Experimental Infection and Repeat Survey Data Indicate the Amphibian Chytrid Batrachochytrium dendrobatidis May Not Occur on Freshwater Crustaceans in Northern Queensland, Australia
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Chytridiomycosis is a fatal disease of amphibians, caused by the amphibian chytrid Batrachochytrium dendrobatidis. The disease is unusual in that it may drive many amphibian species to local extinction during outbreaks. These dramatic declines in host population numbers could be facilitated if the pathogen can grow as a saprobe or on alternative hosts, a feature common to other chytrid species. This is also supported by in vitro work that demonstrates B. dendrobatidis can grow and reproduce in the absence of amphibian cells. In a previous study, B. dendrobatidis was detected on freshwater shrimp from rain forest streams in northern Queensland, Australia, using diagnostic PCR. We set out to confirm and further investigate the presence of B. dendrobatidis on crustaceans by carrying out more extensive sampling of shrimp in the field, experimental B. dendrobatidis infection trials using shrimp and crayfish, and PCR verification of the presence of B. dendrobatidis from shrimp samples that previously tested positive. We could not confirm the presence of B. dendrobatidis on shrimp, and report that original positive tests in shrimp reported by Rowley et al. (2006) were likely false. Thus, we suggest that shrimp may not be an important reservoir host for B. dendrobatidis.
KeywordsBatrachochytrium dendrobatidis amphibian declines chytridiomycosis alternative host freshwater shrimp crayfish
This research was supported by funding from the Australian Geographic Society; the Society for the Study of Amphibian and Reptiles; the Peter Rankin Trust Fund for Herpetology; the Australian Government Department of Environment and Heritage; the US National Science Foundation Integrated Research Challenges in Environmental Biology grant DEB-0213851; and the US National Science Foundation and Australian Academy of Science’s East Asia Summer Pacific Institute, and was carried out under a Scientific Purposes Permit issued by the Queensland Parks and Wildlife Service (WISP01715204), as approved by the James Cook University Animal Care and Ethics Committee (A863). J.J.L.R. was supported by an Australian Postgraduate Research Scholarship. Kathy La Fauce and Leigh Owens provided the crayfish and technical support for the experimental infections. Numerous volunteers assisted in the field.
- Annis SL, Dastoor FD, Ziel H, Daszak P, Longcore J (2004) A DNA-based assay identifies Batrachochytrium dendrobatidis in amphibians. Journal of Wildlife Diseases 40:420–428Google Scholar
- Berger L, Marantelli G, Skerratt LF, Speare R (2005) Virulence of the amphibian chytrid fungus Batrachochytrium dendrobatidis varies with the strain. Diseases of Aquatic Organisms 68:47–50Google Scholar
- Berger L, Speare R, Daszak P, Green DE, Cunningham AA, Goggin CL, et al. (1998) Chytridiomycosis causes amphibian mortality associated with population declines in the rainforests of Australia and Central America. Proceedings of the National Academy of Sciences of the United States of America 95:9031–9036CrossRefGoogle Scholar
- Boyle DG, Boyle DB, Olsen V, Morgan JAT, Hyatt AD (2004) Rapid quantitative detection of chytridiomycosis (Batrachochytrium dendrobatidis) in amphibian samples using real-time Taqman PCR assay. Diseases of Aquatic Organisms 60:141–148Google Scholar
- Johnson ML, Speare R (2003) Survival of Batrachochytrium dendrobatidis in water: quarantine and disease control implications. Emerging Infectious Diseases 9:922–925Google Scholar
- Johnson ML, Speare R (2005) Possible modes of dissemination of the amphibian chytrid Batrachochytrium dendrobatidis in the environment. Diseases of Aquatic Organisms 65:181–186Google Scholar
- Kriger KM, Hero J-M, Ashton KJ (2006) Cost efficiency in the detection of chytridiomycosis using PCR assay. Diseases of Aquatic Organisms 71:149–154Google Scholar
- Nichols DK, Lamirande EW, Pessier AP, Longcore JE (2001) Experimental transmission of cutaneous chytridiomycosis in dendrobatid frogs. Journal of Wildlife Diseases 37:1–11Google Scholar
- White TJ, Bruns T, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (editors), PCR Protocols: A Guide to Methods and Applications, San Diego, CA: Academic Press, pp 315–322Google Scholar