title: Pathogenic chytrid fungus Batrachochytrium dendrobatidis, but not B. salamandrivorans, detected on eastern hellbenders.
abstract: Recent worldwide declines and extinctions of amphibian populations have been attributed to chytridiomycosis, a disease caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). Until recently, Bd was thought to be the only Batrachochytrium species that infects amphibians; however a newly described species, Batrachochytrium salamandrivorans (Bs), is linked to die-offs in European fire salamanders (Salamandra salamandra). Little is known about the distribution, host range, or origin of Bs. In this study, we surveyed populations of an aquatic salamander that is declining in the United States, the eastern hellbender (Cryptobranchus alleganiensis alleganiensis), for the presence of Bs and Bd. Skin swabs were collected from a total of 91 individuals in New York, Pennsylvania, Ohio, and Virginia, and tested for both pathogens using duplex qPCR. Bs was not detected in any samples, suggesting it was not present in these hellbender populations (0% prevalence, 95% confidence intervals of 0.0-0.04). Bd was found on 22 hellbenders (24% prevalence, 95% confidence intervals of 0.16 ≤ 0.24 ≤ 0.34), representing all four states. All positive samples had low loads of Bd zoospores (12.7 ± 4.9 S.E.M. genome equivalents) compared to other Bd susceptible species. More research is needed to determine the impact of Batrachochytrium infection on hellbender fitness and population viability. In particular, understanding how hellbenders limit Bd infection intensity in an aquatic environment may yield important insights for amphibian conservation. This study is among the first to evaluate the distribution of Bs in the United States, and is consistent with another, which failed to detect Bs in the U.S. Knowledge about the distribution, host-range, and origin of Bs may help control the spread of this pathogen, especially to regions of high salamander diversity, such as the eastern United States.
authors.affiliation: Biology Department, James Madison University, Harrisonburg, Virginia, United States of America.
authors.forename: Emma K
authors.initials: EK
authors.lastname: Bales
authors.affiliation: Biology Department, James Madison University, Harrisonburg, Virginia, United States of America.
authors.forename: Oliver J
authors.initials: OJ
authors.lastname: Hyman
authors.affiliation: Biology Department, James Madison University, Harrisonburg, Virginia, United States of America.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Loudon
authors.affiliation: Biology Department, James Madison University, Harrisonburg, Virginia, United States of America.
authors.forename: Reid N
authors.initials: RN
authors.lastname: Harris
authors.affiliation: Gregory Lipps, LLC, Toledo, Ohio, United States of America.
authors.forename: Gregory
authors.initials: G
authors.lastname: Lipps
authors.affiliation: Western Pennsylvania Conservancy, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Eric
authors.initials: E
authors.lastname: Chapman
authors.affiliation: New York Department of Environmental Conservation, Albany, New York, United States of America.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Roblee
authors.affiliation: Virginia Department of Game and Inland Fisheries, Richmond, Virginia, United States of America.
authors.forename: John D
authors.initials: JD
authors.lastname: Kleopfer
authors.affiliation: Smithsonian Conservation Biology Institute, Front Royal, Virginia, United States of America.
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Terrell
mesh_terms: D000663:Amphibians / Q000382:microbiology; D000818:Animals; D008411:Chytridiomycota / Q000472:pathogenicity*; D014481:United States; D014562:Caudata / Q000382:microbiology*