title: Proteomic and phenotypic profiling of the amphibian pathogen Batrachochytrium dendrobatidis shows that genotype is linked to virulence.
abstract: Population genetics of the amphibian pathogen Batrachochytrium dendrobatidis (Bd) show that isolates are highly related and globally homogenous, data that are consistent with the recent epidemic spread of a previously endemic organism. Highly related isolates are predicted to be functionally similar due to low levels of heritable genetic diversity. To test this hypothesis, we took a global panel of Bd isolates and measured (i) the genetic relatedness among isolates, (ii) proteomic profiles of isolates, (iii) the susceptibility of isolates to the antifungal drug caspofungin, (iv) the variation among isolates in growth and phenotypic characteristics, and (v) the virulence of isolates against the European common toad Bufo bufo. Our results show (i) genotypic differentiation among isolates, (ii) proteomic differentiation among isolates, (iii) no significant differences in susceptibility to caspofungin, (iv) differentiation in growth and phenotypic/morphological characters, and (v) differential virulence in B. bufo. Specifically, our data show that Bd isolates can be profiled by their genotypic and proteomic characteristics, as well as by the size of their sporangia. Bd genotypic and phenotypic distance matrices are significantly correlated, showing that less-related isolates are more biologically unique. Mass spectrometry has identified a set of candidate genes associated with inter-isolate variation. Our data show that, despite its rapid global emergence, Bd isolates are not identical and differ in several important characters that are linked to virulence. We argue that future studies need to clarify the mechanism(s) and rate at which Bd is evolving, and the impact that such variation has on the host-pathogen dynamic.
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London, St. Mary's Hospital, Norfolk Place, London W21PG, UK. matthew.fisher@imperial.ac.uk
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Fisher
authors.forename: Jaime
authors.initials: J
authors.lastname: Bosch
authors.forename: Zhikang
authors.initials: Z
authors.lastname: Yin
authors.forename: David A
authors.initials: DA
authors.lastname: Stead
authors.forename: Janet
authors.initials: J
authors.lastname: Walker
authors.forename: Laura
authors.initials: L
authors.lastname: Selway
authors.forename: Alistair J P
authors.initials: AJ
authors.lastname: Brown
authors.forename: Louise A
authors.initials: LA
authors.lastname: Walker
authors.forename: Neil A R
authors.initials: NA
authors.lastname: Gow
authors.forename: Jason E
authors.initials: JE
authors.lastname: Stajich
authors.forename: Trenton W J
authors.initials: TW
authors.lastname: Garner
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D001001:Anura / Q000382:microbiology*; D002023:Bufo bufo / Q000382:microbiology; D000077336:Caspofungin; D008411:Chytridiomycota / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity*; D054714:Echinocandins / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D005838:Genotype; D055666:Lipopeptides; D008826:Microbial Sensitivity Tests; D016533:Mycological Typing Techniques; D010641:Phenotype; D020543:Proteome; D014774:Virulence / Q000235:genetics
chemical_list: D000935:Antifungal Agents; D054714:Echinocandins; D005656:Fungal Proteins; D055666:Lipopeptides; D020543:Proteome; D000077336:Caspofungin