Phaeohyphomycosis due to <i>Exophiala</i> in Aquarium-Housed Lumpfish (<i>Cyclopterus lumpus</i>): Clinical Diagnosis and Description
Colin T. McDermott,
Charles J. Innis,
Akinyi C. Nyaoke,
Kathryn A. Tuxbury,
Julie M. Cavin,
E. Scott Weber,
Deana Edmunds,
Stéphane Lair,
Jill V. Spangenberg,
Amy L. Hancock-Ronemus,
Catherine A. Hadfield,
Leigh A. Clayton,
Thomas B. Waltzek,
Connie F. Cañete-Gibas,
Nathan P. Wiederhold,
Salvatore Frasca
Affiliations
Colin T. McDermott
Department of Veterinary Clinical Sciences, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong 999077, China
Charles J. Innis
Animal Care, New England Aquarium, Boston, MA 02110, USA
Akinyi C. Nyaoke
California Animal Health and Food Safety Laboratory, San Bernardino Branch, University of California Davis, San Bernardino, CA 92408, USA
Kathryn A. Tuxbury
Animal Care, New England Aquarium, Boston, MA 02110, USA
Julie M. Cavin
Gulfarium Marine Adventure Park, Fort Walton Beach, FL 32548, USA
E. Scott Weber
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
Deana Edmunds
Animal Care, New England Aquarium, Boston, MA 02110, USA
Stéphane Lair
Faculté de Médecine Vétérinaire, Université de Montréal, St. Hyacinthe, QC J2R-J2T, Canada
Jill V. Spangenberg
Aquarium of the Bay, Embarcadero at Beach St., San Francisco, CA 94133, USA
Amy L. Hancock-Ronemus
Charles River Laboratories, Wilmington, MA 01887, USA
Catherine A. Hadfield
Seattle Aquarium, Seattle, WA 98101, USA
Leigh A. Clayton
Animal Care, New England Aquarium, Boston, MA 02110, USA
Thomas B. Waltzek
Animal and Plant Health Inspection Services, U.S. Department of Agriculture, Gainesville, FL 32606, USA
Connie F. Cañete-Gibas
Fungus Testing Laboratory, Department of Pathology and Laboratory Medicine, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
Nathan P. Wiederhold
Fungus Testing Laboratory, Department of Pathology and Laboratory Medicine, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229, USA
Salvatore Frasca
Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT 06269, USA
Phaeohyphomycosis caused by Exophiala species represents an important disease of concern for farmed and aquarium-housed fish. The objective of this study was to summarize the clinical findings and diagnosis of Exophiala infections in aquarium-housed Cyclopterus lumpus. Clinical records and postmortem pathology reports were reviewed for 15 individuals from 5 public aquaria in the United States and Canada from 2007 to 2015. Fish most commonly presented with cutaneous ulcers and progressive clinical decline despite topical or systemic antifungal therapy. Antemortem fungal culture of cutaneous lesions resulted in colonial growth for 7/12 samples from 8 individuals. Amplification of the internal transcribed spacer region (ITS) of nuclear rDNA identified Exophiala angulospora or Exophiala aquamarina in four samples from three individuals. Postmortem histopathologic findings were consistent with phaeohyphomycosis, with lesions most commonly found in the integument (11/15), gill (9/15), or kidney (9/15) and evidence of fungal angioinvasion and dissemination. DNA extraction and subsequent ITS sequencing from formalin-fixed paraffin-embedded tissues of seven individuals identified E. angulospora, E. aquamarina, or Cyphellophora sp. in four individuals. Lesion description, distribution, and Exophiala spp. identifications were similar to those reported in farmed C. lumpus. Antemortem clinical and diagnostic findings of phaeohyphomycosis attributable to several species of Exophiala provide insight on the progression of Exophiala infections in lumpfish that may contribute to management of the species in public aquaria and under culture conditions.
