Recommendations on diagnostic tools for <italic>Batrachochytrium salamandrivorans</italic>.

Summary: <italic>Batrachochytrium salamandrivorans</italic> (<italic>Bsal</italic>) poses a major threat to amphibian, and more specifically caudata, diversity. <italic>Bsal</italic> is currently spreading through Europe, and mitigation measures aimed at stopping its spread and preventing its introduction into naïve environments are urgently needed. Screening for presence of <italic>Bsal</italic> and diagnosis of <italic>Bsal</italic>‐induced disease in amphibians are essential core components of effective mitigation plans. Therefore, the aim of this study was to present an overview of all <italic>Bsal</italic> diagnostic tools together with their limitations and to suggest guidelines to allow uniform interpretation. Here, we investigate the use of different diagnostic tools in post‐mortem detection of <italic>Bsal</italic> and whether competition between <italic>Bd</italic> and <italic>Bsal</italic> occurs in the species‐specific <italic>Bd</italic> and <italic>Bsal</italic> duplex real‐time PCR. We also investigate the diagnostic sensitivity, diagnostic specificity and reproducibility of the <italic>Bsal</italic> real‐time PCR and show the use of immunohistochemistry in diagnosis of <italic>Bsal</italic>‐induced chytridiomycosis in amphibian samples stored in formaldehyde. Additionally, we have drawn up guidelines for the use and interpretation of the different diagnostic tools for <italic>Bsal</italic> currently available, to facilitate standardization of execution and interpretation. [ABSTRACT FROM AUTHOR]