First isolation of Trichophyton bullosum from a horse with dermatophytosis in Japan.

This research presents the first instance of the pathogenic fungus Trichophyton bullosum being isolated from a horse in Japan, with identification confirmed through genetic sequencing. The fungus, which leads to skin infections, is more commonly found in Europe and Africa.

Objective of the Research

• The study aimed to report the first isolation of a certain pathogenic fungus, Trichophyton bullosum, from a horse with dermatophytosis in Japan. This particularly focuses on increasing the understanding of the geographical distribution and host range of this fungus.

Methodology

• Trichophyton bullosum was isolated from the skin lesion of an infected horse. Morphological observations showed that the isolated fungus formed a cream-colored and waxy colony.
• This pathogen’s specific identification was performed through a molecular approach, specifically by sequencing the internal transcribed spacer region. This is a well-known method to identify fungi at the species level.

Findings

• The molecular analysis confirmed that the fungus isolated in Japan from a horse was truly Trichophyton bullosum. The isolate sequence was found to be 100% identical to that of Trichophyton bullosum, validating the initial identification.

Significance of the Study

• This is the first reported isolation of Trichophyton bullosum from a horse in Japan, expanding the current knowledge about the geographical spread and host range of this pathogenic fungus.
• The results of this study raise concerns about the potential of this pathogen to jump geographic barriers and infect hosts not previously reported as susceptible, stressing the need for continued surveillance and study of dermatophyte infections in horses and other animals.