Micro Flashcards Unit 1
1) Pieces of deoxyribonucleic acid (DNA)
that move from one genetic element to
another and contain genes for movement
and genes for other features are called
2) Miniature chromosomes composed of
several genes in double-stranded,
closed, circular structures are called
3) A DNA sequence that encodes for a
specific product (ribonucleic acid [RNA]
or protein) is defined as a
4) The enzyme that adds nucleotide bases
to each growing daughter strand in the
replication process is called
5) If a bacterial cell encounters unfavorable
environmental conditions, then its
metabolism will begin to slow until it
eventually transforms into an inactive,
dormant state. This survival mechanism
is known as:
6) Teichoic acids, mycolic acids,
peptidoglycan, and disaccharidepentapeptide subunits are all building
blocks of which bacterial structure?
7) The major difference between grampositive and gram-negative bacteria is
that
8) In gene regulation and
control, repression is defined as the:
9) In gene regulation and
control, induction can be defined as the:
10) Mutation is defined as the:
11) Recombination is defined as the:
12) Transformation is defined as the:
13) Transduction is defined as the:
transposons
plasmids
gene
DNA polymerase
sporulation
Cell wall
gram-negative bacteria contain an outer
membrane that functions as the cell’s initial
barrier to the environment
mechanism of genetic control in which
genes are not transcribed and therefore
are not expressed in the presence of
those target products in sufficient supply
mechanism of genetic control in which
genes are induced only when the
substrate to be degraded by enzymatic
action is present
internal change in the original nucleotide
sequence of a gene or genes within an
organism’s genome
change of the bacterial genotypes
through the exchange of DNA from one
cell to another
uptake of free DNA from the
environment and recombination with the
recipient’s homologous DNA
mechanism that is mediated by viruses,
by which DNA from two bacteria may
come together in one cell, thus allowing
1
Micro Flashcards Unit 1
14) The mechanism for adenosine
triphosphate (ATP) production in which
high-energy phosphate bonds produced
by the central metabolic pathways are
donated to adenosine diphosphate (ADP)
to form ATP is:
15) A pathway that generates ATP by
substrate-level phosphorylation that does
not require oxygen and produces various
end products, including alcohols, acids,
carbon dioxide, and hydrogen, is:
16) The pathway of metabolism that involves
a series of electron transfers from
reduced carrier molecules such as
NADH2 and NADPH2 to a terminal
electron acceptor is
17) The term used when oxidative
phosphorylation uses oxygen as the
terminal electron acceptor is:
18) Which organelle is found in eukaryotic
cells and is responsible for controlled
enzymatic degradation of intracellular
substances
19) Teichoic acids are
20) Pieces of DNA that move from plasmid to
chromosome or vice versa but are not
found as separate entities are called:
21) All genes within an organism make up
that organism’s
22) A bacterial cell that contains teichoic acid
stains which color on the Gram stain?
23) A bacterial cell that contains an outer
membrane and periplasmic space stains
pink to red on Gram stain. Which one of
the following statements explains this
discrepancy
24) Amino acids, fatty acids, sugars, and
nucleotides are produced during which
metabolic reaction?
for recombination
substrate-level phosphorylation
fermentative metabolism
oxidative phosphorylation
aerobic respiration
Lysosomes
glycerol- or ribitol-phosphate polymers that
are combined with various sugars, amino
acids, and amino sugars, which are a part of
the cell wall of gram-positive bacteria.
transposable elements
genome
Purple
No discrepancy is present; organisms
that contain an outer membrane and
periplasmic space should stain pink
because of their cell wall composition.
Biosynthesis
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Micro Flashcards Unit 1
25) A human infection that results from a
microorganism that primarily infects
animal populations is referred to as a(n)
_________ infection.
26) Which of the following processes takes
place in the cytoplasm and involves the
tRNA mediating the sequential addition of
amino acids in a specific sequence that is
dictated by the codon sequence of the
messenger RNA (mRNA) molecule?
27) The persistent survival of microorganisms
on a surface of the human body is called
a(n):
28) Cells that ingest and destroy bacteria and
other foreign particles are called:
29) Cells with a short life span that circulate
in blood and tissues and are usually the
first cells on the scene of a bacterial
invasion are called:
30) Swelling, redness, heat, and pain are
all manifestations of
31) The complement system serves to:
32) The coagulation system serves to:
33) Biochemicals known as cytokines serve
to:
34) Specific proteins produced by cells of the
immune system in response to the
presence of foreign molecules that
circulate in the serum and are present in
secretions such as saliva are called:
35) The antibody that is secreted in various
body fluids and primarily protects those
body surfaces lined with mucous
membranes is:
36) Which stage of infection is characterized
by host deterioration and possibly death?
37) Which immune system cells primarily
function as antibody producers and
originate from stem cells?
38) Which immune system cells destroy
infected or malignant host cells?
39) Infectious processes that quickly develop
are referred to as _________ infections.
Zoonotic
Elongation
Colonization
Phagocytes
Polymorphonuclear neutrophils.
Inflammation
Attract and enhance the activities of
phagocytes
increase blood flow to the area of infection and
can also effectively wall off the infection
through the production of barrier substances
Have substantial effects on the activities
of other cells.
Immunoglobulins (Ig)
IgA
Decline
Lymphocytes
Natural killer cells
Acute
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Micro Flashcards Unit 1
40) Infectious processes that develop and
slowly progress are known as _________
infections.
41) Proper hand-washing and hygiene
procedures by hospital staff are essential
in preventing which types of infections?
42) Which one of the following statements is
true regarding endotoxins?
43) A bacterium that normally colonizes the
skin gains access through a laceration
and causes infection. This type of
infection is classified as:
44) An example of antibody-mediated
immunity is:
45) Latent infections are those that:
46) Pathogens are able to produce enzymes
that directly destroy or inactivate
antibodies. These enzymes are referred
to as:
47) Botulism and tetanus have the ability to
interfere with neuromuscular functions.
The toxins they produce are classified as:
48) IgG is the:
49) IgM is the:
50) IgE is the:
51) Air flow in a microbiology laboratory
should be
52) The agency that requires health care
facilities to provide employees with all
devices and mechanisms necessary to
protect them from the hazards
encountered in the laboratory is
53) Procedures such as grinding, mincing,
vortexing and preparing smears
54) Class I biological safety cabinets
Chronic
Nosocomial
They are released upon cell death.
Opportunistic.
B-cell activation.
Exist as a silent phase in which the
agent is causing no notable effect.
Proteases.
Exotoxins.
Second antibody produced when an
invading microorganism is initially
encountered and the most abundant.
First antibody produced when an
invading microorganism is initially
encountered.
Antibody that is associated with various
parasitic infections.
from lower to higher risk areas
Occupational Safety and Health
Administration (OSHA)
create aerosol droplets and should be
performed only in approved biosafety
cabinet
protect the environment from
contamination by biological agents by
filtering the air as it is exhausted from
the cabinet
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Micro Flashcards Unit 1
55) Optimal protection of specimen,
personnel and environment is
accomplished with which class of
biological safety cabinet?
56) The method of choice for sterilizing items
such as antibiotic solutions, chemicals,
radioisotopes, and vaccines that are
heat-sensitive is
57) To be sterilized in an autoclave,
infectious medical waste should be
58) The autoclave sterilizes material by
59) The most effective antiseptic agent
against blood spills and therefore the
antiseptic of choice in laboratories where
these agents are likely found is
60) Standard precautions in the microbiology
laboratory apply to
61) Standard precautions include
62) Mouth pipetting
63) Biosafety Level 1 agents
64) Working with Biosafety Level 3 agents
requires
65) A cleaning solution used on the
laboratory bench top to kill bacteria that
are potentially harmful to humans would
be called a(n)
66) A cleaning solution used on the
venipuncture site to avoid skin
contamination of the blood sample is
called a(n)
67) Information concerning a chemical
product's health hazards, toxicity, and
disposal procedures is
68) The agency that has published a guide to
hazardous waste reduction is
69) The agency that has published guidelines
known as standard precautions to reduce
the risk of disease transmission in
laboratories is
Class III
filtration
processed for 30 to 60 minutes at 132C and
15psi pressure
applying moist heat at high
temperatures and increased pressure
10% bleach
clinical specimens that contain blood or
bodily fluids
using barrier devices to prevent
exposure to skin and mucous
membranes
should not be performed in any
circumstance in the clinical laboratory
require only standard good laboratory
techniques
laboratory design features that control
air movement
disinfectant
antiseptic
found in the manufacturer's material
safety data sheets (MSDS)
U.S. Environmental Protection Agency
(EPA)
CDC
5
Micro Flashcards Unit 1
70) The agency that has published guidelines
regarding the packaging of biohazardous
specimens is known as
71) Class III biological safety cabinets
72) Minimal protection of specimen,
personnel, and environment is
accomplished with which class of
biological safety cabinet?
73) To be sterilized in an autoclave, media or
instruments should be
74) Biosafety Level 2 agents
75) Biosafety Level 4 agents
76) A principal role of the clinical
microbiologist includes?
77) Rejection of inappropriately collected or
transported specimens?
78) The definitive identification of clinically
significant isolates is?
79) Specimens for microbiologic studies
should be?
80) Holding media, such as Stuart’s medium
and Amie’s transport medium, are used
to?
81) The best anticoagulant to prevent clotting
of specimens, such as blood, bone
marrow, and synovial fluid, which are
submitted for recovery of all types of
microorganisms, is?
82) Direct examinations such as the Gram
stain serve what purpose?
83) Which type of media is designed to
support the growth of a wide range of
microorganisms?
84) Which type of media is designed to
distinguish microorganisms on the basis
of certain growth characteristics?
International Air Transport Association
(IATA)
are completely enclosed and have
gloves that enable the worker to
manipulate the material in the cabinet
Class I
processed for 15 minutes at 121 and
15psi pressure
include those that are the common
agents of infectious disease
require the use of maximum
containment facilities
Quickly and accurately communicating
information about the patient in both
verbal and written formats.
Should be initiated by laboratory
personnel but approved by the nurses or
physicians responsible for the care of
the patient.
Desirable in most cases; however,
limited identification may sometimes be
necessary and helpful.
Transported in sealable, leak-proof
plastic bags with a separate section for
paperwork.
Maintain the viability of microorganisms
present in a specimen.
Sodium polyanethol sulfonate (SPS).
To give the physician an early indication of
what may be wrong with the patient
Nutritive
Differential
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Micro Flashcards Unit 1
85) Which type of media is designed to
support the growth of one group of
organisms, but not another, by containing
antimicrobials, dyes, or alcohol?
86) An example of a selective medium for
gram-positive organisms is?
87) Ambient air, which contains 21% oxygen
(O2) and a small amount (0.03%) of
carbon dioxide (CO2), is the
environmental condition that best suits
which type of organism?
Selective
88) Increased concentrations of CO2 (5% to
10%) and approximately 15% O2 produce
an environmental condition that best suits
which type of organism?
89) Between 5% and 10% hydrogen (H2), 5%
to 10% CO2, 80% to 90% nitrogen (N2),
and 0% O2 produce an environmental
90) Reduced O2 (5% to 10%) and increased
CO2 (8% to 10%) produce an
environmental condition that best suits
91) Colonies of Streptococcus
pneumoniae appear alpha-hemolytic on
blood agar media. Which one of the
following statements explains this
discrepancy?
92) An example of a beta-hemolytic grampositive organism is?
93) Which specimen is quantitatively plated
by using a calibrated loop?
94) Which specimen culture, if positive,
should be immediately reported to the
clinician?
95) The appropriate storage for a cerebral
spinal fluid specimen is ____° C?
96) In microscopy, resolution is defined as
the:
97) How is contrast in microscopy most
commonly achieved?
98) The 1st step in gram stain sequence is
the application of, which is the primary
stain?
99) A mordant that is applied after the
primary stain to bond chemically the
alkaline dye to the bacterial cell wall is:
Capnophiles
colistin and nalidixic acid.
Aerobes
Anaerobes
Microaerophiles
No discrepancy is present. S.
pneumoniae should be alpha-hemolytic
on blood agar.
Staphylococcus aureus.
Urine
Blood
37
Extent to which detail in the magnified
object is maintained
By staining techniques
Crystal violet
Gram's iodine
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Micro Flashcards Unit 1
100) After which step in the Gram-stain
procedure are gram positive bacteria 1st
distinguished from gram negative
bacteria?
101) The acid fast stain is specifically
designed for bacteria whose cell walls
contain:
102) In the Kinyoun acid-fast staining
method, what replaces what in the
primary stain solution?
103) Of the different types of staining and
microscopic techniques, which one of the
following is basically the most sensitive?
104) The fluorochrome stain that can be
used to detect mycobacteria is:
105) The fluorochrome stain used to study a
fungus is:
106) What's true about dark field
microscopy?
107) Magnifications in excess of 100,000 x
are achieved by what microscopy?
108) Bacterial cells with thick peptidoglycan
and numerous teichoic acid cross
linkages are Gram stained. The
organisms stain pink. Why?
109) The most critical step in the Gram
stain is the application of the:
110) An organism such as Mycobacterium
tuberculosis would absorb which stain in
its cell wall?
111) Organisms that have nutritional needs
that are relatively complex and require
extra media components to be used for
growth are called:
112) The role of the agar ingredient in
culture medium is to:
113) A bacterial colony can be described
as:
114) Which category of media can be
described as containing specific nutrients
required for the growth of particular
bacterial pathogens in a patient
specimen?
Gram's decolorizer
Mycolic acids
Increased phenol; heat
Fluorescence
Auramine
Calcofluor white
The condenser does not allow light to
pass directly through the specimen but
directs the light to hit the specimen at an
oblique angle.
Electron
The bacterial cells were subjected to the
decolorizer too long and were
overdecolorized.
Gram's decolorizer.
Carbolfuchsin
fastidious
Solidify the medium and provide a
stable culture surface.
Sufficiently large numbers of a
bacterium that can be observable with
the unaided eye.
Enrichment
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Micro Flashcards Unit 1
115) Which category of media can be
described as containing nutrients that
support the growth of the most
nonfastidious organisms without giving
any particular organism a growth
advantage?
116) Which category of media can be
described as containing some factor or
factors that allow colonies of one
bacterial species or type to exhibit certain
metabolic or culture characteristics that
can be used to distinguish them from
other bacteria growing on the same agar
plate?
117) Which category of media can be
described as containing one or more
agents that are inhibitory to all
organisms except those being sought?
118) In which category of media would
MacConkey agar best fit?
119) In which category of media would
blood agar best fit?
120) In which category of media would
Löwenstein-Jensen medium best fit?
121) Which medium can be described as a
nutritionally rich medium used to grow
various microorganisms, either as a broth
or as an agar, with or without added
blood?
122) Which medium can be described as
containing hemoglobin, hemin (X factor),
and the co-enzyme nicotinamide adenine
dinucleotide (NAD) (V factor)?
123) Which medium can be described as
suppressing the growth of most gramnegative organisms while allowing grampositive bacteria to grow?
124) Which medium can be described as
containing bile salts and dyes (e.g.,
bromothymol blue, acid fuchsin) to slow
selectively the growth of most
nonpathogenic gram-negative bacilli
found in the gastrointestinal tract and
allow Salmonella spp. and Shigella spp.
to grow?
Supportive
Differential
Selective
Selective and differential
Differential
Selective
Brain-heart infusion (BHI)
Chocolate
CNA blood
Hektoen enteric agar
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Micro Flashcards Unit 1
125) Which medium can be described as
containing crystal violet dye to inhibit the
growth of gram-positive bacteria and
fungi and allows many types of gramnegative bacilli to grow?
126) What name is given to the type of
hemolysis that produces incomplete
hemolysis and a greening discoloration of
the medium?
127) What name is given to the type of
hemolysis that produces complete
hemolysis and a clearing of the medium?
128) To read the hemolytic reaction
accurately on a blood agar plate, the
technologist must:
129) Which group of bacteria uses oxygen
as a terminal electron acceptor and
grows well in ambient air?
130) Increased concentrations of carbon
dioxide (CO2) (5% to 10%) and
approximately 15% oxygen (O2) produce
an environmental condition that best suits
which type of organism?
131) Reduced O2 (5% to 10%) and
increased CO2 (8% to 10%) produce an
environmental condition that best suits
which type of organism?
132) A candle jar is used to cultivate which
type of bacteria?
133) The most medically important bacteria
sought in the medical laboratory are
cultivated using incubators with
temperatures maintained in what range?
134) An oxidase test was performed on two
organisms for quality control
purposes. Pseudomonas
aeruginosa andStenotrophomonas
maltophilia tested positive and negative,
respectively. Which of the following
statements explains this discrepancy?
135) A positive pyrrolidonyl arylamidase
(PYR) test was observed on a species
of Enterococcus. What color should be
observed for this reaction?
MacConkey agar
Alpha
Beta
Hold the plate up to the light, and
observe the plate with the light coming
from behind.
Aerobes
Capnophiles
Microaerophiles
Capnophiles
35° to 37° C
No discrepancy is present. The correct
results are obtained.
Red
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Micro Flashcards Unit 1
136) Oxidative or fermentative media were
set up on an organism suspected of
being Pseudomonas aeruginosa. What
results would be expected?
137) Generation time can be defined as the:
138) A catalase test was performed from a
sheep blood agar plate on a colony of
streptococci, and bubbling was observed.
Which of the following statements
explains this discrepancy?
139) Which of the following organisms
grows best at 42º C?
140) Escherichia coli, a member of the
family Enterobacteriaceae, was resistant
to the antibiotic vancomycin. Which of the
following statements explains this
discrepancy?
141) What test methodology differentiates
group A streptococci from other betahemolytic streptococci?
142) What test methodology differentiates
staphylococci (resistant) from micrococci
(sensitive)?
143) True or False:
In order to determine bacitracin
susceptibility, a Taxo A disk is placed on
an inoculated agar and zone of inhibition
are observed.
144) For bacitracin susceptibility, what size
of the zone of inhibition is considered
susceptible (sensitive)?
145) What are the limitations of bacitracin
susceptibility?
146) What two quality control organisms
would test positive for bacitracin
susceptibility?
147) What two quality control organisms
would test negative for bacitracin
susceptibility?
148) What test methodology differentiates
enterococci and group D streptococci
from nongroup D viridans streptococci?
Yellow in the open tube and green in the
closed tube
Time required for a bacterial population
to double.
The colony may have been
contaminated with sheep red blood
cells, causing a false-positive result.
Campylobacter jejuni
No discrepancy is present. E. coli is
resistant to vancomycin.
Bacitracin Susceptibility
Bacitracin Susceptibility
True
any zone >10 mm
Performance depends on the integrity of
the disk.
Streptococcus pyogenes (susceptible)
Micrococcus luteus (susceptible)
Streptococcus agalactiae (resistant)
Staphylococcus aureus (resistant)
Bile Esculin Agar
11
Micro Flashcards Unit 1
149) What color precipitate would form for a
positive reaction of bile esculin agar?
150) What are the limitations of bile esculin
agar?
151) What quality control organism would
test positive on bile esculin agar?
dark brown to black
152) What two quality control organism
would test negative on bile esculin agar?
Escherichia coli (growth, no color
change)
Streptococcus pyogenes (growth, no
color change)
Bile Solubility Test and
Optochin (P Disk) Susceptibility
153) What two tests differentiate
streptococcus pneumococci (sensitive)
from other alpha-streptococci (resistant)?
154) True or False:
For the bile solubility test, bile or bile salts
rapidly lyse pneumococcal colonies on
blood agar.
155) What are the limitations of the bile
solubility test?
156) What quality control organism would
test positive for the bile solubility test?
157) What quality control organism would
test negative for the bile solubility test?
158) What test methodology differentiates
group B streptococci from other
streptococci species?
159) True or False:
Listeria monocytogenes produces a
positive CAMP reaction.
160) True or False:
A diffusible hemolytic protein (Christie,
Atkins, Munch-Petersen [CAMP] factor)
acts synergistically with the beta-lysin of
Staphylococcus aureus causing
enhanced lysis.
161) If an arrowhead zone of hemolysis is
observed during the CAMP test, does this
show a positive or negative result?
162) What are the limitations of the CAMP
test?
163) What quality control organism would
test positive for the CAMP test?
164) What quality control organism would
test negative for the CAMP test?
Some organisms may grow poorly.
Enterococcus faecalis (growth, black
precipitate)
True
Old cultures may not have strong
activity.
Streptococcus pneumoniae
Enterococcus faecalis
CAMP Test
True
True
positive
Some group A streptococci are positive
for CAMP.
Streptococcus agalactiae (enhanced
arrowhead hemolysis)
Streptococcus pyogenes (beta
hemolysis without enhanced arrowhead
formation)
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Micro Flashcards Unit 1
165) What test methodology differentiates
catalase-positive organisms and
staphylococcus species from catalasenegative streptococcus species?
166) True or False:
For the catalase test, the catalase
enzyme converts hydrogen peroxide to
water and oxygen, producing bubbles.
167) What are the limitations of the catalase
test?
168) What quality control organism would
test positive for the catalase test?
169) What quality control organism would
test negative for the catalase test?
170) What test methodology identifies the
organism’s ability to use sodium citrate
as the sole source of carbon?
171) For citrate utilization, the bacteria that
is capable of growing on the medium
uses citrate to convert ammonium
phosphate into ammonia and ammonium
hydroxide, creating an ____ pH which is
indicated by a blue color change.
172) What are the limitations of citrate
utilization?
173) What quality control organism would
test positive for citrate utilization?
174) What quality control organism would
test negative for citrate utilization?
175) What test methodology differentiates
Staphylococcus aureus (positive) from
coagulase-negative staphylococci?
176) During coagulase test, the coagulase
or “clumping factor” reacts with ____ in
plasma, producing a fibrin clot.
177) What are the limitations of the
coagulase test?
178) What quality control organism would
test positive for the coagulase test?
179) What quality control organism would
test negative for the coagulase test?
180) What test methodology is used to
visualize the presence and arrangement
of flagella for the presumptive
identification of motile bacterial species?
Catalase Test
True
Some organisms (enterococci) appear
weakly positive.
Staphylococcus aureus
Streptococcus pyogenes
Citrate Utilization
alkaline
Some organisms will not produce a color
change but will grow.
Enterobacter aerogenes (growth, blue
color)
Escherichia coli (little to no growth, no
color change)
Coagulase Test
fibrinogen
Positive results can revert back to
negative after 24 hours.
Staphylococcus aureus
Staphylococcus epidermidis
Flagella Stain
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Micro Flashcards Unit 1
181) The flagella stain contains a mordant
to better visualize ____.
182) What are the limitations of the flagella
stain?
183) Match the following quality control
organisms to their correct flagella stain
results.
Quality control organism:
Escherichia coli
Pseudomonas aeruginosa
Klebsiella pneumonia
Flagella Stain Results:
nonmotile
Polar
Peritrichous
184) What test methodology is used to
identify organisms that produce
tryptophanase?
185) True or False:
During indole production, tryptophanase
will hydrolyze tryptophan to pyruvate,
ammonia, and indole.
186) Kovac’s reagent used for indole
production will produce what color when
reacted with indole?
187) The alternative spot indole test will
produce a ____ color when positive.
188) What quality control organism would
test positive for the Kovac’s method of
indole production?
189) What quality control organism would
test negative for the Kovac’s method of
indole production?
190) What two test methodology
differentiates members of the
Enterobacteriaceae family?
191) A positive result for the Methyl Red
Test which detects mixed acid
fermentation is indicated by what color?
192) A positive result for the VogesProskauer Test which detects the ability
of an organism to convert the acid
products to acetoin and 2,3-butanediol is
indicated by what color?
flagella
Visualization requires expertise and is
not an entry-level technique.
Escherichia coli – Peritrichous
Pseudomonas aeruginosa – Polar
Klebsiella pneumonia – nonmotile
Indole Production
True
red
blue
Escherichia coli
Klebsiella pneumoniae
Methyl Red and Voges-Proskauer Tests
red
Red
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Micro Flashcards Unit 1
193) For the MRVP Test, is it possible for
an organism to be positive for one test
but not for both of the tests.
194) What are the limitations of the Methyl
Red and Voges-Proskauer Tests?
195) What quality control organism would
test positive for Methyl Red but negative
for Voges-Proskauer Tests?
196) What quality control organism would
test negative for Methyl Red but positive
for Voges-Proskauer Tests?
197) What test methodology determines
whether an enteric organism is motile
and must possess flagella?
198) For mobility testing, ____ agar is used
to visualize a diffuse zone of growth
extending from the line of inoculation.
199) What are the limitations of the motility
testing?
200) What quality control organism would
test positive for motility testing?
201) What quality control organism would
test negative for motility testing?
202) What test methodology determines
whether an organism can reduce nitrite?
203) True or False:
Microorganisms capable of reducing
nitrite to nitrogen will not turn a color and
will produce gas in the nitrate reduction
(nitrate to nitrite) test.
204) What are the limitations of nitrate
reduction?
205) What quality control organism would
test positive for nitrate reduction?
206) What quality control organism would
test negative for nitrate reduction?
207) True or False:
In order to determine optochin
susceptibility, a Taxo P disk is placed on
an inoculated blood agar plate,
incubated, and observed for zone of
inhibition.
yes
208) For optochin susceptibility, what size
of the zone of inhibition is considered
susceptible (sensitive)?
any zone ≥14 mm
MR test should not be read before 48
hours.
Escherichia coli
Enterobacter aerogenes
Motility Testing
semisolid
Some organisms do not display
sufficient growth.
Escherichia coli
Staphylococcus aureus
Nitrate Reduction
True
Zinc dust is added if broth does not
become red or no gas is observed.
Proteus mirabilis (colorless, gas)
Acinetobacter baumanii (red, no gas)
True
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Micro Flashcards Unit 1
209) What are limitations of optochin
susceptibility?
210) What quality control organism would
test positive for optochin susceptibility?
211) What quality control organism would
test negative for optochin susceptibility?
212) What test methodology determines the
presence of cytochrome oxidase activity
for oxidase-negative enteric bacteria from
other gram-negative rods?
213) The oxidase test determines the
presence of cytochrome oxidase using
tetramethyl-p-phenylenediamine
dihydrochloride to indophenol, resulting in
what color end product?
214) What are the limitations of the oxidase
test?
215) What quality control organism would
test positive for oxidase test?
216) What quality control organism would
test negative for oxidase test?
217) What test methodology is used for the
presumptive identification of group A
streptococci and enterococci?
218) Beta-naphthylamine, a byproduct of
hydrolyzation by
L-pyrrolidonyl arylamidase (PYR), will
turn ____ in the presence of
N,N-dimethylamino cinnamaldehyde
reagent.
219) What two quality control organism
would test positive for pyrrolidonyl
arylamidase test?
220) What quality control organism would
test negative for pyrrolidonyl arylamidase
test?
221) What test methodology determines
whether a gram-negative rod ferments
glucose and lactose or sucrose to forms
hydrogen sulfide?
222) Triple sugar iron (TSI) agar contains
__ parts lactose, __ parts sucrose, and
__ part glucose & peptone; and ferrous
sulfate.
Any zone less than 14 mm is
questionable.
Streptococcus pneumoniae (susceptible)
S. pyogenes (resistant)
Oxidase Test
purple
Nickel-base alloy wires that contain
chromium and iron may cause a falsepositive result.
Pseudomonas aeruginosa
Escherichia coli
Pyrrolidonyl Arylamidase Test
red
Enterococcus faecalis
Streptococcus pyogenes
Streptococcus agalactiae
Triple Sugar Iron Agar
10, 10, 1
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Micro Flashcards Unit 1
223) For the triple sugar iron agar, the butt
of tube turns ____ if glucose is fermented
(acid).
224) For the triple sugar iron agar, the slant
of tube turns ____ if lactose or sucrose
are fermented (acid).
225) For the triple sugar iron agar, the tubes
turns ____ if hydrogen sulfide is
produced.
226) Match the following quality control
organisms to their correct TSI results.
Quality control organism:
Pseudomonas aeruginosa
Proteus mirabilis
Shigella flexneri
TSI Results:
K/A (alkaline/acid)
K/K (alkaline/alkaline)
K/A (alkaline/acid), hydrogen sulfide
227) What test methodology differentiates
Haemophilus species?
228) X, V, or XV strips or disks are placed
on ____ inoculation.
229) True or False:
For X and V factor tests, organisms will
grow around the disk that provides the
appropriate factor for growth.
230) Match the following quality control
organisms to their correct X and V factor
test results.
Quality control organism:
Haemophilus influenza
Haemophilus parainfluenzae
Haemophilus ducreyi
X and V factor test results:
requires X disk; grows around XV and X
disks
requires V disk; grows around XV and V
disks
requires XV disk only
yellow
yellow
black
Pseudomonas aeruginosa – K/K
(alkaline/alkaline)
Proteus mirabilis – K/A (alkaline/acid),
hydrogen sulfide
Shigella flexneri – K/A
X and V Factor Tests
confluent
True
Haemophilus influenza – requires XV
disk only
Haemophilus parainfluenzae – requires
V disk; grows around XV and V disks
Haemophilus ducreyi - requires X disk;
grows around XV and X disks
231) True or False:
True
Additional tests exist and result in growth,
turbidity, or color changes.
17
Micro Flashcards Unit 1
232) True or False:
True
Other test examples include the
following:
Use of substances as a source of carbon
Esculin hydrolysis
Fermentation tests
Detection of enzymes
Growth on specific agars
Growth around impregnated disks
233) The most frequent agent of
Coagulase-negative staphylococci.
nosocomial bacteremia is:
234) The species of Staphylococcus, which Staphylococcus aureus.
is one of the most important human
pathogens, is:
Staphylococcus
235) Which group of bacteria is described
as catalase positive and is gram-positive
cocci that grow facultatively anaerobic
and form grapelike clusters?
236) The first identification test performed
Coagulase test.
on a clinical isolate of gram-positive,
catalase-positive cocci would likely be
the:
237) The slide coagulase test is a rapid
Clumping factor.
screening test for the production of:
238) A tube coagulase test was performed
The test should have been read in 1 to 4
on catalase-positive, gram-positive cocci
hours in case any hemolysins are
that were beta hemolytic and grew on
present.
mannitol salt agar. The tube was checked
after overnight incubation and was
negative. Which of the following
statements explains this discrepancy?
239) The tube coagulase test:
Detects extracellular coagulase.
Staphylococcus aureus.
240) In clinical isolates, the most likely
identification of coagulase-positive,
catalase-positive, gram-positive cocci
that are penicillin resistant would be:
Staphylococcus aureus
241) Which virulent and important human
pathogen can also be recovered from the
nares, perineum, and other skin sites of
healthy people, especially in the hospital
setting?
Staphylococcus epidermidis.
242) The resident human flora,
staphylococcus, which is more likely to
cause infections in compromised hosts
such as patients with cancer, is:
18
Micro Flashcards Unit 1
243) The Staphylococcaceae
staphylococcus that is more likely to
cause uncomplicated urinary tract
infections in nonhospitalized hosts,
especially sexually active young women,
is:
244) Isolates of coagulase-negative
Staphylococcus from urinary tract
infections can be presumptively identified
as S. saprophyticuson the basis of its:
245) Quality control should be performed on
which two organisms to determine the
validity of the oxidase reagent?
246) An infected intravenous (IV) catheter
tip grew out gram-positive cocci, which
were catalase positive and coagulase
negative. The zone size of the novobiocin
disk measured 18 mm. The most likely
organism causing infection is:
247) Which organism is catalase positive,
coagulase negative, pyrrolidonyl
arylamidase (PYR) positive, susceptible
to novobiocin, urease negative, and beta
hemolytic on sheep blood agar?
248) Which organism is best described as a
catalase-negative, gram positive coccus
that is beta-hemolytic on sheep blood
agar?
249) Which species of bacteria is
responsible for causing diseases such as
rheumatic fever, glomerulonephritis, and
exudative pharyngitis?
250) Streptococcus pneumoniae can be
described as:
251) The colonial morphologic features of
an organism resembles a donut as it
ages, and it has a polysaccharide
capsule that is responsible for it
virulence. What two characteristics
describe this organism?
Staphylococcus saprophyticus.
252) The development of acute rheumatic
fever and subsequent valvular heart
disease are problems that may be
encountered by patients infected with:
S. pyogenes
novobiocin resistance.
Micrococcus and Aerococcus
Staphylococcus epidermidis.
Staphylococcus haemolyticus
Streptococcus pyogenes
S. pyogenes
Often carrying an antiphagocytic
capsule.
Alpha-hemolytic and bile solubilitypositive
19
Micro Flashcards Unit 1
253) The development of glomerulonephritis
is a problem that may be encountered by
patients infected with:
254) Erythrogenic toxin, hyaluronidase
enzyme, and hemolysins S and O are
extracellular products of:
255) The bacterial species that can be
described as able to hydrolyze hippurate,
is beta-hemolytic, is a major cause of
neonatal meningitis and sepsis, and is a
producer of the Christie, Atkins, MunchPetersen (CAMP) factor is:
256) The CAMP factor is produced by:
257) The major etiologic agent of bacterial
endocarditis in the United States is:
258) Enterococci can be described as:
259) The drugs of choice for most
enterococcal infections are:
260) The bacterial species that can be
described as able to grow in 6.5%
sodium chloride (NaCl) and 40% bile, is
part of the normal fecal flora of animals
and humans, is usually nonhemolytic,
and is a major cause of nosocomial
infections is:
261) Generally speaking, nutritionally
variant streptococci require what
ingredient not found in most conventional
media?
262) What morphologic feature is a major
consideration in determining an
identification scheme for streptococci?
263) Differentiation of the pleomorphic
strains of streptococci and the similar
corynebacteria or lactobacilli can be best
accomplished by:
S. pyogenes
264) Bacitracin, pyrrolidonyl arylamidase
(PYR), CAMP factor, and hippurate are
tests most likely performed on a(n)
_______Streptococcus.
265) Optochin, PYR, bile solubility, esculin,
and 6.5% NaCl are tests most likely
performed on a(n)
_______ Streptococcus.
beta-hemolytic
S. pyogenes
S. agalactiae
S. agalactiae
viridans streptococci
Able to hydrolyze bile esculin.
Penicillin and an aminoglycoside.
Enterococcus faecalis.
Vitamin B6
Hemolytic pattern
Examination of the morphologic features after
growth in thioglycollate broth.
alpha-hemolytic
20
Micro Flashcards Unit 1
266) Media that can be used for isolating
Bacillus anthracis include:
267) Suspect spore-forming, gram-positive
Bacillus species that is nonhemolytic,
nonmotile, and penicillin-susceptible and
that produces a wide zone of lecithinase
on egg yolk agar can be identified as:
268) Induction of sporulation by Bacillus
species can be accomplished with _____
agar.
269) Induction of capsule formation by B.
anthracis can be accomplished with
_____ agar.
270) Which of the following is described as
a spore-forming, gram-positive Bacillus
that is beta-hemolytic, motile, VogesProskauer (VP)–positive, and citratepositive and causes two types of food
poisoning as a result of toxin release?
271) A U.S. Food and Drug Administration
(FDA)–cleared immunochromatographic
test produces a red line on the cassette
and can presumptively identify which
gram-positive Bacillus that is
nonhemolytic and morphologically has a
“Medusa head” appearance when grown
on 5% sheep blood agar?
272) A gram-positive Bacillus, which is
beta-hemolytic on 5% sheep blood agar,
produces a wide zone of lecithinase on
egg yolk agar, is nonmotile, and was
isolated from the stool of a patient with
abdominal pain and watery diarrhea.
Because of the patient’s existing
immunocompromised state, the physician
administered penicillin as the antibiotic
therapy. The patient’s condition did not
improve after 7 days of treatment. Which
one of the following statements explains
the reason for the antibiotic failure?
273) Which of the following types of anthrax
occurs after ingesting the spores and
affects the abdominal or oropharyngeal
area? (Patients usually die from toxemia
and overwhelming sepsis.)
5% sheep blood agar.
Bacillus anthracis.
urea
bicarbonate
Bacillus cereus
Anthracis
The organism produces beta-lactamase,
which renders the drug inactive
Gastrointestinal
21
Micro Flashcards Unit 1
274) A patient diagnosed with Bacillus
anthracis is allergic to penicillin. Which
antibiotic can be given that will be
therapeutically effective?
275) Enzyme-linked immunosorbent assays
(ELISAs) are available that can
serologically identify which Bacillus
species?
276) Not including organisms in
the Enterobacteriaceae family, the
second most common gram-negative
bacilli encountered in clinical specimens
are:
277) Production of exotoxin A and several
proteolytic enzymes and hemolysins are
factors that contribute to the
pathogenicity of which organism?
278) The disease referred to
as melioidosis is caused by which one of
the following?
279) A convenient and reliable identification
scheme for Pseudomonas
aeruginosa involves which of the
following conventional tests?
280) An organism described as oxidasepositive, (K/NC) on TSI media, growth at
42° C, and produces a bright bluishgreen pigment on Mueller-Hinton agar is
281) Which two organisms should be used
to determine the validity of urea agar for
quality control purposes?
282) Which species of Burkholderia is the
one most commonly found in clinical
specimens?
283) Which best describes the source
of Burkholderia cepacia infections?
284) Which organism exhibits bipolar
staining on the Gram stain, which
resembles a “safety-pin” appearance?
285) Oxidative–fermentative base–
polymyxin B–bacitracin-lactose (OFPBL)
media is the best media to use to isolate
which one of the following organisms
from the sputa of patients with cystic
fibrosis?
Ciprofloxacin
Anthracis
Pseudomonas.
Pseudomonas aeruginosa
Burkholderia pseudomallei
Oxidase, triple sugar iron (TSI) slant,
growth at 42° C on Mueller-Hinton agar
or trypticase soy agar
Pseudomonas aeruginosa
Brevundimonas
vesicularis and Ralstonia pickettii
Burkholderia cepacia
Medical devices
Pseudomonas pseudomallei
Burkholderia cepacia
22
Micro Flashcards Unit 1
286) What species causes Pertussis
(whooping cough), an epidemic disease
that is a highly contagious, acute
infection of the upper respiratory tract?
287) What is the best description of the
mode of transmission of Bordetella
bronchiseptica ?
288) What are important identifying
characteristics of Bordetella?
289) Which two organisms should be used
to set up a quality control to determine
the validity of cetrimide agar?
290) What is the best description of the
mode of transmission of Achromobacter
denitrificans?
291) What are Achromobacter,
Alcaligenes, and Bordetella all known as?
292) Which of the following statements best
describes the habitats of Achromobacter,
Alcaligenes, and Bordetella?
293) What is the organism most frequently
associated with various infections in
humans?
294) What is the biochemical description
of Bordetella bronchiseptica?
295) What is the biochemical description
of Myroides?
296) Profuse watery diarrhea (i.e., “rice
water stools”), leading to dramatic fluid
loss, severe dehydration, and
hypotension that frequently leads to
death, is the hallmark of which toxin
activity?
297) Stool specimens suspected of
containing which of the following enteric
pathogens should be collected and
transported only in Cary-Blair medium
because buffered glycerol saline is toxic
for this bacterium?
298) The selective medium, thiosulfate
citrate bile salts sucrose (TCBS) agar, is
especially formulated for isolating what
pathogen from stool cultures?
299) The reagent used in the “string test” is:
Bordetella
close contact with animals
Gram-stain morphologic features,
motility, and flagellar placement
Achromobacter
piechaudii and Bordetella
bronchiseptica
contaminated fluids or medical
solutions
nonglucose utilizers.
The habitats vary from the soil and water
environment to the upper respiratory tract of
various mammals.
Achromobacter.
Oxidase-positive, motile, and rapid
urease–positive.
urease-positive and has a fruity odor
Cholera toxin (CT)
vibrio
vibrio
Sodium deoxycholate
23
Micro Flashcards Unit 1
300) Vibrio cholera and V.
alginolyticus appear what color on TCBS
agar?
301) Colonies growing on modified
cefsulodin-irgasan-novobiocin (CIN) agar
appear to be either Aeromonas spp.
or Yersinia enterocolitica. Which test
should be performed to differentiate
between these two organisms?
302) Vibrio cholerae and Photobacterium
damsela are used to perform quality
control on TCBS agar. After overnight
incubation, no growth is observed. What
is the next course of action?
303) An organism suspected of being one
of the Vibrio spp. grew on MacConkey
agar. To determine whether it was
a vibrio cell or in the Enterobacteriaceae
family, an oxidase test was performed on
the colony. The results of the oxidase
test, however, were negative. Which one
of the following statements explains this
discrepancy?
304) Which of the following statements best
describes the habitats
of Vibrio spp., Aeromonas spp., Plesiomo
nas shigelloides, andChromobacterium
violaceum?
305) The primary habitat for Vibrio spp. is:
306) A vibriostatic test using 0/129 (2,4diamino-6,7-diisopropylpteridine)–
impregnated disks
differentiates vibrio cells, which are
susceptible, and _________, which are
resistant
307) Which organism, which is oxidase
positive, does not grow on TCBS agar,
has the ability to decarboxylate lysine
and ornithine but cannot utilize arginine,
and would have the following colonial
characteristics on sheep blood agar and
MacConkey agar?
308) Which of the following species
of Aeromonas is oxidase-positive,
sucrose-positive, and can decarboxylate
ornithine?
yellow
oxidase
Check the pH to ensure that it is 8.6
The oxidase test should be performed
on a sheep blood agar plate to avoid
false-negative results.
Habitats are mostly soil and water
environment
Brackish or marine water.
aeromonads
Beta-hemolytic and is a nonlactose
fermenter
A. veronii biovar veronii
24
Micro Flashcards Unit 1
309) The transmission of Vibrio spp. to
humans is by:
310) Transmission of Aeromonas spp. to
humans
ingestion of contaminated seafood or
water
ingestion of contaminated seafood or
water
311) Transmission of Plesiomonas
shigelloides to humans is by:
312) Transmission of Chromobacterium
violaceum to humans is by:
313) The drug of choice to treat patients
with Vibrio cholera is:
314) To determine the validity of 0% sodium
chloride (NaCl) broth, which two
organisms should be used for quality
control purposes?
315) Which organism appears green on
TCBS agar and is halophilic?
316) How can true cocci, such as
most Neisseria spp.
and Moraxella (Branhamella) catarrhalis,
be differentiated from morphologically
similar Moraxella species by?
317) What is the species of Moraxella that
is most commonly associated with human
infections, primarily of the respiratory
tract?
318) In Gram-stained preparations, what
will Moraxella atlantae appear as?
ingestion of contaminated seafood or
water
exposure of disrupted skin to
contaminated water
tetracycline
319) In Gram-stained preparations, how
will Moraxella lacunata appear as?
320) What is the virulence of this
organism(s), which is transmitted via a
dog bite, is attributed to?
321) Quality control should be performed on
which two organisms to determine the
validity of deoxyribonuclease (DNase)
media?
322) How can testing for differentiation
of Moraxella nonliquefaciens and M.
osloensis can best be performed by?
323) How can testing for differentiation
of Moraxella lacunata from
other Moraxella species can best be
performed by:
V. parahaemolyticus and V. cholerae
V. vulnificus
Subject the bacterium to noninhibitory
concentrations of penicillin.
M. catarrhalis
It will appear as either gram-negative
coccobacilli or short, broad rods that
tend to resist decolorization and may
appear gram-variable.
It will appear as coccobacilli or mediumsized rods.
It is attributed to as something unknown.
M. nonliquefaciens and M. canis
It can be best performed by the ability to utilize
acetate.
It can best be performed by the ability to
liquefy serum.
25
Micro Flashcards Unit 1
324) Which organism appears clear on
MacConkey agar and resembles some
colonies of the Enterobacteriaceae
family?
325) Which of the following tests can be
performed to differentiate the two
subspecies of Neisseria—elongata and
glycolytica?
326) With one exception, species of the
genus Haemophilus require which of the
following media ingredients for in vitro
growth?
327) Among H. influenzae strains, group
designations (e.g., type b) are based on:
328) Chancroid is the sexually transmitted
disease caused by:
329) Which of the following media provides
the factors necessary for the growth of
Haemophilus spp.?
330) In a phenomenon known as satelliting,
tiny colonies of Haemophilus spp. may be
observed growing on sheep blood agar
close to colonies of:
331) In a phenomenon known as satelliting,
tiny colonies of Haemophilus spp. may be
observed growing on sheep blood agar
close to colonies of bacteria that can
produce:
332) Haemophilus ducreyi requires what
special media to grow?
333) The sputum of a 75-year-old man with
chronic lung infections yields the
following:
• Many gram-negative coccobacilli in Gram
stain; X and V factors required for growth;
Nonhemolytic on rabbit blood agar.
The organism can be identified as:
334) Growth of most Haemophilus species
in culture is enhanced by:
335) Performance of the “factor requirement
test” for Haemophilus involves the:
M. canis
Catalase
Hemin and nicotine adenine
dinucleotide (NAD)
capsular characteristics
H. ducreyi
Chocolate agar
Staphylococcus aureus
NAD
Mueller-Hinton–based chocolate agar,
supplemented with 1% IsoVitaleX and
vancomycin
H. influenzae
5% to 10% carbon dioxide (CO2)
inoculation of unsupplemented media
with a light suspension of the organism
and placement of X and V factor disks
on the agar surface
26
Micro Flashcards Unit 1
336) Isolates from cerebrospinal fluid (CSF)
or respiratory tract specimens that are
gram-negative coccobacilli, grow on
chocolate agar in CO2 but not on blood
agar, and are porphyrin-negative and
nonhemolytic on rabbit or horse blood
may be identified as:
337) H. influenzae can be distinguished
from H. aegyptius by its _____ test for
_____.
338) A 6-year-old boy was diagnosed with
purulent conjunctivitis caused by a
species of Haemophilus.
What would the biochemical profile of the
organism be?
339) Although a useful test in the past, the
particle agglutination assay for the
detection of H. influenzae, type b,
capsular polysaccharide antigen is no
longer reliable because of:
340) Of the following media, which provides
the NAD necessary for the growth of
Haemophilus spp.?
341) Isolates from an ear swab that are
gram-negative coccobacilli grow on
chocolate agar in CO2 but not blood
agar, require both X and V factors for
growth, and are nonhemolytic on rabbit or
horse blood may be identified as:
342) Isolates from CSF that are gramnegative coccobacilli, grow on chocolate
agar in CO2 but not blood agar, require
factor V but not X, and are nonhemolytic
on rabbit or horse blood may be identified
as:
343) To increase the sensitivity of direct
Gram-stain examination of body fluid
specimens, the specimens are usually
344) Which of the following opportunistic
organisms is associated with slowly
progressive subacute bacterial
endocarditis?
345) The virulence of this organism, which
causes chancroid, is most likely attributed
to:
H. influenzae
positive; xylose fermentation
Growth requirements require both X and
V factors; the organism is hemolytic on
rabbit blood.
the increased use of H. influenzae, type
b, vaccination
Chocolate agar
H. influenzae
Haemophilus parainfluenzae
centrifuged before staining
Aggregatibacter aphrophilus
capsular factors
27
Micro Flashcards Unit 1
346) The majority of human infections
with Campylobacter species are caused
by:
347) Campylobacter spp. can sometimes
be detected by direct Gram-stain
examination of fecal sample, which
would reveal many:
348) Curved, microaerophilic, gramnegative rods, with most species having
strong urease activity and the majority of
which colonize mammalian stomachs or
intestines, describe which group of
bacteria?
349) Virulence determinants
of Helicobacter pylori include:
350) Antimicrobial therapy for Helicobacter
pylori infection consists of:
351) A gram-negative, spiral-shaped
organism is isolated from a stool sample
that was hippurate-positive, catalasepositive, susceptible to nalidixic acid,
and resistant to cephalothin. The
organism can be identified as:
352) Ensuring that all foods derived from
animal sources are thoroughly cooked,
all milk is pasteurized, and all drinking
water is chlorinated are ways to avoid
becoming infected with:
353) Campylobacter
jejuni subsp. jejuni grows best at what
conditions?
354) Which of the following genes may
attribute to the virulence of Helicobacter
pylori by encoding for outer membrane
proteins that mediate adherence to a
specific blood group antigen on the
surface of gastric epithelial cells?
355) Which organisms should be used to
perform quality control on hippurate
reagent?
contamination of food, milk, or water with
animal feces.
small curved or seagull-winged gramnegative bacilli.
Helicobacter
urease enzyme
metronidazole, bismuth salt, and
tetracycline
C. jejuni subsp. jejuni.
Campylobacter.
42º C under microaerobic conditions
babA
C. jejuni subsp. jejuni and C. coli
28