title: Composition of symbiotic bacteria predicts survival in Panamanian golden frogs infected with a lethal fungus.
abstract: Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki, a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics.
authors: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA beckerm@si.edu.
authors: Matthew H
authors: MH
authors: Becker
authors: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.
authors: Jenifer B
authors: JB
authors: Walke
authors: Department of Clinical Sciences, Kansas State University, Manhattan, KS, USA.
authors: Shawna
authors: S
authors: Cikanek
authors: Center for Conservation and Evolutionary Genetics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA.
authors: Anna E
authors: AE
authors: Savage
authors: Center for Conservation and Evolutionary Genetics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA.
authors: Nichole
authors: N
authors: Mattheus
authors: Department of Chemistry, Villanova University, Villanova, PA, USA.
authors: Celina N
authors: CN
authors: Santiago
authors: Department of Chemistry, Villanova University, Villanova, PA, USA.
authors: Kevin P C
authors: KP
authors: Minbiole
authors: Department of Biology, James Madison University, Harrisonburg, VA, USA.
authors: Reid N
authors: RN
authors: Harris
authors: Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.
authors: Lisa K
authors: LK
authors: Belden
authors: Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA.
authors: Brian
authors: B
authors: Gratwicke
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002025:Bufonidae / Q000502:physiology; D008411:Chytridiomycota / Q000502:physiology*; D064307:Microbiota; D008969:Molecular Sequence Data; D009181:Mycoses / Q000382:microbiology / Q000401:mortality / Q000662:veterinary*; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S
keywords: amphibians; chytrid fungus; disease; microbiome; probiotics; skin bacteria