Micro Flashcards Unit 2
1) Individuals considered at greatest risk for
contracting brucellosis are:
2) Facultative, intracellular parasitic bacteria
are those that are able to:
3) Organisms belonging to the
genus Brucella are:
4) Although in vitro susceptibility testing is not
reliable, which regimen of antibiotics is
recommended for Brucella infections?
5) The animal reservoir for Brucella
melitensis is:
6) Pertussis (whooping cough) is an epidemic
disease that is a highly contagious, acute
infection of the upper respiratory tract
caused by the
7) The mode of transmission of Bordetella
pertussis can best be described as
8) During the catarrhal stage of pertussis,
symptoms are
9) During the paroxysmal stage of pertussis,
symptoms are
10) Acceptable specimens for the detection
of Bordetella pertussis are
11) Because of its longer shelf life, the medium
of choice to cultivate Bordetella spp. is
12) Which of the following toxins contributes to
the virulence of Bordetella pertussis and
works by hemolyzing red cells and
activating cyclic adenosine monophosphate,
which inactivates several types of host
immune cells?
13) Bordetella pertussis colonies growing on
Regan-Lowe medium yields which of the
following colonial morphologic
appearances?
14) A nasopharyngeal aspirate is cultured on
Bordet-Gengou agar, and growth is
observed. The colonies are also subjected to
a direct fluorescent antibody (DFA) stain,
which is also positive. On the basis of these
findings, the antimicrobial therapy that
should be administered to the patient is
dairy farmers.
exist in both intracellular and extracellular
environments
gram-negative coccobacilli
Doxycycline and rifampin
sheep or goats
Bordetella spp
person-to-person contact
runny nose and mild cough
severe and violent coughing
nasopharyngeal aspirates
Regan-Lowe agar
Adenylate cyclase toxin
Mercury-drop colonies
Azithromycin
1
Micro Flashcards Unit 2
15) If real-time polymerase chain reaction (PCR)
is performed on a Bordetella isolate, then it
must be noted that this type of swab is
unacceptable for collection because of the
presence of which of the following
inhibitory factors?
16) Organisms belonging to the genus Neisseria
are:
17) The JEMBEC transport system for Neisseria
spp. provides an atmosphere with increased
_________ to keep the organism viable
during transport
18) An endocervical swab was collected from a
26-year-old woman with a purulent
discharge. The Gram stain revealed the
following:
• Many white blood cells (WBCs)
• Moderate gram-negative diplococci
• Moderate gram-negative coccobacilli
• Few yeast
Based on these findings, what would be the next
course of action?
19) Gram-negative diplococci are isolated from
a genital specimen and yield the following
results:
• Glucose: positive
• Maltose: negative
• Lactose: negative
The organism can be identified as:
20) The bacterial species that can be described
as oxidase-positive, glucose-positive,
maltose-positive, sucrose-negative, lactosenegative, and a major cause of bacterial
meningitis is:
21) An organism isolated from a sputum sample
that has a “hockey puck” consistency would
have what biochemical profile?
22) Which two organisms should be used to
determine the validity of the nitrate
reduction test?
Calcium alginate
gram-negative diplococci
carbon dioxide (CO2)
Report the Gram stain, and follow up with
culture
Neisseria gonorrhoeae
Neisseria meningitidis
Glucose-negative, maltose-negative, and
lactose-negative
N. lactamica and M. catarrhalis
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Micro Flashcards Unit 2
23) A gram-negative diplococcus grew on 5%
sheep blood agar and chocolate agar, had
scant growth on MacConkey agar, and had
no growth on modified Thayer-Martin
(MTM) agar. The organism was identified as
N. sicca. What explains the discrepancy of
the results obtained on the MTM agar?
24) The differentiation of the similar Moraxella
catarrhalis and Neisseria can be best
accomplished by:
25) MTM, Martin-Lewis (ML), and New York
City (NYC) media were all developed for
the selective isolation of which organism?
26) Gonococci require which of the following
nutrients for growth:
Arginine, Hypoxanthine, Uracil or
IsoVitaleX?
27) Moraxella catarrhalis may be described as:
28) The gram-negative coccus that can be
described as oxidase-positive, glucosenegative, maltose-negative, sucrosenegative, lactose-negative, and DNasepositive is:
29) Moraxella catarrhalis can be described as a:
30) Moraxella catarrhalis may be differentiated
from gonococci and meningococci on the
basis of its:
31) The determination of carbohydrate
utilization patterns for the differentiation
of Neisseria spp. and M. catarrhalis is best
performed by:
32) Which statement is true regarding the
pathogenesis of Neisseria cinerea?
A. N. cinerea is a leading cause of fatal
bacterial meningitis.
B. Virulence factors include pili, capsule
formation, and endotoxin.
C. Disseminated intravascular coagulation
(DIC) and thrombocytopenia are
complications of infection.
D. N. cinerea is commonly encountered as a
contaminant in clinical specimens.
33) Blood cultures collected for the recovery
of Neisseria gonorrhoeae or N.
meningitidis require:
No discrepancy is present. N. sicca does not
grow on MTM agar.
glucose utilization testing
N. gonorrhoeae
IsoVitaleX
oxidase-positive
Moraxella catarrhalis
gram-negative diplococcus
production of DNase
heavy inoculation of buffered, low-peptone
substrate with dextrose, maltose, lactose,
and sucrose.
D. N. cinerea is commonly encountered as
a contaminant in clinical specimens.
less than 0.025% SPS
3
Micro Flashcards Unit 2
34) An advantage of all molecular assays is:
35) Which one of the following statements
is true regarding antimicrobial therapy and
susceptibility testing?
A. Cephalosporins and macrolides are
ineffective against Moraxella catarrhalis.
B. Resistance to quinolones is emerging in
strains of Neisseria gonorrhoeae.
C. Most Neisseria spp. are resistant to
penicillin.
D. Most strains of N. meningitidis are resistant
to penicillin.
36) An acceptable specimen for anaerobic
culture is:
37) During specimen collection, an important
thing to remember when handling a
collection device with an oxygen-free
atmosphere is to:
38) The indicator used to determine whether
anaerobic conditions are achieved in an
anaerobic jar is:
39) Prereduced, anaerobically sterilized (PRAS)
media:
40) Actinomyces spp., Bifidobacterium spp.,
and Clostridium spp. can be described as:
41) Tissue biopsy taken from a puncture wound
is:
42) Aspiration of peritoneal fluid using a needle
and syringe is:
43) Feces in a sterile specimen cup is:
44) Bronchial washing collected with a double
lumen–plugged catheter is:
45) Expectorated sputum is:
46) Cervical swab is:
47) Rectal swab is:
48) Urine via percutaneous aspiration is:
49) Nasopharyngeal swab is:
50) Urine via catheter is:
51) Percutaneous lung aspirate is:
52) The final fill of the anaerobe jar prepared by
the evacuation-replacement method consists
of:
The ability to test for Chlamydia trachomatis
from the same specimen at the same time
B. Resistance to quinolones is emerging in
strains of Neisseria gonorrhoeae.
Tissue obtained at biopsy
Take care not to tip the container
Methylene blue
Are produced, packaged, shipped, and
stored under anaerobic conditions
Microaerophilic organisms that can grow in
the presence of either reduced or
atmospheric oxygen but grow best under
anaerobic conditions
Acceptable
Acceptable
Not acceptable
Acceptable
Not acceptable
Not acceptable
Not acceptable
Acceptable
Not acceptable
Not acceptable
Acceptable
80% to 90% nitrogen, 5% to 10% hydrogen,
and 5% to 10% CO2
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Micro Flashcards Unit 2
53) To isolate anaerobic gram-positive
organisms, which of the following media
should be used?
54) An anaerobic media, which contains ferric
ammonium citrate and hemin, bile salts, and
gentamicin, is used to isolate which group of
organisms?
55) What media isolates Prevotella and
Bacteroides spp?
56) What media inhibits gram-negative rods?
57) What media is non selective; supports the
growth of facultative anaerobes and aerobes?
58) What media determines lecithinase and
lipase production of Clostridia and
Fusobacteria?
59) What media is selective for Clostridium
difficile?
60) Characteristics that strongly indicate the
presence of
pigmented Prevotella or Porphyromonas in
a clinical specimen include
61) In a clinical specimen, sulfur granules
strongly indicate the presence of which
anaerobe?
62) A diabetic patient has developed gas
gangrene of the right foot. The most likely
anaerobe causing this infection is
63) Optimal recovery and identification of
anaerobic bacteria in clinical specimens
occurs when:
64) The ethanol shock or heat shock test will
separate which two bacteria?
65) The most likely identification of a bilesensitive, kanamycin-resistant, catalasenegative, and indole-negative anaerobic
gram-negative bacilli is
66) The most likely identification of a bileresistant, kanamycin-resistant, colistinresistant, and vancomycin-resistant
anaerobic gram-negative bacilli is
67) The most likely identification of an
anaerobic gram-negative bacilli that will
fluoresce brick red or has a brown-to-blackpigment is
Anaerobic phenylethyl alcohol agar (PEA)
Bacteroides spp.
LKV blood agar
PEA agar
Thioglycollate broth
Egg-yolk agar
CCFA
brick-red fluorescence under longwavelength ultraviolet (UV) light
Actinomyces
C. perfringens
the initial incubation period is at 35° to 37°
C for 48 hours
Clostridium and Bifidobacterium
nonpigmented Prevotella
Bacteroides fragilis group
Porphyromonas
5
Micro Flashcards Unit 2
68) The most likely identification of an
anaerobic gram-negative bacillus that
reduces nitrate and requires formate and
fumarate for growth in broth culture is
69) The most likely identification of kanamycinsensitive and anaerobic gram-negative
bacilli that fluoresce a chartreuse color is
70) The primary plating medium used to select
out Clostridia spp. would be
71) Fecal cultures to isolate Clostridium
difficile are plated on
72) Quality control is set up on a new lot of an
indole reagent. Clostridium
bifermentans and Clostridium bolteae are
used, and the following results are obtained:
• C. bifermentans: positive
• C. bolteae: negative
73) Incubation conditions for anaerobic cultures
include
74) The most likely identification of an
anaerobic gram-positive bacillus that is a
very large fusiform bacillus with one pointed
end and one blunt end is:
75) The most likely identification of an
anaerobic gram-negative coccus is
76) The most likely identification of an
anaerobic gram-positive coccus that
is resistant to metronidazole is:
77) The most likely identification of an
anaerobic, curved, gram-variable bacillus
with tapered ends on Gram stain of vaginal
secretions when vaginosis is suggested is:
78) The most likely identification of an
anaerobic gram-positive bacillus that
produces spores is
79) Are kanamycin-resistant, colistin-resistant,
and vancomycin-resistant and grow in 20%
bile
80) Fluoresce brick red or have a brown-to-black
pigment
81) Characteristics that are found in the bacteria
called Mycobacterium are:
Bacteroides ureolyticus
Fusobacterium
phenylethyl alcohol agar (PEA)
cycloserine cefoxitin fructose agar
(CCFA).
No discrepancy is present. The results
obtained are correct
incubation for 48 hours before exposing the
culture to air
Leptotrichia
Veillonella
Streptococcus
Mobiluncus
Clostridium
Bacteroides fragilis group
Pigmented Prevotella
a cell wall that contains N-glycolylmuramic
acid and has a high lipid content.
6
Micro Flashcards Unit 2
82) The term complex as used in the
M. tuberculosis complex:
83) Examples of the mycobacterial species that
occur in humans and belong to the
Mycobacterium tuberculosis complex
include:
84) The recent emergence of epidemic
multidrug-resistant strains of Mycobacterium
tuberculosis, in conjunction with the end of
the downward trend of reported cases of
tuberculosis in the United States, has been
largely attributed to:
85) The tuberculin skin test, or the purified
protein derivative (PPD) test, is based on:
86) A positive tuberculin skin test, or PPD test,
is characterized by:
87) The Runyon system of classification is based
on:
88) Slow-growing NTM whose colonies become
pigmented when exposed to light are
referred to as:
89) Slow-growing NTM whose colonies are
pigmented when grown in the dark or the
light are referred to as:
90) Slow-growing NTM whose colonies produce
no pigment, whether they are grown in the
dark or the light, are referred to as:
91) The most commonly isolated
mycobacterium in the United States is:
92) Known to cause an inflammatory bowel
disease referred to as Johne disease in cattle,
sheep, and goats, which organism has been
isolated from the bowel mucosa of patients
with Crohn disease?
93) Mycobacterium fortuitum, M.
chelonae, and M. abscessus are:
94) Which of the following species
of Mycobacterium causes a chronic disease
of the skin, mucous membranes, and nerve
tissue but has not yet been cultivated in
vitro?
95) The primary reservoir of the
Mycobacterium responsible for leprosy is:
is used to describe two or more species
whose distinction is complicated and of
little or no medical importance
M. tuberculosis, M. bovis, M.
bovis BCG, and M. africanum.
human immunodeficiency virus (HIV)
epidemic.
delayed hypersensitivity cell-mediated
immunity to certain antigenic components
of the organism.
erythema and induration.
growth rate and colonial pigmentation.
photochromogens.
scotochromogens.
nonphotochromogens.
M. avium-intracellulare
M. paratuberculosis
responsible for approximately 90% of
clinical mycobacterial disease.
M. leprae
infected humans.
7
Micro Flashcards Unit 2
96) The specimen of choice for detecting
tuberculous pulmonary mycobacterial
disease is:
97) The specimens of choice for detecting
nontuberculous mycobacterial disease are:
98) The specimens of choice for detecting
urinary tract mycobacterial disease are:
99) What quantity of cerebrospinal fluid (CSF)
is considered sufficient for the detection of
tuberculous meningitis?
100) The specimen of choice for detecting
mycobacterium in a skin lesion or wound is
a:
101) Specimens for Mycobacterium studies
that require concentration, decontamination,
or liquefaction include:
102) Sodium hydroxide (NaOH), Zephiran–
trisodium phosphate, N-acetyl-L-cysteine–
NaOH (NALC-NaOH), and oxalic acid are
associated with:
103) The type of specimen collected for
mycobacterial studies that must be
neutralized with 10% sodium carbonate is:
104) On Gram stain, mycobacteria appear as:
105) The
nonpathogenic Mycobacterium commonly
found in tap water, which has been a problem
when tap water or deionized water has been
used in the preparation of smears, is:
106) The fluorochrome method of
staining Mycobacterium:
107) One drawback associated with the
fluorochrome stain method for
detecting Mycobacterium is that:
108) The stain that requires heating the slide
for better penetration of stain into the
mycobacterial cell wall is known as the:
109) The stain that does not require heating the
slide for better penetration of stain into the
mycobacterial cell wall is known as the:
110) Acid-fast smears should be examined
carefully by scanning at least ________ oil
immersion field.
spontaneously produced sputum.
bronchial lavages, washings, and brushings.
three daily clean-catch midstream urine
samples
10 mL
needle aspiration
sputum.
digestion and decontamination of
specimens for mycobacterial studies
gastric lavage
poorly stained, beaded, gram-positive
bacilli
M. gordonae
enables the smear to be initially examined
at lower magnifications.
many rapid growers may not appear
fluorescent with these reagents
Ziehl-Neelsen
Kinyoun
300
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Micro Flashcards Unit 2
111) Fluorescent staining is more sensitive
than conventional carbolfuchsin stains. What
counterstain is used during the procedure?
112) Optimal conditions for most
mycobacterial cultures are:
113) Optimal conditions for the recovery of M.
haemophilum from specimens include:
114) Negative mycobacterial cultures are
reported final and the cultures are discarded
after what period?
115) The first test that is always performed on
organisms growing on solid or liquid
mycobacterial media is a(n):
116) Quality control is performed to test the
validity of catalase production at 68° C. M.
fortuitum and M. tuberculosis are used,
which yield a positive and negative reaction,
respectively. Which one of the following
statements explains this discrepancy?
117) When culturing for Mycobacterium, rapid
growers usually produce colonies within
how many days after subculture?
118) Under what circumstance might slowgrowing mycobacteria appear to produce
colonies in a few days?
119) For reliable results, the niacin test should
be performed only from cultures that are at
least:
120) In the identification of mycobacterial
isolates, the niacin test involves the:
121) In the identification of mycobacterial
isolates, the catalase test involves the:
122) In the identification of mycobacterial
isolates, the Tween 80 test involves:
123) The 3-day test that is useful for
identifying the rapid growers, M.
fortuitum and M. chelonae, and that
measures the rate by which this enzyme
breaks down phenolphthalein disulfate into
phenolphthalein and other salts is the
____________ test.
124) Which continuous growth system uses a
CO2 sensor to monitor mycobacterial
growth?
Potassium permanganate
35° C in the dark in an atmosphere of 5% to
10% CO2 and high humidity.
placement of an X-factor disk on the
media.
8 weeks
acid-fast stain
No discrepancy is present. M. fortuitum is
catalase-positive and M. tuberculosis is
catalase-negative at 68° C.
3 to 4 days
When the inoculum is too heavy
3 weeks old and show at least 50 colonies
on Löwenstein-Jensen medium
accumulation of niacin in the medium in
which the organism is growing
measurement of the height of a column of
bubbles of oxygen.
a lipase that is able to hydrolyze
polyoxyethylene sorbitan monooleate into
oleic acid and polyoxyethylated sorbitol.
arylsulfatase.
BacT/Alert
9
Micro Flashcards Unit 2
125) A fisherman who cut himself on a fishing
hook later develops a cutaneous disease at
the inoculation site. The exudate is aspirated
and set up on a routine AFB medium for
culture. It is incubated at 37° C, but no
growth is observed after 8 weeks; however,
a slide of the exudate was AFB-positive.
Which one of the following statements
explains these findings?
126) Long, slender, helically curved, gramnegative bacilli with tight coils are identified
as belonging to which species
127) Long, slender, helically curved, gramnegative bacilli with hooked ends are
identified as belonging to which species
128) Systemic symptoms, such as fever,
weight loss, malaise, and a loss of appetite,
along with a widespread rash, can be
observed in patients suffering from
_________ syphilis.
129) A widely used nontreponemal serologic
assay is the ________ test.
130) The most common vector-borne disease
in North America and Europe transmitted by
the bite of Ixodes ticks is caused by:
131) A destructive lesion of the gums, also
known as acute necrotizing ulcerative
gingivitis, that is caused by oral spirochetes
and other bacteria is known as
132) A stage of venereal syphilis characterized
by the appearance of a chancre is known as
__________ syphilis
133) A stage of venereal syphilis, characterized
by tissue destruction, central nervous system
disease, cardiovascular abnormalities, eye
disease, and granuloma-like lesions, is
known as ________ syphilis
134) Treponemal antibodies are those that are
135) Nontreponemal antibodies are those that
are:
136) A nontreponemal flocculation serologic
test in which soluble antigen particles are
coalesced to form larger particles that are
visible as clumps when they are aggregated
by antibody is called the __________ test
The organism should have been incubated
at 30° C
Treponema
Leptospira
secondary
rapid plasma reagin (RPR)
Borrelia burgdorferi
Vincent’s disease
primary
tertiary
produced against antigens of the organisms
themselves
produced by infected patients against
components of mammalian cells
VDRL
10
Micro Flashcards Unit 2
137) A specific treponemal serologic test
performed by overlaying whole treponemes
that are fixed to a slide with serum from
patients suspected of having syphilis and
using fluorescein-conjugated antihuman
antibody reagent to detect specific
antitreponemal antibodies is called the
_________ test
138) A test that uses gelatin particles sensitized
with T. pallidum subsp. pallidum antigens to
detect specific antitreponemal antibodies in
patient serum is called the __________ test.
139) A self-limiting illness and the most
common clinical syndrome associated with
leptospirae that includes fever, headache,
myalgia, and aseptic meningitis in the
immune stage is called
140) The most severe illness associated with
leptospirae, with symptoms of liver, kidney,
and/or vascular dysfunction with lethal
pulmonary hemorrhage and sometimes
death, is called
141) The Centers for Disease Control and
Prevention (CDC) recommendations for
testing in suspected cases of Lyme disease
are to screen with ______ and confirm with
________.
142) A patient has a reactive RPR result and a
positive FTA-ABS test. The drug of choice
to treat this infection is:
143) An automated system uses bead-capture
technology in the detection of which of the
following spirochetes?
144) The Jarisch-Herxheimer reaction is
associated with the clearance of organism
from the bloodstream and the release of
cytokines within hours of antibiotic
treatment. With which spirochete is this
condition associated?
145) This protozoa has a trophozoite stage but
no cyst stage and reproduces via longitudinal
binary fission. The parasite belongs to which
category?
FTA-ABS
TP-PA
anicteric leptospirosis
icteric leptospirosis
IFA; immunoblotting
penicillin G
Treponema
Borrelia
Flagellates
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Micro Flashcards Unit 2
146) Babesia spp. is transmitted via the bite of
a tick and can cause severe disease in
patients who have been splenectomised or
who are immunocompromised. To diagnose
accurately these patient populations, the
specimen of choice is:
147) Wuchereria, Brugia, Loa, and Onchocerca
are all classified as:
148) A bone marrow aspirate is examined for
the presence of parasites from a patient who
has been traveling in Latin America for
several months and who came in contact
with a triatomid bug. Which parasite will
most likely be identified?
149) The eggs of which of the following
intestinal parasites are not commonly found
in feces and must be detected by other
diagnostic techniques?
150) Which of the following intestinal
parasites is found in humans and also in
pigs?
151) Some strains of leishmaniae have
reservoir hosts, including dogs and wild
rodents. Transmission is via the bite of a:
152) A 17-year-old male with a severe eye
infection admits that he does not clean his
contact lenses as often as he should. His eye
infection is most likely the result of which
parasite?
153) A 7-year-old girl was at summer camp
and dove into the lake many times. She
complained that water went up her nose a
few times. Several days later she is
unresponsive and comatose and rushed to
the hospital. A cerebrospinal fluid (CSF)
specimen is drawn, and several motile
amebae are observed. She is most likely
suffering from an infection with which of the
following parasites?
154) The specimen of choice to collect in
suspected cases of Paragonimus infection is:
155) Which of the following is currently the
only fixative available that does not contain
formalin, polyvinyl alcohol (PVA), or
mercury?
Blood
filarial nematodes.
Trypanosoma cruzi
Enterobius vermicularis
Balantidium coli
Sandfly
Acanthamoeba spp.
Naegleria fowleri
sputum
TOTAL-FIX
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Micro Flashcards Unit 2
156) The concentration protocol of the ova and
parasite (O&P) examination:
157) The permanent stained smear protocol of
the O&P examination:
158) A 4-year-old boy who is in day care 3
days per week is irritable and scratching the
area around his anus. What morphologic
characteristics would most likely be
observed on microscopic examination of the
appropriate specimen?
159) The Entero-Test capsule technique
involves the collection of duodenal contents
to examine the presence of which of the
following parasites?
160) A urine sample from a 26-year-old
woman is examined, and an organism is
observed that displays “jerky” motility. This
organism is classified as a(n):
161) A modified acid-fast stain is performed
on lung tissue. The most likely organism that
will be observed is:
162) A medical laboratory scientist (MLS) is
examining a thin blood film from a patient
suspected of having a Plasmodium infection.
After examining the slide for 5 minutes and
viewing approximately 100 oil immersion
fields, the MLS does not observe any
structures associated with Plasmodium.
Which one of the following statements
explains this discrepancy?
163) The PARATECT Cryptosporidium/Giardia test kit uses
which of the following formats for
detection?
164) The parasite Toxoplasma gondii is
acquired via the ingestion of infected
oocysts from cat feces. A diagnosis is
primarily made through:
165) The peripheral chromatin, which contains
fine granules that are uniform in size and are
evenly distributed, can be found in which
protozoa?
is designed to allow the detection of
protozoan cysts, coccidian oocysts,
microsporidial spores, and helminth eggs
and larvae
is designed to facilitate the identification of
intestinal protozoa.
Football-shaped eggs with one flattened
side
Giardia lamblia
flagellate.
Cryptosporidium spp.
The MLS may have missed the organism;
more than 300 files should be viewed.
Direct fluorescent antibody (DFA)
serologic means.
Entamoeba histolytica
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Micro Flashcards Unit 2
166) The presence of which cells is diagnostic
for the intestinal protozoan, Entamoeba
histolytica, which measures 15 to 20
microns?
167) A patient has amebic colitis. A
microscopic examination reveals the
following:
• 18 microns in diameter
• Fine granules
• Centrally located karyosome
• Cytoplasm with a “ground glass”
appearance
• RBC inclusions
This protozoan can be identified as:
168) A tissue sample is sent to the laboratory
and microscopically examined for the
presence of amebae. To differentiate
between the host cells and the organism,
_______ stain is used to allow the organisms
to appear bright pink with a green-blue
background.
169) A patient is diagnosed with a severe
intestinal disease caused by Entamoeba
histolytica. Which treatments should be
administered?
170) Entamoeba coli, a protozoan that ranges
from 15 to 25 microns in diameter, can
contain up to eight nuclei in mature cysts.
How would the karyosome expect to appear
on a stained slide?
171) An intestinal protozoan appeared 8
microns in diameter with a small, compact,
centrally located karyosome. Four nuclei
were observed in the mature cyst. The
organism can be identified as:
172) Which nonpathogenic protozoa has a very
large glycogen vacuole in its cyst form and
measures approximately 5 to 20 microns in
diameter?
173) The drug of choice for the
parasite Blastocystis hominis, which is
believed to produce proteases and is
considered a virulence factor responsible for
its pathogenesis, is:
Red blood cells (RBCs)
Entamoeba histolytica
periodic acid-Schiff (PAS)
Metronidazole plus iodoquinol
Large, not compact
E. hartmanni
Iodamoeba butschlii
Metronidazole
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Micro Flashcards Unit 2
174) Which intestinal protozoa has no cyst
stage, ranges from 9 to 12 microns in
diameter, and has two nuclei in 60% of
clinical specimens?
175) This flagellate is pear-shaped with
“falling leaf” motility. It contains variantspecific surface proteins (VSPs) on its
surface, which provide a mechanism for the
organism to survive in the small intestine as
a result of its ability to resist intestinal
proteases. The organism is:
176) Which flagellate has a single nucleus in
the cyst and the typical curved, cytostomal
fibril, which is called ashepherd’s crook?
177) The cyst form of Balantidium coli is the
infective stage. It has one large kidneyshaped macronucleus and one small, round
micronucleus. The troph is quite large,
measuring 50 to 150 microns in length and
40 to 70 microns in width. What single
feature is associated with this organism?
178) Asexual amplification, called merogony,
is associated with the life cycle of which
organism?
179) Highly active antiretroviral therapy
(HAART) is the most effective prophylaxis
and treatment in patients with acquired
immunodeficiency syndrome (AIDS) with
which type of infection?
180) Outbreaks of infection with the
organism Cyclospora are linked to
contaminated raspberries, lettuce, and snow
peas. The stain of choice to identify the
oocysts in stool samples is:
181) The Isospora belli organism, which
contains two sporocysts with four
sporozoites each, is recovered from fecal
specimens and has also been implicated in
traveler’s diarrhea. The drug of choice to
treat infection caused by I. belli is:
182) The organism Sarcocystis has an
obligatory two-host life cycle—an
intermediate host and definitive host. The
sporocysts found in a stool specimen, which
measure 9 to 16 microns, are broadly oval
with slightly ___________ ends.
Dientamoeba fragilis
Giardia lamblia
Chilomastix mesnili
Cilia covering the troph
Cryptosporidium
Cryptosporidium
modified acid-fast
trimethoprim-sulfamethoxazole
combination
tapered
15
Micro Flashcards Unit 2
183) When cooking meat, an internal
temperature of ____° C must be reached to
kill organisms such as Toxoplasma and
Sarcocystis.
184) The polar tubule, which is responsible for
the entrance of infective sporoplasm into the
host cell, is found in which genera?
185) In cases of malaria, the primary
exoerythrocytic cycle occurs in the?
186) Delicate ring forms and crescent-shaped
gametocytes are the only forms normally
observed in the peripheral blood of which
Plasmodium spp.?
187) A thick ring, large nucleus, and bands
across the cell and 6 to 12 merozoites in a
mature schizont are all characteristics of
which Plasmodium spp.?
188) Cerebral malaria is considered to be the
most serious complication and major cause
of death with which species of
Plasmodium spp.?
189) Plasmodium vivax is suspected in a
patient who has been traveling for months in
the tropics. Blood was collected in a
lavender top tube; however, the slide was
not prepared for examination until the next
day because the specimen came in on the
night shift. Once the slide was prepared and
examined, Schüffner dots were not visible.
Which one of the following statements
explains this discrepancy?
190) Resistance to chloroquine and mefloquine
has been identified in
which Plasmodium spp.?
191) Ring forms and a “Maltese cross” were
observed in a blood smear. The vector that
transmits this disease is a(n)?
192) Chagas disease is caused by?
193) The vector Glossina palpalis group
transmits the Trypanosoma brucei
gambiense organism. The diagnostic stage is
the?
68
Enterocytozoon
liver
P. falciparum
P. malariae
P. falciparum
The blood remained in the tube too long,
yielding false-negative results.
P. falciparum
tick.
T. cruzi.
trypomastigote.
16
Micro Flashcards Unit 2
194) Stage I of trypanosomiasis
characteristically involves systemic
trypanosomiasis infection without central
nervous system (CNS) involvement.
Lymphadenopathy is also a feature of this
disease. The trypomastigotes of which
protozoa are involved?
195) In Trypanosoma brucei
rhodesiense trypanosomiasis infections,
CNS invasion occurs early. The disease
progresses rapidly, and death may occur
before extensive CNS involvement.
Inflammation of which organ is more
common and severe with this disease form?
196) Humans contract Chagas disease when
the reduviid bug defecates while taking a
blood meal and the parasites in the feces are
rubbed or scratched into the bite wound or
onto mucosal surfaces. Which stage in the
blood infects the host cells?
197) The most frequent clinical signs of
chronic Chagas disease involve the
enlargement of which organ?
200) Match the size and shape of the parasitized
RBCs as they appear in Giemsa-stained thin
blood smears.
A. Normal shape and size
B. Normal shape; size may be normal or
slightly smaller
C. 1.5 to 2.0 times larger than normal; oval to
normal
D. 60% of cells are larger than normal and oval
T. brucei gambiense
Heart
Trypomastigote
Heart
1. Plasmodium vivax
2. P. ovale
3. P. falciparum
4. P. malariae
A. = 5 P. knowlesi
B. = 4 P. malariae
C. = 1 Plasmodium vivax
D. = 2 P. ovale
1. Plasmodium vivax
2. P. ovale
3. P. falciparum
4. P. malariae
5. P. knowlesi
17
Micro Flashcards Unit 2
201) Match the vector with the organism it
infects.
A. Anopheles mosquito
B. Tsetse fly
C. Sandfly
D. Reduviid bug
1. Trypanosoma cruzi
2. T. brucei rhodesiense
3. T. brucei gambiense
4. T. rangeli
202) A 15-year-old male was diving in a lake
when he inhaled some of the stagnate water.
Five days later he was admitted to the
hospital, comatose and in critical condition.
A cerebrospinal fluid (CSF) specimen was
taken, and several motile amoebae were
observed. The patient would most likely be
diagnosed with which of the following
conditions?
203) The CSF would reveal which of the
following results in infections caused by N.
fowleri?
204) The Acanthamoeba organism is motile
and has spinelike pseudopods, a single round
nucleus in the cyst form, and a large
karyosome in the nucleus of the troph. An
estimated 70% of clinical cases
of Acanthamoeba keratitis are misdiagnosed
as __________ keratitis.
205) Tissues suspected of
containing Acanthamoeba cysts can be
observed using various stains. A cyst that
stains black has most likely been stained
with the __________ stain.
206) Primates, as well as dogs, sheep, and
horses, have died of central nervous system
(CNS) infections with which organism?
207) Trichomoniasis is the primary nonviral
sexually transmitted disease worldwide. One
complication of this infection is:
A.
B.
C.
D.
None
T. brucei gambiense
None
T. rangeli
Primary amebic meningoencephalitis
Decreased glucose, increased protein, and
negative Gram stain
viral
methenamine silver
Balamuthia mandrillaris
endometritis.
18
Micro Flashcards Unit 2
208) A 26-year-old woman has an odorous
vaginal discharge, lower abdominal pain,
and difficulty urinating. Vaginal secretions
are collected and sent to the laboratory for
examination 3 hours after collection. No
motile organisms are observed on the wet
preparation; however, Trichomonas
vaginalis is suspected. Which one of the
following statements explains this
discrepancy?
209) The troph of the motile Trichomonas
vaginalis organism measures 7 to 23
microns long and 5 to 15 microns wide. The
recommended treatment of choice for this
urogenital infection is:
210) Laboratory diagnosis of Trichomonas
gondii is confirmed by:
211) Tachyzoites (Toxoplasma gondii) appear
as?
212) Bradyzoites (Toxoplasma gondii) appear
as?
213) Sporozoites (Toxoplasma gondii) appear
as?
214) The most common and largest
roundworm encountered is:
215) The eggs of the Ascaris
lumbricoides worm are ingested and hatched
in the duodenum, penetrate the intestinal
wall, and migrate to the hepatic portal
circulation. Its geographic distribution and
infection rate are associated with:
216) Löffler syndrome is associated with
which roundworm infection?
217) A 4-year-old boy attended day care 3
days per week. He was irritable, and his
parents noticed that he had persistent
perianal itching. A sticky paddle was pressed
against the perianal region and sent to the
laboratory for testing. The eggs
microscopically observed would most likely
have which one of the following
morphologic features?
No discrepancy is present; this organism in
nonmotile
metronidazole
serologic testing.
Crescent-shaped
Tissue cysts
Oocysts from cat feces
Ascaris lumbricoides
poor sanitation
Ascaris lumbricoides
Flat-sided, football-shaped
19
Micro Flashcards Unit 2
218) The infective larvae of the
parasite Strongyloides stercoralis penetrate
the skin and migrate through the circulatory
system to the heart and lungs. The organism
enters the bronchial tree and is then
swallowed, entering the digestive tract,
where the organism matures into an adult
worm. This parasite is classified as which
type of infection?
219) A short buccal capsule, large bulb on the
esophagus, and prominent genital
primordium are all characteristics of which
worm?
220) The larvae of the worm Strongyloides
stercoralis are the most common found in
human stool specimens. Depending on the
fecal transit time through the intestine and
the patient’s condition, both rhabditiform
and rare filariform may be present. The
treatment of choice for uncomplicated
infections is:
221) A 36-year-old man entered the emergency
department with bleeding and weight loss
several weeks after returning from a trip to
South America. A stool sample was taken
and microscopically examined. Barrelshaped eggs with bipolar plugs were
observed. The organism can be identified as:
222) Direct penetration of which of the
following worms results in tissue damage at
the site of attachment, blood loss, and an
acute gastrointestinal phase demonstrated by
an increased eosinophilia?
223) Rhabditiform larvae measuring 275
μmicrons with a long buccal capsule and a
small genital primordium was identified as
hookworm. Which one of the following
statements explains this discrepancy?
224) Humans acquire infection
with Trichinella tissue nematode by
ingesting undercooked meat that contains the
infective encysted larvae. In which tissue do
these larvae encyst?
225) A definitive diagnosis can be made in
a Trichinella infection on the basis of which
of the following findings?
Threadworm
Strongyloides stercoralis
ivermectin
Trichuris trichiura
Hookworm
No error occurred. Hookworm is the correct
identification for an organism with these
characteristics
Striated muscle
Identification of encysted larvae through
muscle biopsy
20
Micro Flashcards Unit 2
226) A child is believed to have a Toxocara
cati infection in his eye, which he acquired
after playing with a stray cat for several
weeks. A serum titer was performed, which
revealed a titer of 1:8. This laboratory value
can be interpreted as:
227) Systemic involvement is rare in infection
caused by Ancylostoma braziliense or A.
caninum; however, pneumonitis may occur.
The antihelminthic therapy used to treat this
infection is
228) What is the mode of transmission for
Dracunculus medinensis?
229) What is the mode of transmission for
Parastrongylus cantonensis?
230) What is the mode of transmission for
Trichinella spp.?
231) What is the mode of transmission for
Parastrongylus costaricensis?
232) The definitive host and reservoir
for Wuchereria bancrofti is:
233) Chyluria is a result of lymphatic rupture
and fluid entering the urine. Another
lymphatic condition caused by Wuchereria
bancrofti is:
234) A 36-year-old man who has been
traveling through the orient is experiencing a
tender region in the inguinal region. A blood
film is made, and sheathed microfilariae
with four to five subterminal nuclei and two
terminal nuclei in the tail are identified using
Giemsa stain. The organism is most likely:
235) A skin snip is performed, and
microfilariae with tapered tails, no nuclei,
and unsheathed are microscopically
observed. The recommended therapy for this
infection is:
236) A Giemsa stain is performed on an eye
exudate on a patient with calabar swelling,
eosinophilia, and a recent travel history to
Africa. Loa loa is suspected; however, the
sheath in the adult worm recovered does not
stain. Which one of the following statements
explains this discrepancy?
diagnostic
ivermectin or thiabendazole
Copepods
Crabs
Pigs
Snails
Humans
Elephantiasis.
Brugia malayi
Ivermectin.
No discrepancy is present. The sheath does
not stain with Giemsa stain.
21
Micro Flashcards Unit 2
237) Which organism is transmitted by
Tabanid fly?
238) Which organism is transmitted by Biting
midges?
239) Which organism is transmitted by
Anopheles mosquito?
240) Which organism is transmitted by Black fly?
241) The Diphyllobothrium latum tapeworm
can reach up to 10 meters in length and can
have more than 3000 to 4000 proglottids.
The definitive host and reservoir host,
respectively, are:
242) The double-pored tapeworm,
Diphyllobothrium caninum, consisting of
many small proglottids, measures 10 to 70
cm in length as an adult. The scolex contains
four suckers and an armed rostellum. The
intermediate host in which infective
cysticercoids develop is the:
243) The mode of infection for which of the
following organisms is the ingestion of
cysticercoid in an infected arthropod or by
the direct ingestion of the egg?
Autoinfection may also occur.
244) The Taenia solium organism, which
causes cysticercosis and can grow to be 1.5
to 8 meters long, contains 7 to 13 lateral
uterine branches along the proglottid. The
intermediate host is:
245) A stool specimen is examined, and a
tapeworm with the following characteristics
are observed:
• 15 to 18 lateral branches on each side
• Scolex with four suckers
• No hooklets
The intermediate hosts of this tapeworm are:
246) Epileptic seizures, headaches, and mental
disturbances all result from infection with
the Taenia solium organism. The definitive
diagnosis is based on
247) Hydatid disease is associated with which
tapeworm?
248) In Echinococcus granulosus infections,
the hydatid cysts usually occur in which
organ?
Loa loa
Mansonella spp
Brugia spp.
Onchocerca
humans and fish.
flea.
Hymenolepis nana
pigs.
cattle.
identification of cysts in tissue
Echinococcus granulosus
Liver
22
Micro Flashcards Unit 2
249) Fur trappers and veterinarians are at an
increased risk for this infection by being
exposed to infected animals. The
intermediate hosts of the
organism, Echinococcus multilocularis, are:
250) The Taenia multiceps tapeworm is 5 to 6
cm long and consists of 200 to 250
segments. It has four suckers in its scolex
and a proboscis with 22 to 32 hooks
arranged in two rows. This organism causes
which condition?
251) The intermediate host of
the Platyhelminthes is freshwater
252) The life-cycle stages of the intestinal
trematodes after the eggs are shed from the
body via feces is best described as
253) The adult form of the fluke, Fasciolopsis
buski, is elongated in shape and ranges from
20 to 75 mm long and 8 to 20 mm wide with
an oral sucker at the anterior and a ventral
sucker approximately midway to the
posterior. The reservoir host for the fluke is
254) The Heterophyes heterophyes worm,
which has a genital sucker that surrounds the
genital pore, has a variety of reservoir hosts
including dogs, cats, and birds and a second
intermediate host of freshwater:
255) A 36-year-old man who has traveled for
several weeks in the orient is experiencing
abdominal pain and diarrhea with a large
amount of mucus. A Heterophyes
heterophyes egg measuring 28 by 15
microns is identified in the stool. The
treatment of choice for this intestinal
trematode is:
256) Which second intermediate host ingests
the cercariae of Clonorchis and
Opisthorchis?
257) The adult worm of Fasciola measures 2
to 5 cm by 0.8 to 1.3 cm with a cephalic
cone at the anterior end that contains the oral
sucker. The drug of choice to
treat Fasciola infections is:
258) Charcot-Leyden crystals are often
observed in specimens infected with which
one of the following trematodes?
Rodents
Coenurosis
snails
miracidium larva, redia, cercariae, and
metacercariae
dogs
Fish
Praziquantel
Freshwater fish
bithionol.
Paragonimus westermani
23
Micro Flashcards Unit 2
259) The eggs of Paragonimus
mexicanus measure approximately 80
microns by 40 microns, are unembryonated
and operculated, and have thick shells that
are brownish yellow. An individual with this
infection has most likely traveled to which
endemic area?
260) Match the fluke classification with the
corresponding organism
Opisthorchis viverrini
Fasciola spp.
Clonorchis (Opisthorchis) sinensis
Paragonimus westermani
261) The only intermediate host required in the
life cycle of blood flukes is a:
262) The eggs of the blood fluke Schistosoma
haematobium range from 110 to 170
microns long by 40 to 70 microns wide and
have a sharp, pointed terminal spine. In
which specimen is this organism most likely
found?
263) A large lateral spine is characteristic of
which Schistosoma egg?
264) Rodents, marsupials, and nonhuman
primates are all reservoirs for
hich Schistosoma species?
265) An egg of the organism of Schistosoma
mansoni is isolated from the feces of an
adult man who has been traveling in Africa.
An unoperculated egg with a large lateral
spine is recovered. The patient is
administered the standard dose of
praziquantel; however, his infection does not
improve. Which one of the following
statements explains this discrepancy?
266) Which of the following organisms causes
visceral Larval migrans?
267) Enterobius vermicularis infection is
usually diagnosed by finding eggs from
268) The infective stage for Strongyloides
stercoralis is
269) If humans ingest the egg of Taenia
solium, they may develop
270) A silver methenamine stained slide of a
bronchial washing from an AIDs patient is
examined. Which of the following parasites
South America
Southeast Asian liver fluke
Sheep liver fluke
Chinese liver fluke
Lung fluke
freshwater snail.
Urine
S. mansoni
S. intercalatum
A larger dose may be required to be
effective against this organism
Toxocara canis
Cellulose tape preps
Filariform larvae
Cystercercosis
Pneumocystis carinii
24
Micro Flashcards Unit 2
is most likely to be identified?
271) A blood smear showed crescent shaped
gametocytes in several red cells. What is the
most probable identity of the organisms?
272) Which organism is transmitted to humans
by ticks and blood transfusions?
273) The ameba which can cause liver or lung
abscesses is
274) Which of the following can cause a fatal
maningoencephalitis?
275) The trophozoite of which organism is
characterized by “falling leaf motility”, two
nuclei, an axostyle, 4 pair of flagella and a
sucker on the underside of the organism?
276) Which of the following eggs may not be
detected in zinc flotation procedures?
202) Which trophozoite is suspected if ingested red
cells are seen on saline wet prep?
203) Pregnant women are to avoid cleaning
litter boxes of their house cats until after
delivery to prevent congenital infection of?
204) A patient visiting from overseas is
hospitalized due to suspected tuberculosis.
The sputum sample submitted to the
laboratory is bloody with orange-brown
flecks. Preliminary TB tests are negative.
Which parasite may be suspected?
205) Which of the following cysts has a
prominent karyosome with a clear
karyolymph space (no achromatic granules).
The nuclei no peripheral chromatin?
206) Differential diagnosis of Cryptosporidium
parvum and Cyclospora cayetanesis
cayetanesis is based on:
Plasmodium falciparum
Babesia
Entamoeba histolytica
Naegleria fowleri
Giardia lamblia
Schistosoma mansoni
Entamoeba histolytica
Toxoplasma gondii.
Paragonimus westermani
Endolimax nana
Oöcyst size – Cyclospora is larger.
25