Efficacy of chemical disinfectants for the containment of the salamander chytrid fungus <i>Batrachochytrium salamandrivorans</i>

<div><p>The recently emerged chytrid fungus <i>Batrachochytrium salamandrivorans</i> (<i>Bsal</i>) causes European salamander declines. Proper hygiene protocols including disinfection procedures are crucial to prevent disease transmission. Here, the efficacy of chemical disinfectants in killing <i>Bsal</i> was evaluated. At all tested conditions, Biocidal^®, Chloramine-T^®, Dettol medical^®, Disolol^®, ethanol, F10^®, Hibiscrub^®, potassium permanganate, Safe4^®, sodium hypochlorite, and Virkon S^®, were effective at killing <i>Bsal</i>. Concentrations of 5% sodium chloride or lower, 0.01% peracetic acid and 0.001–1% copper sulphate were inactive against <i>Bsal</i>. None of the conditions tested for hydrogen peroxide affected <i>Bsal</i> viability, while it did kill <i>Batrachochytrium dendrobatidis</i> (<i>Bd</i>). For <i>Bsal</i>, enzymatic breakdown of hydrogen peroxide by catalases and specific morphological features (clustering of sporangia, development of new sporangia within the original sporangium), were identified as fungal factors altering susceptibility to several of the disinfectants tested. Based on the <i>in vitro</i> results we recommend 1% Virkon S^®, 4% sodium hypochlorite and 70% ethanol for disinfecting equipment in the field, lab or captive setting, with a minimal contact time of 5 minutes for 1% Virkon S^® and 1 minute for the latter disinfectants. These conditions not only efficiently target <i>Bsal</i>, but also <i>Bd</i> and <i>Ranavirus</i>.</p>