Micro-Aerobic Gram-Positive Rods, Spirochetes, Mycoplasmas and Ureaplasmas, and Chlamydia Flashcards
1
Q
- 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.
A
B. Bacillus spp.
2
Q
- 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
A. Motility and β-hemolysis on a blood agar plate
3
Q
- Which is the specimen of choice for proof of food
poisoning by Bacillus cereus?
A. Sputum
B. Blood
C. Stool
D. Food
A
D. Food
4
Q
- 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
A. Penicillin (10-unit) susceptibility test
5
Q
- 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
A. Gram stain, motility at room temperature,
catalase
6
Q
- 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?
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
A
C. Erysipelothrix rhusiopathiae
7
Q
- 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
A. Lactobacillus spp.
8
Q
- 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
A
D. All of these options
9
Q
- 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
A
D. All of these options
10
Q
- 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
A
B. Nocardia spp.
11
Q
- Routine laboratory testing for Treponema
pallidum involves:
A. Culturing
B. Serological analysis
C. Acid-fast staining
D. Gram staining
A
B. Serological analysis
12
Q
- 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
A. Borrelia spp.
13
Q
- Which of the following organisms is the cause of
Lyme disease?
A. Treponema pallidum
B. Neisseria meningitidis
C. Babesia microti
D. Borrelia burgdorferi
A
D. Borrelia burgdorferi
14
Q
- 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
A. Serology
15
Q
- Primary atypical pneumonia is caused by:
A. Streptococcus pneumoniae
B. Mycoplasma pneumoniae
C. Klebsiella pneumoniae
D. Mycobacterium tuberculosis
A
B. Mycoplasma pneumoniae
