American Society of Microbiology ABMM - ABMM Exam Practice Test
A microbiology laboratory receives a corneal scraping from a patient with keratitis. Microscopic examination with calcofluor white stain reveals the presence of septate hyphae and conidiophores with a foot cell and phialides. The MOST likely genus is:
Correct Answer: A
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A patient presents with symptoms suggestive of primary syphilis. Which diagnostic test typically becomes positive earliest in the course of infection?
Correct Answer: A
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A patient with HIV infection and a low CD4+ T-cell count presents with fever, weight loss, and cough. Chest X-ray shows diffuse interstitial infiltrates. Sputum induction reveals oval yeast cells with narrow-based budding. The MOST likely diagnosis is:
Correct Answer: C
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During a primary infection with Epstein-Barr virus (EBV), the virus establishes latency in B lymphocytes.
The transition from lytic to latent infection is tightly regulated by viral gene expression. Which of the following viral proteins is crucial for the establishment and maintenance of EBV latency and is a key target in EBV-associated lymphomas?
The transition from lytic to latent infection is tightly regulated by viral gene expression. Which of the following viral proteins is crucial for the establishment and maintenance of EBV latency and is a key target in EBV-associated lymphomas?
Correct Answer: B
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A microbiology laboratory is investigating an outbreak of bloodstream infections in a neonatal intensive care unit. Isolates of Staphylococcus epidermidis from multiple infants show indistinguishable banding patterns by pulsed-field gel electrophoresis (PFGE). This finding MOST strongly suggests:
Correct Answer: A
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A clinical microbiology laboratory is investigating a cluster of bloodstream infections caused by Staphylococcus aureus. To differentiate between community-associated (CA-MRSA) and healthcare- associated (HA-MRSA) strains, they may look for the presence of:
Correct Answer: A
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A research laboratory is studying the pathogenesis of respiratory syncytial virus (RSV) infection in infants.
They find that a specific viral surface glycoprotein is primarily responsible for attachment to host cells. This glycoprotein is:
They find that a specific viral surface glycoprotein is primarily responsible for attachment to host cells. This glycoprotein is:
Correct Answer: A
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A patient with a history of travel to a tropical region presents with cyclical fevers and chills.Peripheral blood smear reveals the presence of merozoites and schizonts within erythrocytes. The absence of crescent-shaped gametocytes makes Plasmodium falciparum less likely. The MOST probable species is:
Correct Answer: D
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An outbreak of gastroenteritis occurs among attendees of a company picnic. Epidemiological investigation points towards contaminated potato salad. Stool cultures from affected individuals grow non-lactose fermenting, Gram-negative rods that are H2S positive on TSI agar. Which pathogen is most likely responsible?
Correct Answer: D
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A microbiology laboratory is performing antimicrobial susceptibility testing using the Kirby-Bauer disk diffusion method. A bacterial isolate shows no zone of inhibition around a specific antibiotic disk. This result could be due to:
Correct Answer: C
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A researcher is investigating the mechanism of action of a novel antibacterial agent that inhibits bacterial protein synthesis. The agent binds to the 50S ribosomal subunit and prevents the translocation of peptidyl- tRNA. This mechanism of action is similar to which of the following antibiotics?
Correct Answer: B
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A fungal isolate grown from a blood culture at 37°C shows budding yeast cells. When subcultured to cornmeal agar with Tween 80 and incubated at 25°C, it produces pseudohyphae and terminal chlamydospores.
Growth on CHROMagar Candida yields green colonies. This organism is most likely:
Growth on CHROMagar Candida yields green colonies. This organism is most likely:
Correct Answer: A
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A patient with a history of chronic obstructive pulmonary disease (COPD) experiences an acute exacerbation.
Sputum culture grows numerous Gram-negative coccobacilli that are oxidase-positive and grow on chocolate agar but not on sheep blood agar. The MOST likely organism is:
Sputum culture grows numerous Gram-negative coccobacilli that are oxidase-positive and grow on chocolate agar but not on sheep blood agar. The MOST likely organism is:
Correct Answer: D
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A patient develops a febrile illness with a diffuse petechial rash after a camping trip. Serological testing reveals a four-fold rise in antibody titer to Rickettsia rickettsii. The vector responsible for transmitting this organism is a:
Correct Answer: A
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An immunocompromised patient develops a disseminated fungal infection. Blood cultures are consistently negative. However, a serum beta-D-glucan assay is markedly elevated. Tissue biopsy reveals the presence of hyaline, septate hyphae with dichotomous branching. The MOST likely causative organism is:
Correct Answer: C
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