HARR EE2 7.6 Flashcards
Large gram-positive spore-forming rods growing
on blood agar as large, raised, β-hemolytic colonies
that spread and appear as frosted green-gray glass
are most likely:
A. Pseudomonas spp.
B. Bacillus spp.
C. Corynebacterium spp.
D. Listeria spp.
B. Bacillus spp.
Bacillus anthracis and Bacillus cereus can best be
differentiated by which tests?
A. Motility and β-hemolysis on a blood agar plate
B. Oxidase and β-hemolysis on a blood agar plate
C. Lecithinase and glucose
D. Lecithinase and catalase
A. Motility and β-hemolysis on a blood agar plate
Which is the specimen of choice for proof of food poisoning by Bacillus cereus? A. Sputum B. Blood C. Stool D. Food
D. Food
A suspected Bacillus anthracis culture obtained
from a wound specimen produced colonies that
had many outgrowths (Medusa-head appearance),
but were not β-hemolytic on sheep blood agar.
Which test should be performed next?
A. Penicillin (10-unit) susceptibility test
B. Lecithinase test
C. Glucose test
D. Motility test
A. Penicillin (10-unit) susceptibility test
Which of the following tests should be performed
for initial differentiation of Listeria monocytogenes
from group B streptococci?
A. Gram stain, motility at room temperature, catalase
B. Gram stain, CAMP test, H2S/TSI
C. Oxidase, CAMP test, glucose
D. Oxidase, bacitracin
A. Gram stain, motility at room temperature, catalase
Culture of a finger wound specimen from a meat
packer produced short gram-positive bacilli on a
blood agar plate with no hemolysis. Given the Following test results at 48 hours, what is the most
likely identification?
ikely identification?
Catalase = Neg H2S/TSI = + Motility (wet prep) = Neg Motility (media) = Neg (bottle-brush growth in stab culture)
A. Bacillus cereus
B. Listeria monocytogenes
C. Erysipelothrix rhusiopathiae
D. Bacillus subtilis
C. Erysipelothrix rhusiopathiae
A non–spore-forming, slender gram-positive rod
forming palisades and chains was recovered from a
vaginal culture and grew well on tomato juice agar.
The most likely identification is:
A. Lactobacillus spp.
B. Bacillus spp.
C. Neisseria spp.
D. Streptococcus spp
A. Lactobacillus spp.
A Corynebacterium species recovered from a throat
culture is considered a pathogen when it produces:
A. A pseudomembrane of the oropharynx
B. An exotoxin
C. Gray-black colonies with a brown halo on
Tinsdale’s agar
D. All of these options
D. All of these options
A presumptive diagnosis of Gardnerella vaginalis can be made using which of the following findings? A. Oxidase and catalase tests B. Pleomorphic bacilli heavily colonized on vaginal epithelium C. Hippurate hydrolysis test D. All of these options
D. All of these options
A gram-positive branching filamentous organism
recovered from a sputum specimen was found to
be positive with a modified acid-fast stain method.
What is the most likely presumptive identification?
A. Bacillus spp.
B. Nocardia spp.
C. Corynebacterium spp.
D. Listeria spp.
B. Nocardia spp.
Routine laboratory testing for Treponema pallidum involves: A. Culturing B. Serological analysis C. Acid-fast staining D. Gram staining
B. Serological analysis
Spirochetes often detected in the hematology
laboratory, even before the physician suspects the
infection, are:
A. Borrelia spp.
B. Treponema spp.
C. Campylobacter spp.
D. Leptospira spp
A. Borrelia spp.
Which of the following organisms is the cause of Lyme disease? A. Treponema pallidum B. Neisseria meningitidis C. Babesia microti D. Borrelia burgdorferi
D. Borrelia burgdorferi
The diagnostic method most commonly used for the identification of Lyme disease is: A. Serology B. Culture C. Gram stain D. Acid-fast stain
A. Serology
Primary atypical pneumonia is caused by: A. Streptococcus pneumoniae B. Mycoplasma pneumoniae C. Klebsiella pneumoniae D. Mycobacterium tuberculosis
B. Mycoplasma pneumoniae
Which organism typically produces “fried-egg”
colonies on agar within 1–5 days of culture from a
genital specimen?
A. Mycoplasma hominis
B. Borrelia burgdorferi
C. Leptospira interrogans
D. Treponema pallidum
A. Mycoplasma hominis
The manganous chloride–urea test is used for the identification of which organism? A. Mycoplasma pneumoniae B. Ureaplasma urealyticum C. Bacillus cereus D. Borrelia burgdorferi
B. Ureaplasma urealyticum
A gram-positive (gram-variable), beaded organism
with delicate branching was recovered from the
sputum of a 20-year-old patient with leukemia.
The specimen produced orange, glabrous, waxy
colonies on Middlebrook’s agar that showed
partial acid-fast staining with the modified
Kinyoun stain. What is the most likely
identification?
A. Rhodococcus spp.
B. Actinomadura spp.
C. Streptomyces spp.
D. Nocardia spp.
D. Nocardia spp.
A direct smear from a nasopharyngeal swab
stained with Loeffler methylene blue stain showed
various letter shapes and deep blue, metachromatic
granules. The most likely identification is:
A. Corynebacterium spp.
B. Nocardia spp.
C. Listeria spp.
D. Gardnerella spp.
A. Corynebacterium spp.
Which of the following is the best, rapid, noncultural test to perform when Gardnerella
vaginalis is suspected in a patient with vaginosis?
A. 10% KOH test
B. 3% H2O2 test
C. 30% H2O2 test
D. All of these options
A. 10% KOH test
Which is the test of choice for the confirmation of
Chlamydia trachomatis infection in urine?
A. Enzyme immunoassay antigen testing
B. PCR molecular testing
C. Culture using McCoy and Hela cells
D. Microimmunofluorescence (MIF) test
B. PCR molecular testing
Which test is the most reliable for the detection of
Mycoplasma pneumonia in serum and for the
confirmation of diagnosis?
A. EIA testing and direct antigen testing
B. Cold agglutinin testing using Group O RBCs
C. Culture on SP4 glucose broth with arginine
D. Complement fixation
A. EIA testing and direct antigen testing
Identify the following bacterium and specimen
pairing that is mismatched (specimen not
appropriate for isolation).
A. Chlamydia (Chlamydophila) psittaci: fecal swab
B. Chlamydia trachomatis: first voided urine
C. Chlamydia trachomatis: endocervical swab
D. Chlamydia pneumonia: throat swab or sputum
A. Chlamydia (Chlamydophila) psittaci: fecal swab
Which of the following organisms are transmitted to animals and humans after a tick bite? A. Leptospira. B. Chlamydia and Mycoplasma spp. C. Neisseria sicca D. Ehrlichia and Anaplasma spp
D. Ehrlichia and Anaplasma spp
Following a hike in the woods, a young male
noted a tick on his ankle. He removed the tick,
but 2 weeks later noticed a circular, bull’s eye rash
at the site of the bite. Which specimen(s) should
be obtained to establish a diagnosis of Lyme
borreliosis?
A. Lymph node biopsy, skin scraping
B. Blood, CSF, and skin biopsy
C. Hair, fingernails
D. Saliva, sputum
B. Blood, CSF, and skin biopsy
