Unit for Environmental Sciences and Management, North-West University, South Africa
One of the most important drivers of amphibian declines and extinction is the infectious disease chytridiomycosis, which is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd).1,3 In vitro Bd is susceptible to a range of disinfectants, but not all have been tested in animals. Some disinfectants have been proven effective, but have harmful side effects to animals or the surrounding environment.2,4 This study tested the efficacy of F10SC Veterinary Disinfectant to treat Bd in experimentally infected guttural toads (Sclerophrys gutturalis), Power’s toad (S. poweri) and the Phofung river frog (Amietia hymenopus). The minimum inhibitory concentration for F10SC in vitro Bd ranged between 1:7000 for 5 min contact time and 1:10000 for 10 min contact time. Based on the survival data of test animals, the no-observed-effect concentration for 15-min contact time was estimated to be 1:2000 dilution for juveniles, and 1:10000 for tadpoles. In S. gutturalis juveniles, an 86% infection clearance rate was achieved after five 15-min doses of 1:3000 dilution. A 100% clearance was achieved in A. hymenopus tadpoles after seven 15-min doses of 1:10000 dilution, and after nine doses of the same treatment in S. poweri tadpoles. F10SC shows great promise as a treatment protocol for chytridiomycosis which is nontoxic to tadpoles and post-metamorphic individuals, and is effective against Bd during short contact times, but further testing on different species of amphibians is advised.
This work was supported by the National Research Foundation [grant number IFR2011033000079].
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