Fungal Infections in Reptiles—An Emerging Problem

Abstract

Dermatomycoses as well as disseminated systemic mycoses are caused by emerging obligate pathogenic fungi of the families Onygenaceae and Clavicipitaceae in captive as well as in free-living reptiles. Isolation and differentiation of fungal agents and evaluation of their pathogenicity in diseased reptiles using histopathological examination are necessary to determine the pathogenicity of a fungal isolate in the disease process. Fungi formerly known as Chrysosporium anamorph of Nannizziopsis vriesii have recently been reassigned to the family Onygenaceae, order Onygenales (Eurotiomycetidae, Eurotiomycetes, and Ascomycota), based on phylogenetic studies. To date, 9 different reptile pathogenic species are known from this family, grouped in 3 phylogenetic lineages. The most relevant are Nannizziopsis guarroi affecting inland bearded dragons (Pogona viticeps) and green iguanas (Iguana iguana), as well as Ophidiomyces ophiodiicola in free-living snakes, which cause deep fungal dermatitis. Treatment with voriconazole is possible in bearded dragons and girdled lizards (Cordylus giganteus). Other obligate pathogenic fungi belong to the family Clavicipitaceae, which causes granulomatous glossitis, pharyngitis, and dermatitis, as well as disseminated visceral mycosis, in various lizards, tortoises, turtles, and crocodilians. No reports exist about successful treatments against fungal pathogens in the family Clavicipitaceae. Also, voriconoazole should be used carefully in chameleons, as it does not seem to be well tolerated in these species.