Last but not least, the reliability of the diagnostic assay was proven on a set of relevant related pathogens and during an acute crayfish-plague outbreak in the small, noble crayfish (Astacus astacus) population inhabiting the lake “”Gleinkersee”" located at an altitude of about 800 meters above sea level at the foothills of the Austrian Alps. In addition to qPCR/MCA typing (not shown), the presence of the pathogen A. astaci was independently confirmed by ITS-sequence analysis and testing see more for constitutive

chitinase activity (A. astaci-strain GKS07 in Additional file 1). Finally, the A. astaci strain GKS07 was isolated on PG-1 agar from an infected noble crayfish. Numerous crayfish individuals were found to be affected but were

still alive during the outbreak of late March 2007. At that time the ice of the lake Gleinkersee was melting and the physiological selleck chemical activities of both pathogen and victim would have been expected to be at a minimum. These circumstances strongly indicated the acuteness of the outbreak. The suspicion of a deliberate introduction of the pathogen could not be confirmed by an inquiry led by the local criminal investigation department. Fish stocking performed in autumn 2006 may be the most likely source of disease transmission. Sensitive quantitative detection of the crayfish-plague pathogen is currently of increasing importance for screening natural non-native crayfish populations or for certifying a pathogen-free Nintedanib (BIBF 1120) status of hatchery fish before introduction into natural habitats or aquaculture facilities. Samples of fish transport water including sediments can be filtered

via membrane filters [59] and subsequently screened by TaqMan qPCR (see Results and Additional file 8). This circumvents pathogen transmission via transport water, fish faeces, mucus and scales. Conclusion The identification of two new chitinase genes showing specific patterns of constitutive temporal expression in the absence of substrate has facilitated the development of a discriminative, robust and reliable method for qualitative and quantitative detection for A. astaci. Methods Biological material Isolates of Oomycetes and related fungi used to validate the molecular assays were either obtained from The Centraalbureau voor Schimmelcultures (CBS) Fungal Biodiversity Centre (Utrecht, The Netherlands), the German Collection of Microorganisms and Cell Cultures (DSMZ) (Braunschweig, Germany), the American Type Culture Collection (ATCC) or cultured from lesioned tissue by standard methods [60, 61]. The A. astaci-types 1 to 4 were purchased from Lage Cerenius (Uppsala University, Uppsala, Sweden). Javier Diéguez-Uribeondo (Real Jardín Botánico CSIC, Madrid, Spain) provided the A. frigidophilus isolate SAP472 [29]. A DNA aliquot of A. frigidophilus NJM 9665 [6, 62] and A. invadans WIC [6] was obtained from Mark W.