scholarly journals Worldwide recombination in emergent white-nose syndrome pathogen Pseudogymnoascus destructans

2019 ◽  
Author(s):  
Lav Sharma ◽  
Márcia Sousa ◽  
Ana S. Faria ◽  
Margarida Nunes-Pereira ◽  
João A. Cabral ◽  
...  

AbstractPseudogymnoascus destructans (Pd), the emergent fungus causing bat “White-Nose Syndrome”, responsible for ∼6 million mortalities in the United States (US), is thought to expand clonally in North America and Europe. Presence of distinct mating-types in Europe led to numerous research attempts searching for population sexuality worldwide. This study not only presents the first evidence of genetic recombination in Pd but also detects recombination in Pd genotype data generated by previous studies in Europe and North America, through clone-corrected linkage disequilibrium analysis. Portuguese and other European populations are apparently reproducing through sex between two mating-types. Seeming parasexual recombination in the invasive single mating-type US population rings alarms for the North American bat populations and deserves urgent attention. This study emphasizes on clone-correction in linkage disequilibrium analysis.One Sentence SummaryClone-correction yielded signs of elusive recombination in the global “clonal” populations of white-nose syndrome pathogen.

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Kevin P. Drees ◽  
Jeffrey M. Lorch ◽  
Sebastien J. Puechmaille ◽  
Katy L. Parise ◽  
Gudrun Wibbelt ◽  
...  

ABSTRACT Globalization has facilitated the worldwide movement and introduction of pathogens, but epizoological reconstructions of these invasions are often hindered by limited sampling and insufficient genetic resolution among isolates. Pseudogymnoascus destructans , a fungal pathogen causing the epizootic of white-nose syndrome in North American bats, has exhibited few genetic polymorphisms in previous studies, presenting challenges for both epizoological tracking of the spread of this fungus and for determining its evolutionary history. We used single nucleotide polymorphisms (SNPs) from whole-genome sequencing and microsatellites to construct high-resolution phylogenies of P. destructans . Shallow genetic diversity and the lack of geographic structuring among North American isolates support a recent introduction followed by expansion via clonal reproduction across the epizootic zone. Moreover, the genetic relationships of isolates within North America suggest widespread mixing and long-distance movement of the fungus. Genetic diversity among isolates of P. destructans from Europe was substantially higher than in those from North America. However, genetic distance between the North American isolates and any given European isolate was similar to the distance between the individual European isolates. In contrast, the isolates we examined from Asia were highly divergent from both European and North American isolates. Although the definitive source for introduction of the North American population has not been conclusively identified, our data support the origin of the North American invasion by P. destructans from Europe rather than Asia. IMPORTANCE This phylogenetic study of the bat white-nose syndrome agent, P. destructans , uses genomics to elucidate evolutionary relationships among populations of the fungal pathogen to understand the epizoology of this biological invasion. We analyze hypervariable and abundant genetic characters (microsatellites and genomic SNPs, respectively) to reveal previously uncharacterized diversity among populations of the pathogen from North America and Eurasia. We present new evidence supporting recent introduction of the fungus to North America from a diverse Eurasian population, with limited increase in genetic variation in North America since that introduction.


mSphere ◽  
2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Jigar Trivedi ◽  
Josianne Lachapelle ◽  
Karen J. Vanderwolf ◽  
Vikram Misra ◽  
Craig K. R. Willis ◽  
...  

ABSTRACT Emerging fungal diseases of wildlife are on the rise worldwide, and the white-nose syndrome (WNS) epidemic in North American bats is a catastrophic example. The causal agent of WNS is a single clone of the fungus Pseudogymnoascus destructans. Early evolutionary change in this clonal population has major implications for disease ecology and conservation. Accumulation of variation in the fungus through mutation, and shuffling of variation through recombination, could affect the virulence and transmissibility of the fungus and the durability of what appears to be resistance arising in some bat populations. Our genome-wide analysis shows that the clonal population of P. destructans has expanded in size from a single genotype, has begun to accumulate variation through mutation, and presents no evidence as yet of genetic exchange among individuals. IMPORTANCE Since its discovery in 2006, the emerging infectious disease known as white-nose syndrome has killed millions of bats in North America, making it one of the most devastating wildlife epidemics in recorded history. We demonstrate that there has been as yet only spontaneous mutation across the North American population of P. destructans, and we find no indication of recombination. Thus, selective forces, which might otherwise impact pathogenic virulence, have so far had essentially no genetic variation on which to act. Our study confirmed the time of origin for the first and, thus far, only introduction of P. destructans to North America. This system provides an unprecedented opportunity to follow the evolution of a host-pathogen interaction unfolding in real time.


2016 ◽  
Author(s):  
Ping Ren ◽  
Sunanda S. Rajkumar ◽  
Haixin Sui ◽  
Paul S. Masters ◽  
Natalia Martinkova ◽  
...  

ABSTRACTBat White-nose Syndrome (WNS) fungus Pseudogymnoascus destructans had caused mass mortality in the North American bats. A single clone of the pathogen (Hap_1) was likely introduced in the United States while Eurasian population comprised of several haplotypes. The origin and spread of P. destructans remain enigmatic due in part to a lack of precise population markers. We searched for P. destructans mycoviruses as they are highly host-specific, and their spread could provide a window on the origin of the host fungus. We discovered a P. destructans bipartite virus PdPV-1 with two double-stranded RNA (dsRNA) segments - LS (1,683 bp) and SS (1,524 bp) with motifs similar to viral RNA-dependent RNA polymerase (RdRp) and putative capsid proteins (CPs), respectively. Both LS and SS ORFs were embedded only in the positive strand of each dsRNA segment. Sequence alignments and phylogenetic analysis suggested that both segments constitute the genome of a new virus similar to the mycoviruses in the family Partitiviridae genus Gammapartitivirus. Purified viral particles appeared as isometric virions with approximately 33 nm diameters typical of partitiviruses. A newly developed RT-PCR assay revealed that all US isolates and only a few Eurasian isolates were infected with PdPV-1. PdPV-1 was P. destructans - specific as closely related non-pathogenic fungi P. appendiculatus and P. roseus tested negative. Thus, PdPV-1 establishes a link between the Eurasian and North American P. destructans. PdPV-1 could be used as an experimental tool to further investigate fungal biogeography, and the host - pathogen interactions.


2021 ◽  
Vol 7 (3) ◽  
pp. 182
Author(s):  
Adrian Forsythe ◽  
Karen J. Vanderwolf ◽  
Jianping Xu

White-Nose Syndrome is an ongoing fungal epizootic caused by epidermal infections of the fungus, Pseudogymnoascus destructans (P. destructans), affecting hibernating bat species in North America. Emerging early in 2006 in New York State, infections of P. destructans have spread to 38 US States and seven Canadian Provinces. Since then, clonal isolates of P. destructans have accumulated genotypic and phenotypic variations in North America. Using microsatellite and single nucleotide polymorphism markers, we investigated the population structure and genetic relationships among P. destructans isolates from diverse regions in North America to understand its pattern of spread, and to test hypotheses about factors that contribute to transmission. We found limited support for genetic isolation of P. destructans populations by geographic distance, and instead identified evidence for gene flow among geographic regions. Interestingly, allelic association tests revealed evidence for recombination in the North American P. destructans population. Our landscape genetic analyses revealed that the population structure of P. destructans in North America was significantly influenced by anthropogenic impacts on the landscape. Our results have important implications for understanding the mechanism(s) of P. destructans spread.


2018 ◽  
Vol 84 (16) ◽  
Author(s):  
Adrian Forsythe ◽  
Victoria Giglio ◽  
Jonathan Asa ◽  
Jianping Xu

ABSTRACTWhite-nose syndrome (WNS) is an ongoing epizootic affecting multiple species of North American bats, caused by epidermal infections of the psychrophilic filamentous fungusPseudogymnoascus destructans. Since its introduction from Europe, WNS has spread rapidly across eastern North America and resulted in high mortality rates in bats. At present, the mechanisms behind its spread and the extent of its adaptation to different geographic and ecological niches remain unknown. The objective of this study was to examine the geographic patterns of phenotypic variation and the potential evidence for adaptation among strains representing broad geographic locations in eastern North America. The morphological features of these strains were evaluated on artificial medium, and the viability of asexual arthroconidia of representative strains was investigated after storage at high (23°C), moderate (14°C), and low (4°C) temperatures at different lengths of time. Our analyses identified evidence for a geographic pattern of colony morphology changes among the clonal descendants of the fungus, with trait values correlated with increased distance from the epicenter of WNS. Our genomic comparisons of three representative isolates revealed novel genetic polymorphisms and suggested potential candidate mutations that might be related to some of the phenotypic changes. These results show that even though this pathogen arrived in North America only recently and reproduces asexually, there has been substantial evolution and phenotypic diversification during its rapid clonal expansion.IMPORTANCEThe causal agent of white-nose syndrome in bats isPseudogymnoascus destructans, a filamentous fungus recently introduced from its native range in Europe. Infections caused byP. destructanshave progressed across the eastern parts of Canada and the United States over the last 10 years. It is not clear how the disease is spread, as the pathogen is unable to grow above 23°C and ambient temperature can act as a barrier when hosts disperse. Here, we explore the patterns of phenotypic diversity and the germination of the fungal asexual spores, arthroconidia, from strains across a sizeable area of the epizootic range. Our analyses revealed evidence of adaptation along geographic gradients during its expansion. The results have implications for understanding the diversification ofP. destructansand the limits of WNS spread in North America. Given the rapidly expanding distribution of WNS, a detailed understanding of the genetic bases for phenotypic variations in growth, reproduction, and dispersal ofP. destructansis urgently needed to help control this disease.


2021 ◽  
Author(s):  
Andrew M. Kramer ◽  
Alex Mercier ◽  
Sean Maher ◽  
Yaw Kumi-Ansu ◽  
Sarah Bowden ◽  
...  

AbstractWhite-nose syndrome has caused massive mortality in multiple bat species and spread across much of North America, making it one of the most destructive wildlife diseases on record. This has also resulted in it being one of the most well-documented wildlife disease outbreaks, making it possible to look for changes in the pattern of spatial spread over time. We fit a series of spatial interaction models to the United States county-level observations of the pathogenic fungus, Pseudogymnoascus destructans, that causes white-nose syndrome. Models included the distance between caves, cave abundance, measures of winter length and winter onset, and species richness of all bats and hibernating bats only. We found that the best supported models included all of these factors, but that the particular structure and most informative covariates changed over the course of the outbreak, with winter length displacing winter onset as the most informative measure of winter conditions, and evidence for the effects total species richness and hibernation varying from year to year. We also found that weather had detectable effects on spread. While the effect sizes for cave abundance and species richness were relatively stable over the length of the outbreak, distance became less important as time went on. These findings indicate that although models produced early in the outbreak captured important and consistent aspects of the spatial spread of white-nose syndrome, there were also changes over time in the factors associated with spread, suggesting that forecasts may be improved by iterative model refinement.


Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1278
Author(s):  
Michael Glenn O’Connor ◽  
Amjad Horani ◽  
Adam J. Shapiro

Primary Ciliary Dyskinesia (PCD) is a rare, under-recognized disease that affects respiratory ciliary function, resulting in chronic oto-sino-pulmonary disease. The PCD clinical phenotype overlaps with other common respiratory conditions and no single diagnostic test detects all forms of PCD. In 2018, PCD experts collaborated with the American Thoracic Society (ATS) to create a clinical diagnostic guideline for patients across North America, specifically considering the local resources and limitations for PCD diagnosis in the United States and Canada. Nasal nitric oxide (nNO) testing is recommended for first-line testing in patients ≥5 years old with a compatible clinical phenotype; however, all low nNO values require confirmation with genetic testing or ciliary electron micrograph (EM) analysis. Furthermore, these guidelines recognize that not all North American patients have access to nNO testing and isolated genetic testing is appropriate in cases with strong clinical PCD phenotypes. For unresolved diagnostic cases, referral to a PCD Foundation accredited center is recommended. The purpose of this narrative review is to provide insight on the North American PCD diagnostic process, to enhance the understanding of and adherence to current guidelines, and to promote collaboration with diagnostic pathways used outside of North America.


2016 ◽  
Vol 9 (1) ◽  
pp. 60-70 ◽  
Author(s):  
David R. Clements ◽  
Todd Larsen ◽  
Jennifer Grenz

AbstractInvasive species with distributions that encompass much of the North American environment often demand a range of management approaches, for several key reasons. Firstly, the North American environment includes a large number of highly variable habitats in terms of climatic, edaphic, and landscape features. Secondly, these regional habitat differences are accentuated by jurisdictions within Canada and the United States, whereby approaches and available resources differ at local, regional, and national scales. Another important consideration is whether an invasive species or complex also possesses genetic variation. All three of these factors render the knotweed complex in North America a highly variable target for management. In this paper we review existing knowledge of the variable nature of knotweed species (Fallopia japonica (Houtt.) Ronse Decr., Fallopia sachalinensis (F. Schmidt ex Maxim) Ronse Decr., and Fallopia × bohemica, (Chrtek and Chrtková) J. P. Bailey in North America, and evaluate how herbicidal, mechanical and biological control measures must account for this genetic variation, as well as accounting for regional differences and the potential northward expansion of knotweed under climate change. The imminent release of the psyllid, Aphalara itadori Shinji as a biological control agent in North America must also navigate regional and genetic differences. Prior European experience dealing with the three knotweed species should prove useful, but additional research is needed to meet the emerging challenge posed by F. × bohemica in North America, including the possibility of glyphosate resistance. Managers also face challenges associated with posttreatment restoration measures. Furthermore, disparities in resources available to address knotweed management across the continent need to be addressed to contain the rapid spread of this highly persistent and adaptable species. Linking practitioners dealing with knotweed “on the ground” with academic research is a crucial step in the process of marshalling all available resources to reduce the rapidly spreading populations of knotweed.


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