Bacterial Cell Flashcards
1
Q
Bacteria with no cell wall
A
- Mycoplasma
- Ureaplasma
- Spiroplasma
- Anaeroplasma
2
Q
2 alternating dissacharides in peptidoglycan/murein layer
A
- N-acetyl-D-glucosamine
2. N- acetyl-D-muramic acid
3
Q
small circular molecule of DNA containing accessory information
A
Plasmids
4
Q
most commonly found in gram negative bacteria, each carries genes for its own replication. It can confer resistance to antibiotices
A
Plasmids
5
Q
What is the chromosomal DNA of prokaryotes?
A
Circular, complexed with RNA
6
Q
Typical size of bacteria
A
- 4 - 2 micrometer in diameter
0. 5 - 5 micrometer in length
7
Q
Site of energy production in prokaryotes
A
Cytoplasmic membrane
8
Q
Present in most prokaryotes as an organized capsule or unorganized slime layer
A
Glycocalyx
9
Q
gives the bacterial cell shape and strength to withstand changes in environmental osmotic pressures
A
Cell wall
10
Q
Protects against mechanical disruption of the cell
A
cell wall
11
Q
Offers some barrier to the passage of larger substances
A
cell wall
12
Q
Characteristics of Gram positive cell wall
A
- Thich cell wall
2. Presence of techoic and lipotechoic acid
13
Q
provides rigidity to cell wall by attracting cations such as magnesium and calcium
A
Teichoic acid
14
Q
Characteristics of Gram negative cell wall
A
- Thin peptidoglycan later
- Periplasmic space
- outer membrane
15
Q
Componentes of the outer membrane
A
- proteins
- phospholipids
- lipopolysaccahride
16
Q
It acts as a barrier to hydrophobic compounds and harmful substances
A
Outer membrane
17
Q
It acts as a sieve, allowing water-soluble molecules to enter through protein-lined channels called porins
A
Outer membrane
18
Q
It provides attachment sites that enhance attachment to host cells
A
outer membrane
19
Q
How long are the cells saturated/flooded with primary stain in gram staining?
A
60 seconds or 1 minute
20
Q
How long will the mordant stay before rinsing off in gram staining?
A
60 seconds or 1 minute
21
Q
How long is the slide rinsed with alcohol in gram staining?
A
20 seconds or until there is no run off of color
22
Q
Color of gram positive bacteria
A
mid - dark purple
23
Q
Color of gram negative bacteria
A
pink - red
24
Q
what decolorizer is used in gram staining?
A
acetone alcohol
25
Reagents of gram staining
V (crystal Violet)
I (Iodine)
A (Alcohol)
S (Safranin red)
26
Characteristic exhibited by gram positive bacteria
Gram variability
27
Bacteria with natural gram variability
1. Mobiluncus spp.
| 2. Gardnerella vaginalis
28
Contributing factors of gram variability
1. Use of old culture
2. pH of staining reagents
3. Bacterial autolysis
4. Staining reaction time
29
very difficult to stain using gram staining
Spirals
30
Result of gram staining in spirals
gram negative
31
contain a waxy layer of glycolipids and fatty acids (mycolic acid)
Acid fast organisms such as mycobacterium spp. and nocardia spp.
32
specifically designed for a subset of bacteria whose cell walls contain long-chain fatty (mycolic) acids.
acid fast staining
33
render the cells resistant to decolorization, even with acid alcohol decolorizers
Mycolic acid
34
most commonly encountered acid-fast bacteria
Mycobacterium
35
What specimen is used for Mycobacterium tuberculosis?
sputum or phlegm specimen
36
Partially acid-fast organisms
1. Nocardia
2. Rhodococcus
3. Legionella micdadei
37
Distinctly acid-fast organisms
1. Cryptosporidium
| 2. Isospora (Cystoisospora belli/Isospora belli)
38
Mordant used in Ziehl-Nee Isen method
Heat
39
Reagents used in Ziehl-Nee Isen method
1. Carbol Fuschin
2. Acid Alcohol
3. Methylene Blue
40
Reagents used in Kinyoun method
1. Carbol Fuschin
2. Tergitol
3. Acid alcohol
4. Methylene blue
41
Acid alcohol in Ziehl-Nee Isen method
3% HCl in 95% Ethanol
42
Acid alcohol in Kinyoun method
3% H2S04 in 95% Ethanol
43
Color of acid fast organism
Red
44
Color of non acid fast organism
Blue
45
Fluorochrome stain used in Acid fast staining
Auramine-Rhodamine
46
Color of acid fast bacteria using fluorochrome stain
Yellow or orange
47
Stain used for observation of metachromatic granules
Methylene Blue / LAMB
48
Stain used to detect WBC such as in stool samples
Methylene Blue
49
How long is the cell counterstained in Gram staining?
30 Seconds
50
Color of the stained cells in the specimen (such as epithelium, WBC, RBC, and amporphous background material) in gram staining
It should appear pink (gram-negative)
51
Stain used to locate bacteria in blood cultures and other specimens where discerning bacteria might be difficult
Acridine orange ( a fluorochrome dye)
52
Stain that binds to chitin in fungal cell walls
Calcofluor White
53
It fluoresces a bright apple green or blue-white, allowing visualization of fungal structures with a fluorescent microscope
Calcofluor White
54
Used to stain the cell walls of medically important fungi grown in slide culture
Lactophenol Cotton Blue
55
Negative stains used for visualization of certain yeasts such as cryptococcus spp.
India ink and nigrosin
56
Commonly used to stain bacterial spores
Schaefer-Fulton spore stain
57
Primary stain of Schaefer-Fulton
Malachite green
58
How long is the heat-fixed smear heated to steaming with the primary stain in Schaefer-fulton spore stain
about 5 minutes
59
How long is the preparation washed to remove primary stain in schaefer-fulton stain?
30 seconds
60
What counterstain is used in schaefer-fulton stain?
Safranin
61
What is the color of the endospores and the bacterial cells in schaefer-fulton stain?
Green endospores within pink or red appearing bacterial cells
62
0 AFB seen Fuchsin stain in 1000x magnification
No AFB seen
63
1-2/300 fields AFB seen Fuchsin stain in 1000x magnification
Doubtful
64
1-9/100 fields AFB seen Fuchsin stain in 1000x magnification
1+
65
1-9/10 fields AFB seen Fuchsin stain in 1000x magnification
2+
66
1-9/field AFB seen Fuchsin stain in 1000x magnification
3+
67
>9/field AFB seen Fuchsin stain in 1000x magnification
4+
68
0 AFB seen Fluorochrome stain in 450x magnification
No AFB seen
69
1-2/70 fields AFB seen Fluorochrome stain in 450x magnification
Doubtful
70
2-18/50 fields AFB seen Fluorochrome stain in 450x magnification
1+
71
4-36/10 fields AFB seen Fluorochrome stain in 450x magnification
2+
72
4-36/field AFB seen Fluorochrome stain in 450x magnification
3+
73
>36/field AFB seen Fluorochrome stain in 450x magnification
4+
74
0 AFB seen Fluorochrome stain in 250x magnification
No AFB seen
75
1-2/30 fields AFB seen Fluorochrome stain in 250x magnification
Doubtful
76
1-9/10 fields AFB seen Fluorochrome stain in 250x magnification
1+
77
1-9/fields AFB seen Fluorochrome stain in 250x magnification
2+
78
10-90/field AFB seen Fluorochrome stain in 250x magnification
3+
79
>90/field AFB seen Fluorochrome stain in 250x magnification
4+
80
Contains sterols
Mycoplasma and ureaplasma
81
phospholipid bilayer embedded with proteins that envelops the cytoplasm but does not contain sterols
Cytoplasmic membrane
82
Separates the intracellular components of the bacterial cell from the extracellular environment
Cytoplasmic membrane
83
Acts as an osmotic barrier between the inside and outside of the bacterial cell by allowing selective permeability of the
membrane to macromolecules
Cytoplasmic membrane
84
Site of electron chain transport
Cytoplasmic membrane
85
Deepest layer of cell envelope
Cytoplasmic membrane
86
Houses enzymes involved in outer membrane and cell wall synthesis, and the assembly and secretion of extracytoplasmic and extracellular substances
Cytoplasmic membrane
87
Folds or invagination along the length of the cytoplasmic/plasma membrane which serves as a point of attachment for chromosomes
Mesosomes
88
Sites of protein synthesis
Free ribosomes
89
Size of ribosomes in bacterial cells
70s; two subunits 50s and 30s
90
Storage deposits and may consisits of polysaccharides and lipids
Cytoplasmic granules mainly in Mycobacterium tuberculosis
91
Some bacteria produce this in response to harsh environmental conditions
Endospores
92
Small, dormant, asexual spores that develop inside bacterial cell as a mean of survival
Endospores
93
Their thick protein coat makes them highly resistant to chemical agents, temperature change, starvation, dehydration, UV and gamma radiation, and dessication.
Endospores
94
Highly refractile bodies in the cell
Endospores
95
Has a terminal spore that gives it a tennis racquet shaped or lollipop shaped appearance
Clostridium tetani
96
Why is antimicrobial agents more effective in gram positive organisms rather than gram negative organisms?
Antimicrobial agents prevent synthesis of peptidoglycan. Gram negative bacteria have a thinner layer with different wall structure so they are less affected by these agents
97
Two important sporulating bacteria
1. Bacillus
| 2. Clostridium
98
Anchored to the cell wall or peptidoglycan
teichoic acid
99
Anchored to the plasma membrane
lipoteichoic acid
100
One of its region has an antigenic 0 specific polysaccharide
Lipopolysaccharide of the outer membrane
101
Responsible for producing fever and shock conditions infected with gram negative bacteria
Lipid A moiety (endotoxin)
102
A strong hydrophobic molecule that forms a lipid shell around the organism and affects its permeability
Mycolic acid
103
It avoids chemical damage and dehydration; Allows bacteria to grow inside macrophage
Mycolic acid
104
Seen in various shapes microscopically
pleomorphic
105
Acts as a virulence factor in helping the pathogen evade phagocytosis
Capsule
106
Why capsule needs to be removed during identification of certain bacteria by serologic typing
To detect the somatic (cell wall) antigens present underneath them
107
Why the Salmonella thypi must have its capsular (Vi) antigen removed?
To observe agglutination with Salmonella somatic (O) antisera
108
Medically important capsulated bacteria
1. Neisseria Meningitidis
2. Haemophilus influenza serotype B
3. Streptococcus Pneumoniae
4. Klebsiella Pneumoniae
5. Bacillus anthracis
6. Pseudomonas areuginosa
7. Salmonella typhi
8. Cryptococcus neoformans
109
gel-like matrix containing nutrient-binding proteins and degradative and detoxifying enzymes
Periplasmic space
110
Associated with K Antigen
Capsule
111
uniform and condensed organized material that is firmly attached to the cell wall of the bacteria
Capsule
112
Loose or diffused, thick, viscous unorganized material that appears to be detached from the bacterial or not firmly attached to the cell wall of the bacteria
Slime layer
113
serves as a form of protection from
phagocytosis, or in some instances, it helps the
bacteria to adhere to host tissues or synthetic
implants such as prosthetic heart valves
Slime layer
114
exterior protein filaments or whip-like projections which is embedded in the cell envelope with a motor attached in a basal body responsible for its propeller-like rotation of the flagella which makes bacteria move.
Flagella
115
Associated with H Antigen (Hauch Antigen) which is very useful in serologically typing and identifying species of Salmonella
Flagella
116
Protein projections that are thinner and shorter than flagella and are most usually found in gram negative bacteria
Pili
117
Main compositions of Endospores
Calcium Dipicolinate or Calcium-Dipicolinic Acid Complex
118
It means no definite form or shapeless
Amorphous
