Tiffany Kosch

• PhD
• Research Fellow at University of Melbourne

Southern corroboree frogs (Pseudophryne corroboree) have declined to near extinction in the wild after the emergence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in southeastern Australia in the 1980s. A major captive breeding and reintroduction program is underway to preserve this iconic species, but improving resistance to B. de...

Panzootic chytrid fungus out of Asia Species in the fungal genus Batrachochytrium are responsible for severe declines in the populations of amphibians globally. The sources of these pathogens have been uncertain. O'Hanlon et al. used genomics on a panel of more than 200 isolates to trace the source of the frog pathogen B. dendrobatidis to a hyperdi...

Hundreds of amphibian species have declined worldwide after the emergence of the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd). Despite captive breeding efforts, it is unlikely that wild populations for many species will be reestablished unless Bd resistance increases. We performed a Bd‐challenge study in the functionally extinct so...

The global rate of wildlife extinctions is accelerating, and the persistence of many species requires conservation breeding programs. A central paradigm of these programs is to preserve the genetic diversity of the founder populations. However, this may preserve original characteristics that make them vulnerable to extinction. We introduce targeted...

The demise of amphibians? Rapid spread of disease is a hazard in our interconnected world. The chytrid fungus Batrachochytrium dendrobatidis was identified in amphibian populations about 20 years ago and has caused death and species extinction at a global scale. Scheele et al. found that the fungus has caused declines in amphibian populations every...

Chytridiomycosis poses a significant extinction threat to many amphibians, including the critically endangered southern corroboree frog ( Pseudophryne corroboree ). Captive breeding programs have become essential to maintain populations while effective long-term conservation strategies are developed. Understanding the variation in susceptibility to...

Amphibians represent a diverse group of tetrapods, marked by deep divergence times between their three systematic orders and families. Studying amphibian biology through the genomics lens increases our understanding of the features of this animal class and that of other terrestrial vertebrates. The need for amphibian genomic resources is more urgen...

Amphibians are the most threatened major group of vertebrates worldwide and yet they are lagging behind other taxa in genomic resources that could aid in their conservation management. Here, we provide a status update on genomics technologies, how they have been used in amphibian research, and an outlook on how these approaches could inform future...

Amphibians are the most threatened group of vertebrates and are in dire need of conservation intervention to ensure their continued survival. They exhibit unique features including a high diversity of reproductive strategies, permeable and specialized skin capable of producing toxins and antimicrobial compounds, multiple genetic mechanisms of sex d...

As the most threatened vertebrate class on earth, amphibians are at the forefront of the biodiversity crisis, with the recognition of global amphibian declines and extinctions dating back several decades now. The current Amphibian Conservation Action Plan is adopting two strategies to address the goal of the amelioration of the amphibian crisis: th...

Amphibians represent a diverse group of tetrapods, marked by deep divergence times between their three systematic orders and families. Studying amphibian biology through the genomics lens increases our understanding of the features of this animal class and that of other terrestrial vertebrates. The need for amphibian genomics resources is more urge...

Extensive knowledge gains from research worldwide over the 25 years since the discovery of chytridiomycosis can be used for improved management. Strategies that have saved populations in the short term and/or enabled recovery include captive breeding, translocation into disease refugia, translocation from resistant populations, disease-free exclosu...

The problem of global amphibian declines has prompted extensive research over the last three decades. Initially, the focus was on identifying and characterizing the extent of the problem, but more recently efforts have shifted to evidence-based research designed to identify best solutions and to improve conservation outcomes. Despite extensive accu...

Simple Summary This study explored the major histocompatibility complex (MHC) of a variety of Japanese frog species, to further understand why they may have resistance to the deadly chytrid fungus Batrachochytrium dendrobatidis (Bd), which causes mortality and decline in many other amphibians. MHC supertyping analysis showed that all examined East...

Amphibians are the most threatened group of vertebrates and are in dire need of conservation intervention to ensure their continued survival. They have many unique features including a high diversity of reproductive strategies, permeable and specialized skin capable of producing toxins and antimicrobial compounds, multiple genetic mechanisms of sex...

The Critically Endangered southern corroboree frog Pseudophryne corroboree is dependent upon captive assurance colonies for its continued survival. Although the captive breeding programme for this species has largely been successful, embryonic mortality remains high (40-90% per year). This study aimed to investigate the causes of mortality in P. co...

Mycoviruses may influence the pathogenicity of disease-causing fungi. Although mycoviruses have been found in some chytrid fungi, limited testing has not detected them in Batrachochytrium dendrobatidis (Bd), the cause of the devastating amphibian disease, chytridiomycosis. Here we conducted a survey for mycovirus presence in 38 Bd isolates from Aus...

Lambert et al . question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm th...

Until recently, it was assumed that the pathogenic fungus Batrachochytrium dendrobatidis (Bd) was not widely distributed in warm ecosystems such as lowland tropical rainforests because high environmental temperatures limit its growth. However, several studies have documented Bd infection in lowland rainforest amphibians over the past decade. In add...

This PDF file includes: Materials and Methods - Figs. S1, S3, S4, S6, S7, and S9 to S16 - Tables S2 to S5 - Captions for figs. S2, S5, and S8 - Caption for table S1 - Captions for data S1 to S3 - References

Toll-like receptors (TLRs) are an important component of innate immunity, the first line of pathogen defence. One of the major roles of TLRs includes recognition of pathogen-associated molecular patterns. Amphibians are currently facing population declines and even extinction due to chytridiomycosis caused by the Batrachochytrium dendrobatidis (Bd)...

Supplementary Tables and Figures

Parasitic chytrid fungi have emerged as a signifcant threat to amphibian species worldwide, necessitating the development of techniques to isolate these pathogens into culture for research purposes. However, early methods of isolating chytrids from their hosts relied on killing amphibians. We modifed a pre-existing protocol for isolating chytrids f...

Captive and wild amphibians are under threat of extinction from the deadly fungal pathogen Batrachochytrium dendrobatidis (Bd). The antifungal drug terbinafine (TBF) is used by pet owners to treat Bd-infected frogs; however, it is not widely used in academic or zoological institutions due to limited veterinary clinical trials. To assess TBF's effic...

Southern corroboree frogs (Pseudophryne corroboree) have been driven to functional extinction in the wild after the emergence of the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd) in southeastern Australia in the 1980s. This species is currently maintained in a captive assurance colony and is managed to preserve the genetic diversity...

Parasitic chytrid fungi have emerged as a significant threat to amphibian species worldwide, necessitating the development of techniques to isolate these pathogens into sterile culture for research purposes. However, early methods of isolating chytrids from their hosts relied on killing amphibians. We modified a pre-existing protocol for isolating...

Background: In Japan and East Asia, endemic frogs appear to be tolerant or not susceptible to chytridiomycosis, a deadly amphibian disease caused by the chytrid fungus Batrachochytridium dendrobatidis (Bd). Japanese frogs may have evolved mechanisms of immune resistance to pathogens such as Bd. This study characterizes immune genes expressed in va...

[This corrects the article DOI: 10.1371/journal.pone.0177860.].

Call surveys for Dryophytes suweonensis and Lithobates catesbeianus. For “L. catesbeianus” and “D. suweonensis”, data is binary encoded: 0 = absent and 1 = present. (DOCX)

Bd prevalence for the two Dryophytes species. Sampling sites, sex of frogs and Bd prevalence for this study. (DOCX)

Bullfrogs, Lithobates catesbeianus, have been described as major vectors of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd). Bd is widespread throughout the range of amphibians yet varies considerably within and among populations in prevalence and host impact. In our study, the presence of L. catesbeianus is correlated with a 2.5...

Bd prevalence for the two Dryophytes species. Sampling sites, sex of frogs and Bd prevalence for this study. (DOCX)

Call surveys for Dryophytes suweonensis and Lithobates catesbeianus. For “L. catesbeianus” and “D. suweonensis”, data is binary encoded: 0 = absent and 1 = present. (DOCX)

Pathogen-driven selection can favour major histocompatibility complex (MHC) alleles that confer immunological resistance to specific diseases. However, strong directional selection should deplete genetic variation necessary for robust immune function in the absence of balancing selection or challenges presented by other pathogens. We examined selec...

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Contrasting with birds and mammals, poikilothermic vertebrates often have homomorphic sex chromosomes, possibly resulting from high rates of sex-chromosome turnovers and/or occasional X-Y recombination. Strong support for the latter mechanism was provided by four species of European tree frogs, which inherited from a common ancestor (~ 5 Mya) the s...

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The pathogenic chytrid fungus, Batrachochytrium dendrobatidis (denoted Bd), causes large-scale epizootics in naïve amphibian populations. Intervention strategies to rapidly respond to Bd incursions require sensitive and accurate diagnostic methods. Chytridiomycosis usually is assessed by quantitative polymerase chain reaction (qPCR) amplification o...

Chytridiomycosis is an amphibian disease of global conservation concern that is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). Since the discovery of Bd in 1998, several methods have been used for detection of Bd; among these polymerase chain reaction (PCR) from skin swabs is accepted as the best method due to its noninvasivenes...

Gene structures and subcellular localizations of serine peptidases in Bd. This file contains information about gene identifiers, numbers of exon, and predicted subcellular localizations for serine peptidases that were identified in Bd JAM 81.

LFLAK domain of the CRN protein family in oomycetes and Bd. This file shows that the LFLAX domain of the CRN protein family is largely conserved between oomycetes and Bd.

Data sources for Bd isolates and oomycetes used in the analyses. This file shows data types and download sites for two Bd isolates and seven oomycetes used in the analyses.

Two different conserved N-terminal domains of Bd CRN proteins. This file shows two different types of N-terminal domain for Bd CRN proteins. These domain types are also indicated in Table 1.

Results of selection analyses. This file contains results of positive selection analyses using site-specific and branch-site models, respectively. It also shows amino acid residues that are critical to functional divergence between serine peptidase clades A and B.

The decline in amphibian populations across the world is frequently linked to the infection of the chytrid fungus Batrachochytrium dendrobatidis (Bd). This is particularly perplexing because Bd was only recently discovered in 1999 and no chytrid fungus had previously been identified as a vertebrate pathogen. In this study, we show that two large fa...