First Isolation of Arthroderma fulvum in Japan

Area of Science:

• Medical Mycology
• Veterinary Dermatology
• Environmental Microbiology

Background:

• Microsporum gypseum is a dermatophyte known to cause infections in various animals and humans.
• Environmental sources, such as soil, are potential reservoirs for dermatophyte transmission.
• Understanding the genetic characteristics and mating potential of clinical isolates is crucial for epidemiological studies.

Purpose of the Study:

• To characterize the morphology and molecular features of Microsporum gypseum isolates from a rabbit and its environment.
• To identify the isolates using internal transcribed spacer (ITS) sequence analysis.
• To investigate the presence of mating type genes and mating capability in these isolates.

Main Methods:

• Morphological examination of fungal isolates.
• Molecular identification via internal transcribed spacer (ITS) region sequencing.
• Polymerase chain reaction (PCR) for mating type gene detection (MAT1-1 and MAT1-2).

Main Results:

• All 11 clinical isolates, from rabbit fur and soil, showed homology with Arthroderma fulvum ITS sequences.
• MAT1-1 mating type gene was detected in 10 isolates, and MAT1-2 in one isolate.
• No mating reactions were observed between the clinical isolates and reference strains of Arthroderma fulvum.

Conclusions:

• The clinical isolates of Microsporum gypseum were identified as Arthroderma fulvum based on molecular data.
• The isolates possess the genetic machinery for mating (both MAT1-1 and MAT1-2), but failed to mate under experimental conditions.
• Further research is needed to understand the factors influencing mating behavior in Arthroderma fulvum in natural and experimental settings.