Batrachochytrium dendrobatidis gen. et sp. nov., a chytrid pathogenic to amphibians

TLDR: Batrachochy-type chytridiomycete has been identified as a member of the Chytridiales and its microtubule root has thread-like rhizoids that arise from single or multiple areas on the developing zoo sporangium as mentioned in this paper.

Abstract: Captive and wild frogs from North and Central America and Australia recently have died with epidermal infections by chytridiomycete fungi. We isolated a chytridiomycete into pure culture from a captive, blue poison dart frog that died at the Na- tional Zoological Park in Washington, D.C. Using this isolate, we photographed developmental stages on nutrient agar, examined zoospores with transmission electron microscopy, and inoculated test frogs. This inoperculate chytrid develops either monocentrically or colonially and has thread-like rhizoids that arise from single or multiple areas on the developing zoo- sporangium. The taxonomically important features of the kinetosomal region of the zoospore indicate that this chytrid is a member of the Chytridiales but differs from other chytrids studied with transmission electron microscopy. Its microtubule root, which be- gins at kinetosome triplets 9-1 and extends parallel to the kinetosome into the aggregation of ribosomes, is distinctive. Histologic examination of test frogs re- vealed that the pure culture infected the skin of test frogs, whereas the skin of control frogs remained free of infection. The fungus is described as Batrachochy-