LAB 4 TEST BANK
CH. 25 Questions
Pasteur and others observed that infecting an animal with ________ protected the animal against_______.
a.
b.
c.
d.
Pseudomonas aeruginosa; Bacillus anthracis
Bacillus anthracis; Pseudomonas aeruginosa
Staphylococcus aerus; Bacillus anthracis
Bacillus anthracis; Pseudomonas aeruginosa
In 1928, Alexander Fleming found that culture filtrates of Pecinicillum inhibited the growth of many
_______ of staphylococci.
a. gram-negative
b. gram-positive
Actinomycetes remain an important source of antibiotics.
a. True
b. False
Antimicrobial chemicals absorbed or used internally, whether natural (antibiotics) or synthetic, are called
what?
a. Antibiotic drugs
b. Synthetic drugs
c. Antimicrobial drugs
d. Natural drugs
A pathogen is a disease-inhibiting organism.
a. True
b. False
In a Petri plate containing agar growth medium is inoculated uniformly over its entire surface is called
what?
a. Agar-diffusion method
b. Complete-diffusion method
c. Disk-diffusion method
d. Petri-diffusion method
An effective agent will inhibit bacterial growth, and measurements can be made of the size of the zones of
inhibition around the disks.
a. True
b. False
The zone size of inhibition is affected by what factors?
a. diffusion rate of the antimicrobial agent
b. growth rate of organism
c. diffusion rate of bacteria
d. A and B
e. All of the above
What standardized test for agar diffusion methods is performed in many clinical laboratories with strict
quality controls?
a. Fleming-Kirby test
b. James-Kirby test
c. Kirby-David test
d. Kirby- Bauer test
1
The minimum inhibitory concentration (MIC) of an antibiotic is determined by testing for bacterial growth
in dilutions of the ______ in ______.
a. pathogen in nutrient agar
b. pathogen in blood agar
c. antibiotic in blood agar
d. antibiotic in nutrient agar
Pasteur and others observed that infecting an animal with pseudomonas aeruginosa protected the animal
against?
A. Sheep anthrax
B. Bacillus anthracis
C. Rabies
D. A and C only
Who observed antibiosis around a penicillum mold growth on a culture of staphylococci?
A. Louis Pasteur
B. Alexander Fleming
C. Paul Elrich
D. Robert Hook
In 1940, ___________ isolated the antibiotic streptomycin, produced by actinomycetes.
A. Alexander Fleming
B. Louis Pasteur
C. Selman A.Waksman
D. Paul Elrich
Antimicrobial chemicals absorbed or used internally whether natural (antibiotics) or synthetic are called
antimicrobial drugs. T
What are pathogens?
A. Normal microbiota
B. Disease causing organism.
C. Antimicrobial drugs
D. All of the above
A petri plate containing an agar growth medium inoculated uniformly over its entire surface is called?
A. Disk-diffusion method
B. Chemical method
C. Biological method
D. None of the above
Kirby-Bauer test uses Mueller-Hinton agar. T
Mueller-Hinton agar allows the antimicrobial agent to diffuse freely. T
The observation that some microbes inhibited the growth of others was made as early as
A. 1800
B. 1940
C. 1874
D. 1600
2
Chapter 45
What is secreted by the skin’s oil glands that inhibit bacterial growth?
a. water
b. Sebum
c. hydrochloric acid
d. mannitol
What also contributes to creating the skin’s hypertonic environment?
a. Salts
b. water
c. sugar
d. plasma
To what do the normal microbiota of the skin tend to be resistant?
a. Drying
b. High salt concentrations
c. water
d. A and B
Where are transient microbiota generally most present on the body?
A. Toes
B. Hands
C. Arms
D. B and C
What does propionbacterium produce that maintains the pH of the skin?
a. coagulase
b. Propionic acid
c. water
d. none of the above
What pH level does the skin generally stay between?
a. 1 and 2
b. 3 and 4
c. 3 and 5
d. 4 and 6
Of what type are most bacteria found on the skin?
a. Gram negative
b. Gram positive
c. Salt tolerant
d. B and C
True or False.
Staphylococcus aureus is normally found on the skin and is considered a pathogen.True
The skin is generally an inhospitable environment for most microorganisms.
TRUE
Salts in perspiration create a hypotonic environment. FALSE (hypertonic)
Perspiration and sebum are part of the normal microbiota of the skin. TRUE
The skin is generally an inhospitable environment for most microorganisms. True
Propionibacterium live in hair follicles. True
3
The epidermis is composed of what type of cells?
A) Keratin
B) Collagen
C) Elastic
D) A and B
Choose from the following microbes that are part of the normal microbiota of the skin.
A) Batrachochytrium dendrobatidis
B) Propioibacterium
C) S. aureus
D) A and C
E) B and C
Which agar is selective for salt-tolerant organisms?
A) Nutrient agar
B) EMB agar
C) Mannitol salt agar
How is mannitol salt agar differential to mannitol-fermenting organisms?
A) Organism will produce acid
B) Indicator will turn medium yellow.
C) Indicator will turn purple.
D) A and B
E) A and C
F) None of the above
What enzyme does S. aureus produce?
A) Neuraminidase
B) Coagulase
C) Collagenase
D) None of the above
What is the purpose of testing for the presence of coagulase?
A) Distinguish S. aureus from other species of Staphylococcus.
B) Distinguish S. aureus from propionibacterium.
C) Distinguish Gram positive from Gram negative organisms.
D) None of the above.
What is an indicator of a coagulase-positive?
A) Clumping
B) No clumping
What is an indicator of a coagulase-negative?
A) Clumping
B) No clumping
CHAPTER 46
Alpha-hemolysis is ____________________________________________.
A. No hemolysis, and no change in the blood agar around the colony
B. Green, cloudy zone around the colony. Partial destruction of rbc’s.
C. Complete hemolysis, giving a clear zone with a clean edge around the colony
D. All of the above
Beta-hemolysis is complete hemolysis, giving a clear zone with a clean edge around the colony.
True
False
4
Gamma-hemolysis is no hemolysis and no change in the blood agar around the colony.
True
False
The upper respiratory tract consists of the larynx and trachea.
True
False
The lower respiratory tract consists of the nose and throat.
True
False
Over 90% of streptococcal infections are caused by _________________.
A. Streptococcus
B. Neisseria
C. Beta-hemolytic group A streptococci
D. Haemophilus
Blood agar is usually made with defibrinated sheep blood, ______________ and nutrient agar.
A. Sodium chloride
B. Pig blood
C. Protein
D. Potassium chloride
Does the upper respiratory consist of the nose and throat?
A. True
B. False
What does the lower respiratory consist of?
A. Consists of the larynx, trachea, bronchial tubes, and alveoli
B. The trachea, larynx, and throat
C. Larynx, nose, and throat
Is the upper respiratory tract normally sterile?
A. Yes
B. No
Is the lower respiratory tract normally sterile?
A. Yes, because of the efficient functioning of the ciliary escalator
B. No, because the alveoli catches everything
C. Depends on how hard the person breathes
Is it normal to find Staphylococcus, Streptococcus, Neisseria, and Haemophilus living in the throat?
A. Yes
B. No
What are the predominant organisms in the throat cultures?
A. Staphylococcus
B. Streptococcus
What are hemolysins produced by?
A. Staphylococcus
B. Streptococcus
C. Both A and B
5
HOW TO ID AN UNKNOWN ORGANISM
True or False
T Each week, a new working stock tube is made so the culture stays young.
T
When you perform a gram stain, motility stab, and capsule stain to an unknown, you are looking for
morphological characteristics.
T
When you first receive your unknown stock, you use the stock to inoculate a working stock and a
reserve stock.
What is the first stain you do on an unknown bacterium?
a. Gram stain
b. Acid fast stain
c. Flagella stain
What type of characteristics are you observing when you look at GROWTH patterns in broth and on agar
slants and plates?
a. Physiological characteristics
b. Cultural characteristics
c. Morphological characteristics
d. All of the above
Determining _______________ characteristics will require about 18-20 individual tests.
a. Morphological
b. Cultural
c. Physiological
What type of characteristics relate to determining what enzymes your organism makes?
a. Morphological characteristics
b. Physiological characteristics
c. Cultural characteristics
Motility media uses TTC as a terminal electron acceptor
A. True
B. False
In a motility test, incubate at room temperature, or the flagella will detach, giving a false negative result for
motile organisms
A. False
B. True
If you have a Gram + organism, mix a loopful of it with a loopful of
A. Gram + organism whose size is known
B. Gram – organism whose size is known
C. Neither
D. Both A and B
Culture Characteristics are
A. Growth patterns
B. Temperature
C. Homolysis
D. Oxygen requirements
E. A, B, and C only
F. All of the above
6
After you record your morphology of your reserve stock, keep it
A. the refrigerator
B. at room temperature
Use the spectrophotometer to calculate optical density
A. True
B. False
When determining the optimal temperature for your unknown organism, the tube with the most growth is
the optimal temperature
A. False
B. True
A sign that your unknown might be an opportunistic pathogen is when the organism with grow well
A. In room temperature
B. At body temperature
C. Both
MORPHOLOGICAL CHARACTERISTICS when identifying an unknown include
A. Gram Stain
B. Size
C. Motility
D. Capsule stain
E. Oxygen requirements
F. A, B, C, and D
G. All of the above
When inoculating a motility stab, use
A. A needle
B. A loop
What does Beta hemolysis mean?
A: Means that the organism can completely lyse red blood cells and they digest the
hemoglobin (pathogenic bacteria), so there will be clear areas around the colonies on your
plate.
B: Means that the organism is non-hemolytic, so there will be NO clear areas, and the colony will
not be green.
C: Means that the bacteria can oxidize the iron in the hemoglobin, which turns the colony green,
with NO clear areas.
What does Alpha hemolysis mean?
A: Means that the organism can completely lyse red blood cells and they digest the hemoglobin
(pathogenic bacteria), so there will be clear areas around the colonies on your plate.
B: Means that the organism is non-hemolytic, so there will be NO clear areas, and the colony will
not be green.
C: Means that the bacteria can oxidize the iron in the hemoglobin, which turns the colony
green, with NO clear areas.
What does Gamma hemolysis mean?
A: Means that the organism can completely lyse red blood cells and they digest the hemoglobin
(pathogenic bacteria), so there will be clear areas around the colonies on your plate.
B: Means that the organism is non-hemolytic, so there will be NO clear areas, and the colony
will not be green.
C: Means that the bacteria can oxidize the iron in the hemoglobin, which turns the colony green,
with NO clear areas.
7
SODIUM THIOGLYCOLATE TUBES (OXYGEN REQUIREMENT)
What does it mean when this medium has an oxygen gradient?
A: REDUCING MEDIUM. It gets rid of the oxygen.
B: Removes the free oxygen by chemically binding with it.
C: where the oxygen is.
D: Means that most of the oxygen is at the top of the tube, and the least amount of oxygen is at the
bottom of the tube.
To prepare this medium, a reducing agent called Sodium thioglycolate was added. What does this do?
A: REDUCING MEDIUM. It gets rid of the oxygen.
B: Removes the free oxygen by chemically binding with it.
C: where the oxygen is.
D: Means that most of the oxygen is at the top of the tube, and the least amount of oxygen is at the bottom of
the tube.
The thioglycolate broth is called a
A: REDUCING MEDIUM. It gets rid of the oxygen.
B: Removes the free oxygen by chemically binding with it.
C: where the oxygen is.
D: Means that most of the oxygen is at the top of the tube, and the least amount of oxygen is at the bottom of
the tube.
This broth contains a pink indicator dye called rasazarin that shows you:
A: REDUCING MEDIUM. It gets rid of the oxygen.
B: Removes the free oxygen by chemically binding with it.
C: where the oxygen is.
D: Means that most of the oxygen is at the top of the tube, and the least amount of oxygen is at the bottom of
the tube.
What organisms grow best aerobically but do not require it. Growth is throughout the tube, but is
best at the top and decreases as one descends. (E.coli, staph aureus)
A) STRICT AEROBES
B) STRICT ANAEROBES
C) FACULTATIVE ANAEROBES
What organisms require oxygen to grow. There will only be growth on the surface of the thio broth
tube
A) STRICT AEROBES
B) STRICT ANAEROBES
C) FACULTATIVE ANAEROBES
What organisms require the absence of all oxygen. There will only be growth at the butt (bottom) of
the tube (clostridium).
A) STRICT AEROBES
B) STRICT ANAEROBES
C) FACULTATIVE ANAEROBES
Which are examples of a physiological test?
A. Catalase Test
B. Oxidase Test
C. Microbiology Lab 2 Test
D. Both A & B
8
What enzyme allows for hydrogen peroxide to be broken down into water?
A. Catalase
B. Glyoxalase
C. Carboxylase
D. Anhydrase
A catalase test is useful in testing for which organism?
A. Pseudomonas aeruginosa
B. Staph Aureus
Fill in the blank:
Having a positive test for catalase will cause _____1_____ to appear when putting one drop of ____2____
onto a colony.
A. 1=Red liquid / 2=Blood Agar
B. 1=Oxygen bubbles / 2=Hydrogen Peroxide
C. 1=Steam / 2=Nitrogen
D. 1=Rainbows / 2=Happiness
What is the importance of catalase in organism?
A. They help the organism from being destroyed by the H2O2 in the lysosomes of WBCs.
B. It builds up the peptidoglycan in bacteria cell walls.
C. It is an important enzyme necessary to make flagella, which helps the bacteria be more motile and swim
away from danger.
D. All of the above.
An oxidase test is useful in testing for which organism?
A. Pseudomonas aeruginosa
B. Staph Aureus
Oxidase reagent Dimethyl-p-phenylene diaminic hydrochloride is what?
A. Used to test for the enzyme cytochrome oxidase, a molecule that is a terminal electron acceptor in the
electron transport chain.
B. Is carcinogenic
C. Both A & B
D. None of the above
True of False?
An oxidase test should be done in comparison to a control because time is essential in the development of
the test results.
A. True
B. False
If purple is observed at any time of an oxidase test, it is negative for cytochrome oxidase.
True
False
Catalase breaks down H2O2 into oxygen, so it is an oxidase test.
True
False
The medium has a pH indicator called?
A. carbon dioxide
B. ammonium
C. phenol red
D. phenol blue
9
What test checks for the enzymes called urease?
A. UREA BROTH (control=Proteus vulgaris)
B. CASEIN TEST (control=Bacillus)
C. CITRATE TEST (control:positive=Enterbacter aerogenes)
Some organisms produce an enzyme called caseinase?
A. TRUE
B. FALSE
In the Citrate Test what does the medium turn out to be if it is a positive test?
A. Black
B. Blue
C. Red
D. No Color
In the Casein Test, Negative is a clearing (halo) around the area of growth of the organism.
A. TRUE
B. FALSE
In the Urea Broth, when the pH goes up, it will turn bright pink (positive).
A. TRUE
B. FALSE
What will increase the pH in the Urea Broth?
A. bromthymol
B. carbon dioxide
C. ammonium
D. nothing
In the Citrate Test, the indicator dye is Bromthymol blue, which is green when acids are present.
A. TRUE
B. FALSE
In the Citrate Test, the nitrogen source is NOT ammonium salts.
A. TRUE
B. FALSE
In the Citrate Test, Citrate is the sole carbon source in the medium.
A. TRUE
B. FALSE
The Spirit Blue media has lipids
A. TRUE
B. FALSE
A positive result when testing an organism with lipase:
A. Will yield a foul stench
B. Will yield a dark blue streak in the center of the plate where you inoculated it
C. Will glow in the dark
D. Will begin to smoke, seek shelter immediately
True or False
If lipase is produced by the organism when doing a Spirit Blue test, the concentration of blue will increase
where it was inoculated True
You can see an organisms arrangement best with a negative stain True
10
An organism can only use starch if it has an enzyme called Amylase True
Iodine reacts to starch by turning it black True
A positive result to an Acid-fast stain:
A. Means your test has failed
B. Means you have mycobacterium
C. Means there is no way to know what it is you are dealing with
Amylase
A.
B.
C.
D.
Can break down starch
Allows a cell to absorb starch
Turns starch into sugar to be used in the cell
All of the above
When doing an iodine test for the presence of starch
A. You must read the test immediately because the color only lasts a few minutes
B. Gloves and a mask must be worn because Iodine is toxic
C. A rainbow means that starch is present
D. No organism should be tested for the presence of starch
Gelatinase
A.
B.
C.
D.
Breaks down gelatin
Is a carcinogen
Can create gelatin out of nothing
Is a neurotransmitter
The IMViC tests are used for identifying an organism in the coliform group.
True
False
What are we looking for with MR-VP testing?
A. Single acid fermenters
B. Bacteria
C. Lactose
D. Glucose fermentation
A coliform is _____________________________________.
A. Gram positive and produces liquid within 24 hours
B. Gram positive
C. Gram negative, aerobic and produces gas from lactose with 24 hours.
D. Gram negative and produces gas from lactose within 1 hour.
The presence of coliform can indicate fecal contamination.
True
False
MR-VP test stands for _____________________.
E. Methyl Right/Vice-Precise
F. Menthol Red/Vogue-Proskauer
G. Methyl Red/Voges-Proskauer
H. Methylene Rose/Voges-Proskauer
Which pathway produces neutral end products, including acetonin and 2, 3 butanediol?
E. Butylene glycol pathway
F. Mixed acid pathway
G. Methyl pathway
H. Citrate pathway
11
Which pathway produces stable acidic end products which remain acidic?
A. Citrate pathway
B. Butylene glycol pathway
C. Mixed acid pathway
D. Methyl pathway
Methyl Red starts off _________, turns __________ when acids are present
A. Blue, yellow
B. Yellow, orange
C. Yellow, red
D. Red, yellow
Phenol red starts off ___________, turns ____________ when acids are present
A. Red, yellow
B. Yellow, red
C. Red, orange
D. none of the above
IMViC tests are used to identify an organism in the _____________ group.
A. Coliform
B. Cauliflower
C. Aerobic
D. Boy band
Bacteria convert glucose to pyruvate using different metabolic pathways. What are they?
A. A pathway that produces unstable acidic products which quickly convert to neutral compounds.
B. The butylene glycol pathway produces neutral end products, including acetoin and 2,3-butanediol
C. The mixed acid pathway, which produces stable acidic end products which remain acidic
D. All of the above
E. There is no pathway
FALSE: Organisms that ferment many sugars will turn an MR-VP broth yellow.
FALSE: Organisms that ferment only one sugar will turn an MR-VP broth red
What color is the pH indicator of Methyl Red?
A. Double Rainbow
B. Starts red and turns yellow when acids are present
C. Starts yellow and turns red when acids are present
What is an indirect method of testing for non-acid end products of glucose fermentation?
A. Nitrate Reduction test
B. Voges-Proskauer (VP) test
C. Casein test
D. Methyl Red (MR) test
What is used to detect organisms that utilize the butylene glycon pathway and produces acetoin?
A. Nitrate Reduction test
B. Voges-Proskauer (VP) test
C. Casein test
D. Methyl Red (MR) test
Using VP test we can not test for butylene glycol, but we can test for acetoin. T
12
What are VP reagents called?
A. Barritts A
B. Barrett's B
C. A and B
D. None of the Above
Barretts A and Barrett's B are added to ___________ broth that has been inoculated with an organism that
uses the butyleneglycol fermentation pathway.
A. MR
B. MR-VP
C. A and B
D. None
The acetoin end product causes
A. Rust or red color
B. Carbon dioxide
C. Ammonium
D. All of the above
What color is a positive result for an acetoin end product?
A. Red
B. Blue
C. Yellow
D. Colorless
What color is a negative result for an acetoin end product?
A. Red
B. Blue
C. Yellow
D. Colorless
Barretts A is
A.
B.
C.
D.
Skim milk
Alhpa- naphthol
Potassium hydroxide KOH
Methly Red
Barrett's B is
A. Skim milk
B. Alpha- naphthol
C. Potassium hydroxide KOH
D. Methly Red
In the Nitrate Reduction Test, which is the control?
A. S. aureas
B. Calcium nitrate
The two enzymes used in the test are:
A. H20
B. Nitrate
E. B and D
C. E. Coli
D. zinc powder
c. Ca carbonate
D. Nitrite
F. A and C
In the test, a nitrate broth is used which contain nutrients plus _______
and the tube is ___________.
A. Nitrate, clear
C. nitrite, red
B. Nitrate, red
D. nitrite, clear
13
In the tube, if the organism has _____________________, it will reduce to nitrate, to nitrite, so there will
be no more nitrate present, just nitrite.
A. Sulfanilic acid
C. Zinc powder
B. nitrate reductase
D. Alpha naphthalamine
If we add Reagent A to the tube, it will bind with the nitrite and the tube will be
A. Purple
C. red
B. Pink
D. clear
If another reagent is added, Reagent B, the liquid will turn:
A. Red
C. clear
B. Purple
D. pink
Reagent A is called:
A. Zinc powder
B. Sulfanilic acid
Reagent B is called:
A. alpha naphthalamine
B. Sulfanilic acid
Reagent C is called:
A. Sulfanilic acid
B. nitrate reductase
C. alpha naphthalamine
D. nitrate reductase
C. Zinc powder
D. nitrate reductase
C. Zinc powder
D. alpha naphthalamine
Which two reagents are added to the tube to make a positive test?
A. Reagents A and C
C. Reagents B and C
B. None
D. Reagents A and B
To make a negative test, which Reagents are added?
A. None
C. all three A,B, C
B. A and B
D. B and C
True or False:
The controls for ornithine are Enterobacter aerogenes=pos, Klebsiella pneumoniae=neg. TRUE
Decarboxylase broth tests for the enzyme decarboxylase and is useful for differentiating the
Enterobacteriaceae. TRUE
Decarboxylase removes and digests the acidic carboxyl group (COOH) from amino acids, cleave of NH 3,
which will raise the pH. TRUE
The pH indicator is bromcresal purple. TRUE
We test the ability of organisms to produce arginine decarboxylase, lysine decarboxylase, and ornithine
decarboxylase using three different but very similar media. TRUE
If an organism is able to decarboxylate the amino acid present in the medium, alkaline byproducts are not
produced. FALSE
If the pH becomes alkaline because the organism has the decarboxylase enzyme, the media will turn purple
in 48 hours (pos). TRUE
What color is bromcresal purple when acids are present?
A. Yellow
B. Purple
What color is bromcresal purple when bases are present?
A. Yellow
B. Purple
14
Three tubes are inoculated that contains which of the following?
A. Glucose plus amino acids lysine, arginine and ornithine
B. Glucose plus amino acids lysine and ornithine
C. Glucose plus one amino acid; lysine, argine
D. Glucose plus one amino acid; lysine, argine or ornithine
What alkaline byproducts does the following amino acids produce?
Ornithine decarboxylation Putrescine
Lysine decarboxylation Cadaverine
After 48 hours, the byproducts raises the pH and turns the broth what color? Purple
After 24 hours, the byproducts lowers the pH and turns the broth what color? Yellow
What is the DNASE test control?
A.) Serratus marcescens or Staph Aureus
B.) proteus vulgaris
C.) all of the above
What is the indicator dye for the DNASE test?
A.) Methyl green complexed with DNA
B.) safranin
C.) alcohol
D.) crystal violet
What enzyme are we looking for in the phenylalanine agar slant?
A.) Phenylalanine deaminase
B.) cysteine desulfurase
C.) typtophanase
D.) none of the above
Phenylalanine deaminase removes an NH2 group from cysteine to produce what substances?
A.) pyruvic acid
B.) ammonia
C.) hydrogen sulfide
D.) All of the above
What indicates a positive test for in the phenylalanine agar slant?
A.) When 5 drops of ferric chloride is added turning it green
B.) when 5 drops of hydrogen sulfide is added turning it yellow
C.) when 5 drops of Kovac’s reagent is added turning the media black
SIM media requires 10 drops of what reagent?
A.) Kovac’s reagent
B.) ferrous sulfate
C.) ammonia
D.) pyruvic acid
What things can be tested using the single SIM media tube?
A.) Sulfur production
B.) Indole production
C.) Motility
D.) All of the above
15
What color will the media turn in a positive test for sulfur production (SIM Media)?
A.) green
B.) yellow
C.) Black
D.) red ring
Tryptophanase breaks typtophan (an amino acid) down into what?
A.) Indole
B.) Pyruvic acid
C.) Ammonia
D.) All of the above
What color will the media turn in a positive test for indole production (SIM Media)?
A.) green
B.) yellow
C.) black
D.) Red ring
Fermentation broths are looking for _________ or __________ + gas.
E. Gas, acid
F. Acid, acid
G. Gas, gas
H. Glucose, lactose
The Durham tube is a miniature tube that is inverted on the inside of the test tube.
True
False
If fermentation is present what color will be present?
A. Blue
B. Colorless
C. Red
D. Yellow
If gas is present the inverted miniature tube inside the media will fill with a _____________.
I. Red gas
J. Gas bubble
K. Yellow acid
L. Blue bubble
The presence of coliform can indicate fecal contamination.
True
False
If fermentation is NOT present, what color will appear?
E. Yellow
F. Blue
G. Red
H. Colorless
Tubes must be read in _____ hours, because in _____ hours, any change in color
original color?
I. 24, 48
J. 12,24
K. 24, 36
L. 20, 40
will revert to the
16
Some organisms that ferment sugars can also digest proteins.
A. True B. False
When organisms begin to ferment a sugar, the media becomes __________ in 24 hrs.
E. Alkaline
F. Odorless
G. Acidic
H. All of the above
True or False (Mark your scantron with A for true and B for false.
1. Oxidase is an enzyme that breaks down hydrogen peroxide to oxygen and water. False
2. Gelatinase positive organisms destroy the ability of gelatin to solidify True
3. Working stock cultures are transferred every ten days and are used as a support supply if you
should lose the original stock. False
4. Decarboxylation requires an anaerobic environment. True
5. The indole test uses Kovac’s reagent True
6. A positive confirmation Test to check for the presence of coliforms shows colonies with a black
nucleus on EMB agar True
7.
SIM medium is a multiple test medium that detects the production of H2S and indole. True
8.
Bacteria such as Proteus vulgaris can degrade cysteine to produce pyruvic acid, ammonia, and
hydrogen sulfide. True
9.
The enzyme responsible for urea hydrolysis is urease, which splits the molecule into carbon
dioxide and water. False
10.
Some bacteria have the ability to degrade tryptophan, producing indole, ammonia, and pyruvic
acid. True
11.
The O-F test determines whether or not the organism can ferment or oxidize glucose True
12. A culture grown on Spirit Blue agar turned deep blue. This indicates that
a. The organism has ingested the spirit blue
b. Lipase digested the lipids and released fatty acids, dropping the pH
c. The organism has fermented the sugar in the media
d. The organism has digested the protein and the media has turned alkaline
e. Both B and D are true
13. An lysine decarboxylase broth is inoculated with Klebsiella pneumoniae and incubated for 48
hours, and turned purple. What you know for certain is that the organism
a. Has used the lysine in the media
b. Has not used the lysine in the media
c. Has used the lysine and the glucose in the media
d. Has not used the lysine but has used the glucose in the media
e. Did not grow
14. A phenylalanine slant is inoculated with Proteus vulgaris and incubated for 24 hours. After the
addition of ferric chloride, the slant turned ________ indicating a positive test.
a. Black
b. Green
c. Yellow
d. Red
e. Fuchsia (bright pink)
15. Simmon’s citrate medium is used to determine
a. Nitrogen source
b. Carbon source
c. H2S production
d. Indole production
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e.
Oxygen requirement
16. Casein hydrolysis appears in skim milk medium as
a. Alkaline pH change indicated by a red color by phenol red
b. Renin production
c. A clearing around the area of growth of the organism
d. All of the above
e. None of the above
17. Which one of the following statements about pH indicators is true:
a. Phenol red is yellow when acidic
b. Methyl red is yellow when acidic
c. Bromthymol blue is yellow when acidic
d. Bromcresol purple is yellow when acidic
e. Both A and D are true
18. Amylase hydrolyzes
a. Casein
b. Starch
c. Gelatin
d. Glucose
e. Tryptophan
19. Indole is an end product of ____________ hydrolysis
a. Arginine
b. Lysine
c. Urea
d. Tryptophan
e. DNA
20. If bacteria are able to digest DNA, this will be indicated on DNA agar by
a. In otherwise green agar, a clear halo formed around the growth
b. In otherwise clear agar, a pink halo forms around growth
c. The addition of iodine, which will stain any remaining DNA
d. The fact that the bacteria grew; if it could not digest DNA, no growth would occur
21. A black precipitate in a SIM stab after 48 hours of incubation is indicative of
a. Positive mannitol fermentation
b. Positive indole fermentation
c. Positive H2S production
d. Positive motility
e. None of the above; this tests for slow inositol metabolism
22. A starch agar plate was inoculated with an unknown organism and incubated for 48 hours. The
addition of iodine turned the plate black.
a. The organism was capable of using cysteine as a terminal electron acceptor for the
production of H2S.
b. The iodine complexes with the glucose product of starch digestion and gave a black
precipitate
c. The organism could not use the starch and the starch complexes with iodine to give a
black precipitate.
d. The organism is negative for amylase
e. Both C and D
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23. You have identified a Gram negative rod. According to your lab manual, your next step should be
to perform a(n)
a. Spore stain
b. Acid fast stain
c. Thioglycollate test
d. Motility determination
e. Negative stain
24. A strict anaerobe will grow ___________ in thioglycollate agar.
a. On the surface
b. Throughout the medium
c. At the butt (bottom) of the tube
d. Just under the surface
e. It will not grow
25. Cellular arrangement (singles, diplo, chains, and clusters) is best determined by a
a. Gram stain
b. Blood agar streak
c. Tryptic soy agar streak
d. Wet mount
e. Negative stain
26. A Simmon’s citrate slant is inoculated with Enterobacter aerogenes and incubated for 48 hours.
Examination of the slant reveals a deep blue color to the medium.
a. The test is positive for the use of citrate
b. The organism has grown and releases a diffusible pigment into the medium
c. The test is negative for the use of citrate
d. The organism used the ammonium salts and lowered the pH of the medium
e. Both A and D.
27. MR-VP broth differentiates the single acid fermenter from the mixed acid fermenter
a. By the over-riding buffers in the media
b. By variation in the intensity of the color change of the media
c. By killing the multiple acid producer in all the acid
d. By floating the single acid to the surface providing an interface separation
e. None of the above; you cannot differentiate using this media.
28. Assume you are investigating a bacterium that turns out to be a Gram positive rod. According to
your lab manual, the next test you should do is a
a. Capsule stain
b. Thioglycollate broth
c. Spore stain
d. Flagellar stain
e. Lactose fermentation broth
29. Bacteria which are capable of beta hemolysis
a. Produce toxic endospores
b. Lyse RBC’s and digest hemoglobin
c. Lyse RBC’s
d. Produce large quantities of the pigment, hemolyarian
e. Cannot grow on ordinary tryptic soy agar
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>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Matching (answers may be used more than once)
30.
31.
32.
33.
34.
Catalase B
Lipase D
Mixed acid fermentation E
Butanediol fermentation C
Phenylalanine deamination A
A. Ferric chloride
B. hydrogen peroxide
C. alpha naphthol
D. Spirit blue
E. methyl red
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Indole test E
Hydrogen sulfide C
Voges-Proskauer A
Methyl red test D
Decarboxylase tests B
A. butanediol production
B. amino acid utilization
C. cysteine use
D. mixed acid fermentation
E. tryptophan hydrolysis
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Decarboxylase broth C
Citrate agar D
Fermentation broth A
Urea broth A
MR-VP broth B
A. phenol red
B. Methyl red
C. Bromcresol purple
D. Bromthymol blue
E. none of the above
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Use the following choices to answer the below questions (answers may be used more than once:
A.
B.
C.
D.
E.
Methyl red test
Voges-Proskauer test
Catalase production
Oxidase production
Nitrate reduction
35.
Most microbes produce an enzyme that converts hydrogen peroxide to water and oxygen.
Which of the above tests for this enzyme? C
36.
If an organism produces large amounts of acids from the fermentation of glucose, it can
override the buffer in the test media. If this happens, the normally amber media will turn red when
developed. Which of the above tests does this describe? A
37.
One of the most significant tests for differentiating bacterial groups, this test determines
whether an important molecule in the electron transport chain is present. The test should be done
in comparison to a positive control, because time is essential in the development of the test results.
Which of the above tests does this describe? D
38.
An indirect method of testing for non-acid end products of glucose fermentation, the reagents
of this test change to rust or red color in the presence of acetoin, which is the confirmation of the
presence of butanediol. Which of the above tests does this describe? B
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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Use the following choices to answer the below questions:
A.
B.
C.
D.
E.
Hydrogen sulfide production
Citrate utilization
Indole production
Urea hydrolysis
Starch hydrolysis
39.
Proteus vulgaris hydrolyzes this substance by splitting ammonia off from the molecule. The
ammonia raises the pH, which can be detected with a pH indicator. D
40.
A synthetic media in which nitrogen is supplied by ammonium salts instead of peptones in order
to test the ability of an organism to use a single specific carbon source. B
41.
The test agar is developed with iodine. The bacteria produce the enzyme that digests starch into
small sugars that can be transported into the cell. E
42.
Certain bacteria produce H2S from cysteine. When the H2S reacts with ferrous sulfate in the
medium, a dark precipitate of iron sulfide is produced. A
43.
This test determines whether or not the organism has the ability to hydrolyze a specific amino
acid to pyruvic acid and this end product. C
ANTIMICROBIALS
True or False.
The antibiotic with the largest zone of inhibition is the most effective one.
False
Just because one zone is the largest, does NOT mean that is the most effective antibiotic
True
What types of antimicrobials do narrow spectrum kill?
1. Either Gram positive or Gram negative, but not both
2. Always Gram negative only
3. Always Gram positive only
4. Both gram positive and gram negative
5. Neither Gram positive or Gram negative
What types of organisms do broad spectrum antibiotics kill?
a. Either Gram positive or Gram negative, but not both
b. Always Gram negative only
c. Always Gram positive only
d. Both gram positive and gram negative
e. Neither Gram positive or Gram negative
Why is it always good to be careful with broad spectrum antimicrobials?
2. if there are a lot of gram negative bacteria, and you kill them, their endotoxins will be released
in to the bloodstream and it could be fatal for the patient
b. if there are a lot of gram positive bacteria, and you kill them, their endotoxins will be released in to
the bloodstream and it could be fatal for the patient
c. Both A and B are true
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What is intermediate sensitivity?
D. it implies clinical efficacy only in body sites where the drugs are physiologically concentrated
E. it implies clinical efficacy only when higher than normal dose is used
F. it implies clinical efficacy if given drugs when using a lower amount of drugs
G. it implies clinical efficacy if given drugs the patient is slightly allergic to
H. Both A and B
If a patient is allergic to the medication that needs to be prescribed for them, what is the next best option for
their care?
3. choosing two antibiotics in the intermediate category
4. choosing two antibiotics in the sensitive category
5. choosing two antibiotics in the resistant category
d choosing one antibiotic in the intermediate category
What is the zone of inhibition ?
C. the zone on the inner part of the disc with little bacterial growth
D. the zone that is clear around the disc, with no bacterial growth.
E. the zone that is covered with bacterial growth
What does the zone of inhibition measure?
a. the effectiveness of the antimicrobials ONLY when checked against the Kirby-Bauer chart
b. the effectiveness of the antimicrobials only pertaining to intermediate level antibiotics
c. the effectiveness of the antimicrobials only pertaining to sensitive level antibiotics
d. the effectiveness of the antimicrobials only pertaining to resistant level antibiotics
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