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

American Society of Microbiology ASM-ABMM Online Questions & Answers

• Question 81:

  A clinical microbiology laboratory is validating a new automated blood culture system. To assess the system's ability to detect true positive results, they should:

  A. Process a large number of sterile blood samples.
  B. Spike known concentrations of various microorganisms into blood culture bottles.
  C. Compare the time to detection with the current manual blood culture method.
  D. Evaluate the system's performance with samples from patients with known bloodstream infections.
  B. Spike known concentrations of various microorganisms into blood culture bottles.

• Question 82:

  A microbiology laboratory receives a wound swab from a patient with a chronic, non- healing ulcer. Culture yields a Gram-positive, branching filamentous bacterium that is partially acid-fast. The MOST likely genus is:

  A. Streptomyces
  B. Nocardia
  C. Actinomyces
  D. Mycobacterium
  B. Nocardia

• Question 83:

  A patient with AIDS develops a disseminated fungal infection. Blood cultures grow a yeast that produces pseudohyphae and terminal chlamydospores on cornmeal agar. The patient's CD4+ T-cell count is below 50 cells/A. Aspergillus fumigatus
  B. Cryptococcus neoformans
  C. Candida albicans
  D. Pneumocystis jirovecii

  C. Candida albicans

• Question 84:

  A clinical microbiology laboratory is using isothermal nucleic acid amplification techniques for rapid detection of Mycobacterium tuberculosis in sputum. Compared to conventional PCR, isothermal methods offer the advantage of:

  A. Higher sensitivity and specificity for detecting low levels of target DNA.
  B. Faster reaction times and the ability to be performed without sophisticated thermocyclers.
  C. The ability to simultaneously amplify multiple targets in a single reaction.
  D. Easier integration with downstream analysis techniques such as Sanger sequencing.
  B. Faster reaction times and the ability to be performed without sophisticated thermocyclers.

• Question 85:

  A clinical microbiology laboratory isolates a Gram-negative rod from a wound infection following a dog bite. The organism grows on MacConkey agar, is oxidase-positive, and produces a characteristic bleach-like odor. The MOST likely identification is:

  A. Pasteurella multocida
  B. Capnocytophaga canimorsus
  C. Bordetella bronchiseptica
  D. Pseudomonas aeruginosa
  B. Capnocytophaga canimorsus

• Question 86:

  A clinical microbiology laboratory is using PCR to detect the presence of the mecA gene in Staphylococcus aureus isolates. The mecA gene encodes for:

  A. Beta-lactamase enzyme
  B. Altered penicillin-binding protein (PBP2a)
  C. An efflux pump protein
  D. An aminoglycoside-modifying enzyme
  B. Altered penicillin-binding protein (PBP2a)

• Question 87:

  A patient presents with a pruritic rash consisting of raised, serpiginous tracks on their skin. The patient recently returned from a Caribbean vacation and reported walking barefoot on the beach. The MOST likely causative organism is:

  A. Sarcoptes scabiei
  B. Pediculus humanus
  C. Larvae of Ancylostoma braziliense
  D. Larvae of Strongyloides stercoralis
  C. Larvae of Ancylostoma braziliense

• Question 88:

  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:

  A. The mecA gene, which is common to both CA-MRSA and HA-MRSA.
  B. Specific staphylococcal cassette chromosome mec (SCCmec) types, such as SCCmec IV or V inCA-MRSA.
  C. Panton-Valentine leukocidin (PVL) toxin genes, which are exclusively found in HA- MRSA.
  D. Resistance to non-beta-lactam antibiotics, which is more common in CA-MRSA.
  B. Specific staphylococcal cassette chromosome mec (SCCmec) types, such as SCCmec IV or V inCA-MRSA.

• Question 89:

  A clinical microbiology laboratory is using CRISPR-based technology for rapid and sensitive detection of specific bacterial DNA sequences directly from patient samples. This method relies on the ability of the Cas enzyme to:

  A. Reverse transcribe RNA into complementary DNA.
  B. Amplify target DNA sequences using specific primers and thermal cycling.
  C. Specifically bind to and cleave target DNA sequences guided by a short RNA molecule.
  D. Detect the presence of specific antibodies produced in response to bacterial infection.
  C. Specifically bind to and cleave target DNA sequences guided by a short RNA molecule.

• Question 90:

  A 6-year-old child presents with a pharyngitis characterized by a grayish-white pseudomembrane covering the tonsils and posterior pharynx. Gram stain of the membrane reveals Gram-positive bacilli. Culture on Loeffler's medium shows growth of metachromatic granules. The MOST significant virulence factor associated with this organism's pathogenicity is:

  A. Hyaluronidase
  B. Protein A
  C. Diphtheria toxin
  D. Streptolysin O
  C. Diphtheria toxin