Exophiala angulospora Causes Systemic Mycosis in Atlantic Halibut: a Case Report

AbstractFilamentous black yeasts from the genus Exophiala are ubiquitous, opportunistic pathogens causing both superficial and systemic mycoses in warm- and cold-blooded animals. Infections by black yeasts have been reported relatively frequently in a variety of captive and farmed freshwater and marine fishes. In November 2012, moribund and recently dead, farm-raised Atlantic Halibut Hippoglossus hippoglossus were necropsied to determine the cause of death. Histopathology revealed that three of seven fish were affected by a combination of an ascending trans-ductual granulomatous mycotic nephritis, necrotizing histiocytic encephalitis, and in one fish the addition of a fibrogranulomatous submucosal branchitis. Microbial cultures of kidney using selective mycotic media revealed pure growth of a black-pigmenting septated agent. Application of molecular and phenotypic taxonomy methodologies determined that all three isolates were genetically consistent with Exophiala angulospora. This is the first report of E...