Independent Origin of Chytrid Fungus in China

Chytridiomycosis is an emerging infectious fungal disease of wildlife worldwide. This disease implicated in the decline or extinction of about 200 amphibian species, thereby contributing to the ongoing sixth great extinction event on the world. With this emerging disease, international trade, specifically import and export from unknown sources, has been associated with novel pathogen transmission. Thus, identifying the potential sources of transmission of the pathogen is a key step in international risk management. China may unknowingly be an important source of pathogen in this regard and a «mixer» of pathogens in the import and export trade. Here, we report evidence for an independent origin of Batrachochytrium dendrobatidis in China. We evaluated American bullfrog ( Lithobates catesbeianus ) introductions over time and performed phylogenetic analyses of DNA recovered from native Chinese B. dendrobatidis infections in comparison with B. dendrobatidis DNA sequences from other geographically distinct isolates. It is hoped that this study can be used to improve international risk management of chytridiomycosis. The pathogenic mechanism and implications of B. dendrobatidis isolates from China warrants reassessment.