Barkley Infectious Disease Practice Questions
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Section 1: Bacterial Infections
1. A 24-year-old patient presents with fever, malaise, and a
productive cough. Which finding most strongly supports a bacterial
rather than viral respiratory infection?
A. Rhinorrhea
B. Myalgias
C. Focal lobar consolidation
D. Nonproductive cough
Correct Answer: C. Focal lobar consolidation
Rationale: Focal consolidation on examination or imaging is more
suggestive of bacterial pneumonia, although clinical findings alone
do not always distinguish bacterial from viral infection.
2. Which component of the immune system provides the most
immediate, nonspecific defense against invading pathogens?
A. Adaptive immunity
B. Innate immunity
,C. Immunologic memory
D. Antibody-mediated immunity
Correct Answer: B. Innate immunity
Rationale: Innate immunity includes physical barriers, complement,
phagocytes, and inflammatory responses that act rapidly without
requiring prior exposure.
3. Which organism is classified as a gram-positive coccus?
A. Escherichia coli
B. Pseudomonas aeruginosa
C. Staphylococcus aureus
D. Neisseria gonorrhoeae
Correct Answer: C. Staphylococcus aureus
Rationale: Staphylococcus aureus is a gram-positive coccus that
commonly appears in clusters.
4. A patient develops watery diarrhea several days after completing
clindamycin. Which pathogen is most likely responsible?
A. Giardia lamblia
B. Clostridioides difficile
C. Salmonella enterica
D. Campylobacter jejuni
Correct Answer: B. Clostridioides difficile
Rationale: Recent antibiotic exposure, particularly clindamycin, is
strongly associated with C. difficile infection.
,5. Which laboratory test is most useful for confirming active
tuberculosis?
A. Tuberculin skin test alone
B. Interferon-gamma release assay alone
C. Sputum nucleic acid amplification testing
D. Chest radiograph alone
Correct Answer: C. Sputum nucleic acid amplification testing
Rationale: Nucleic acid amplification testing can rapidly detect M.
tuberculosis complex in respiratory specimens and may provide
information about rifampin resistance.
6. Which transmission-based precaution is required for a patient
with suspected pulmonary tuberculosis?
A. Contact
B. Droplet
C. Airborne
D. Protective isolation
Correct Answer: C. Airborne
Rationale: Suspected or confirmed infectious pulmonary
tuberculosis requires airborne precautions, including an
appropriate respirator and airborne infection isolation room.
7. Which pathogen is an obligate intracellular bacterium?
A. Chlamydia trachomatis
B. Staphylococcus aureus
, C. Streptococcus pyogenes
D. Escherichia coli
Correct Answer: A. Chlamydia trachomatis
Rationale: Chlamydia trachomatis requires host cells for replication.
8. Which organism is most commonly associated with uncomplicated
urinary tract infection in a young woman?
A. Escherichia coli
B. Pseudomonas aeruginosa
C. Enterococcus faecium
D. Candida albicans
Correct Answer: A. Escherichia coli
Rationale: E. coli is the most common cause of uncomplicated
cystitis.
9. A patient has a rapidly expanding erythematous lesion with
severe pain out of proportion to examination findings. Which
diagnosis should be considered urgently?
A. Impetigo
B. Necrotizing fasciitis
C. Tinea corporis
D. Erysipelas
Correct Answer: B. Necrotizing fasciitis
Rationale: Severe pain out of proportion to findings and rapid
progression suggest necrotizing fasciitis, a surgical emergency.
|Original Questions & Answers |Detailed Rationales
|Hinted Complete Exam Prep Graded A+*Instant
Download Pdf
Section 1: Bacterial Infections
1. A 24-year-old patient presents with fever, malaise, and a
productive cough. Which finding most strongly supports a bacterial
rather than viral respiratory infection?
A. Rhinorrhea
B. Myalgias
C. Focal lobar consolidation
D. Nonproductive cough
Correct Answer: C. Focal lobar consolidation
Rationale: Focal consolidation on examination or imaging is more
suggestive of bacterial pneumonia, although clinical findings alone
do not always distinguish bacterial from viral infection.
2. Which component of the immune system provides the most
immediate, nonspecific defense against invading pathogens?
A. Adaptive immunity
B. Innate immunity
,C. Immunologic memory
D. Antibody-mediated immunity
Correct Answer: B. Innate immunity
Rationale: Innate immunity includes physical barriers, complement,
phagocytes, and inflammatory responses that act rapidly without
requiring prior exposure.
3. Which organism is classified as a gram-positive coccus?
A. Escherichia coli
B. Pseudomonas aeruginosa
C. Staphylococcus aureus
D. Neisseria gonorrhoeae
Correct Answer: C. Staphylococcus aureus
Rationale: Staphylococcus aureus is a gram-positive coccus that
commonly appears in clusters.
4. A patient develops watery diarrhea several days after completing
clindamycin. Which pathogen is most likely responsible?
A. Giardia lamblia
B. Clostridioides difficile
C. Salmonella enterica
D. Campylobacter jejuni
Correct Answer: B. Clostridioides difficile
Rationale: Recent antibiotic exposure, particularly clindamycin, is
strongly associated with C. difficile infection.
,5. Which laboratory test is most useful for confirming active
tuberculosis?
A. Tuberculin skin test alone
B. Interferon-gamma release assay alone
C. Sputum nucleic acid amplification testing
D. Chest radiograph alone
Correct Answer: C. Sputum nucleic acid amplification testing
Rationale: Nucleic acid amplification testing can rapidly detect M.
tuberculosis complex in respiratory specimens and may provide
information about rifampin resistance.
6. Which transmission-based precaution is required for a patient
with suspected pulmonary tuberculosis?
A. Contact
B. Droplet
C. Airborne
D. Protective isolation
Correct Answer: C. Airborne
Rationale: Suspected or confirmed infectious pulmonary
tuberculosis requires airborne precautions, including an
appropriate respirator and airborne infection isolation room.
7. Which pathogen is an obligate intracellular bacterium?
A. Chlamydia trachomatis
B. Staphylococcus aureus
, C. Streptococcus pyogenes
D. Escherichia coli
Correct Answer: A. Chlamydia trachomatis
Rationale: Chlamydia trachomatis requires host cells for replication.
8. Which organism is most commonly associated with uncomplicated
urinary tract infection in a young woman?
A. Escherichia coli
B. Pseudomonas aeruginosa
C. Enterococcus faecium
D. Candida albicans
Correct Answer: A. Escherichia coli
Rationale: E. coli is the most common cause of uncomplicated
cystitis.
9. A patient has a rapidly expanding erythematous lesion with
severe pain out of proportion to examination findings. Which
diagnosis should be considered urgently?
A. Impetigo
B. Necrotizing fasciitis
C. Tinea corporis
D. Erysipelas
Correct Answer: B. Necrotizing fasciitis
Rationale: Severe pain out of proportion to findings and rapid
progression suggest necrotizing fasciitis, a surgical emergency.
