INTRODUCTION
Diseases-causing fungi pose a serious threat to wildlife populations,
yet despite the impact they have had on global biodiversity, they are
notably understudied (Ghosh, Fisher, & Bates, 2018). New fungal
pathogens are emerging that are capable of infecting an increasingly
diverse range of taxa and their impacts are being exacerbated by
changing climate conditions and globalisation (Fisher et al., 2012;
Ghosh et al., 2020). Urbanisation can be a key driver of disease
emergence, facilitating transmission due to newly overlapping geographic
expansions (Hassell, Begon, Ward, & Fèvre, 2017), increasing the risk
of disease spillover from wildlife into humans and other animals
(Heesterbeek et al., 2015). Reports of emerging fungal pathogens are
rising (Fisher et al., 2020) and over the past few decades, a group of
Onygenalean fungi from the genera Nannizziopsis ,Paranannizziopsis , and Ophidiomyces have emerged as a
leading cause of severe mycoses in reptiles (Paré & Sigler, 2016).
Fungi from the genus Nannizziopsis are capable of causing disease
in several species of reptiles and have also been known to infect humans
(Nourrisson et al., 2018). Infection in reptiles is contagious and
initially presents as cutaneious disease with characteristic lesions
forming crusts, ulcers and hyperkeratosis, that often progresses to
fatal mycoses (Sigler, Hambleton, & Pare, 2013). Among several species
from this genus identified as reptile pathogens, infection withNannizziopsis barbatae has become increasingly observed in
free-living populations of Australian reptiles with a wide variety of
species being reported with this disease (Peterson et al., 2020). Urban
wildlife populations in particular have become a focal point for
outbreaks and the need for effective detection and monitoring of
pathogen occurrence is considered vital for mitigating the spread and to
minimise any potential for transmission to humans (Ghosh et al., 2018).
Molecular diagnostic tests are powerful tools for disease surveillance
offering a low cost and rapid means to assist in the early detection in
both captive and wild populations (Boyle, Boyle, Olsen, Morgan, &
Hyatt, 2004). Such tools also enable long-term tracking of pathogens
which facilitate the study of often complex host-pathogen interactions,
such as how disease tolerance may effect prevalence and transmission
(Seal, Dharmarajan, & Khan, 2021; Tedersoo, Drenkhan, Anslan,
Morales‐Rodriguez, & Cleary, 2019). Genomic data are valuable resources
for the development of diagnostic tools enabling swift identification of
target regions for designing highly specific markers, and these data can
also serve as a foundation for studies on the molecular basis for
pathogen evolution (DeCandia, Dobson, & VonHoldt, 2018; Ghosh et al.,
2020, 2021). A rapid diagnostic tool to confirm the presence ofN. barbatae in clinical samples is currently unavailable. AsNannizziopsis fungi are typically first isolated on selective
media prior to PCR and sequencing, laboratory diagnosis may involve
delays of up to a week due to the slow growth of these species. The aim
of this study is to develop a molecular diagnostic for the specific
detection of N. barbatae infections and to contribute genomic
resources for further research into this group of emerging fungal
pathogens.