How to characterize a strain? Clonal heterogeneity in industrial Saccharomyces influences both phenotypes and heterogeneity in phenotypes.

Populations of microbes are constantly evolving heterogeneity that selection acts upon, yet heterogeneity is nontrivial to assess methodologically. The necessary practice of isolating single-cell colonies and thus subclone lineages for establishing, transferring, and using a strain results in single-cell bottlenecks with a generally neglected effect on the characteristics of the strain itself. Here, we present evidence that various subclone lineages for industrial yeasts sequenced for recent genomic studies show considerable differences, ranging from loss of heterozygosity to aneuploidies. Subsequently, we assessed whether phenotypic heterogeneity is also observable in industrial yeast, by individually testing subclone lineages obtained from products. Phenotyping of industrial yeast samples and their newly isolated subclones showed that single-cell bottlenecks during isolation can indeed considerably influence the observable phenotype. Next, we decoupled fitness distributions on the level of individual cells from clonal interference by plating single-cell colonies and quantifying colony area distributions. We describe and apply an approach using statistical modeling to compare the heterogeneity in phenotypes across samples and subclone lineages. One strain was further used to show how individual subclonal lineages are remarkably different not just in phenotype but also in the level of heterogeneity in phenotype. With these observations, we call attention to the fact that choosing an initial clonal lineage from an industrial yeast strain may vastly influence downstream performances and observations on karyotype, on phenotype, and also on heterogeneity.

Birth of an order: Comprehensive molecular phylogenetic study excludes Herpomyces (Fungi, Laboulbeniomycetes) from Laboulbeniales.

The class Laboulbeniomycetes comprises biotrophic parasites associated with arthropods and fungi. Two orders are currently recognized, Pyxidiophorales and Laboulbeniales. Herpomyces is an isolated genus of Laboulbeniales, with species that exclusively parasitize cockroaches (Blattodea). Here, we evaluate 39 taxa of Laboulbeniomycetes with a three-locus phylogeny (nrSSU, ITS, nrLSU) and propose a new order in this class. Herpomycetales accommodates a single genus, Herpomyces, with currently 26 species, one of which is described here based on morphological and molecular data. Herpomyces shelfordellae is found on Shelfordella lateralis cockroaches from Hungary, Poland, and the USA. We also build on the six-locus dataset from the Ascomycota Tree of Life paper (Schoch and colleagues, 2009) to confirm that Laboulbeniomycetes and Sordariomycetes are sister classes, and we apply laboulbeniomyceta as a rankless taxon for the now well-resolved node that describes the most recent common ancestor of both classes.

Candida albicans isolates from a single hospital show low phenotypical specialization.

Candida albicans is the best-studied opportunistic human pathogenic yeast species, and its virulence factors, susceptibility to antimycotics, the diversity of its physiological properties and the determinative factors of these traits are interesting from a clinical as well as from an evolutionary perspective. By applying statistical modeling for the phenotypical differences observed among a collection of 63 C. albicans isolates originating from different clinical care units, from a diverse group of patients with or without mycosis, collected in a Hungarian clinic, we found that (i) host-related aspects like anatomical source, care unit of isolation, patients' age, sex, and disease severity, or ABC genotypes of the isolates had less effect on the phenotypic features of this opportunistic pathogen than host-independent aspects, for example, year or month of isolation; (ii) different phenotypic traits did not show any significant correlations with each other; and (iii) different genotypes displayed no anatomical specialization and rarely showed any significant correlation with parameters of isolation either. These results shed light on the dynamic nature and low specialization of the C. albicans populations observable in a narrow geographic range, namely in the patients hospitalized in the different care units of the clinic.

Metahyphopichia laotica gen. nov., sp. nov., a polymorphic yeast related to Hyphopichia.

Four strains alternating between yeast and filamentous growth morphologies were isolated from flowers in two regions of Laos. In liquid environment the isolates propagated by budding and developed irregularly shaped pseudohyphae. On solid media, their yeast cells switched to hyphal growth which could return to the yeast phase by developing lateral blastoconidia. The sequences of the D1/D2 domains of the large subunit (LSU) 26S rRNA genes, the internal transcribed spacer (ITS) regions and the small subunit (SSU) 18S rRNA genes were identical in the four strains and differed from the corresponding sequences of other yeast species available in databases by at least 11 % (D1/D2), 13 % (ITS) and 7 % (SSU). In an independent project, two strains with D1/D2 and ITS sequences very similar to those of the Laotian strains were found in bark samples collected in Brazil. The six strains also differed from the closest yeast species in physiological properties, indicating that they represented a hitherto undescribed species. Phylogenetic analysis of the D1/D2 sequences, and the concatenated sequences of the SSU rRNA genes, D1/D2 domains of LSU rRNA genes as well as the protein-encoding genes ACT1 and TEF1 placed thestrains close to Hyphopichia. To reflect this position, the novel genus name Metahyphopichia gen. nov. and the novel species name Metahyphopichia laotica gen. nov., sp. nov. are proposed for them. The type strain of the type species is 11-1006T(=CBS 13022T=CCY 092-001-001T=NCAIM Y.02126T) and was isolated in Luang Prabang (Laos). MycoBank registration numbers are MB 808253 (Metahyphopichia) and MB 808254 (Metahyphopichia laotica).

Genotypic and phenotypic evolution of yeast interspecies hybrids during high-sugar fermentation.

The yeasts of the Saccharomyces genus exhibit a low pre-zygotic barrier and readily form interspecies hybrids. Following the hybridization event, the parental genomes undergo gross chromosomal rearrangements and genome modifications that may markedly influence the metabolic activity of descendants. In the present study, two artificially constructed hybrid yeasts (Saccharomyces cerevisiae x Saccharomyces uvarum and S. cerevisiae x Saccharomyces kudriavzevii) were used in order to evaluate the influence of high-sugar wine fermentation on the evolution of their genotypic and phenotypic properties. It was demonstrated that the extent of genomic modifications differs among the hybrids and their progeny, but that stress should not always be a generator of large genomic disturbances. The major genome changes were observed after meiosis in the F1 segregants in the form of the loss of different non-S. cerevisiae chromosomes. Under fermentation condition, each spore clone from a tetrad developed a mixed population characterized by different genotypic and phenotypic properties. The S. cerevisiae x S. uvarum spore clones revealed large modifications at the sequence level of the S. cerevisiae sub-genome, and some of the clones lost a few additional S. cerevisiae and S. uvarum chromosomes. The S. cerevisiae x S. kudriavzevii segregants were subjected to consecutive loss of the S. kudriavzevii markers and chromosomes. Both the hybrid types showed increased ethanol and glycerol production as well as better sugar consumption than their parental strains. The hybrid segregants responded differently to stress and a correlation was found between the observed genotypes and fermentation performances.

Mycotoxins - prevention and decontamination by yeasts.

The application of yeasts has great potential in reducing the economic damage caused by toxigenic fungi in the agriculture. Some yeasts may act as biocontrol agents inhibiting the growth of filamentous fungi. These species may also gain importance in the preservation of agricultural products and in the reduction of their mycotoxin contamination, yet the extent of mycotoxin production in the presence of biocontrol agents is relatively less understood. The application of yeasts in various technological processes may have a direct inhibitory effect on the toxin production of certain molds, which is independent of their growth suppressing effect. Furthermore, several yeast species are capable of accumulating mycotoxins from agricultural products, thereby effectively decontaminating them. Probiotic yeasts or products containing yeast cell wall are also applied to counteract mycotoxicosis in livestock. Several yeast strains are also able to degrade toxins to less-toxic or even non-toxic substances. This intensively researched field would greatly benefit from a deeper knowledge on the genetic and molecular basis of toxin degradation. Moreover, yeasts and their biotechnologically important enzymes may exhibit sensitivity to certain mycotoxins, thereby mounting a considerable problem for the biotechnological industry. It is noted that yeasts are generally regarded as safe; however, there are reports of toxin degrading species that may cause human fungal infections. The aspects of yeast-mycotoxin relations with a brief consideration of strain improvement strategies and genetic modification for improved detoxifying properties and/or mycotoxin resistance are reviewed here.

Double sterility barrier between Saccharomyces species and its breakdown in allopolyploid hybrids by chromosome loss.

The analysis of 57 synthetic interspecies hybrids revealed that Saccharomyces cerevisiae and Saccharomyces uvarum ( Saccharomyces bayanus var. uvarum) are isolated by a double sterility barrier: by hybrid sterility (hybrid cells cannot produce viable spores) operating in allodiploids and by F1 sterility (F1 cells cannot produce viable spores) operating in allopolyploids. F1-sterility is caused by mating-type heterozygosity. It can be overcome by eliminating chromosome 2 of the S. uvarum subgenome that carries a MAT locus. The loss of this MAT gene abolishes the repression of mating activity. In cultures of the resulting fertile alloaneuploid F1 segregants, the cells can conjugate with each other like haploids and form zygotes capable of performing meiotic divisions producing viable and fertile F2 spores. To the best of our knowledge, this is the first report on breaking down interspecies hybrid sterility by chromosome loss in eukaryotic organisms. The filial generations are genetically unstable and can undergo additional changes mainly in the S. uvarum subgenome (directional changes). It is proposed that regaining fertility and subsequent preferential reduction in one of the subgenomes may account for the formation of chimerical ('natural hybrid') genomes found among wine and brewery strains and may also play roles in speciation of hybrid taxa in the Saccharomyces genus.

Heme Oxygenase-1 (HMX1) Loss of Function Increases the In-Host Fitness of the Saccharomyces 'boulardii' Probiotic Yeast in a Mouse Fungemia Model.

The use of yeast-containing probiotics is on the rise; however, these products occasionally cause fungal infections and possibly even fungemia among susceptible probiotic-treated patients. The incidence of such cases is probably underestimated, which is why it is important to delve deeper into the pathomechanism and the adaptive features of S. 'boulardii'. Here in this study, the potential role of the gene heme oxygenase-1 (HMX1) in probiotic yeast bloodstream-derived infections was studied by generating marker-free HMX1 deletion mutants with CRISPR/Cas9 technology from both commercial and clinical S. 'boulardii' isolates. The six commercial and clinical yeasts used here represented closely related but different genetic backgrounds as revealed by comparative genomic analysis. We compared the wild-type isolates against deletion mutants for their tolerance of iron starvation, hemolytic activity, as well as kidney burden in immunosuppressed BALB/c mice after lateral tail vein injection. Our results reveal that the lack of HMX1 in S. 'boulardii' significantly (p < 0.0001) increases the kidney burden of the mice in most genetic backgrounds, while at the same time causes decreased growth in iron-deprived media in vitro. These findings indicate that even a single-gene loss-of-function mutation can, surprisingly, cause elevated fitness in the host during an opportunistic systemic infection. Our findings indicate that the safety assessment of S. 'boulardii' strains should not only take strain-to-strain variation into account, but also avoid extrapolating in vitro results to in vivo virulence factor determination.

Virulence Factors and in-Host Selection on Phenotypes in Infectious Probiotic Yeast Isolates (Saccharomyces 'boulardii').

Saccharomyces yeast probiotics (S. 'boulardii') have long been applied in the treatment of several gastrointestinal conditions. Despite their widespread use, they are rare opportunistic pathogens responsible for a high proportion of Saccharomyces mycosis cases. The potential virulence attributes of S. 'boulardii' as well as its interactions with the human immune system have been studied, however, no information is available on how these yeasts may change due to in-host evolution. To fill this gap, we compared the general phenotypic characteristics, cell morphology, virulence factors, epithelial and immunological interactions, and pathogenicity of four probiotic product samples, two mycosis, and eight non-mycosis samples of S. 'boulardii'. We assessed the characteristics related to major steps of yeast infections. Mycosis and non-mycosis isolates both displayed novel characters when compared to the product isolates, but in the case of most virulence factors and in pathogenicity, differences were negligible or, surprisingly, the yeasts from products showed elevated levels. No isolates inflicted considerable damage to the epithelial model or bore the hallmarks of immune evasion. Our results show that strains in probiotic products possess characteristics that enable them to act as pathogens upon permissive conditions, and their entry into the bloodstream is not due to active mechanisms but depends on the host. Survival in the host is dependent on yeast phenotypic characteristics which may change in many ways once they start evolving in the host. These facts call attention to the shortcomings of virulence phenotyping in yeast research, and the need for a more thorough assessment of probiotic use.

Associations between carabid beetles and fungi in the light of 200 years of published literature.

Describing and conserving ecological interactions woven into ecosystems is one of the great challenges of the 21st century. Here, we present a unique dataset compiling the biotic interactions between two ecologically and economically important taxa: ground beetles (Coleoptera: Carabidae) and fungi. The resulting dataset contains the carabid-fungus associations collected from 392 scientific publications, 129 countries, mostly from the Palearctic region, published over a period of 200 years. With an updated taxonomy to match the currently accepted nomenclature, 3,378 unique associations among 5,564 records were identified between 1,776 carabid and 676 fungal taxa. Ectoparasitic Laboulbeniales were the most frequent fungal group associated with carabids, especially with Trechinae. The proportion of entomopathogens was low. Three different formats of the data have been provided along with an interactive data digest platform for analytical purposes. Our database summarizes the current knowledge on biotic interactions between insects and fungi, while offering a valuable resource to test large-scale hypotheses on those interactions.

A new species of Gloeandromyces from Ecuador and Panama revealed by morphology and phylogenetic reconstruction, with a discussion of secondary barcodes in Laboulbeniomycetes taxonomy.

This paper describes and illustrates a new species of Laboulbeniales (Ascomycota, Laboulbeniomycetes) recovered from Mastoptera guimaraesi bat flies (Diptera, Streblidae) in Ecuador and Panama. Bat fly-associated Laboulbeniales are still unexplored in the Neotropics, with only four described species of Gloeandromyces and one species of Nycteromyces known. Morphological characteristics and phylogenetic analyses support placement of the new taxon in Gloeandromyces and its recognition as an undescribed species. Gloeandromyces hilleri sp. nov. is easily recognized by 2-3 longitudinal rows of undulations at its perithecial venter. Phylogenetic reconstructions of the large subunit (LSU) ribosomal DNA and the translation elongation factor 1α (TEF1) both resolve G. hilleri and G. nycteribiidarum as sister species. We discuss the utility of LSU and TEF1 as secondary barcodes in Laboulbeniomycetes taxonomy.

Comparative biocompatibility and antimicrobial studies of sorbic acid derivates.

Nowadays, the sorbates are the third largest group of antimicrobial preservatives in food and pharmaceutical industries, following the parabens and benzoates whose safety is questioned by recent publications. A disadvantage of sorbates is their pH dependence, as their antimicrobial effect is greatly reduced in alkaline environment. The main, widely used sorbate derivatives are sorbic acid and potassium sorbate, no sorbic acid esters are involved in current industrial application. We aimed to test whether the esters of sorbic acid are capable to extend the antimicrobial spectrum of the original molecule while maintaining its advantageous biocompatibility profile. A comparative biocompatibility study of different derivatives (sorbic acid, potassium sorbate, isopropyl sorbate and ethyl sorbate) was carried out. In vitro cell viability assays of MTT (2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide), Neutral Red (3-amino-7-dimethylamino-2-methylphenazine hydrochloride) and flow cytometry with propidium iodide and annexin were performed on Caco-2 cells. In case of in vivo toxicity study, G. mellonella larvae were injected with different concentrations of the test compounds. Time-kill tests were executed on reference strains of C. albicans, E. coli, and S. aureus. According to the MTT-assay, the IC50 values were the following: ethyl sorbate, sorbic acid <0.045% w/w, isopropyl sorbate 0.32% w/w, potassium sorbate >0.75% w/w, while Neutral Red values were >0.75% w/w for the esters and potassium sorbate and 0.66% w/w for sorbic acid. Flow cytometry results indicated the higher cell damage in case of isopropyl sorbate. However, the cytotoxic results of isopropyl sorbate, in vivo toxicity study on G. mellonella larvae did not show significant mortality. It was found, that the antimicrobial properties of isopropyl sorbate were outstanding compared to sorbic acid and potassium sorbate. These results indicate, that the use of sorbate esters can be advantageous, hence, further toxicity studies are needed to prove their safety.

Shed Light in the DaRk LineagES of the Fungal Tree of Life-STRES.

The polyphyletic group of black fungi within the Ascomycota (Arthoniomycetes, Dothideomycetes, and Eurotiomycetes) is ubiquitous in natural and anthropogenic habitats. Partly because of their dark, melanin-based pigmentation, black fungi are resistant to stresses including UV- and ionizing-radiation, heat and desiccation, toxic metals, and organic pollutants. Consequently, they are amongst the most stunning extremophiles and poly-extreme-tolerant organisms on Earth. Even though ca. 60 black fungal genomes have been sequenced to date, [mostly in the family Herpotrichiellaceae (Eurotiomycetes)], the class Dothideomycetes that hosts the largest majority of extremophiles has only been sparsely sampled. By sequencing up to 92 species that will become reference genomes, the "Shed light in The daRk lineagES of the fungal tree of life" (STRES) project will cover a broad collection of black fungal diversity spread throughout the Fungal Tree of Life. Interestingly, the STRES project will focus on mostly unsampled genera that display different ecologies and life-styles (e.g., ant- and lichen-associated fungi, rock-inhabiting fungi, etc.). With a resequencing strategy of 10- to 15-fold depth coverage of up to ~550 strains, numerous new reference genomes will be established. To identify metabolites and functional processes, these new genomic resources will be enriched with metabolomics analyses coupled with transcriptomics experiments on selected species under various stress conditions (salinity, dryness, UV radiation, oligotrophy). The data acquired will serve as a reference and foundation for establishing an encyclopedic database for fungal metagenomics as well as the biology, evolution, and ecology of the fungi in extreme environments.

The Aspergilli and Their Mycotoxins: Metabolic Interactions With Plants and the Soil Biota.

Species of the highly diverse fungal genus Aspergillus are well-known agricultural pests, and, most importantly, producers of various mycotoxins threatening food safety worldwide. Mycotoxins are studied predominantly from the perspectives of human and livestock health. Meanwhile, their roles are far less known in nature. However, to understand the factors behind mycotoxin production, the roles of the toxins of Aspergilli must be understood from a complex ecological perspective, taking mold-plant, mold-microbe, and mold-animal interactions into account. The Aspergilli may switch between saprophytic and pathogenic lifestyles, and the production of secondary metabolites, such as mycotoxins, may vary according to these fungal ways of life. Recent studies highlighted the complex ecological network of soil microbiotas determining the niches that Aspergilli can fill in. Interactions with the soil microbiota and soil macro-organisms determine the role of secondary metabolite production to a great extent. While, upon infection of plants, metabolic communication including fungal secondary metabolites like aflatoxins, gliotoxin, patulin, cyclopiazonic acid, and ochratoxin, influences the fate of both the invader and the host. In this review, the role of mycotoxin producing Aspergillus species and their interactions in the ecosystem are discussed. We intend to highlight the complexity of the roles of the main toxic secondary metabolites as well as their fate in natural environments and agriculture, a field that still has important knowledge gaps.

A new, rapid multiplex PCR method identifies frequent probiotic origin among clinical Saccharomyces isolates.

An increasing number of infections originating from probiotic use are reported worldwide, with the majority of such cases caused by the yeast Saccharomyces 'boulardii', a subtype of S. cerevisiae. Reliably linking infectious cases to probiotic products requires unequivocal genotyping data, however, these techniques are often time-consuming and difficult to implement in routine diagnostics. This leads to a widespread lack of genetic data regarding the origin of Saccharomyces infections. We propose a quick and reliable PCR-based protocol for the identification of S. 'boulardii' based on a combined analysis of interdelta fingerprinting and microsatellite typing. By applying various typing methods and our proposed method to the clinical yeast collection of a Hungarian hospital we show that probiotic origin is common among clinical Saccharomyces, and that the new multiplex method enables rapid and unequivocal identification of probiotic yeast infections. This method can be applied for the identification of yeast infection sources, helping decisions on probiotic use.

Adverse Effects, Transformation and Channeling of Aflatoxins Into Food Raw Materials in Livestock.

Aflatoxins are wide-spread harmful carcinogenic secondary metabolites produced by Aspergillus species, which cause serious feed and food contaminations and affect farm animals deleteriously with acute or chronic manifestations of mycotoxicoses. On farm, both pre-harvest and post-harvest strategies are applied to minimize the risk of aflatoxin contaminations in feeds. The great economic losses attributable to mycotoxin contaminations have initiated a plethora of research projects to develop new, effective technologies to prevent the highly toxic effects of these secondary metabolites on domestic animals and also to block the carry-over of these mycotoxins to humans through the food chain. Among other areas, this review summarizes the latest findings on the effects of silage production technologies and silage microbiota on aflatoxins, and it also discusses the current applications of probiotic organisms and microbial products in feeding technologies. After ingesting contaminated foodstuffs, aflatoxins are metabolized and biotransformed differently in various animals depending on their inherent and acquired physiological properties. These mycotoxins may cause primary aflatoxicoses with versatile, species-specific adverse effects, which are also dependent on the susceptibility of individual animals within a species, and will be a function of the dose and duration of aflatoxin exposures. The transfer of these undesired compounds from contaminated feed into food of animal origin and the aflatoxin residues present in foods become an additional risk to human health, leading to secondary aflatoxicoses. Considering the biological transformation of aflatoxins in livestock, this review summarizes (i) the metabolism of aflatoxins in different animal species, (ii) the deleterious effects of the mycotoxins and their derivatives on the animals, and (iii) the major risks to animal health in terms of the symptoms and consequences of acute or chronic aflatoxicoses, animal welfare and productivity. Furthermore, we traced the transformation and channeling of Aspergillus-derived mycotoxins into food raw materials, particularly in the case of aflatoxin contaminated milk, which represents the major route of human exposure among animal-derived foods. The early and reliable detection of aflatoxins in feed, forage and primary commodities is an increasingly important issue and, therefore, the newly developed, easy-to-use qualitative and quantitative aflatoxin analytical methods are also summarized in the review.

Studies of Laboulbeniales on Myrmica ants (IV): host-related diversity and thallus distribution patterns of Rickia wasmannii.

Fungal species identities are often based on morphological features, but current molecular phylogenetic and other approaches almost always lead to the discovery of multiple species in single morpho-species. According to the morphological species concept, the ant-parasitic fungus Rickia wasmannii (Ascomycota, Laboulbeniales) is a single species with pan-European distribution and a wide host range. Since its description, it has been reported from ten species of Myrmica (Hymenoptera, Formicidae), of which two belong to the rubra-group and the other eight to the phylogenetically distinct scabrinodis-group. We found evidence for R. wasmannii being a single phylogenetic species using sequence data from two loci. Apparently, the original morphological description (dating back to 1899) represents a single phylogenetic species. Furthermore, the biology and host-parasite interactions of R. wasmannii are not likely to be affected by genetic divergence among different populations of the fungus, implying comparability among studies conducted on members of different ant populations. We found no differences in total thallus number on workers between Myrmica species, but we did observe differences in the pattern of thallus distribution over the body. The locus of infection is the frontal side of the head in Myrmica rubra and M. sabuleti whereas in M. scabrinodis the locus of infection differs between worker ants from Hungary (gaster tergites) and the Netherlands (frontal head). Possible explanations for these observations are differences among host species and among populations of the same species in (i) how ant workers come into contact with the fungus, (ii) grooming efficacy, and (iii) cuticle surface characteristics.

Birth-and-Death Evolution and Reticulation of ITS Segments of Metschnikowia andauensis and Metschnikowia fructicola rDNA Repeats.

The internal transcribed spacer (ITS) region (ITS1, 5.8S rDNA, and ITS2) separates the genes coding for the SSU 18S and the LSU 26S genes in the rDNA units which are organized into long tandem arrays in the overwhelming majority of fungi. As members of a multigenic family, these units are subject of concerted evolution, which homogenizes their sequences. Exceptions have been observed in certain groups of plants and in a few fungal species. In our previous study we described exceptionally high degree of sequence diversity in the D1/D2 domains of two pulcherrimin-producing Metschnikowia (Saccharomycotina) species which appeared to evolve by reticulation. The major goals of this study were the examination of the diversity of the ITS segments and their evolution. We show that the ITS sequences of these species are not homogenized either, differ from each other by up to 38 substitutions and indels which have dramatic effects on the predicted secondary structures of the transcripts. The high intragenomic diversity makes the D1/D2 domains and the ITS spacers unsuitable for barcoding of these species and therefore the taxonomic position of strains previously assigned to them needs revision. By analyzing the genome sequence of the M. fructicola type strain, we also show that the rDNA of this species is fragmented, contains pseudogenes and thus evolves by the birth-and-death mechanism rather than by homogenisation, which is unusual in yeasts. The results of the network analysis of the sequences further indicate that the ITS regions are also involved in reticulation. M. andauensis and M. fructicola can form interspecies hybrids and their hybrids segregate, providing thus possibilities for reticulation of the rDNA repeats.

Herpomyces ectoparasitic fungi (Ascomycota, Laboulbeniales) are globally distributed by their invasive cockroach hosts and through the pet trade industry.

The introduction of non-native animals occasionally results in the co-introduction of their microbial symbionts or parasites. The trade of exotic pets and zoo animals has inadvertently introduced several parasitic species to countries where they are non-native. Both the presence of suitable native hosts and opportunity for dispersal determine whether these non-native species become naturalized. During our studies dealing with species of Herpomyces (Ascomycota, Laboulbeniomycetes), fungi that are exclusively ectoparasitic on cockroaches (Hexapoda, Blattodea), we make use of artificial colonies. Most of our specimens originate from pet stores and laboratory populations. Although they were originally intended for transmission studies, we discovered that some cockroaches from artificial colonies carried fruiting bodies of Herpomyces. We screened a total 292 cockroaches from 11 populations that we maintained after purchase. Sources were different pet stores, a toxicological laboratory, and a biological supply company. In eight populations, we found at least some Herpomyces-infected cockroaches. Parasite prevalence varied between 8.77% and 86.33%. Host associations were Blatta orientalis with Herpomyces stylopygae, Blattella germanica with H. ectobiae, Periplaneta americana with H. periplanetae, Phoetalia pallida with H. leurolestis, and Shelfordella lateralis with an undescribed species of Herpomyces. Apart from the new reports, host associations, and consequences for taxonomy (a new species based on morphological and molecular characters), we started to think about the geographic distributions of these fungi and how we, humans, shape them through spreading hosts and through international pet trade. We reviewed the currently known records of Herpomyces-associated cockroaches and host-parasite relationships. Based on the available data, on a global scale, at least half of the currently known species of Herpomyces are spread by globally invasive host species and through international pet trade. This indicates that the distribution and host range of these obscure and often unnoticed fungi are affected by human activities.

Laboulbeniales (Fungi: Ascomycota) infection of bat flies (Diptera: Nycteribiidae) from Miniopterus schreibersii across Europe.

BACKGROUND: Bat flies (Diptera: Nycteribiidae and Streblidae) are obligate, blood-sucking ectoparasites of bats with specialized morphology, life-cycle and ecology. Bat flies are occasionally infected by different species of Laboulbeniales (Fungi: Ascomycota), microscopic fungal ectoparasites belonging to three genera: Arthrorynchus spp. are restricted to the Eastern Hemisphere, while species of Gloeandromyces and Nycteromyces occur on Neotropical bat flies. Little is known about the distribution and host specificity of Arthrorynchus spp. on bat flies. In this study, we focused on sampling bat flies from the cave-dwelling bat species Miniopterus schreibersii. Bat and ectoparasite collection took place in Albania, Croatia, Hungary, Italy, Portugal, Slovakia, Spain and Switzerland. Flies were inspected for Laboulbeniales infections. RESULTS: Six hundred sixty seven bat flies of five species were collected: Nycteribia latreillii, N. pedicularia, N. schmidlii, Penicillidia conspicua, and P. dufourii. Laboulbeniales infection was observed on 60 specimens (prevalence = 9%). Two Laboulbeniales species, Arthrorhynchus eucampsipodae and A. nycteribiae, were present on three bat fly species. All observations of A. eucampsipodae were on N. schmidlii, and A. nycteribiae was present on P. conspicua and P dufourii. Arthrorhynchus eucampsipodae is, for the first time, reported from Slovakia and Spain. Arthrorhynchus nycteribiae represents a new country record for Portugal and Slovakia. There were no significant differences among infection rates in different countries. Females of N. schmidlii showed a higher infection rate than males with an observable trend (P = 0.0502). No sex differences in infection rate for P. conspicua and P. dufourii were detected. Finally, thallus density was significantly lower in N. schmidlii compared to P. conspicua and P. dufourii. CONCLUSIONS: With this study, we contribute to the knowledge of the geographical distribution and host specificity of Laboulbeniales fungi associated with ectoparasitic bat flies within Europe. We discuss parasite prevalence and host specificity in the light of our findings and the available literature. Penicillidia conspicua is unambiguously the main host species for A. nycteribiae based on our and previous findings. Differences in parasite intensity and sex-biased infections of the fungi are possible depending on the species.