Closing the Brief Case: A Case of Prosthetic Valve Endocarditis Due to Lodderomyces elongisporus

ANSWERS TO SELF-ASSESSMENT QUESTIONS

• 1.
  What organism is Lodderomyces elongisporus closely related to and was historically misidentified as using biochemical techniques?

  • a.
    Staphylococcus aureus
  • b.
    Candida parapsilosis
  • c.
    Candida albicans
  • d.
    Candida tropicalis

Answer: b. While L. elongisporus is closely related to C. albicans and C. tropicalis, it is most closely related to C. parapsilosis and is often misidentified biochemically as C. parapsilosis.

• 2.
  Which of the following descriptions is correct for identification of Lodderomyces elongisporus?

  • a.
    Colonies appear as cream-colored colonies with colony projections on CNA
  • b.
    Sequencing cannot readily differentiate between L. elongisporus and Candida parapsilosis
  • c.
    Colonies develop a distinct turquoise color on CHROMagar Candida medium
  • d.
    Colonies develop a pink or lavender color on CHROMagar Candida medium

Answer: c. Lodderomyces elongisporus colonies develop a distinct turquoise color on CHROMagar Candida medium. L. elongisporus appears as cream-colored, opaque colonies without colony projections on nonchromogenic medium. L. elongisporus is often misidentified as C. parapsilosis by biochemical assays and biochemical-based identification systems. L. elongisporus is readily identified by sequencing and molecular techniques.

• 3.
  Which of the following is a risk factor for Lodderomyces elongisporus infection?

  • a.
    Intravenous drug use
  • b.
    Catheterization
  • c.
    Immunosuppression
  • d.
    All of the above

Answer: d. Lodderomyces elongisporus is an emerging pathogenic yeast associated with catheter-related and bloodstream infections. L. elongisporus has been recovered from infections in persons who inject drugs and in patients with underlying health conditions, such as immunosuppression.

TAKE-HOME POINTS

• •Lodderomyces elongisporus is an emerging pathogenic yeast associated with catheter-related infections. It is normally found associated with fresh fruits and fruit concentrates and insects.
• •Risk factors for Lodderomyces elongisporus infection include intravenous drug use and catheterization. As L. elongisporus is often misidentified by biochemical identification systems as C. parapsilosis, the risk factors for the two organisms may be the same.
• •Lodderomyces elongisporus is often misidentified by biochemical-based identification assays as C. parapsilosis, as the two species are physiologically similar. L. elongisporus can be readily differentiated from C. parapsilosis by its characteristic turquoise color on CHROMagar, matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and by sequencing approaches.
• •There are no established breakpoint values for L. elongisporus antifungal susceptibility testing. L. elongisporus appears relatively susceptible to antifungals based on published MICs.

See https://doi.org/10.1128/JCM.01225-20 in this issue for case presentation and discussion.