Techniques for detecting chytridiomycosis in wild frogs: comparing histology with real-time Taqman PCR

Dis Aquat Organ. 2006 Jul 25;71(2):141-8. doi: 10.3354/dao071141.

Abstract

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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Wild / microbiology
  • Anura / microbiology*
  • Body Size
  • Chytridiomycota / isolation & purification*
  • Cryopreservation / standards
  • Cryopreservation / veterinary
  • Mycoses / diagnosis
  • Mycoses / microbiology
  • Mycoses / veterinary*
  • Polymerase Chain Reaction / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Skin / microbiology
  • Time Factors