Micro 8.6 Aerobic Gram-Positive Rods, Spirochetes, Mycoplasmas and Ureaplasmas, and Chlamydiae Flashcards

1
Q
  1. 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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  1. 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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  1. Which is the specimen of choice for proof of food poisoning by B. cereus?

A. Sputum
B. Blood
C. Stool
D. Food

A

D. Food

The best specimen is the suspected food itself. Stool cultures are not useful because B. cereus is part of the normal fecal flora. The suspected food can be the source of food poisoning by B. cereus if 100,000 or greater organisms per gram of infected food are demonstrated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  1. A suspected B. 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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. Which of the following tests should be performed for initial differentiation of L. 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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  1. Culture of a finger wound specimen from a meat packer produced short gram-positive, non–spore-forming bacilli on a blood agar plate showing 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 (gel media 22 oC) = + (bottle-brush growth in stab culture)

A. Bacillus cereus
B. Listeria monocytogenes
C. Erysipelothrix rhusiopathiae
D. Bacillus subtilis

A

C. Erysipelothrix rhusiopathiae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  1. Nonspore-forming, slender, gram-positive, rod-forming palisades and chains were 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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  1. 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 agar
D. All of these options

A

D. All of these options

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  1. 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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  1. 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.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. Routine laboratory testing for Treponema pallidum involves:

A. Culturing
B. Serological analysis
C. Acid-fast staining
D. Gram staining

A

B. Serological analysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  1. Spirochetes often detected in the hematology laboratory while scanning a blood film, even before the physician suspects the infection, are:

A. Borrelia spp.
B. Treponema spp.
C. Campylobacter spp.
D. Leptospira spp.

A

A. Borrelia spp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  1. 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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  1. The diagnostic method most commonly used for the identification of Lyme disease is:

A. Serology
B. Culture
C. Gram staining
D. Acid-fast staining

A

A. Serology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. Primary atypical pneumonia is caused by:

A. Streptococcus pneumoniae
B. Mycoplasma pneumoniae
C. Klebsiella pneumoniae
D. Mycobacterium tuberculosis

A

B. Mycoplasma pneumoniae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  1. Which organism typically produces “fried egg” colonies on agar within 1 to 5 days of culture obtained from a genital specimen?

A. Mycoplasma hominis
B. Borrelia burgdorferi
C. Leptospira interrogans
D. Treponema pallidum

A

A. Mycoplasma hominis

17
Q
  1. 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

A

B. Ureaplasma urealyticum

18
Q
  1. 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 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.

A

D. Nocardia spp.

19
Q
  1. 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

A. Corynebacterium spp.

20
Q
  1. Which of the following is the best, rapid, nonculture test to perform when G. 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

A. 10% KOH test

21
Q
  1. 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

A

B. PCR molecular testing

22
Q
  1. Which test is the most reliable for the detection of M. 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

A. EIA testing and direct antigen testing

23
Q
  1. Identify the following bacterium–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

A. Chlamydia (Chlamydophila) psittaci–fecal swab

24
Q
  1. Which of the following organisms are transmitted to animals and humans after a tick bite?

A. Leptospira spp.
B. Chlamydia and Mycoplasma spp.
C. Neisseria sicca
D. Ehrlichia and Anaplasma spp.

A

D. Ehrlichia and Anaplasma spp.

25
Q
  1. Following a hike in the woods, a young male noted a tick on his ankle. He removed the tick, but 2 weeks later, he 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, skin biopsy
C. Hair, fingernails
D. Saliva, sputum

A

B. Blood, CSF, skin biopsy

26
Q
  1. Partially acid-fast, gram-positive, filamentous-branching bacteria that fragmented into rods and cocci were seen in a sputum sample from a patient with HIV infection. Which of the following is the most likely presumptive identification?

A. Rhodococcus equi
B. Streptococcus spp.
C. Bacillus subtillus
D. Corynebacterium spp. (diphtheroids)

A

A. Rhodococcus equi

27
Q
  1. An asymptomatic 25-year-old female patient with persistent nongonococcal urethritis (NGC) and pelvic inflammatory disease (PID) was suspected of being infected with Mycoplasma genitalium. Which category of testing should not be utilized to establish a final identification?

A. Nucleic acid amplification test (NAAT)
B. Real time PCR
C. PCR
D. Culture

A

D. Culture