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

American Society of Microbiology ASM-ABMM Online Questions & Answers

• Question 111:

  A clinical microbiology laboratory is monitoring the emergence of antimicrobial resistance. The detection of a bacterial isolate with reduced susceptibility to multiple classes of antibiotics, often due to horizontal gene transfer of resistance determinants, is characteristic of:

  A. An intrinsically resistant organism.
  B. A pan-susceptible organism.
  C. A multidrug-resistant (MDR) organism.
  D. A naturally competent organism.
  C. A multidrug-resistant (MDR) organism.

• Question 112:

  A clinical microbiology laboratory is evaluating a new multiplex PCR assay for the detection of respiratory viruses. To assess the assay's specificity, they test a panel of samples known to contain various bacterial pathogens. A positive result is obtained for rhinovirus in a sample containing only Streptococcus pneumoniae. This indicates:

  A. Poor analytical sensitivity of the PCR assay for rhinovirus.
  B. Cross-reactivity of the PCR primers with Streptococcus pneumoniae DNA.
  C. A mixed infection in the original patient sample.
  D. Degradation of the rhinovirus target sequence during storage.
  B. Cross-reactivity of the PCR primers with Streptococcus pneumoniae DNA.

• Question 113:

  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:

  A. Mucor
  B. Rhizopus
  C. Aspergillus
  D. Candida
  C. Aspergillus

• Question 114:

  A traveler returning from sub-Saharan Africa presents with cyclical fevers, chills, and sweats. A Giemsa-stained peripheral blood smear reveals multiple ring forms within red

  blood cells, some appliqué forms, and occasional banana-shaped gametocytes. No Schüffner's dots or red blood cell enlargement is observed. Which Plasmodium species is the most likely cause?

  A. Plasmodium vivax
  B. Plasmodium ovale
  C. Plasmodium malariae
  D. Plasmodium falciparum
  D. Plasmodium falciparum

• Question 115:

  A research laboratory is investigating the mechanism of action of a novel antiviral compound that inhibits the replication of a specific RNA virus. They find that the compound binds directly to the viral RNA-dependent RNA polymerase, preventing its elongation activity. This mechanism is most similar to that of:

  A. Acyclovir
  B. Oseltamivir
  C. Ribavirin
  D. Interferon-beta
  C. Ribavirin

• Question 116:

  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?

  A. Shigella sonnei
  B. Salmonella Enteritidis
  C. Enterotoxigenic
  D. Vibrio cholerae
  E. coli (ETEC)
  B. Salmonella Enteritidis

• Question 117:

  A patient with a history of travel to Southeast Asia presents with fever, severe headache, and altered mental status. CSF analysis reveals lymphocytic pleocytosis and elevated protein, but routine bacterial and viral cultures are negative. Serological testing of CSF is positive for IgM antibodies against Japanese encephalitis virus. The MOST likely mode of transmission for this infection is:

  A. Ingestion of contaminated food or water.
  B. Respiratory droplets from an infected individual.
  C. Bite of an infected mosquito.
  D. Direct contact with infected animals.
  C. Bite of an infected mosquito.

• Question 118:

  A microbiology laboratory is processing a throat swab for the detection of Group A Streptococcus. Culture on sheep blood agar reveals beta-hemolytic colonies. Which of the following tests can be used to presumptively identify Streptococcus pyogenes?

  A. Catalase test
  B. Coagulase test
  C. Bacitracin susceptibility
  D. Bile esculin hydrolysis
  C. Bacitracin susceptibility

• Question 119:

  A patient with a history of solid organ transplantation develops a severe respiratory illness. Bronchoalveolar lavage fluid is positive for cytomegalovirus (CMV) DNA by PCR, and cytological examination reveals characteristic "owl's eye" inclusions in enlarged cells. The MOST appropriate management strategy for this patient would include:

  A. Supportive care and monitoring for spontaneous resolution.
  B. Initiation of broad-spectrum antibiotics to cover potential bacterial coinfections.
  C. Treatment with antiviral agents such as ganciclovir or valganciclovir.
  D. Administration of corticosteroids to reduce inflammation.
  C. Treatment with antiviral agents such as ganciclovir or valganciclovir.

• Question 120:

  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:

  A. Tuberculosis
  B. Pneumocystis pneumonia
  C. Histoplasmosis
  D. Cryptococcosis
  C. Histoplasmosis