Chemotaxis of the amphibian pathogen Batrachochytrium dendrobatidis and its response to a variety of attractants

Abstract

Batrachochytrium dendrobatidis is a fungal pathogen of amphibians that is increasingly implicated as a major cause of large-scale mortalities of amphibian species worldwide. Previous studies indicate that motile zoospores of B. dendrobatidis colonize the keratinized tissues of susceptible amphibians. Infections spread to adults and cause destruction of epidermal tissue. In an effort to understand how the chytrid cues into its host we developed an assay to study chemotaxis in the fungus. Here we show that zoospores exhibit positive movement toward a variety of attractants including sugars, proteins and amino acids. These observations suggest that the chytrid can respond to nutritional cues, including those of host origin. Implications of these observations to amphibian susceptibility to infection and chytrid virulence are discussed.

• amphibians
• chemotaxis
• chytrids

The authors thank Adam Lord and Jordan Owens for their assistance in counting the chemotaxis assays and Dr Reynaldo Patiño for the use of his microscope. We also thank Heath Grizzle and Jennifer Huddleston for their help with the statistical analyses. This work is supported by the National Science Foundation under grant No. 0201105.