar staining
139
what stain is this adn what are the colors
endospore, endospores are green, and vegetative cells pink
140
what stain is this
capsule stain with india ink
141
what stain is this
flagellar
141
what stain is campsule stain
differential
142
what stain is acid fast stain
differential
143
what stain is crystal violet
simple
144
what stain is gram stain
differentialha
145
what stain is flagellar
special
146
