Edited by David B. Wake, University of California, Berkeley, CA, and approved August 1, 2013 (received for review April 18, 2013)
Maximum likelihood tree (−Ln L = 9,562.04266) for the analysis of a 1,513-bp data matrix of partial 18S + 28S rRNA genes. Together with B. dendrobatidis, B. salamandrivorans sp. nov. forms a well-supported clade [maximum parsimony bootstrap support = 100; maximum likelihood bootstrap support (MLBS) = 100; Bayesian posterior probability (BPP) = 100] of Chytridiomycota that parasitize amphibians with potentially lethal consequences. Squares on branches indicate MLBS > 70 and BPP > 95; triangles indicate MLBS < 70 and BPP > 95.
In vitro culture of B. salamandrivorans in TGhL broth at 15 °C. (A) Monocentric thalli predominate, with the rare presence of colonial thalli (black arrow). Sporangia develop discharge tubes (white arrow) to release zoospores (Scale bar, 100 µm.) (B) Scanning electron microscopic image of a mature sporangium with rhizoids (R), discharge tubes (D), and germ tube formation (arrow) (Scale bar, 10 µm.)
Microscopy of the skin of a fire salamander that died due to infection with B. salamandrivorans. (A) Immunohistochemical staining of a 5-µm skin section. Intracellular colonial thalli abound throughout all epidermal cell layers and are associated with erosive lesions. (Scale bar, 20 µm.) (B) Transmission electron microscopy picture of an intracellular colonial thallus of B. salamandrivorans inside a keratinocyte (Scale bar, 4 µm.)
Growth of B. salamandrivorans in TGhL broth at different temperatures. (A) Growth was quantified by calculating the average percentage ± SD of the surface area of three wells covered by the fungus after 10 d of incubation at a given temperature. Motile zoospores were present at 5–20 °C, but not at 22, 24, and 30 °C. (B) B. salamandrivorans growth after 10 d at 4 °C (a), 15 °C (b), 20 °C (c), and 30 °C (d) (Scale bar, 200 µm.)
