Apophysomyces variabilis as an emerging pathogen in Mainland China

Mycoses. 2023 Sep;66(9):795-800. doi: 10.1111/myc.13605. Epub 2023 May 25.

Abstract

Background: Mucormycosis is a rare form of invasive, rapidly progressive and lethal opportunistic fungal infection caused by Mucorales. Although Rhizopus arrhizus (R. arrhizus) is the most commonly isolated Mucorales worldwide, infections caused by Apophysomyces variabilis (A. variabilis) are increasing.

Objectives and methods: We present a case of necrotizing fasciitis caused by A. variabilis in an immunocompetent woman. In order to further understand the characteristics of the strain isolated from the patient, we identified the strain through ITS sequencing, assessed the ability to tolerate salt concentrations and temperature conditions, in addition to performing in vitro drug susceptibility testing against common antifungal agents.

Results: The strain showed 98.76% identity with A. variabilis in the NCBI database, and it was found to tolerate higher temperatures and salt concentrations than previously reported strains. The strain was sensitive to amphotericin B and posaconazole, but not to voriconazole, itraconazole, 5-fluorocytosine and echinocandins.

Conclusions: This case indicates that Mucorales caused by A. variabilis should be recognised as an emerging pathogen that can cause a high mortality rate in the absence of prompt diagnosis and proper treatment in China, aggressive surgical debridement combined with prompt and appropriate antifungal treatment may improve outcomes.

Keywords: Apophysomyces variabilis; emerging; immunocompetent; mucormycosis; necrotizing fasciitis.

Publication types

  • Case Reports

MeSH terms

  • Antifungal Agents / therapeutic use
  • Female
  • Humans
  • Microbial Sensitivity Tests
  • Mucorales*
  • Mucormycosis* / diagnosis
  • Mucormycosis* / drug therapy
  • Mucormycosis* / microbiology
  • Mycobacterium tuberculosis*

Substances

  • Antifungal Agents

Supplementary concepts

  • Apophysomyces variabilis