Fungicidal effects of chemical disinfectants, UV light, desiccation and heat on the amphibian chytrid Batrachochytrium dendrobatidis

Diseases of Aquatic Organisms

Lara Philips¹  Lee Berger¹  Megan L. Johnson¹  Richard Speare¹ 

关键词: Batrachochytrium dendrobatidis;    Disinfectant;    Ultraviolet light;    Didecyl dimethyl ammonium chloride;    DDAC;    Desiccation;    Sodium hypochlorite;   

DOI  :  10.3354/dao057255

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The efficacy of a number of disinfection treatments was tested on in vitro cultures of the fungus Batrachochytrium dendrobatidis, the causative agent of chytridiomycosis in amphibians. The aim was to evaluate the fungicidal effectsof chemical disinfectants, sterilising ultraviolet (UV) light, heat and desiccation, using methods that were feasible for either disinfection in the field, in amphibian husbandry or in the laboratory. The chemical disinfectants tested were: sodiumchloride, household bleach (active ingredient: sodium hypochlorite), potassium permanganate, formaldehyde solution, Path-X^TM agricultural disinfectant (active ingredient: didecyl dimethyl ammonium chloride, DDAC), quaternary ammoniumcompound 128 (DDAC), Dithane, Virkon, ethanol and benzalkonium chloride. In 2 series of experiments using separate isolates of B. dendrobatidis, the fungicidal effect was evaluated for various time periods and at a range of chemicalconcentrations. The end point measured was death of 100% of zoospores and zoosporangia. Nearly all chemical disinfectants resulted in 100% mortality for at least one of the concentrations tested. However, concentration and time of exposure was criticalfor most chemicals. Exposure to 70% ethanol, 1 mg Virkon ml^-1 or 1 mg benzalkonium chloride ml^-1 resulted in death of all zoosporangia after 20 s. The most effective products for field use were Path-X^TM and the quaternaryammonium compound 128, which can be used at dilutions containing low levels (e.g. 0.012 or 0.008%, respectively) of the active compound didecyl dimethyl ammonium chloride. Bleach, containing the active ingredient sodium hypochlorite, was effective atconcentrations of 1% sodium hypochlorite and above. Cultures did not survive complete drying, which occurred after <3 h at room temperature. B. dendrobatidis was sensitive to heating, and within 4 h at 37°C, 30 min at 47°C and 5 min at 60°C,100% mortality occurred. UV light (at 1000 mW m^-2 with a wavelength of 254 nm) was ineffective at killing B. dendrobatidis in culture.

【 授权许可】

Unknown