Quiz #2 Flashcards
3/10-3/24
1
Q
what does acid-fast bacterial cell wall contain
A
mycolic acid
2
Q
what is mycolic acid
A
- waxy lipid
- makes cell impermeable to most stains/dyes
3
Q
what does mycolic acid prevent
A
dessication
digestion after phagocytosis
4
Q
what are acid-fast genera
A
Mycobacterium
Nocardia
5
Q
pathogenic examples of acid-fast bacteria
A
Mycobacterium tuberculosis
Mycobacterium leprae
6
Q
what bacteria causes tuberculosis
A
Mycobacterium tuberculosis
7
Q
what does Mycobacterium tuberculosis cause
A
tuberculosis
8
Q
what bacterium causes leprosy
A
Mycobacterium leprae
9
Q
what does Mycobacterium leprae cause
A
leprosy
10
Q
what does acid alcohol do in acid-fast stains
A
de-stains non-acid-fast bacteria previously stained with a primary dye
11
Q
acid-fast bacteria is/is not affected by acid alcohol
A
is not - it retains primary dye coloring
12
Q
Acid-fast procedure
A
1) make a smear, heat fix
2) flood slide with carbolfuchsin over steam heat
3) add acid alcohol
4) counterstain with Methylene Blue
13
Q
what is carbolfuchsin
A
dark red basic dye that contains phenol
14
Q
what color is bacteria after step 2 of acid-fast stain procedure
A
all bact. = red
15
Q
what color is bacteria after step 3 of acid-fast stain procedure
A
non-acid-fast bact. = colorless
acid-fast bact. = red
16
Q
what is a major component of carbolfuchsin
A
phenol
17
Q
phenol is more/less soluble in waxy lipids than acid alcohol
A
more soluble
18
Q
what color is bacteria after step 4 of acid-fast stain procedure
A
non-acid-fast bact. = blue
acid-fast bact. = red
19
Q
what is a capsule
A
gelatinous coat surrounding some bacteria
20
Q
what are capsules made of
A
uncharged polysaccharides
21
Q
capsules increase/decrease bacterial virulance
A
increase
22
Q
virulance definition
A
degree of pathogenicity
23
Q
how do capsules increase bacterial virulance
A
- prevents dessiccation
- adheres to surfaces
- resists phagocytosis
- nutritional reserve
24
Q
how are capsules used as a nutritional reserve
A
capsule is composed of polysaccharides -> carbs that can be used as a nutritional backup
25
capsule differential stain procedure
1) make a negative stain with Nigrosin
2) Add crystal violet
26
what color is the bacteria after step 1 of capsule differential stain
bact = colorless
background = black
27
what color is the bact. after step 2 of capsule differential stain
bact = purple
capsule = colorless
background = black
28
does the capsule get dyed
no - it is uncharged and stains are colored ions
29
what is a vegetative body
actively metabolizing
30
what is an endospore
not actively metabolizing
31
can all cells produce endospores?
no, only specific bacteria
32
which types of bact. produce endospores
Bacillus
Clostridium
33
what does Bacillus anthracis cause
anthrax
34
what causes anthrax
Bacillus anthracis
35
what does Clostridium botulinum cause
botulism
36
what bacteria causes botulism
Clostridium botulinum
37
what does Clostridium tetani cause
tetanus
38
what causes tetanus
Clostridium tetani
39
what does Clostridium difficile
colitis
40
what causes colitis
Clostridium difficile
41
what is the formation of endospores called
sporogenesis
42
what triggers sporogenesis
harsh environments
43
endospore structure
- smaller and more compact than vegetative bodies
- endospore coat
44
what is an endospore coat made of
thick layer of keratin + calcium diplocholinate
45
what are endospores resistant to
heat
alcohol
UV
drying
etc.
46
what is endospore germination
when the environment inmproves, an endospore can germinate back into vegetative body
47
endospore differential stain procedure
1) make a smear, heat fix
2) add malachite green over steam heat
3) completely rinse malachite green off with water
4) counterstain with safranin
48
why is steam heat important for endospore differential stain
heating is required to allow malachite green to cook into thick endospore coat
49
what is the destainer for endospore differential stain
water
50
what color is the bact after step 4 of endospore differential stain
vegetative bodies = red
endospores = green
51
why does safranin not stain endospores
not over steam heat so cannot penetrate endospore coat
52
motility definition
self-directed movement of an organism
53
how is motility done
via cilia, pseudopods, or flagella
54
brownian motion definition
vibrational movement caused by collusion with H2O molecules
55
is brownian motion true motility
no
56
can flagella be seen with basic dye
no - too thin
57
example of bact. with flagella
Spirillum volutans
58
Flagellar arrangements
monotrichous
amphitrichous
lophotrichous
peritrichous
59
what is a monotrichous arrangement
one flagellum on cell
60
what is an amphitrichous arrangement
flagella on both ends of cell
61
what is a peritrichous arrangement
flagella go around entire cell
62
what is a lophotrichous arrangement
multiple flagella at one end of cell
63
3 ways to check for motility
wet mount
hanging drop
semi-solid agar
64
microscopic techniques to check for motility
wet mount
hanging drop
65
culture-based techniques to check for motility
semi-solid agar
66
how much agar does semi-solid agar contain
0.5%
67
how much agar does normal solid media contain
1.5%
68
procedure of culturing motility
1) aseptically inoculate bact. using inoculating needle
2) incubate @ 37°C
69
results of semi-solid agar culturing
motile = hazy growth away from stab line
non-motile = one crisp line of growth
70
advantage of semi-solid agar culturing
only accounts for living cells
71
disadvantages of semi-solid agar culturing
- requires ~24 hours of incubation
- results can be difficult to interpret
72
fungi are eukaryotes/prokaryotes
eukaryotes
73
are fungi autotrophs or heterotrophs
heterotrophs
74
saprotrophic definition
obtain nutrients from dead, organic matter
75
are all fungi pathogenic
no - only some
76
what is mycosis
fungal infection
77
what is fungal cell wall made of
chitin
78
how are fungi useful in industry
antibiotics
cheese
bread
alcohol
79
do fungi prefer more or less sugar
more sugar
80
do fungi prefer more basic or more acidic environments
acidic/lower pH
81
On what do you culture fungi
Sabouraud Dextrose Agar (SAB)
82
traits of SAB
higher sugar conc.
pH of 5.6
83
types of microscopic fungi
yeast
mold
dimorphic
84
are yeasts uni or multicellular
unicellular
85
what shape are yeasts
round/ovoid
86
how do yeasts reproduce
asexual budding
87
are molds uni or multicellular
multicellular
88
what shape are molds
fillamentous w/ hyphae
89
how to molds reproduce
asexual or sexual via spores
90
what are dimorphic fungi
can switch between yeast form and mold form due to the environment
91
hyphae definition
long filaments
92
types of hyphae
vegetative hyphae
reproductive hyphae
rhizoids
93
mold structures
hyphae
septate vs non-septate
94
what are vegetative hyphae
grow laterally on surface
95
reproductive hyphae definition
grow vertically and give rise to spores
96
what are rhizoids
grow beneath surface
97
septate definition
separated into compartments
98
non-septate definition
not separated into compartments
99
types of spores
sporangiospores
conidiospores
ascospores
zygospores
100
sporangiospores definition
spores in a sac
101
sporangium definition
sac
102
sporangiophore definition
reproductive hyphae giving rise to sporangiospores
103
conidiospores definition
free spores
104
conidium definition
entire head of conidiospores
105
conidiophore definition
reproductive hyphae giving rise to conidiospores
106
ascospore definition
spores inside of an ascus
107
zygospore formation
formed by sexual reproduction
108
types of chemical control agents (3)
disinfectants
antiseptics
chemotherapeutic agents
109
when to use disinfectants
- inanimate surfaces
- NOT on skin
- do NOT ingest
110
example of a disinfectant
bleach
lysol
111
when to use antiseptics
- on living tissue
- skin is ok
- do not ingest
112
examples of antiseptics
rubbing alcohol
iodine
soap
mouthwash
113
chemotherapeutic agents use
taken into body
114
3 types of chemotherapeutic agents
antibiotics
semisynthetics
synthetics
115
Where do antibiotics come from
produced by microbes
116
anitibiotic example
penicillin by Penicillium chrysogenum
117
semisynthetics definiton
modified antibiotics
118
semisynthetics example
ampicillin (modified penicillin)
119
synthetics example
sulfa drugs
120
narrow spectrum definition
only effective against one group of organisms
121
narrow spectrum is effective against ___
EITHER gram-pos OR gram-neg bact.
122
example of narrow spectrum
Penicillin G - gram-pos
123
broad spectrum definition
effective against wide range of bact.
124
broad spectrum is effective against
BOTH gram-pos AND gram-neg
125
broad spectrum example
Ampicillin
126
2 ways to test effectiveness of a Chemical Control Agent
Disk Diffusion Method
Kirby Bauer Test
127
disk diffusion method procedure
1) make a 3x lawn of bact. on Nutrient Agar Plate
2) soak disks in CCAs
3) place disks on 3x lawn
4) incubate plate @ 37°C for ~24-48 hours
5) after incubation, visually check for Zones of Inhibition (ZOI)
128
ZOI definition
clear zone around disk where bacteria didn't grow
129
what does it mean that there is a ZOI present
agent is effective
130
when ZOI present, bacteria is ___
susceptible/sensitive to agent
131
what does it mean that there is not a ZOI present
agent is ineffective
132
when ZOI is not present, bacteria is ___
resistant to agent
133
Kirby Bauer test definition
disk diffusion test used in clinical labs to determine effectiveness of chemotherapeutic agents
134
medium for Kirby Bauer test
Mueller-Hinton Agar
135
are disk diffusion tests standardized
no
136
is the Kirby Bauer test standardized
yes
137
how is the Kirby Bauer test standardized
pH = 7.2-7.4
thickness = 4mm
138
Kirby Bauer test procedure
1) make a 3x lawn of bact onto Mueller-Hinton Agar
2) add disks containing standard concentrations of chemotherapeutic agents (CAs)
3) incubate @ 37°C for 16-18 hours
4) after incubating, measure the diameter of ZOI with a ruler, then compare to table to determine if bact. are susceptible, intermediate, or resistant to CAs
139
microbial antagonism definition
microbes suppress growth of other microbes
140
example of microbial antagonism
Penicillum chrysogenum & Staphylococcus aureus
