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ASCP MLS EXAM COMPLETE QUESTIONS AND
CORRECT VERIFIED ANSWERS LATEST UPDATE JUST
RELEASED THIS YEAR
1. Question: Which Gram-positive bacillus is catalase-positive, spore-forming, and commonly
found in soil?
A. Listeria monocytogenes
B. Bacillus anthracis
C. Corynebacterium diphtheriae
D. Lactobacillus spp.
Answer: B. Bacillus anthracis
Explanation: Bacillus anthracis is a large, non-motile, spore-forming, Gram-positive rod.
Catalase-positive and found in soil. Listeria is catalase-positive but non-spore-forming.
2. Question: Which Gram-positive rod is β-hemolytic, tumbling motile, and can cause
meningitis in neonates?
A. Bacillus cereus
B. Listeria monocytogenes
C. Clostridium perfringens
D. Erysipelothrix rhusiopathiae
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Answer: B. Listeria monocytogenes
Explanation: Listeria is a small, Gram-positive rod, motile at 25°C (tumbling), and can cause
neonatal sepsis/meningitis.
3. Question: Which organism is a Gram-positive rod, anaerobic, part of normal skin flora, and
urease-negative?
A. Cutibacterium acnes
B. Actinomyces israelii
C. Bacillus subtilis
D. Lactobacillus spp.
Answer: A. Cutibacterium acnes
Explanation: Cutibacterium (formerly Propionibacterium) acnes is anaerobic, part of normal
skin flora, and urease-negative.
4. Question: Which Gram-positive bacillus is urease-positive and part of the oral flora?
A. Lactobacillus spp.
B. Actinomyces naeslundii
C. Clostridium tetani
D. Bacillus cereus
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Answer: B. Actinomyces naeslundii
Explanation: Only Actinomyces naeslundii among Gram-positive rods is urease-positive and
commonly found in the oral cavity.
5. Question: Which Gram-positive rod is H₂S positive, catalase-negative, and associated with
handling fish or meat?
A. Listeria monocytogenes
B. Erysipelothrix rhusiopathiae
C. Corynebacterium jeikeium
D. Bacillus anthracis
Answer: B. Erysipelothrix rhusiopathiae
Explanation: Erysipelothrix is catalase-negative, H₂S positive in TSI, and occupationally
associated with animals/fish/meat.
6. Question: Which Gram-positive bacillus is non-spore-forming, club-shaped, and causes
diphtheria?
A. Listeria monocytogenes
B. Corynebacterium diphtheriae
C. Bacillus cereus
D. Lactobacillus spp.
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Answer: B. Corynebacterium diphtheriae
Explanation: Club-shaped, Gram-positive rods, non-spore-forming, cause diphtheria.
Metachromatic granules can be seen on Albert or Loeffler stain.
7. Question: Which Gram-positive rod is spore-forming, anaerobic, and can cause gas
gangrene?
A. Clostridium perfringens
B. Bacillus subtilis
C. Listeria monocytogenes
D. Actinomyces israelii
Answer: A. Clostridium perfringens
Explanation: Clostridium perfringens is anaerobic, spore-forming, and produces toxins causing
gas gangrene.
Q
:A patient has a high absolute eosinophil count of 2000/uL. Organ biopsies show infiltration of
eosinophils. The patient is diagnosed as having Chronic Eosinophilic Leukemia. Other causes for
high eosinophil counts include all of the following except:
A. Infections of parasitic helminths
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SUCCESS!
ASCP MLS EXAM COMPLETE QUESTIONS AND
CORRECT VERIFIED ANSWERS LATEST UPDATE JUST
RELEASED THIS YEAR
1. Question: Which Gram-positive bacillus is catalase-positive, spore-forming, and commonly
found in soil?
A. Listeria monocytogenes
B. Bacillus anthracis
C. Corynebacterium diphtheriae
D. Lactobacillus spp.
Answer: B. Bacillus anthracis
Explanation: Bacillus anthracis is a large, non-motile, spore-forming, Gram-positive rod.
Catalase-positive and found in soil. Listeria is catalase-positive but non-spore-forming.
2. Question: Which Gram-positive rod is β-hemolytic, tumbling motile, and can cause
meningitis in neonates?
A. Bacillus cereus
B. Listeria monocytogenes
C. Clostridium perfringens
D. Erysipelothrix rhusiopathiae
1
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Answer: B. Listeria monocytogenes
Explanation: Listeria is a small, Gram-positive rod, motile at 25°C (tumbling), and can cause
neonatal sepsis/meningitis.
3. Question: Which organism is a Gram-positive rod, anaerobic, part of normal skin flora, and
urease-negative?
A. Cutibacterium acnes
B. Actinomyces israelii
C. Bacillus subtilis
D. Lactobacillus spp.
Answer: A. Cutibacterium acnes
Explanation: Cutibacterium (formerly Propionibacterium) acnes is anaerobic, part of normal
skin flora, and urease-negative.
4. Question: Which Gram-positive bacillus is urease-positive and part of the oral flora?
A. Lactobacillus spp.
B. Actinomyces naeslundii
C. Clostridium tetani
D. Bacillus cereus
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Answer: B. Actinomyces naeslundii
Explanation: Only Actinomyces naeslundii among Gram-positive rods is urease-positive and
commonly found in the oral cavity.
5. Question: Which Gram-positive rod is H₂S positive, catalase-negative, and associated with
handling fish or meat?
A. Listeria monocytogenes
B. Erysipelothrix rhusiopathiae
C. Corynebacterium jeikeium
D. Bacillus anthracis
Answer: B. Erysipelothrix rhusiopathiae
Explanation: Erysipelothrix is catalase-negative, H₂S positive in TSI, and occupationally
associated with animals/fish/meat.
6. Question: Which Gram-positive bacillus is non-spore-forming, club-shaped, and causes
diphtheria?
A. Listeria monocytogenes
B. Corynebacterium diphtheriae
C. Bacillus cereus
D. Lactobacillus spp.
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Answer: B. Corynebacterium diphtheriae
Explanation: Club-shaped, Gram-positive rods, non-spore-forming, cause diphtheria.
Metachromatic granules can be seen on Albert or Loeffler stain.
7. Question: Which Gram-positive rod is spore-forming, anaerobic, and can cause gas
gangrene?
A. Clostridium perfringens
B. Bacillus subtilis
C. Listeria monocytogenes
D. Actinomyces israelii
Answer: A. Clostridium perfringens
Explanation: Clostridium perfringens is anaerobic, spore-forming, and produces toxins causing
gas gangrene.
Q
:A patient has a high absolute eosinophil count of 2000/uL. Organ biopsies show infiltration of
eosinophils. The patient is diagnosed as having Chronic Eosinophilic Leukemia. Other causes for
high eosinophil counts include all of the following except:
A. Infections of parasitic helminths
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