Emerging fungal diseases: understanding their emergence to combat the threat

• Applicant: Professor Dr. Gerald Kerth, since 1/2019
• Subject Area: Evolution, Anthropology ; Evolution and Systematics of Plants and Fungi
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 396686709

• Final Report Year: 2023

Final Report Abstract

Emerging infectious diseases are a severe conservation threat for a variety of plants and animals. Among them, an unprecedented number of fungal diseases have recently caused some of the most severe die-offs and extinctions ever witnessed in wild species. They pose difficult challenges to conservation because of their typically rapid and unexpected onset combined with high mortality rates. This increase in dangerousness of fungi seems related to human activities and particularly the transport of different species of fungi to places they had never been before, leading to major disease outbreaks in naive hosts. These introductions followed by disease emergence offer great opportunities to concomitantly answer fundamental questions in evolutionary biology and provide critical information to inform and thus drive the management of these diseases. We propose here to use the White-Nose Disease as a case study. In North America, several species of bats are being threatened by the disease that has caused unprecedented mass mortality of >6 million hibernating bats since 2006. The fungus Pseudogymnoascus destructans (Pd), the causative agent of the disease, has only recently been confirmed to be an introduced species from Europe where the species is native and does not cause mass mortality in bats. Combining a large genetic/genomic dataset of isolates collected across the species’ native range in Europe and state-of-the-art analyses, we aim to better understand population structure and evolutionary processes occurring in the native range of the pathogen and during the recent invasion of North America. We characterised the population structure at different scales and identified large scale differentiation (across continents/countries) that contrast with locally (within sites) homogeneous populations. Hence human-mediated movements of the fungus, even within the same continent, should be avoided. Besides, we identified the source population in Europe and pinpoint key genomic traits that differentiate it from the introduced North-American population. We also investigated the relationship between the disease occurrence and climatic factors (including temperature) and how climate changes will affect the species distribution and revealed drastic shifts that will inevitably be associated with movement of the pathogen, most likely leading to exacerbated contact between fungal populations that are strongly differentiated. By illuminating population structure and evolutionary processes occurring in the native range, our work brings important information to predict how the fungus will react to future conditions and what are the associated risks in terms of new disease emergence.

Publications

• Mating type determination within a microsatellite multiplex for the fungal pathogen Pseudogymnoascus destructans, the causative agent of white-nose disease in bats. Conservation Genetics Resources, 12(1), 45-48.
  Dool, Serena; Altewischer, Andrea; Fischer, Nicola M.; Drees, Kevin P.; Foster, Jeffrey T.; Fritze, Marcus & Puechmaille, Sebastien J.
  
• Screening and Biosecurity for White-Nose Fungus Pseudogymnoascus destructans (Ascomycota: Pseudeurotiaceae) in Hawai‘i1. Pacific Science, 73(3), 357.
  Zhelyazkova, Violeta L.; Toshkova, Nia L.; Dool, Serena E.; Bonaccorso, Frank J.; Pinzari, Corinna A.; Montoya-Aiona, Kristina & Puechmaille, Sebastien J.
  
• Did you wash your caving suit? Cavers’ role in the potential spread of Pseudogymnoascus destructans, the causative agent of White-Nose Disease. International Journal of Speleology, 49(2), 149-159.
  Zhelyazkova, Violeta; Hubancheva, Antonia; Radoslavov, Georgi; Toshkova, Nia & Puechmaille, Sebastien
  
• Seasonal patterns of Pseudogymnoascus destructans germination indicate host–pathogen coevolution. Biology Letters, 16(6), 20200177.
  Fischer, Nicola M.; Dool, Serena E. & Puechmaille, Sebastien J.
  
• A Rapid, in-Situ Minimally-Invasive Technique to Assess Infections with Pseudogymnoascus destructans in Bats. Acta Chiropterologica, 23(1).
  Fritze, Marcus; Puechmaille, Sébastien J.; Fickel, Jörns; Czirják, Gábor Á. & Voigt, Christian C.
  
• Determinants of defence strategies of a hibernating European bat species towards the fungal pathogen Pseudogymnoascus destructans. Developmental & Comparative Immunology, 119, 104017.
  Fritze, Marcus; Puechmaille, Sebastien J.; Costantini, David; Fickel, Jörns; Voigt, Christian C. & Czirják, Gábor Á.
  
• Heterothermy and antifungal responses in bats. Current Opinion in Microbiology, 62, 61-67.
  Whiting-Fawcett, Flora; Field, Kenneth A.; Puechmaille, Sébastien J.; Blomberg, Anna S. & Lilley, Thomas M.
  
• Population genetics as a tool to elucidate pathogen reservoirs: Lessons fromPseudogymnoascus destructans, the causative agent of White‐Nose disease in bats. Molecular Ecology, 31(2), 675-690.
  Fischer, Nicola M.; Altewischer, Andrea; Ranpal, Surendra; Dool, Serena; Kerth, Gerald & Puechmaille, Sebastien J.
  
• Development and Application of Loop-Mediated Isothermal Amplification (LAMP) Assays for Rapid Diagnosis of the Bat White-Nose Disease Fungus Pseudogymnoascus destructans. Mycopathologia, 187(5-6), 547-565.
  Niessen, Ludwig; Fritze, Marcus; Wibbelt, Gudrun & Puechmaille, Sebastien J.
  
• Climatic factors and host species composition at hibernation sites drive the incidence of bat fungal disease. Cold Spring Harbor Laboratory.
  Blomberg, AS; Lilley, TM; Fritze, M. & Puechmaille, SJ