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Flashcards in Lab Practical 1: Study Guide Deck (174)
1

____ means "without microorganisms"

aseptic

2

______ refers to practices that help reduce the risk of microbial exposure, transmission, and contamination.

aseptic technique

3

Aseptic techniques ____ or kill microorganisms from hands and objects, reducing the risk of transfer of potential pathogens.

remove

4

Aseptic techniques employ ______ instruments and other items.

sterile

5

Aseptic techniques _____ patient's risk of exposure to microorganisms.

reduce

6

_____ are 100-1000 times smaller than most mammalian cells; they range from 0.5 to 3 micrometers.

bacteria

7

Microorganisms differ widely in ____ and ____.

shape and size

8

The majority of bacteria are either spheres or ____.

rods

9

shaped spheres are called ____.

cocci, plural coccus

10

shaped rods are called ____.

bacilli, plural bacillus

11

a mix between cocci and bacilli are called _____.

coccobacili, plural coccobacillus

12

curved rods are called ____.

vibrio

13

The ____ and ____ of the cells with their staining properties are used for classifying and preliminarily identifying clinical isolates.

shape and arrangement

14

To grow and isolate microorganisms, the specimen is spread (______) onto agar media containing nutrients to yield individual colonies. These individual ______ can be then further tested for identification.

streaked

15

_____ is used to grow (culture) microorganisms.

growth media

16

Different types of media used in the lab are to be chosen to suit the ______ of the species to be grown.

species

17

Typically, media is a mixture of nutrients, moisture, amino acids, _____, buffers, etc.

growth factors

18

Two main categories of media used for microbial growth

artificial culture media
tissue culture media

19

This type of media contains the necessary nutrients to grow a variety of bacteria and fungi.

artificial culture media

20

This type of media can be solid or broth form.

artificial culture media

21

______ media is broth that has had agar added to it allowing it to take on the consisenticy of firm gelatin.

artificial culture media

22

Certain bacterial species of clinical interest will not grow on artificial culture media, including ______ and ______ as well as viruses.

chlamydiae genus: Chlamydia
Rickettsiae genus: Rickettsia

23

This type of media contains living cell/tissues which act like "host" cells in order to grow and study viruses and other obligate intracellular organisms.

tissue culture media

24

These two obligate intracellular pathogens need tissue culture media to grow.

Chlamydia
Rickettsia

25

3 forms of artificial media

broth
agar slant
agar plates

26

_____ is a liquid medium that becomes turbid as bacteria grow in numbers. There are many different types.

broth

27

_____ refers to the change that occurs in broth as bacteria grow - the more bacteria grow, the more they increase the cloudiness of the broth, changing it from the original clear to "cloudy" appearance.

turbidity

28

______ is agar, derived from seaweed, is added to liquid media, heated and allowed to solidify so that the agar surface in the test tube is slanted.

agar slant

29

____ is agar poured into a petri dish and allowed to solifify. This produces a relatively large flat surface for bacterial growth and isolation.

agar plates

30

3 varieties of agar and broth

selective
non-selective
differential

31

_____ is media that supports the growth of most (but not all) bacteria of clinical interest.

non selective

32

3 types of non selective media

sheep's blood agar (SBA)
Trypticase soy agar (TSA)
nutrient agar (NA)

33

_____ is media that encourages the growth of one species or group of species while inhibiting the growth of others.

selective media

34

____ can be useful when attempting to grow a particular organism, while inhibiting the growth of other organisms which might be found in the same environment.

selective media

35

Selective media often contains certain ____ in low concentration, bile salts, high NaCl concentration or other substances to inhibit and/ or encourage growth.

dyes

36

_______ allows for a specific metabolic activity of an organism to be detected by visual inspection of the growth of the organism. This is often accomplished by observing changes in the ____ of a pH indicator.

Differential media
color

37

______ can provide information about characteristics of various microbes aiding in their identification.

differntial media

38

4 types of differential media

triple sugar iron agar (TSI)
mannitol salt agar (MSA)
sheep's blood agar (SBA)
MacConkey agar

39

Some media can be both differential and selective. They ____.

do not have to be both

40

What variety is Mannitol Salt Agar?

selective and differential

41

_______ contains 8.5% salt which inhibits many common microorganisms, while allowing for the growth of Staphylococcus species which are naturally salt tolerant.

Mannitol Salt Agar (MSA)

42

What variety is MacConkey Agar?

selective and differential

43

_____ is selective for gram negative orgnaisms. It contains bile salts and crystal violet dye which inhibit the growth of gram poisitive organisms.

MacConkey agar

44

_____ media is differntial for lactose fermentation. Lactose ferminting species turn dark purple/pink while lactose negative species remain tan or light colored.

MacConkey agar

45

______ is made by adding 5% sheep's blood to a nutrient TSA medium. The intact red blood cells give the medium a bright red color similar to the color of fresh blood.

Sheep's blood agar (SBA)

46

What variety is sheep's blood agar?

non selective and differential

47

Sheep's blood agar allows for the growth of a variety of microbes, but the media is differential by means of ____.

red blood cell hemolysis

48

____ hemolysis is the complete breakdown of RBCs. Bacterial cells secrete ______ hemolysins that completely lyse the RBCS.

Beta
beta

49

The result of beta hemolysis results in a clearing of the "blood" around the colonies that can appear ____ to clear depending on the strength of hemolysis.

yellowish

50

_____ hemolysis is the partial breakdown of RBC. Bacterial cells secrete hemolysins that cause lysis of the RBCs without completely breaking down the hemoglobin. This leaves a _____ hue in the medium.

alpha
greenish

51

______ hemolysis is no hemolysis. Bacteria grow on blood agar without disturbing the red blood cells -leaving them intact.

gamma

52

Lab 1 compared ways to reduce bacterial contamination by comparing ____ with ____.

hand washing
hand sanitization

53

Hand washing is a mechanical ______ of microorganisms that results from soap creating an emulsification of oils and water, trapping dirt and microbes in the process.

removal

54

Alcohol based hand sanitizers contain a high enough concentration of alcohol (typically 60-95%) to have a ______ on most bacteria and viruses.

killing effect

55

Unlike soap and water, hand santiizers do not remove ____. So it is recommended that people in health care settings who use hand sanitizer also use soap and water intermittently throughout the day.

dirt and grime

56

What was more effective at reducing bacterial numbers....soap or hand sanitizer?

soap

57

____ is normal and permanently colonizes the haost and is established during the first few month of life.

resident microbiota

58

______ is normal and colonizes the host for a short period of time and do not persist in the host's body due to the body's defenses.

transient microbiota

59

Do we want our skin to be "sterile", completely free of microbes?

No, microbes that live on the skin prevent other dangerous microbes from being able to get a foothold. Microbes have also been show to prime the immune system to respond to pathogens.

60

______ is the ability to see two items that are close together as two separate and individual objects.

resolution

61

_______ is a numerical measure indicating the resolution of lens, the smaller the distance between objects that can be distinguished, the greater the _____ of the lens.

resolving power of lens
resolving power

62

In a ____ microscope an object is in focus at low magnification it will remain in focus when switching to a higher magnification.

parfocal

63

In a _____ microscope, when an object is centered in the field of view at low magnification it will remain centered when switching to a higher magnification.

parcentric

64

____ is the fending of light as it passes from one medium to another of different density.

refraction

65

_______ is the measure of how greatly a substance slow the velocity of light (causing refracation)

refractive index

66

______ indicates the magnification power of that lens alone.

lens power

67

____ is defined as the total magnification power of all lenses used. In this class we will be using a ____ light microscope which use use two lenses to magnify an image.

magnification
compound

68

Ocular lens has a magnification power of ____.

10x

69

There are 3 to 4 different ____ lenses you can choose from that range from 4 x, 10x, 40x, and 100x.

objective lens

70

____ is the ocular magnification x the objective magnification.

total magnification

71

___ is the lens that you look through.

ocular lens (10x)

72

______ aka turret is what holds the objective lenses and can be rotated to lock each objective into place directly above the specimen.

revolving nosepiece

73

______ range in power from 4x to 100x. The shortest lens is the lowest power, the longest lens has the greatest magnification power.

objective lense

74

____- is the flat platform where you place your slide.

stage

75

____ hold teh slides firmly in place.

slide clips

76

_____ is the smaller round knob that is inset into the course adjustment knob on the side of the microscope. This is used to fine-tune the focus of your specimen. This know also focuses by adjusting the distance between the specimen and the objective, but at much smaller increments that the course focus knob. Higher power lenses should use this knob only.

fine focus know

77

______ is the large round knob on the side of the microscope. IT is used for course or rough focusing of the specimen only. This serves to adjust the distance between the slide and the objective lens (either by moving the stage up and down, or moving the objectives). Should only be used with lower power lenses.

Coarse focus knob

78

_____ is used to focus the light that passes through the specimen.

condenser lens

79

_____ aka iris allows the user to adjust the size and intensity of the light beam that project through the slide from below. The proper amount of light your should let through will depend on the magnification used and the contrast of the specimen itself.

diaphragm

80

_____ provides a light source which illuminates the specimen from below. Most light sources allow the user to adjust intensity of light being emitted.

light source

81

____ is the backbone of the microscope, providing support to the overall structure.

arm

82

____ are located off the side of the stage. You will use these to move the slide and scan the specimen. One know moves the stage left and right, the other moves the stage forward and backward.

stage adjustment knobs

83

You should life the microscope using the ____ and base.

arm

84

Lenses are only to be cleaned using the ___ with a few drops of lens cleaner. Use this to remove oil from lenses.

lens paper

85

Use _____ to clean any oil off the stage and slides. Never use ___ on the lenses.

kimwipes
kimwipes

86

Oil has a similar refractive index as ____. By connectign the two refractive surface (____ and ____) the magnifications of 1000x can be reached while still preserving good resolution.

glass
oil and glass

87

____ total magnification must be used for all bacterial specimens.

1000x

88

______ the smear is essential to good staining and visualization.

heat fixing

89

Heat fixing ____ the bacteria/sample to the slide.

physically attaches

90

Heat fixing ____ key enzymes in the bacterial cells, allowing them to pick up more stain and thus be easier to see.

deactivates

91

Heat fixing will ____ a majority of the bacteria present.

kill

92

How to heat fix?

1. take your dry smear prepped slide to the Bunsen burner
2. grasp the edge of your dry slide, pass your slide (speciment side up) through the flame of the bunsen burner three times

93

_____ uses only one stain (dye) to make the cells visible under the microscope.

simple stain

94

Bacteria are ____, so to see them, and better see any epithelial cells than may be present from our gum line, we must stain them.

colorless

95

Syphillis

Treponema pallidum

96

Gram-negative, spirochete (cork screw)

Treponema pallidum

97

Gram-positive, rod

Bacillus anthracis

98

capsules, diplococci

Bacterial capsule

99

Gram-negative, diplococci - coffee bean shaped

Neisseria gonorrhoeae

100

Gram-negative, rod shaped, endospores (look like bicolored capsules)

Clostridium

101

botulism

Clostridium

102

Gram-positive, rod shaped ( a little curved)

Lactobacillus

103

Why do you want to let more light in when your go from a low magnification objective to a higher magnification objective?

the area in the field of view gets smaller as well as darker. To see the specimens clearly, additional light may need to pass through the slide.

104

Whey do we need to use oil with the oil immersion lens?

Oil has a similar refractive index as glass. By connecting the two refractive surfaces (oil and glass) the magnification of 1000x can be achieved while still preserving good resolution.

105

Aseptic technique employs laboratory methods designed to prevent ____ by undesirable organisms.

contamination

106

Aseptic technique protects your experiment from becoming ____, but it also protect you and the environment from becoming contaminated as well.

contaminated

107

An ______ is a tool often used to inoculate different media in the lab.

inoculating loop

108

The _____ can be used to effectively and precisely spread bacteria across teh surface of an agar plate.

inoculating loop

109

When working in a lab, you must sterilize your inoculating loop to ensure that no ____ from previous experiments, or microbes from the environment, contaminate your experiment.

residual organisms

110

The incinerator must be preheated for ____ minutes prior to use.

10

111

When using an ____ place the inoculating loop in until the wire portion of the loop glows oragne-hot. Hold the loop at all times, do not "rest" the loop in the ____ or it will melt.

incinerator
incinerator

112

Cooling the loop ensures that you do not overheat a sample and create potentially dangerous _____.

aerosols.

113

Cooling the loop can be done two ways. Hold the loop in the air for ___ seconds. or touch the loop to a portion of the plate without ______ along the edge.

10 to 15 seconds
bacteria

114

When using an inoculating loop to transfer bacteria to an agar plate, open the lid ___ degrees.

45

115

The ____ technique depends on the spatial isolation of a single bacterial cell on a solid medium.

streak for isolation (SFI)

116

We cannot see individual bacterial cells with the naked eye, but we can see the ___ that result after an overnight incubation.

colonies

117

A colony is formed from reproduction of a ______ cell so that all the members of a colony are descendants from that original cell.

single

118

The term _____ refers to the one bacterial cell that started the colony.

CFU or colony forming unit

119

During the streak plate technique you will be spreading our bacterial sample across the surface of an agar with the goal of achieving ____.

spatial separation of individual cells

120

A properly executed streak plate will give nice isolation of colonies, allowing for ________ of colonies that form after an overnight incubation.

visual differentiation

121

If the streak plate technique shows colonies that are visually distinct (different), the original sample is a _____ sample.

mixed - contains more than one type of bacteria

122

If the streak plate technique shows colonies that are visually the same shape, size, and color the original sample was a ____.

pure specimen - one bacterial specimen

123

A streak plate is an excellent way to separate out bacterial species that are in a ____.

mixed culture

124

If a patient has a UTI, the streak for isolation allows you to choose and eventually test ____ colonies to see which potential pathogens you are dealing with.

indvidual

125

What needs to be written on all agar plates.

Name - section - date - sample

126

Practice quadrants for SFI

p 26

127

Why do we incubate plates upside down?

Excessive moisture from the condensation of water, derived from the initial cooling of the hot sterile media, can collect on the inside of the lid and sides of the plate. If the water drops down onto the agar surface, spreading and mergin of colonies can occur. Always incubate paltes upside down.

128

If the inoculating loop is not sterilized between quadrants during the SFI the result will be ____.

equally heavy growth in all four sections of the plate

129

Properly executed streak for isolation technique showing successful isolation of individual colonies in the ___.

3rd and 4th quadrants

130

A ____ is a visible mass of microorganisms all originating from a single cell.

colony

131

The ____ is almost always the first step in the identification of a bacterial organism.

Gram stain

132

The Gram staining method is used to differentiate bacterial species into ____ large groups; _____ and _____.

two
Gram-positive
Gram-negative

133

The difference between Gram-positive and Gram-negative is based on their ____ composition, specifically the levels of _____.

cell wall
peptidoglycan

134

Gram positive bacteria is ____ in color.

purple

135

Gram negative bacteria ____ in color.

pink

136

Gram positive bacteria has a ____ of peptidoglycan.

thick layer

137

Gram negative bacteria has a _____ of peptidoglycan.

thin layer

138

Gram positive streptococci

?

139

Gram negative bacillus

?

140

Gram positive bacillus

?

141

Gram positive staphylococci

?

142

_____ can be made from broth cultures or from an agar plate.

smear preps

143

Gram stain protoco

?

144

How to label a slide

initials
section
sample

145

Smear prep

?

146

gram positive, rods, streptococci

Bacillus anthracis

147

gram positive, cluster of coccous - staphylococci

Staphylococci aureus

148

gram-negative, rods, bacillus

Escherichia coli

149

Can a gram stain be used to as the only means to identify bacterial pathogens in a patient fecal sample?

No, a fecal sample will likely display dozens of bacteria within the sample. It would be a good first step, but idetifiying the particular pathogen by just gram staining would not be possible.

150

What is the difference between a simple stain and a differential stain?

a simple stain requires only a single dye. A differential stain requires a primary stain and a counterstain

151

Step 1 gram staining

flood slide with crystal violet (CV)

152

Step 1 of the gram staining is called the ____ that will enter teh cell wall and stain all the bacteria.

primary stain

153

Step 2 of gram staining

Flood slide with grams iodine also called the mordant

154

The ____ will bind with the CV in the cell wall forming a large CV-I complex.

mordant

155

Step 3 gram staining

Drizzle slide with alcohol (decolorizer)

156

_____ dissolves the outer membrane lipids allowing the CV-I complex to escape the thin peptidoglycan layer of gram negative cells. Gram negative cells now colorless, gram positive cells still purple.

decolorizer

157

Step 4 of gram staining

Flood slide with safranin

158

Safranin is the ____ that stains everything pink but you will only see this in the gram negative cells because they were just streipped of all color by the alcohol.

counterstain

159

After gram staining blot the slide gently with ____ paper to dry excess water.

bibulous

160

______ is an effective way in which to control microbial growth.

ultraviolet light

161

In the healthcare industry _________ is used to sterilize open surfaces like in hospital rooms or operating room surfaces.

uv light

162

_____ is also used in some restaurants to keep food surfaces sterile and in lab biosafety hoods to control microbial contamination.

UV light

163

UV light controls bacterial growth by causing irreparable levels of damage to the ______.

bacterial cell DNA

164

UV light is a form of ____ radiation that creates thymine thymine dimers which inturn disrupts ____. This type of mutation is lethal to bacteria.

nonionizing radiation
DNA replication

165

UV light is most effective when the light waves can come ____ with the surface.

in direct contact

166

Any substance like the plastic lid of a Petri dish can ____ UV rays will prevent the germicidal effects of UV.

block

167

UV light experiment examined the ___ and ____.

length of time of exposure
type of bacteria

168

Did one organism survive exposure to UV better than the other? Which one? What about this organism made it more resitant?

Yes, Escheriachia coli was more resistant to the UV light. The gram negative specimen has the thick outter membrane to sheild from the UV light.

169

What happened when the index card was not used?

more uv light would effect the bacterial cells even if indirectly ner the lgith

170

What would happen if the Petri dish lid was left on?

There would have been 100% growth in all sections of the Petri dishes since the lid blocked the UV light from having an effect on the bacteria.

171

What effect would endospore formation have on this experiment?

There would have been a greater number of bacteria left after UV light exposure if there had been endospor formation. Endospores are refractile so the UV lgiht cannot penetrate them to do damage to teh DNA, resulting in cell death.

172

The purpose of the Kirby Bauer Disk Diffusion Assay is to test ____.

antibiotic sensitivity

173

The _________ is used to determine the susceptibility of bacteria to various antibiotics.

Kirby Bauer Disk Diffusion Assay

174

The Kirby Bauer Disk Diffusion Assay is a standardized test used to measure the effectiveness o fa variety of antibiotics on a _____ in order to prescribe the most suitable antibotic therapy.

specific organism