MMSC 438 EXAM 3 QUESTIONS & ANSWERS
1. When drawing blood cultures for a 5-year-old, the correct blood volume
(according to ASM) is .
A. Based upon the child's weight.
B. 1 mL for each year of life of the child.
C. 10 to 20 mL of blood per bottle to assure positive rate of 99%.
D. Any volume is sufficient since blood is more concentrated in children.: A. Based
upon the child's weight.
2. A patient presents with acute onset of signs and symptoms consistent with
endocarditis. The patient has a history of IV drug abuse. An echocardiogram
demonstrates vegetations on the mitral valve. The most likely pathogen is:
A. Cryptococcus
neoformans
B.Escherichia coli
C.Treponema
pallidum
D. Staphylococcus aureus: D. Staphylococcus aureus
3. What is the single most important variable for positive blood culture detec-
tion?
A. Blood volume
B. Incubation time
C. Time of collection
D. Prep of venipuncture site: A. Blood volume
4. A 24-year-old female is diagnosed with gonorrhea and the physician also
suspects chlamydia. The correct treatment is
1/
17
,A. A
m
oxi
cill
in.
B. Ce
ftri
ax
on
e.
C. Cefixime and amoxicillin.
D. Ceftriaxone and azithromycin.: D.Ceftriaxone and azithromycin.
5. Three sets of blood cultures (6 bottles) are drawn from a car accident
patient in the emergency department. One aerobic bottle demonstrates a
positive signal in a continuous monitoring system at 24 hours. Gram stain
reveals Gram-positive cocci in clusters, which are catalase positive, and
produced non-hemolytic colonies on a sheep blood agar plate. Which of the
following is the most likely explanation for these findings?
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17
, A. Septicemia due to Staphylococcus
aureus B.Septicemia due to Bacteroides
fragilis group C.Contamination due to
staphylococci
D.Contamination due to fecal biota: C.Contamination due to staphylococci
6. Which of the following is a common principle of continuous monitoring blood
culture systems?
A. The amount of ATP produced is measured by determining changes over
time comparing to bottle background levels at primary reading.
B. The amount of LPS is measured and monitored over time comparing to
bottle background levels at primary reading.
C. The amount of CO2 produced is measured by determining changes over
time comparing to bottle background levels at primary reading.
D. The amount of O2 produced is measured by determining changes over
time comparing to bottle background levels at primary reading.: C.The amount of CO2
produced is measured by determining changes over time comparing to bottle background levels at primary reading.
7. A 2-year-old patient with a history of leukemia is admitted to the hospital with
a diagnosis of possible sepsis. A set of blood cultures is collected, and after
11 hours on the automated system, both aerobic and anaerobic bottles are
positive. Gram stain reveals rare coccobacilli. The next step is to:
A. Call the physician
B. Report findings to the laboratory manager
C. Reincubate the bottles
D. Recollect the blood cultures: A. Call the physician
8. Pelvic inflammatory disease in women is most frequently caused
by: A.Chlamydia trachomatis and Neisseria gonorrhoeae.
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17
1. When drawing blood cultures for a 5-year-old, the correct blood volume
(according to ASM) is .
A. Based upon the child's weight.
B. 1 mL for each year of life of the child.
C. 10 to 20 mL of blood per bottle to assure positive rate of 99%.
D. Any volume is sufficient since blood is more concentrated in children.: A. Based
upon the child's weight.
2. A patient presents with acute onset of signs and symptoms consistent with
endocarditis. The patient has a history of IV drug abuse. An echocardiogram
demonstrates vegetations on the mitral valve. The most likely pathogen is:
A. Cryptococcus
neoformans
B.Escherichia coli
C.Treponema
pallidum
D. Staphylococcus aureus: D. Staphylococcus aureus
3. What is the single most important variable for positive blood culture detec-
tion?
A. Blood volume
B. Incubation time
C. Time of collection
D. Prep of venipuncture site: A. Blood volume
4. A 24-year-old female is diagnosed with gonorrhea and the physician also
suspects chlamydia. The correct treatment is
1/
17
,A. A
m
oxi
cill
in.
B. Ce
ftri
ax
on
e.
C. Cefixime and amoxicillin.
D. Ceftriaxone and azithromycin.: D.Ceftriaxone and azithromycin.
5. Three sets of blood cultures (6 bottles) are drawn from a car accident
patient in the emergency department. One aerobic bottle demonstrates a
positive signal in a continuous monitoring system at 24 hours. Gram stain
reveals Gram-positive cocci in clusters, which are catalase positive, and
produced non-hemolytic colonies on a sheep blood agar plate. Which of the
following is the most likely explanation for these findings?
2/
17
, A. Septicemia due to Staphylococcus
aureus B.Septicemia due to Bacteroides
fragilis group C.Contamination due to
staphylococci
D.Contamination due to fecal biota: C.Contamination due to staphylococci
6. Which of the following is a common principle of continuous monitoring blood
culture systems?
A. The amount of ATP produced is measured by determining changes over
time comparing to bottle background levels at primary reading.
B. The amount of LPS is measured and monitored over time comparing to
bottle background levels at primary reading.
C. The amount of CO2 produced is measured by determining changes over
time comparing to bottle background levels at primary reading.
D. The amount of O2 produced is measured by determining changes over
time comparing to bottle background levels at primary reading.: C.The amount of CO2
produced is measured by determining changes over time comparing to bottle background levels at primary reading.
7. A 2-year-old patient with a history of leukemia is admitted to the hospital with
a diagnosis of possible sepsis. A set of blood cultures is collected, and after
11 hours on the automated system, both aerobic and anaerobic bottles are
positive. Gram stain reveals rare coccobacilli. The next step is to:
A. Call the physician
B. Report findings to the laboratory manager
C. Reincubate the bottles
D. Recollect the blood cultures: A. Call the physician
8. Pelvic inflammatory disease in women is most frequently caused
by: A.Chlamydia trachomatis and Neisseria gonorrhoeae.
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17
