Systemic Ophidiomyces ophiodiicola Infection in a Free-Ranging Plains Garter Snake (Thamnophis radix)
A free-ranging plains garter snake (Thamnophis radix) with a brown, encrusted, cutaneous facial lesion presented depressed, emaciated, and dehydrated. It developed respiratory distress and was later euthanized after it failed to respond to antibiotics and supportive treatment. Disseminated granulomatous disease with prominent lung involvement was diagnosed at necropsy. Intralesional hyaline fungal elements, consisting of septate hyphae, were detected histologically among the necrotic core of granulomas and aggregates of epithelioid macrophages. Ophidiomyces ophiodiicola was cultured from tissue specimens and identification was confirmed using 18S rRNA ITS DNA sequencing. Isolation of O. ophiodiicola from lesions that contain morphologically consistent fungal elements strongly incriminates this fungus as the cause of disease in this garter snake.Abstract
Plains garter snake, systemic mycosis. There is a 1cm round, non-proliferative, brown, dry, encrusted lesion caudal to the left eye.
Plains garter snake, systemic mycosis, histologic section of the left eye. There is diffuse granulomatous panophthalmitis with corneal edema, cataract, retina effacement, and orbital cellulitis. At higher magnification (inserted box), the granulomas (*) consist primarily of coalescing aggregates of epitheloid and foamy macrophages. H&E.
Plains garter snake, systemic mycosis, histologic section of lung. There are interspersed granulomas (*) and a coagulum of inflammatory exudate in a bronchus (arrow). At higher magnification (right panel), the granuloma (*) comprises a central coagulum of necrotic cellular debris surrounded by layers of epithelioid and foamy macrophages. H&E.
Plains garter snake, systemic mycosis, histologic section of lung. Fungal elements, consisting of septate hyphae, are detected in the bronchial exudate described previously in Figure 3 (arrow). The hyphae form a thick, dense carpet–tuft of arthroconidia at the air–tissue interface. Grocott's methenamine silver stain.
