Madurella pseudomycetomatis 2

 

Etymology:

Yan, Deng, Zhou, Zhong, et Hao ex de Hoog, van Diepeningen, Mahgoub, et van de Sande, sp. nov. Etymology: named after a mycetomatis-like infection. Coloniae modice expandentes, siccae, fuscae ad griseae; reversum fuscum ad griseum. Fuscum-aurantium excretum. Cellulae gemmantes absentes. Hyphae septatae, modice crassitunicatae, pallide brunneae. Conidiophora absentes. Chlamydosporae praesentes. Teleomorphosis ignota. Optime crescit 30°C. Typus vivus et exsiccatus CBS-H 20691 (ex-typus CBS 129177) in herbario CBS praeservatur.

Morphological Description:

The growth rate is slow and the colonies' morphology varied on different media. Colonies on SDA (Sabaroud dextrose agar) were granular, raised, and cauliflower-like and measured 3 to 8 mm in diameter. Microscopically, numerous chlamydospores, which were subglobose, thick-walled, 15 μm in diameter, and intercalary or terminal, were observed on SDA and Potato dextrose agar (PDA). The fungus showed optimal growth at 37°C, could tolerate 42°C, but stopped growth at 44°C. Assimilation of glucose, arabinose, xylose, cellose, maltose, and trehalose was positive in the API 20C AUX system.

Molecular Identification:

ITS sequencing is recommended. Species specific PCR was designed for Madurella pseudomycetomatis by Nyuykonge and associates in 2020 (Ref. No 3).

In vitro antifungal activity

Madurella pseudomycetomatis

  1. pseudomycetomatis showed high susceptibilities to itraconazole (MIC-0 = 0.0625 μg/ml), voriconazole (MIC-0 = 0.0313 μg/ml), and amphotericin B (100% growth inhibition [MIC-0] = 0.0313 μg/ml), while it was resistant to fluconazole (≥50% growth inhibition [MIC-2] = 32 μg/ml) and flucytosine (MIC-2 = 64 μg/ml). The strain was less susceptible to terbinafine. The MIC-0 was 2 μg/ml.

 

References:

  1. de Hoog GS, van Diepeningen AD, Mahgoub el-S, van de Sande WW. New species of Madurella, causative agents of black-grain mycetoma. J Clin Microbiol. 2012; 50(3):988-994.
  2. Yan J, Deng J, Zhou CJ, Zhong BY, Hao F. Phenotypic and molecular characterization of Madurella pseudomycetomatis sp. nov., a novel opportunistic fungus possibly causing black-grain mycetoma. J Clin Microbiol. 2010;48(1):251-257.
  3. Nyuykonge B, Klaassen CHW, Zandijk WHA, de Hoog GS, Ahmed SA, Desnos-Ollivier M, Verbon A, Bonifaz A, van de Sande WWJ. Diagnostic implications of mycetoma derived from Madurella pseudomycetomatis isolates from Mexico. J Eur Acad Dermatol Venereol. 2020:e16402.