title: Host species vary in infection probability, sub-lethal effects, and costs of immune response when exposed to an amphibian parasite.
abstract: The amphibian parasite Batrachochytrium dendrobatidis (Bd) is regarded as an extreme generalist, infecting over 500 species, but amongst these hosts there exists a great deal of variation in the susceptibility to and the costs of parasite exposure. We use two infection experiments to determine whether inter-specific variation in the sublethal and lethal effects of parasite exposure exist in two host species. We then tested the relative roles of host density and diversity on infection probability of a focal susceptible host. Our results show significant heterogeneity in host species response to parasite exposure, and that both lethal and sub-lethal costs exist in individuals that are able to resist infection, indicating that successful immune response to infection comes at a cost. Further, we show that increasing host density significantly increased the likelihood of susceptible individuals becoming infected with Bd irrespective of host diversity and variation in host susceptibility. These results suggest that populations of resistant species are likely to suffer ill-effects of exposure to Bd regardless of their infection status, and that at the stage of initial infection there was no support for the dilution of transmission events, in contrast to other studies that focus on subsequent transmission of infection.
authors.affiliation: 1] The Institute of Zoology, The Zoological Society of London, Regent's Park, London, NW1 4RY, UK [2] Department of Infectious Disease Epidemiology, Imperial College London W2 1PG, UK.
authors.forename: Jon
authors.initials: J
authors.lastname: Bielby
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London W2 1PG, UK.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Fisher
authors.affiliation: 1] The Institute of Zoology, The Zoological Society of London, Regent's Park, London, NW1 4RY, UK [2] Department of Infectious Disease Epidemiology, Imperial College London W2 1PG, UK.
authors.forename: Frances C
authors.initials: FC
authors.lastname: Clare
authors.affiliation: 1] The Institute of Zoology, The Zoological Society of London, Regent's Park, London, NW1 4RY, UK [2] Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK [3] Centre for Ecology, Evolution and Environmental Changes (CE3C), Faculdade de Ciências da Universidade de Lisboa, Bloco C2, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Gonçalo M
authors.initials: GM
authors.lastname: Rosa
authors.affiliation: The Institute of Zoology, The Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
authors.forename: Trenton W J
authors.initials: TW
authors.lastname: Garner
mesh_terms: D000818:Animals; D001001:Anura / Q000469:parasitology*; D008411:Chytridiomycota / Q000235:genetics / Q000472:pathogenicity*; D004198:Disease Susceptibility; D058507:Host Specificity / Q000235:genetics; D006790:Host-Parasite Interactions; D010271:Parasites / Q000472:pathogenicity