Techniques for detecting chytridiomycosis in wild frogs: comparing histology with real-time Taqman PCR.
Chytridiomycosis is a lethal disease of amphibians associated with mass mortalities and population declines worldwide. An accurate, non-invasive technique for detecting chytridiomycosis is urgently needed to determine the current geographical distribution of the disease, and its prevalence in wild amphibian populations. Herein we evaluate a recently devised, rapid, non-invasive, swab-PCR assay. We sampled 101 wild juvenile Mixophyes iteratus by both a skin swab for use in PCR analysis, and a toe-clip for examination by histological methods. The swab-PCR assay detected chytridiomycosis infection in a minimum of 14.9% of frogs, whereas histology detected infection in no more than 6.9% of frogs. We conclude that the swab-PCR technique is the more reliable means of detecting chytridiomycosis in wild amphibians, and that it precludes the need for toe-clipping as a means of sampling for the presence of the disease in future surveys. Further, we document a significant negative relationship between a juvenile frog's snout-vent length and its likelihood of being infected with the disease.
Kriger
Kerry M
KM
Griffith University, School of Environmental and Applied Sciences, Queensland, Australia. kerry@savethefrogs.com
Hines
Harry B
HB
Hyatt
Alex D
AD
Boyle
Donna G
DG
Hero
Jean-Marc
JM
D000818:Animals; D000835:Animals, Wild / Q000382:microbiology; D001001:Anura / Q000382:microbiology*; D049628:Body Size; D008411:Chytridiomycota / Q000302:isolation & purification*; D015925:Cryopreservation / Q000592:standards / Q000662:veterinary; D009181:Mycoses / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000382:microbiology; D013997:Time Factors