Mycobiome of the bat white nose syndrome affected caves and mines reveals diversity of fungi and local adaptation by the fungal pathogen Pseudogymnoascus (Geomyces) destructans

The Mycobiome of Bats in the American Southwest Is Structured by Geography, Bat Species, and Behavior

Bats are widespread mammals that play key roles in ecosystems as pollinators and insectivores. However, there is a paucity of information about bat-associated microbes, in particular their fungal communities, despite the important role microbes play in host health and overall host function. The emerging fungal disease, white-nose syndrome, presents a potential challenge to the bat microbiome and understanding healthy bat-associated taxa will provide valuable information about potential microbiome-pathogen interactions. To address this knowledge gap, we collected 174 bat fur/skin swabs from 14 species of bats captured in five locations in New Mexico and Arizona and used high-throughput sequencing of the fungal internal transcribed (ITS) region to characterize bat-associated fungal communities. Our results revealed a highly heterogeneous bat mycobiome that was structured by geography and bat species. Furthermore, our data suggest that bat-associated fungal communities are affected by bat foraging, indicating the bat skin microbiota is dynamic on short time scales. Finally, despite the strong effects of site and species, we found widespread and abundant taxa from several taxonomic groups including the genera Alternaria and Metschnikowia that have the potential to be inhibitory towards fungal and bacterial pathogens.

Characterizing the blood microbiota of omnivorous and frugivorous bats (Chiroptera: Phyllostomidae) in Casanare, eastern Colombia

Bats are known reservoirs of seemingly-innocuous pathogenic microorganisms (including viruses, bacteria, fungi, and protozoa), which are associated with triggering disease in other zoonotic groups. The taxonomic diversity of the bats' microbiome is likely associated with species-specific phenotypic, metabolic, and immunogenic capacities. To date, few studies have described the diversity of bat blood microbial communities. Then, this study used amplicon-based next generation sequencing of the V4 hypervariable region of the 16S-rRNA gene in blood samples from omnivorous (n = 16) and frugivorous (n = 9) bats from the department of Casanare in eastern Colombia. We found the blood microbiota in bats to be composed of, among others, Bartonella and Mycoplasma bacterial genera which are associated with various disease phenotypes in other mammals. Furthermore, our results suggest that the bats' dietary habits might determine the composition and the persistence of some pathogens over others in their bloodstream. This study is among the first to describe the blood microbiota in bats, to reflect on co-infection rates of multiple pathogens in the same individual, and to consider the influence of diet as a factor affecting the animal's endogenous microbial community.

Higher white-nose syndrome fungal isolate yields from UV-guided wing biopsies compared with skin swabs and optimal culture media

BACKGROUND

North American bat populations have suffered severe declines over the last decade due to the Pseudogymnoascus destructans fungus infection. The skin disease associated with this causative agent, known as white-nose syndrome (WNS), is specific to bats hibernating in temperate regions. As cultured fungal isolates are required for epidemiological and phylogeographical studies, the purpose of the present work was to compare the efficacy and reliability of different culture approaches based on either skin swabs or wing membrane tissue biopsies for obtaining viable fungal isolates of P. destructans.

RESULTS

In total, we collected and analysed 69 fungal and 65 bacterial skin swabs and 51 wing membrane tissue biopsies from three bat species in the Czech Republic, Poland and the Republic of Armenia. From these, we obtained 12 viable P. destructans culture isolates.

CONCLUSIONS

Our results indicated that the efficacy of cultures based on wing membrane biopsies were significantly higher. Cultivable samples tended to be based on collections from bats with lower body surface temperature and higher counts of UV-visualised lesions. While cultures based on both skin swabs and wing membrane tissue biopsies can be utilised for monitoring and surveillance of P. destructans in bat populations, wing membrane biopsies guided by UV light for skin lesions proved higher efficacy. Interactions between bacteria on the host's skin also appear to play an important role.

Development and Application of Loop-Mediated Isothermal Amplification (LAMP) Assays for Rapid Diagnosis of the Bat White-Nose Disease Fungus Pseudogymnoascus destructans

Pseudogymnoascus destructans (= Geomyces destructans) is a psychrophilic filamentous fungus that causes White-Nose Disease (WND; the disease associated with White-Nose Syndrome, WNS) in hibernating bats. The disease has caused considerable reductions in bat populations in the USA and Canada since 2006. Identification and detection of the pathogen in pure cultures and environmental samples is routinely based on qPCR or PCR after DNA isolation and purification. Rapid and specific direct detection of the fungus in the field would strongly improve prompt surveillance, and support control measures. Based on the genes coding for ATP citrate lyase1 (acl1) and the 28S-18S ribosomal RNA intergenic spacer (IGS) in P. destructans, two independent LAMP assays were developed for the rapid and sensitive diagnosis of the fungus. Both assays could discriminate P. destructans from 159 tested species of filamentous fungi and yeasts. Sensitivity of the assays was 2.1 picogram per reaction (pg/rxn) and 21 femtogram per reaction (fg/rxn) for the acl1 and IGS based assays, respectively. Moreover, both assays also work with spores and mycelia of P. destructans that are directly added to the master mix without prior DNA extraction. For field-diagnostics, we developed and tested a field-applicable version of the IGS-based LAMP assay. Lastly, we also developed a protocol for preparation of fungal spores and mycelia from swabs and tape liftings of contaminated surfaces or infected bats. This protocol in combination with the highly sensitive IGS-based LAMP-assay enabled sensitive detection of P. destructans from various sources.

Phylogenetic and ecological reevaluation of the order Onygenales

The order Onygenales is classified in the class Eurotiomycetes of the subphylum Pezizomycotina. Families in this order have classically been isolated from soil and dung, and two lineages contain causative agents of superficial, cutaneous and systemic infections in mammals. The ecology and habitat choices of the species are driven mainly by the keratin and cellulose degradation abilities. The present study aimed to investigate whether the ecological trends of the members of Onygenales can be interpreted in an evolutionary sense, linking phylogenetic parameters with habitat preferences, to achieve polyphasic definitions of the main taxonomic groups. Evolutionary processes were estimated by multiple gene genealogies and divergence time analysis. Previously described families, namely, Arthrodermataceae, Ajellomycetaceae, Ascosphaeraceae, Eremascaceae, Gymnoascaceae, Onygenaceae and Spiromastigoidaceae, were accepted in Onygenales, and two new families, Malbrancheaceae and Neogymnomycetaceae, were introduced. A number of species could not be assigned to any of the defined families. Our study provides a revised overview of the main lines of taxonomy of Onygenales, supported by multilocus analyses of ITS, LSU, TUB, TEF1, TEF3, RPB1, RPB2, and ribosomal protein 60S L10 (L1) (RP60S) sequences, combined with available data on ecology, physiology, morphology, and genomics.

Diversity of Microfungi in a High Radon Cave Ecosystem

Castañar Cave is a clear example of an oligotrophic ecosystem with high hygrothermal stability both seasonal and interannual and the particularity of registering extraordinary levels of environmental radiation. These environmental conditions make the cave an ideal laboratory to evaluate both the responses of the subterranean environment to sudden changes in the matter and energy fluxes with the exterior and also any impact derived from its use as a tourist resource under a very restrictive access regime. In 2008, a fungal outbreak provoked by a vomit contaminated the sediments which were removed and subsequently treated with hydrogen peroxide. Fungal surveys were carried out in 2008 and 2009. The visits were resumed in 2014. Here, 12 years after the outbreak, we present an exhaustive study on the cave sediments in order to know the distribution of the different fungal taxa, as well as the prevalence and spatio-temporal evolution of the fungi caused by the vomit over the years under the conditions of relative isolation and high radiation that characterize this cave.

Population genetics as a tool to elucidate pathogen reservoirs: Lessons from Pseudogymnoascus destructans, the causative agent of White-Nose disease in bats

Emerging infectious diseases pose a major threat to human, animal, and plant health. The risk of species-extinctions increases when pathogens can survive in the absence of the host. Environmental reservoirs can facilitate this. However, identifying such reservoirs and modes of infection is often highly challenging. In this study, we investigated the presence and nature of an environmental reservoir for the ascomycete fungus Pseudogymnoascus destructans, the causative agent of White-Nose disease. Using 18 microsatellite markers, we determined the genotypic differentiation between 1497 P. destructans isolates collected from nine closely situated underground sites where bats hibernate (i.e., hibernacula) in Northeastern Germany. This approach was unique in that it ensured that every isolate and resulting multilocus genotype was not only present, but also viable and therefore theoretically capable of infecting a bat. The distinct distribution of multilocus genotypes across hibernacula demonstrates that each hibernaculum has an essentially unique fungal population. This would be expected if bats become infected in their hibernaculum (i.e., the site they spend winter in to hibernate) rather than in other sites visited before they start hibernating. In one hibernaculum, both the walls and the hibernating bats were sampled at regular intervals over five consecutive winter seasons (1062 isolates), revealing higher genotypic richness on walls compared to bats and a stable frequency of multilocus genotypes over multiple winters. This clearly implicates hibernacula walls as the main environmental reservoir of the pathogen, from which bats become reinfected annually during the autumn.

Environment-driven control of fungi in subterranean ecosystems: the case of La Garma Cave (northern Spain)

Airborne microorganisms can cause important conservation problems in caves with Paleolithic art and therefore the knowledge of cave aerodynamic is essential. La Garma Cave (Cantabria, Spain), an exceptional archaeological site with several levels of galleries interconnected and two entrances, presents a complex atmospheric dynamics. An approach including aerobiological sampling together with microclimate monitoring was applied to assess the factors controlling the origin of airborne fungi. Here we show that winter ventilation is critical for the increasing of Basidiomycota spores in the cave air and the highest concentrations were found in the most ventilated areas. On the contrary, Ascomycota spores prevailed in absence of ventilation. Besides, most Ascomycota were linked to insects and bats that visit or inhabit the cave. The combination of aerobiological and microclimate data constitutes a good approach to evaluate the influence of external climatic conditions and design the most suitable strategies for the conservation of cultural heritage in the cave environment.

Hibernacula microclimate and declines in overwintering bats during an outbreak of white-nose syndrome near the northern range limit of infection in North America

We document white-nose syndrome (WNS), a lethal disease of bats caused by the fungus Pseudogymnoascus destructans (Pd), and hibernacula microclimate in New Brunswick, Canada. Our study area represents a more northern region than is common for hibernacula microclimate investigations, providing insight as to how WNS may impact bats at higher latitudes. To determine the impact of the March 2011 arrival of Pd in New Brunswick and the role of hibernacula microclimate on overwintering bat mortality, we surveyed bat numbers at hibernacula twice a year from 2009 to 2015. We also collected data from iButton temperature loggers deployed at all sites and data from HOBO temperature and humidity loggers at three sites. Bat species found in New Brunswick hibernacula include Myotis lucifugus (Little Brown Bat) and M. septentrionalis (Northern Long-eared Bat), with small numbers of Perimyotis subflavus (Tricolored Bat). All known hibernacula in the province were Pd-positive with WNS-positive bats by winter 2013. A 99% decrease in the overwintering bat population in New Brunswick was observed between 2011 and 2015. We did not observe P. subflavus during surveys 2013-2015 and the species appears to be extirpated from these sites. Bats did not appear to choose hibernacula based on winter temperatures, but dark zone (zone where no light penetrates) winter temperatures did not differ among our study sites. Winter dark zone temperatures were warmer and less variable than entrance or above ground temperatures. We observed visible Pd growth on hibernating bats in New Brunswick during early winter surveys (November), even though hibernacula temperatures were colder than optimum for in vitro Pd growth. This suggests that cold hibernacula temperatures encountered near the apparent northern range limit for Pd do not sufficiently slow fungal growth to prevent the onset of WNS and associated bat mortality over the winter.

A common partitivirus infection in United States and Czech Republic isolates of bat white-nose syndrome fungal pathogen Pseudogymnoascus destructans

The psychrophilic (cold-loving) fungus Pseudogymnoascus destructans was discovered more than a decade ago to be the pathogen responsible for white-nose syndrome, an emerging disease of North American bats causing unprecedented population declines. The same species of fungus is found in Europe but without associated mortality in bats. We found P. destructans was infected with a mycovirus [named Pseudogymnoascus destructans partitivirus 1 (PdPV-1)]. The virus is bipartite, containing two double-stranded RNA (dsRNA) segments designated as dsRNA1 and dsRNA2. The cDNA sequences revealed that dsRNA1 dsRNA is 1,683 bp in length with an open reading frame (ORF) that encodes 539 amino acids (molecular mass of 62.7 kDa); dsRNA2 dsRNA is 1,524 bp in length with an ORF that encodes 434 amino acids (molecular mass of 46.9 kDa). The dsRNA1 ORF contains motifs representative of RNA-dependent RNA polymerase (RdRp), whereas the dsRNA2 ORF sequence showed homology with the putative capsid proteins (CPs) of mycoviruses. Phylogenetic analyses with PdPV-1 RdRp and CP sequences indicated that both segments constitute the genome of a novel virus in the family Partitiviridae. The purified virions were isometric with an estimated diameter of 33 nm. Reverse transcription PCR (RT-PCR) and sequencing revealed that all US isolates and a subset of Czech Republic isolates of P. destructans were infected with PdPV-1. However, PdPV-1 appears to be not widely dispersed in the fungal genus Pseudogymnoascus, as non-pathogenic fungi P. appendiculatus (1 isolate) and P. roseus (6 isolates) tested negative. P. destructans PdPV-1 could be a valuable tool to investigate fungal biogeography and the host-pathogen interactions in bat WNS.

Description of four Apiotrichum and two Cutaneotrichosporon species isolated from guano samples from bat-inhabited caves in Japan

Four new yeast species belonging to the genus Apiotrichum and two new yeast species belonging to Cutaneotrichosporon are described for strains isolated from guano samples from bat-inhabited caves in Japan. In 2005, we reported these isolates as Trichosporon species based on sequence analyses of the D1/D2 domain of large subunit (LSU) rRNA genes according to available basidiomycetous yeast classification criteria; however, to date, they have not been officially published as new species with descriptions. Their phylogenetic positions have been reanalysed based on comparison of internal transcribed spacer (ITS) region sequences (including the 5.8S rRNA gene) and the D1/D2 domain of the LSU rRNA gene with those of known species; we confirmed clear separation from previously described species. Physiological and biochemical properties of the isolates also suggest their distinctiveness. Therefore, we describe Apiotrichum akiyoshidainum (holotype JCM 12595^T), Apiotrichum chiropterorum (JCM 12594^T), Apiotrichum coprophilum (JCM 12596^T), Apiotrichum otae (JCM 12593^T), Cutaneotrichosporon cavernicola (JCM 12590^T) and Cutaneotrichosporon middelhovenii (JCM 12592^T) as new species. C. cavernicola showed particularly distinctive morphology including large inflated anomalous cells on the hyphae and germination from the cells, although clear clamp connections on the hyphae were not confirmed. Further study is needed to elucidate the morph of this species.

Seasonal patterns of Pseudogymnoascus destructans germination indicate host-pathogen coevolution

Emerging infectious diseases rank among the most important threats to human and wildlife health. A comprehensive understanding of the mode of infection and presence of potential reservoirs is critical for the development of effective counter strategies. Fungal pathogens can remain viable in environmental reservoirs for extended periods of time before infecting susceptible individuals. This may be the case for Pseudogymnoascus destructans (Pd), the causative agent of bat white-nose disease. Owing to its cold-loving nature, this fungal pathogen only grows on bats during hibernation, when their body temperature is reduced. Bats only spend part of their life cycle in hibernation and do not typically show signs of infection in summer, raising the question of whether Pd remains viable in hibernacula during this period (roughly six months). If so, this could facilitate the re-infection of bats when they return to the sites the following winter. In a laboratory experiment, we determined the germination rate of Pd spores kept under constant conditions on a wall-like substrate, over the course of two years. Results showed that the seasonal pattern in Pd germination mirrored the life cycle of the bats, with an increased germination rate at times when hibernating bats would naturally be present and lower germination rates during their absence. We suggest that Pd is dependent on the presence of hibernating bats and has therefore coupled its germination rate to host availability. Furthermore, we demonstrate that Pd spores survive extended periods of host absence and can remain viable for at least two years. There is, however, a strong decrease in spore viability between the first and second years (98%). Pd viability for at least two years on a solid mineral-based substrate establishes the potential for environmental reservoirs in hibernacula walls and has strong implications for the efficacy of certain management strategies (e.g. bat culling).

Genome-Wide Changes in Genetic Diversity in a Population of Myotis lucifugus Affected by White-Nose Syndrome

Novel pathogens can cause massive declines in populations, and even extirpation of hosts. But disease can also act as a selective pressure on survivors, driving the evolution of resistance or tolerance. Bat white-nose syndrome (WNS) is a rapidly spreading wildlife disease in North America. The fungus causing the disease invades skin tissues of hibernating bats, resulting in disruption of hibernation behavior, premature energy depletion, and subsequent death. We used whole-genome sequencing to investigate changes in allele frequencies within a population of Myotis lucifugus in eastern North America to search for genetic resistance to WNS. Our results show low F_ST values within the population across time, i.e., prior to WNS (Pre-WNS) compared to the population that has survived WNS (Post-WNS). However, when dividing the population with a geographical cut-off between the states of Pennsylvania and New York, a sharp increase in values on scaffold GL429776 is evident in the Post-WNS samples. Genes present in the diverged area are associated with thermoregulation and promotion of brown fat production. Thus, although WNS may not have subjected the entire M. lucifugus population to selective pressure, it may have selected for specific alleles in Pennsylvania through decreased gene flow within the population. However, the persistence of remnant sub-populations in the aftermath of WNS is likely due to multiple factors in bat life history.

Antifungal Norditerpene Oidiolactones from the Fungus Oidiodendron truncatum, a Potential Biocontrol Agent for White-Nose Syndrome in Bats

White-nose syndrome (WNS) is a devastating disease of hibernating bats caused by the fungus Pseudogymnoascus destructans. We obtained 383 fungal and bacterial isolates from the Soudan Iron Mine, an important bat hibernaculum in Minnesota, then screened this library for antifungal activity to develop biological control treatments for WNS. An extract from the fungus Oidiodendron truncatum was subjected to bioassay-guided fractionation, which led to the isolation of 14 norditerpene and three anthraquinone metabolites. Ten of these compounds were previously described in the literature, and here we present the structures of seven new norditerpene analogues. Additionally, this is the first report of 4-chlorophyscion from a natural source, previously identified as a semisynthetic product. The compounds PR 1388 and LL-Z1271α were the only inhibitors of P. destructans (MIC = 7.5 and 15 μg/mL, respectively). Compounds were tested for cytotoxicity against fibroblast cell cultures obtained from Myotis septentrionalis (northern long eared bat) and M. grisescens (gray bat) using a standard MTT viability assay. The most active antifungal compound, PR 1388, was nontoxic toward cells from both bat species (IC₅₀ > 100 μM). We discuss the implications of these results in the context of the challenges and logistics of developing a substrate treatment or prophylactic for WNS.

Candida pseudoglaebosa and Kodamaea ohmeri are capable of degrading alkanes in the presence of heavy metals

The aim of this study was to examine four strains of two yeast species in relation to their capability for assimilating alkanes in the presence of heavy metals (HMs). The four strains tested were Candida pseudoglaebosa ENCB-7 and Kodamaea ohmeri ENCB-8R, ENCB-23, and ENCB-VIK. Determination was made of the expression of CYP52 genes involved in alkane hydroxylation. When exposed to Cu²⁺ , Zn²⁺ , Pb²⁺ , Cd²⁺ , and As³⁺ at pH 3 and 5, all four strains could assimilate several n-alkanes having at least six carbon atoms. The three K. ohmeri strains could also utilize branched alkanes, cycloalkanes, and n-octanol as sole carbon sources. Kinetic assays demonstrated greater biomass production and specific growth of the yeasts exposed to long-chain n-alkanes. Fragments of paralogous CYP52 genes of C. pseudoglaebosa ENCB-7 and K. ohmeri ENCB-23 were amplified, sequenced, and phylogenetically evaluated. Reverse-transcription polymerase chain reaction revealed that n-nonane and n-decane induced to CpCYP52-G3, CpCYP52-G9, and CpCYP52-G10. KoCYP52-G3 was induced with n-decane and n-octanol. Also, CpCYP52-G3 and CpCYP52-G9 were induced by glucose. In conclusion, C. pseudoglaebosa and K. ohmeri were able to degrade several alkanes in the presence of HMs and under acidic conditions. These yeasts harbor paralogous alkane-induced CYP52 genes, which display different profiles of transcriptional expression.

Candida pseudoglaebosa and Kodamaea ohmeri are capable of degrading alkanes in the presence of heavy metals

The aim of this study was to examine four strains of two yeast species in relation to their capability for assimilating alkanes in the presence of heavy metals (HMs). The four strains tested were Candida pseudoglaebosa ENCB-7 and Kodamaea ohmeri ENCB-8R, ENCB-23, and ENCB-VIK. Determination was made of the expression of CYP52 genes involved in alkane hydroxylation. When exposed to Cu2+ , Zn2+ , Pb2+ , Cd2+ , and As3+ at pH 3 and 5, all four strains could assimilate several n-alkanes having at least six carbon atoms. The three K. ohmeri strains could also utilize branched alkanes, cycloalkanes, and n-octanol as sole carbon sources. Kinetic assays demonstrated greater biomass production and specific growth of the yeasts exposed to long-chain n-alkanes. Fragments of paralogous CYP52 genes of C. pseudoglaebosa ENCB-7 and K. ohmeri ENCB-23 were amplified, sequenced, and phylogenetically evaluated. Reverse-transcription polymerase chain reaction revealed that n-nonane and n-decane induced to CpCYP52-G3, CpCYP52-G9, and CpCYP52-G10. KoCYP52-G3 was induced with n-decane and n-octanol. Also, CpCYP52-G3 and CpCYP52-G9 were induced by glucose. In conclusion, C. pseudoglaebosa and K. ohmeri were able to degrade several alkanes in the presence of HMs and under acidic conditions. These yeasts harbor paralogous alkane-induced CYP52 genes, which display different profiles of transcriptional expression.

Trichoderma polysporum selectively inhibits white-nose syndrome fungal pathogen Pseudogymnoascus destructans amidst soil microbes

BACKGROUND

Pseudogymnoascus destructans (Pd), the causative fungal agent of white-nose syndrome (WNS), has led to the deaths of millions of hibernating bats in the United States of America (USA) and Canada. Efficient strategies are needed to decontaminate Pd from the bat hibernacula to interrupt the disease transmission cycle without affecting the native microbes. Previously, we discovered a novel Trichoderma polysporum (Tp) strain (WPM 39143), which inhibited the growth of Pd in autoclaved soil samples. In the present investigation, we used culture-based approaches to determine Tp-induced killing of native and enriched Pd in the natural soil of two bat hibernacula. We also assessed the impact of Tp treatment on native microbial communities by metagenomics.

RESULTS

Our results demonstrated that Tp at the concentration of 105 conidia/g soil caused 100% killing of native Pd in culture within 5 weeks of incubation. A 10-fold higher concentration of Tp (106 conidia/g soil) killed an enriched Pd population (105 conidia/g soil). The 12,507 fungal operational taxonomic units (OTUs, dominated by Ascomycota and Basidiomycota) and 27,427 bacterial OTUs (dominated by Acidobacteria and Proteobacteria) comprised the native soil microbes of the two bat hibernacula. No significant differences in fungal and bacterial relative abundances were observed between untreated and Tp-treated soil (105 Tp conidia/g soil, p ≤ 0.05).

CONCLUSIONS

Our results suggest that Tp-induced killing of Pd is highly specific, with minimal to no impact on the indigenous microbes present in the soil samples. These findings provide the scientific rationale for the field trials of Tp in the WNS-affected hibernacula for the effective decontamination of Pd and the control of WNS.

Green Fluorescent Protein Expression in Pseudogymnoascus destructans to Study Its Abiotic and Biotic Lifestyles

Pseudogymnoascus destructans (Pd) is the etiologic agent of bat White-nose syndrome, a disease that has caused the unprecedented reduction in the hibernating bat populations across eastern North America. The Pd pathogenesis appears to be a complex adaptation of fungus in its abiotic (caves and mines) and biotic (bats) environments. There is a general lack of experimental tools for the study of Pd biology. We described the successful expression of codon-optimized synthetic green fluorescent protein sGFP in Pd. The sGFP(S65T) gene was first fused in frame with the Aspergillus nidulans promoter in the tumor-inducing plasmid pRF-HUE, and the resulting plasmid pHUE-sGFP(S65T) was transformed into Pd by Agrobacterium tumefaciens-mediated transformation system. The integration of sGFP(S65T) in Pd genome was analyzed by PCR, and single integration frequency of approximately 66% was confirmed by Southern hybridization. Fluorescent microscopy and flow cytometric analyses of two randomly selected transformants with single integration revealed high expression of sGFP in both spores and hyphal structures. The biology of mutants as judged by sporulation, growth rate, and urease production was not altered indicating sGFP is not toxic to Pd. Thus, we have generated a valuable tool that will facilitate the elucidation of Pd biology, ecology, and pathogenicity in real time.

Phylogenetic systematics of Syncephalis (Zoopagales, Zoopagomycotina), a genus of ubiquitous mycoparasites

We examined phylogenetic relationships among species of the mycoparasite genus Syncephalis using sequences from three nuclear ribsosomal DNA genes (18S, 5.8S, and 28S nuc rDNA) and a gene encoding the largest subunit of RNA polymerase II (RPB1). Our data set included 88 Syncephalis isolates comprising 23 named species and several unnamed taxa. We also revived a culturing technique using beef liver and cellophane to grow several Syncephalis isolates without their host fungi to obtain pure parasite DNA. Most isolates, however, were grown in co-cultures with their host fungi, so we designed Syncephalis-specific primers to obtain sequence data. Individual and combined data sets were analyzed by maximum likelihood (ML) and Bayesian methods. We recovered 20 well-supported lineages and 38 operational taxonomic units (OTUs). Most major clades contained isolates from distant localities on multiple continents. There were taxonomic and nomenclature issues within several clades, probably due to high phenotypic plasticity or species dimorphism. We also conducted an analysis of Syncephalis nuc rDNA internal transcribed spacer (ITS) sequences for 31 phylogenetically diverse isolates, and we determined that most Syncephalis species have long ITS sequences relative to other fungi. Although commonly employed eukaryotic and fungal primers are compatible with diverse Syncephalis species, the ITS sequences of Syncepahlis are nonetheless rarely recovered in environmental molecular diversity surveys.

Novel Trichoderma polysporum Strain for the Biocontrol of Pseudogymnoascus destructans, the Fungal Etiologic Agent of Bat White Nose Syndrome

White-nose syndrome (WNS), an emerging disease of hibernating bats, has rapidly spread across eastern North America killing millions of bats. Pseudogymnoascus destructans (Pd), the sole etiologic agent of WNS, is widespread and persistent in bat hibernacula. Control of Pd in the affected sites is urgently needed to break the transmission cycle while minimizing any adverse impact on the native organisms. We isolated a novel strain of Trichoderma polysporum (Tp) from one of the caves at the epicenter of WNS zoonotic. Detailed experimental studies revealed: (1) Tp WPM 39143 was highly adapted to grow at temperatures simulating the cave environment (6°C-15°C), (2) Tp WPM 39143 restricted Pd colony growth in dual culture challenges, (3) Tp WPM 39143 caused four logs reduction of Pd colony forming units and genome copies in autoclaved soil samples from one of the WNS affected caves, (4) Tp WPM 39143 extract showed specific fungicidal activity against Pd in disk diffusion assay, but not against closely related fungus P. pannorum (Pp), (5) Tp WPM 39143 extract retained inhibitory activity after exposure to high temperatures, light and proteinase K, and (6) Inhibitory metabolites in Tp WPM 39143 extract comprised of water-soluble, high polarity compounds. These results suggest that Tp WPM 39143 is a promising candidate for further evaluation as a biocontrol agent of Pd in WNS affected sites.