Abstract
AbstractChytridiomycosis, a disease in amphibians caused by Batrachochytrium dendrobatidis (Bd), has led to a population decline and extinction of frog species since 1996. The objective of this study was to determine the prevalence of and the need for establishing a surveillance system for monitoring chytridiomycosis in five national zoos and five free ranging protected areas across Thailand. A total of 492 skin swab samples were collected from live and dead animals and tested by polymerase chain reaction (PCR) for the presence of Bd. The positive specimens were confi rmed by amplicon sequencing and examined by histopathology and immunohistochemistry. From July 2009 to August 2012, the prevalence of Bd from frog skin samples was low (4.27%), monitored by PCR. All samples from live amphibians were negative. The positive cases were only from dead specimens (21/168, 12.5% dead samples) of two non-native captive species, poison dart frog (Dendrobates tinctorius) and tomato frog (Dyscophus antongilii) in one zoo. Immunohistochemistry and histopathology revealed the typical feature of fl ask-shaped zoosporangia and septate thalli, supporting the PCR-based evidence of chytridiomycosis in captive amphibians in Thailand, but detected Bd in only 7/21 of the PCR-positive samples. Although the introduction of a pathogenic strain of Bd from imported carriers might have a serious impact on the native amphibian populations in Thailand, chytridiomycosis has not currently been detected in native Thai amphibians. An active surveillance system is needed for close monitoring of the fungus crossing into Thai amphibian populations
Highlights
Chytridiomycosis is an emerging fungal disease in amphibians caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd) [1,2,3]
With respect to the Year of the Frog 2008, designated by the association of zoos and aquariums and several other environmental organizations, a working group that consisted of veterinarians and herpetologists was established in Thailand in order to systematically survey and monitor the presence of deadly fungal diseases in both captive and wild amphibians
The study confirmed the presence of chytridiomycosis in two introduced frog species in one zoo in Thailand, but not in any samples of native amphibians, either in zoo captivity or in free-ranging areas
Summary
Chytridiomycosis is an emerging fungal disease in amphibians caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd) [1,2,3]. Bd has been detected in almost 700 different amphibian species on every continent where amphibian exist [3,15,16]. Japanese giant salamander (Andrias japonicus) preserved in the museum since 1902 [17]. In the skin of an African clawed frog (Xenopus laevis) collected in 1938 and kept in the museum [18]. The hypothesis that chytridiomycosis is spreading worldwide through the amphibian trade for scientific research has received a great deal of attention, and the widely distributed American bullfrog (Lithobates catesbeiana) has been proposed as a potential major reservoir of Bd [19,20]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
