wildlife and zoo assay data sheet

Chytrid fungus

Test code: F0005 - Qualitative detection of Batrachochytrium dendrobatidis by real time PCR

F0005 is included in P0031 - amphibian screening panel

In the past, chytrid fungi were considered to be predominantly free-living saprophytes, with a few species capable of infecting only invertebrates and vascular plants. A new species, Batrachochytrium dendrobatidis, was discovered in 1999 which was shown to be capable of infecting amphibians and causing an often-fatal disease known as chytridiomycosis. Subsequent studies further showed that B. dendrobatidis was associated with amphibian population declines on every amphibian-inhabited continent.

Once amphibians are infected with this fungus, it can spread quickly through watercourses and animal-to-animal contact, and possibly by other mechanisms not yet fully understood. In Central America, where the spread of the fungus has been extensively studied, its rate of progression has been calculated at 28-100 km/yr.

Captive amphibians are not entirely safe from chytrid fungus. Mortality in private and zoo collections has been reported in several countries. Various treatment regimes have been used with varying degrees of success, including antifungal drugs and exposure to high temperatures.

Detection of this fungus can currently only be reliably performed by molecular techniques such as PCR (Annis et al., 2004). Repeat PCR testing is recommended for confirmation of a fungus-free environment for amphibians.

Utilities:

• Confirm the disease causing agent
• Shorten the time required to confirm a clinical diagnosis of chytrid fungus infection
• Ensure that amphibian colonies are free of chytrid fungus
• Early prevention of spread of this fungus among the colony
• Environmental monitoring for this fungus
• Minimize human exposure to this fungus
• Safety monitoring of biological products that derive from amphibians

References:
Annis, S.L., Dastoor, F., Ziel, H., Daszak, P., Longcore, J.E. (2004). A DNA-based assay to identify Batrachochytrium dendrobatidis in amphibians. Journal of Wildlife Diseases 40: 420-428.

Specimen requirement: Skin swab, or 0.5 ml water, or fungal culture, or 0.2 ml fresh, frozen or fixed tissue, or environmental surface swab.

For specimen types other than those listed here, please call to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Real time polymerase chain reaction

Normal range: Nondetected