“50 High-Yield Case-Based Microbiology
Questions for Nursing & Medical Students
(With Answers for Self-Assessment)”
Description:
This collection of 50 case-based microbiology questions covers bacteriology,
virology, mycology, and parasitology. Each case presents realistic clinical
scenarios with questions designed to enhance critical thinking and diagnostic
skills.
Complete answer key is included for self-practice and assessment—perfect for
exam preparation or quizzes.
,Case-Based Microbiology Questions
Case 1:
A 25-year-old woman presents with painful urination, increased frequency, and
cloudy urine. Urine culture shows growth of E. coli.
Question: What is the most likely diagnosis and the first-line treatment?
Answer: Urinary Tract Infection (UTI); treat with nitrofurantoin or trimethoprim-
sulfamethoxazole.
Case 2:
A 6-year-old boy has fever, sore throat, and a grayish-white membrane in the
throat. Gram-positive bacilli are seen on culture.
Question: Which organism is responsible and what is the key prevention?
Answer: Corynebacterium diphtheriae; prevent with DPT vaccination.
Case 3:
A 30-year-old man develops sudden onset of high fever, severe headache, and neck
stiffness. CSF shows gram-negative diplococci.
Question: Likely pathogen and immediate management?
Answer: Neisseria meningitidis; start IV antibiotics (e.g., ceftriaxone)
immediately.
Case 4:
A diabetic patient presents with black nasal discharge, facial swelling, and fever.
KOH mount shows broad, aseptate hyphae.
Question: Diagnosis and first-line treatment?
Answer: Mucormycosis (black fungus); treat with IV amphotericin B and surgical
debridement.
Case 5:
A child presents with malarial paroxysms (fever, chills, sweating). Blood smear
shows ring-shaped trophozoites inside RBCs.
Question: Causative organism and drug of choice?
Answer: Plasmodium falciparum or vivax; treat with artemisinin-based
combination therapy (ACT).
Case 6:
A 2-year-old presents with a maculopapular rash starting on the face, Koplik spots
in the mouth, and fever.
,Question: Probable infection and preventive measure?
Answer: Measles (rubeola); MMR vaccination for prevention.
Case 7:
A 35-year-old man develops sudden flaccid paralysis after eating improperly
canned food.
Question: Causative agent and pathophysiology?
Answer: Clostridium botulinum; botulinum toxin blocks acetylcholine release
causing flaccid paralysis.
Case 8:
A neonate presents with fever, lethargy, and purulent umbilical discharge. Blood
culture shows Group B Streptococcus.
Question: Management and prophylaxis?
Answer: Treat with IV antibiotics (penicillin/ampicillin); maternal screening and
intrapartum antibiotic prophylaxis.
Case 9:
A 28-year-old woman presents with vaginal discharge, foul smell, and itching. Wet
mount shows motile pear-shaped organisms.
Question: Organism and treatment?
Answer: Trichomonas vaginalis; treat with metronidazole.
Case 10:
A patient presents with watery diarrhea after traveling to a cholera-endemic area.
Stool culture grows comma-shaped, oxidase-positive bacteria.
Question: Likely pathogen and key treatment?
Answer: Vibrio cholerae; rehydration therapy is key, antibiotics like doxycycline
can be used.
Case 11:
A patient has persistent cough with blood-stained sputum. Chest X-ray shows
upper lobe cavitation. Acid-fast bacilli are seen in sputum.
Question: Diagnosis and treatment?
Answer: Pulmonary tuberculosis (Mycobacterium tuberculosis); treat with RIPE
therapy (rifampicin, isoniazid, pyrazinamide, ethambutol).
Case 12:
A 5-year-old presents with fever, headache, myalgia, and rash. Blood test confirms
dengue NS1 antigen positivity.
, Question: Key preventive measure and warning signs?
Answer: Prevent mosquito bites (Aedes aegypti); warning signs: bleeding, plasma
leakage, shock.
Case 13:
A patient presents with severe watery diarrhea, rice-water stools, and dehydration.
He recently consumed street food.
Question: Likely organism and main treatment?
Answer: Vibrio cholerae; rehydration therapy is main treatment.
Case 14:
A 30-year-old woman presents with painless genital ulcers. Dark-field microscopy
shows spirochetes.
Question: Diagnosis and treatment?
Answer: Primary syphilis (Treponema pallidum); treat with intramuscular
benzathine penicillin.
Case 15:
A 60-year-old immunocompromised patient presents with cough, fever, and chest
pain. CT shows ground-glass opacities.
Question: Likely pathogen and treatment?
Answer: Pneumocystis jirovecii pneumonia; treat with high-dose TMP-SMX.
Case 16:
A 7-year-old child presents with itchy perianal region at night. Scotch tape test
shows eggs.
Question: Organism and treatment?
Answer: Enterobius vermicularis (pinworm); treat with mebendazole or
albendazole.
Case 17:
A patient presents with fever, fatigue, hepatosplenomegaly, and anemia. Bone
marrow shows Leishmania donovani amastigotes.
Question: Diagnosis and treatment?
Answer: Kala-azar (Visceral leishmaniasis); treat with liposomal amphotericin B.
Case 18:
A 25-year-old man presents with sudden onset fever, headache, myalgia after tick
bite in wooded area. Blood smear shows intracellular bacteria.
Question: Likely pathogen and treatment?
Questions for Nursing & Medical Students
(With Answers for Self-Assessment)”
Description:
This collection of 50 case-based microbiology questions covers bacteriology,
virology, mycology, and parasitology. Each case presents realistic clinical
scenarios with questions designed to enhance critical thinking and diagnostic
skills.
Complete answer key is included for self-practice and assessment—perfect for
exam preparation or quizzes.
,Case-Based Microbiology Questions
Case 1:
A 25-year-old woman presents with painful urination, increased frequency, and
cloudy urine. Urine culture shows growth of E. coli.
Question: What is the most likely diagnosis and the first-line treatment?
Answer: Urinary Tract Infection (UTI); treat with nitrofurantoin or trimethoprim-
sulfamethoxazole.
Case 2:
A 6-year-old boy has fever, sore throat, and a grayish-white membrane in the
throat. Gram-positive bacilli are seen on culture.
Question: Which organism is responsible and what is the key prevention?
Answer: Corynebacterium diphtheriae; prevent with DPT vaccination.
Case 3:
A 30-year-old man develops sudden onset of high fever, severe headache, and neck
stiffness. CSF shows gram-negative diplococci.
Question: Likely pathogen and immediate management?
Answer: Neisseria meningitidis; start IV antibiotics (e.g., ceftriaxone)
immediately.
Case 4:
A diabetic patient presents with black nasal discharge, facial swelling, and fever.
KOH mount shows broad, aseptate hyphae.
Question: Diagnosis and first-line treatment?
Answer: Mucormycosis (black fungus); treat with IV amphotericin B and surgical
debridement.
Case 5:
A child presents with malarial paroxysms (fever, chills, sweating). Blood smear
shows ring-shaped trophozoites inside RBCs.
Question: Causative organism and drug of choice?
Answer: Plasmodium falciparum or vivax; treat with artemisinin-based
combination therapy (ACT).
Case 6:
A 2-year-old presents with a maculopapular rash starting on the face, Koplik spots
in the mouth, and fever.
,Question: Probable infection and preventive measure?
Answer: Measles (rubeola); MMR vaccination for prevention.
Case 7:
A 35-year-old man develops sudden flaccid paralysis after eating improperly
canned food.
Question: Causative agent and pathophysiology?
Answer: Clostridium botulinum; botulinum toxin blocks acetylcholine release
causing flaccid paralysis.
Case 8:
A neonate presents with fever, lethargy, and purulent umbilical discharge. Blood
culture shows Group B Streptococcus.
Question: Management and prophylaxis?
Answer: Treat with IV antibiotics (penicillin/ampicillin); maternal screening and
intrapartum antibiotic prophylaxis.
Case 9:
A 28-year-old woman presents with vaginal discharge, foul smell, and itching. Wet
mount shows motile pear-shaped organisms.
Question: Organism and treatment?
Answer: Trichomonas vaginalis; treat with metronidazole.
Case 10:
A patient presents with watery diarrhea after traveling to a cholera-endemic area.
Stool culture grows comma-shaped, oxidase-positive bacteria.
Question: Likely pathogen and key treatment?
Answer: Vibrio cholerae; rehydration therapy is key, antibiotics like doxycycline
can be used.
Case 11:
A patient has persistent cough with blood-stained sputum. Chest X-ray shows
upper lobe cavitation. Acid-fast bacilli are seen in sputum.
Question: Diagnosis and treatment?
Answer: Pulmonary tuberculosis (Mycobacterium tuberculosis); treat with RIPE
therapy (rifampicin, isoniazid, pyrazinamide, ethambutol).
Case 12:
A 5-year-old presents with fever, headache, myalgia, and rash. Blood test confirms
dengue NS1 antigen positivity.
, Question: Key preventive measure and warning signs?
Answer: Prevent mosquito bites (Aedes aegypti); warning signs: bleeding, plasma
leakage, shock.
Case 13:
A patient presents with severe watery diarrhea, rice-water stools, and dehydration.
He recently consumed street food.
Question: Likely organism and main treatment?
Answer: Vibrio cholerae; rehydration therapy is main treatment.
Case 14:
A 30-year-old woman presents with painless genital ulcers. Dark-field microscopy
shows spirochetes.
Question: Diagnosis and treatment?
Answer: Primary syphilis (Treponema pallidum); treat with intramuscular
benzathine penicillin.
Case 15:
A 60-year-old immunocompromised patient presents with cough, fever, and chest
pain. CT shows ground-glass opacities.
Question: Likely pathogen and treatment?
Answer: Pneumocystis jirovecii pneumonia; treat with high-dose TMP-SMX.
Case 16:
A 7-year-old child presents with itchy perianal region at night. Scotch tape test
shows eggs.
Question: Organism and treatment?
Answer: Enterobius vermicularis (pinworm); treat with mebendazole or
albendazole.
Case 17:
A patient presents with fever, fatigue, hepatosplenomegaly, and anemia. Bone
marrow shows Leishmania donovani amastigotes.
Question: Diagnosis and treatment?
Answer: Kala-azar (Visceral leishmaniasis); treat with liposomal amphotericin B.
Case 18:
A 25-year-old man presents with sudden onset fever, headache, myalgia after tick
bite in wooded area. Blood smear shows intracellular bacteria.
Question: Likely pathogen and treatment?
