Nichols D K, Weyant R S, Lamirande E W, Sigler L, Mason R T
Laboratory Sciences Section, Veterinary Resources Program, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Zoo Wildl Med. 1999 Mar;30(1):111-8.
Cutaneous fungal infections occurred in four captive brown tree snakes (Boiga irregularis). The ventral scales were most commonly affected, and lesions began as areas of erythema and edema with vesicle formation, followed by development of caseous brown plaques. Lesions usually started where ventral scales overlapped and spread rapidly. All snakes died within 14 days after clinical signs were first noted. The deaths of three of the snakes were directly attributable to the cutaneous disease; the other snake died from renal failure and visceral gout, most likely induced by gentamicin therapy. Histologically, lesions consisted of epidermal hyperplasia and hyperkeratosis, with foci of epidermal necrosis, intraepidermal vesicle formation, and subacute inflammation of the underlying dermis. These lesions were associated with bacteria and numerous septate, branched fungal hyphae within the epidermis and overlying serocelluar crusts. Hyphae that penetrated through the superficial surface of the epidermis often formed terminal arthroconidia. The same species of fungus was isolated in pure culture from the skin of three snakes, but fungal cultures were not performed on samples from the fourth snake. The fungus has been identified as the Chrysosporium anamorph of Nannizziopsis vriesii based on its formation of solitary dermatophytelike aleurioconidia and alternate and fission arthroconidia. The source of the fungus in this outbreak was not determined; however, the warm, moist conditions under which the snakes were housed likely predisposed them to opportunistic cutaneous fungal infections.
四只圈养的棕树蛇（Boiga irregularis）发生了皮肤真菌感染。腹侧鳞片最常受到影响，病变开始为红斑和水肿区域，并形成水疱，随后发展为干酪样棕色斑块。病变通常始于腹侧鳞片重叠处，并迅速蔓延。所有蛇在首次出现临床症状后的14天内死亡。其中三只蛇的死亡直接归因于皮肤病；另一只蛇死于肾衰竭和内脏痛风，很可能是由庆大霉素治疗引起的。组织学上，病变包括表皮增生和角化过度，伴有表皮坏死灶、表皮内水疱形成以及真皮下层的亚急性炎症。这些病变与细菌以及表皮内和覆盖的浆液性结痂内大量有隔、分支的真菌菌丝有关。穿透表皮表面的菌丝通常形成末端关节孢子。从三条蛇的皮肤中纯培养分离出了同一种真菌，但未对第四条蛇的样本进行真菌培养。根据其形成单独的类皮肤癣菌粉孢子以及交替和裂生关节孢子的情况，该真菌已被鉴定为Nannizziopsis vriesii的Chrysosporium无性型。此次疫情中真菌的来源尚未确定；然而，蛇的饲养环境温暖潮湿，这可能使它们易患机会性皮肤真菌感染。
