Detection of Ophidiomyces and Nannizziopsis spp. in the dermal lesions of free-roaming native snakes in Taiwan.

Chrysosporium-related fungi refers to an assemblage of fungi belonging to the Nannizziopsis, Ophidiomyces, and Paranannizziopsis genera. Chrysosporium-related fungi infection results in various skin lesions, such as necrosis and ulcers, in both captive and free-roaming reptiles. To update the prevalence of ophidiomycosis in Taiwan, which was first detected in 2019, we conducted a large-scale ecological survey of free-roaming native snakes with skin lesions in Taiwan. To the best of our knowledge, this is the first study on Chrysosporium-related fungi prevalence in Southeast Asia. Fungal samples collected from the skin lesions of snakes were cultured and subjected to morphological, histopathological, and molecular analyses. We examined 2382 free-roaming snakes representing 42 snake species; among them, 132 (5.54%) had skin lesions. Ten (0.42%) snakes, representing four species, tested positive for Ophidiomyces (five snakes, four species) or a possibly novel Nannizziopsis species (five snakes, three species). The infected snakes were generally healthy, with mild clinical signs. The low prevalence rate, mild clinical signs, and broad pathogen/host range suggest that Ophidiomyces and Nannizziopsis are endemic to Southeast Asia. The newly reported presence of Nannizziopsis in free-roaming snakes suggests the need for modifying the currently used surveillance strategy.