American Society of Microbiology ASM-ABMM Online Practice Questions and Exam Preparation

American Society of Microbiology ASM-ABMM Online Questions & Answers

• Question 91:

  A patient who received a solid organ transplant develops a pneumonia. Bronchoalveolar lavage fluid is positive for a single-stranded RNA virus that can cause giant cell formation with intranuclear and intracytoplasmic inclusions. The MOST likely causative agent is:

  A. Respiratory syncytial virus (RSV)
  B. Adenovirus
  C. Parainfluenza virus
  D. Human metapneumovirus
  C. Parainfluenza virus

• Question 92:

  A patient with a history of intravenous drug use develops a fever and new heart murmur. Blood cultures are positive for Gram-positive cocci that are catalase-positive and coagulase-positive. The MOST likely complication of this infection is:

  A. Glomerulonephritis
  B. Septic arthritis
  C. Embolic stroke
  D. Reactive arthritis
  C. Embolic stroke

• Question 93:

  What is the most appropriate method for sterilizing a heat-labile liquid solution containing essential proteins for use in tissue culture?

  A. Autoclaving at 121°C for 15 minutes
  B. Filtration through a 0.22 μm pore size membrane filter
  C. Exposure to ethylene oxide gas
  D. Irradiation with ultraviolet (UV) light
  B. Filtration through a 0.22 μm pore size membrane filter

• Question 94:

  A clinical microbiology laboratory is performing Gram staining on a sputum sample. After adding the crystal violet stain, a delay in the washing step with decolorizer (alcohol- acetone) would MOST likely result in:

  A. Poor adherence of the stain to Gram-positive bacteria.
  B. Gram-negative bacteria appearing purple.
  C. Gram-positive bacteria appearing pink.
  D. Increased background staining.
  B. Gram-negative bacteria appearing purple.

• Question 95:

  A patient presents with a chronic, non-healing skin ulcer in a tropical region. Microscopic examination of a biopsy reveals amastigotes within macrophages. Culture of the biopsy on Novy-MacNeal-Nicolle (NNN) medium yields flagellated promastigotes. The MOST likely diagnosis is cutaneous leishmaniasis caused by:

  A. Leishmania donovani
  B. Leishmania tropica or Leishmania major
  C. Trypanosoma cruzi
  D. Trypanosoma brucei gambiense
  B. Leishmania tropica or Leishmania major

• Question 96:

  Metagenomic analysis of a bronchoalveolar lavage (BAL) sample from a patient with severe pneumonia reveals a complex microbial community with a high abundance of both bacterial and fungal sequences. This approach is particularly useful in identifying:

  A. The specific antibiotic susceptibility profile of the predominant bacterial pathogen.
  B. The presence of fastidious or unculturable pathogens that may be missed by traditional methods.
  C. The relative proportions of different immune cell populations in the BAL fluid.
  D. The presence of specific virulence factors expressed by the identified pathogens.
  B. The presence of fastidious or unculturable pathogens that may be missed by traditional methods.

• Question 97:

  A patient with a history of inflammatory bowel disease is diagnosed with primary sclerosing cholangitis and undergoes liver transplantation. Post-transplant, they develop a bloodstream infection with a Gram-negative bacterium that is identified as Fusobacterium nucleatum. This organism's role in the pathogenesis of colorectal cancer is primarily attributed to its ability to:

  A. Produce potent exotoxins that damage the intestinal epithelium.
  B. Modulate the host immune response and promote a pro-inflammatory microenvironment.
  C. Directly induce mutations in colonic epithelial cells.
  D. Form biofilms that physically obstruct the bile ducts.
  B. Modulate the host immune response and promote a pro-inflammatory microenvironment.

• Question 98:

  A patient presents with symptoms suggestive of primary syphilis. Which diagnostic test typically becomes positive earliest in the course of infection?

  A. Rapid Plasma Reagin (RPR)
  B. Venereal Disease Research Laboratory (VDRL) test on CSF
  C. Darkfield microscopy of lesion exudate
  D. Treponema pallidum particle agglutination (TP-PA)
  C. Darkfield microscopy of lesion exudate

• Question 99:

  Lyme disease, characterized initially by erythema migrans, is caused by Borrelia burgdorferi. What is the primary arthropod vector responsible for transmitting this spirochete to humans in the Northeastern United States?

  A. Dermacentor variabilis (American dog tick)
  B. Ixodes scapularis (Blacklegged tick)
  C. Amblyomma americanum (Lone Star tick)
  D. Pulex irritans (Human flea)
  B. Ixodes scapularis (Blacklegged tick)

• Question 100:

  A patient with a history of recurrent fungal skin infections presents with a scaly, erythematous rash on their feet. Microscopic examination of skin scrapings treated with potassium hydroxide (KOH) reveals septate hyphae and arthroconidia. The MOST likely genus of the dermatophyte is:

  A. Candida
  B. Malassezia
  C. Trichophyton
  D. Aspergillus
  C. Trichophyton