title: Amphibians acquire resistance to live and dead fungus overcoming fungal immunosuppression.
abstract: Emerging fungal pathogens pose a greater threat to biodiversity than any other parasitic group, causing declines of many taxa, including bats, corals, bees, snakes and amphibians. Currently, there is little evidence that wild animals can acquire resistance to these pathogens. Batrachochytrium dendrobatidis is a pathogenic fungus implicated in the recent global decline of amphibians. Here we demonstrate that three species of amphibians can acquire behavioural or immunological resistance to B. dendrobatidis. Frogs learned to avoid the fungus after just one B. dendrobatidis exposure and temperature-induced clearance. In subsequent experiments in which B. dendrobatidis avoidance was prevented, the number of previous exposures was a negative predictor of B. dendrobatidis burden on frogs and B. dendrobatidis-induced mortality, and was a positive predictor of lymphocyte abundance and proliferation. These results suggest that amphibians can acquire immunity to B. dendrobatidis that overcomes pathogen-induced immunosuppression and increases their survival. Importantly, exposure to dead fungus induced a similar magnitude of acquired resistance as exposure to live fungus. Exposure of frogs to B. dendrobatidis antigens might offer a practical way to protect pathogen-naive amphibians and facilitate the reintroduction of amphibians to locations in the wild where B. dendrobatidis persists. Moreover, given the conserved nature of vertebrate immune responses to fungi and the fact that many animals are capable of learning to avoid natural enemies, these results offer hope that other wild animal taxa threatened by invasive fungi might be rescued by management approaches based on herd immunity.
authors.affiliation: 1] University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA [2] University of Tampa, Department of Biology, Tampa, Florida 33606, USA [3].
authors.forename: Taegan A
authors.initials: TA
authors.lastname: McMahon
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Brittany F
authors.initials: BF
authors.lastname: Sears
authors.affiliation: Allegheny College, Department of Biology, Meadville, Pennsylvania 16335, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Venesky
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Bessler
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Jenise M
authors.initials: JM
authors.lastname: Brown
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Kaitlin
authors.initials: K
authors.lastname: Deutsch
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Neal T
authors.initials: NT
authors.lastname: Halstead
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Garrett
authors.initials: G
authors.lastname: Lentz
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Nadia
authors.initials: N
authors.lastname: Tenouri
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Young
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Civitello
authors.affiliation: University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Ortega
authors.affiliation: Vanderbilt University, Biological Sciences Department, Nashville, Tennessee 37232, USA.
authors.forename: J Scott
authors.initials: JS
authors.lastname: Fites
authors.affiliation: Vanderbilt University, School of Medicine, Departments of Pathology, Microbiology and Immunology and Pediatrics, Nashville, Tennessee 37232, USA.
authors.forename: Laura K
authors.initials: LK
authors.lastname: Reinert
authors.affiliation: 1] Vanderbilt University, Biological Sciences Department, Nashville, Tennessee 37232, USA [2] Vanderbilt University, School of Medicine, Departments of Pathology, Microbiology and Immunology and Pediatrics, Nashville, Tennessee 37232, USA.
authors.forename: Louise A
authors.initials: LA
authors.lastname: Rollins-Smith
authors.affiliation: Oakland University, Department of Biology, Rochester, Michigan 48309, USA.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Raffel
authors.affiliation: 1] University of South Florida, Department of Integrative Biology, Tampa, Florida 33620, USA [2].
authors.forename: Jason R
authors.initials: JR
authors.lastname: Rohr
mesh_terms: D000663:Amphibians / Q000276:immunology* / Q000382:microbiology*; D000818:Animals; D000946:Antigens, Fungal / Q000276:immunology; D049109:Cell Proliferation; D008411:Chytridiomycota / Q000276:immunology*; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000166:cytology; D009181:Mycoses / Q000276:immunology* / Q000517:prevention & control; D011156:Population Density; D016019:Survival Analysis
chemical_list: D000946:Antigens, Fungal