Detection of Batrachochytrium dendrobatidis (Chytrid Fungus) in Aquatic Environments
Global amphibian declines are a huge concern, as amphibians are believed to be an indicator species of environmental health. There is also interest because understanding amphibian declines may be a model for assessing other species. The fungal pathogen Batrachochytrium dendrobatidis (Bd) causes chytridiomycosis, a disease implicated in amphibian declines on five continents. Bd attacks the pigmented mouthparts of infected tadpoles and is frequently lethal to postmetamorphic frogs.
Despite the threats to amphibians posed by Bd and its widespread distribution, little is known about its life history, the circumstances under which it becomes infectious, or the mechanisms by which it spreads. Chytridiomycosis has been studied in laboratories but field investigations have been impeded by a lack of available detection methods, as Bd can be detected in infected animals but not in their environment. There exists a need for field studies addressing the distribution and transport, exposure mechanisms and transmission, infectivity, ecology, and life history of Bd. Polymerase chain reaction (PCR) primer sets exist with which amphibians can be tested for this disease and advances in sampling techniques allow non-invasive testing of animals. We recently developed filtering and PCR based quantitative methods by modifying existing PCR assays to detect Bd DNA in water and sediments without the need for testing amphibians. This technique will allow researchers to study the implications of Bd's presence in water bodies, to monitor water bodies before reintroduction efforts and to investigate the spread of Bd across the landscape.
Amplification Plots and standard curve, USGS Bd-SYBR Boyle standards 1e7-1e1 copies (click to enlarge)
Paper
Kirshtein, JD, Anderson, CA, Wood, JS, Loncore, JE and Voytek, MA. A method for quantitative PCR detection of Batrachochytrium dendrobatidis DNA from sediments and water. Dis. Aquat. Org.
Pictures
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| Julie Kirshtein collects sediment at Two Medicine Pond, Glacier National Park | Big Meadow, Rocky Mountain National Park | Rana luteventris at Two Medicine Pond, Glacier National Park |
