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Cazabonne J, Walker AK, Lesven J, Haelewaters D. Singleton-based species names and fungal rarity: Does the number really matter? IMA Fungus 2024; 15:7. [PMID: 38504339 PMCID: PMC10953280 DOI: 10.1186/s43008-023-00137-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 12/13/2023] [Indexed: 03/21/2024] Open
Abstract
Fungi are among the least known organisms on earth, with an estimated number of species between 1.5 and 10 million. This number is expected to be refined, especially with increasing knowledge about microfungi in undersampled habitats and increasing amounts of data derived from environmental DNA sequencing. A significant proportion of newly generated sequences fail to match with already named species, and thus represent what has been referred to as fungal "dark taxa". Due to the challenges associated with observing, identifying, and preserving sporophores, many macro- and microfungal species are only known from a single collection, specimen, isolate, and/or sequence-a singleton. Mycologists are consequently used to working with "rare" sequences and specimens. However, rarity and singleton phenomena lack consideration and valorization in fungal studies. In particular, the practice of publishing new fungal species names based on a single specimen remains a cause of debate. Here, we provide some elements of reflection on this issue in the light of the specificities of the fungal kingdom and global change context. If multiple independent sources of data support the existence of a new taxon, we encourage mycologists to proceed with formal description, irrespective of the number of specimens at hand. Although the description of singleton-based species may not be considered best practice, it does represent responsible science in the light of closing the Linnean biodiversity shortfall.
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Affiliation(s)
- Jonathan Cazabonne
- Ecology Research Group of Abitibi RCM, Forest Research Institute, Université du Québec en Abitibi-Témiscamingue, Amos, QC, J9T 2L8, Canada.
- Centre for Forest Research, Université du Québec à Montréal, Montreal, QC, H3C 3P8, Canada.
| | - Allison K Walker
- Department of Biology, Acadia University, Wolfville, NS, B4P 2R6, Canada
| | - Jonathan Lesven
- Laboratoire Chrono-Environnement, UMR 6249 CNRS, Université de Bourgogne Franche-Comté, 25000, Besançon, France
- Forest Research Institute, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, J9X 5E4, Canada
| | - Danny Haelewaters
- Research Group Mycology, Department of Biology, Ghent University, 9000, Ghent, Belgium.
- Faculty of Science, University of South Bohemia, 370 05, Ceske Budejovice, Czech Republic.
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, 80309, USA.
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, 370 05, Ceske Budejovice, Czech Republic.
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2
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Meghana R, Anand PP, Vardhanan YS. Molecular and morphometric analyses reveal host-specific cryptic speciation in a mite species, Tetranychus neocaledonicus (Andre, 1933) (Acari: Tetranychidae). Zootaxa 2023; 5306:61-96. [PMID: 37518535 DOI: 10.11646/zootaxa.5306.1.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Indexed: 08/01/2023]
Abstract
Host- and habitat-induced morphological shape and size variations are common in phytophagous and parasitic taxa. Several integrated morphological and molecular techniques have been commonly used to understand host-induced morpho-cryptic species forms. Compared to other arthropods, cryptic speciation was more common in Acari. This study focused on the host-specific morphological cryptic shape and size variations of Tetranychus neocaledonicus, collected from moringa and cassava hosts. We used geometric morphometric analysis to uncover the shape and size of inter-and intra-spider mite populations, and discovered that host-specific shape and size variations existed in spider mites regardless of sex. Interestingly, there was no phylogenetic signal in spider mites, implying that the morpho-cryptic speciation of T. neocaledonicus is solely based on the host-induced selection. The molecular clock hypothesis was accepted in our CO1 and 18s rRNA phylogeny analyses, and spider mites collected from both hosts were genetically less diverse. We conclude that T. neocaledonicus exhibited morphologically detectable cryptic population diversity in each host but that these populations are evolutionarily young form. Apart from these host-induced variations, we also monitored the impact of the clearing agent (lactic acid) on the shape and size of T. neocaledonicus; from this study, we proved that the clearing agent significantly alters the taxonomically important morphological traits of spider mites irrespective of the mites' sex, as confirmed by multivariate statistical analysis. This is the first study report to investigated the host-induced morphological variations of spider mites and the impact of a clearing agent.
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Affiliation(s)
- R Meghana
- Biochemistry & Toxicology Division; Department of Zoology; University of Calicut; Kerala; India.
| | - P P Anand
- Biochemistry & Toxicology Division; Department of Zoology; University of Calicut; Kerala; India.
| | - Y Shibu Vardhanan
- Biochemistry & Toxicology Division; Department of Zoology; University of Calicut; Kerala; India.
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3
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The pan-genome of Aspergillus fumigatus provides a high-resolution view of its population structure revealing high levels of lineage-specific diversity driven by recombination. PLoS Biol 2022; 20:e3001890. [PMID: 36395320 PMCID: PMC9714929 DOI: 10.1371/journal.pbio.3001890] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 12/01/2022] [Accepted: 10/26/2022] [Indexed: 11/18/2022] Open
Abstract
Aspergillus fumigatus is a deadly agent of human fungal disease where virulence heterogeneity is thought to be at least partially structured by genetic variation between strains. While population genomic analyses based on reference genome alignments offer valuable insights into how gene variants are distributed across populations, these approaches fail to capture intraspecific variation in genes absent from the reference genome. Pan-genomic analyses based on de novo assemblies offer a promising alternative to reference-based genomics with the potential to address the full genetic repertoire of a species. Here, we evaluate 260 genome sequences of A. fumigatus including 62 newly sequenced strains, using a combination of population genomics, phylogenomics, and pan-genomics. Our results offer a high-resolution assessment of population structure and recombination frequency, phylogenetically structured gene presence-absence variation, evidence for metabolic specificity, and the distribution of putative antifungal resistance genes. Although A. fumigatus disperses primarily via asexual conidia, we identified extraordinarily high levels of recombination with the lowest linkage disequilibrium decay value reported for any fungal species to date. We provide evidence for 3 primary populations of A. fumigatus, with recombination occurring only rarely between populations and often within them. These 3 populations are structured by both gene variation and distinct patterns of gene presence-absence with unique suites of accessory genes present exclusively in each clade. Accessory genes displayed functional enrichment for nitrogen and carbohydrate metabolism suggesting that populations may be stratified by environmental niche specialization. Similarly, the distribution of antifungal resistance genes and resistance alleles were often structured by phylogeny. Altogether, the pan-genome of A. fumigatus represents one of the largest fungal pan-genomes reported to date including many genes unrepresented in the Af293 reference genome. These results highlight the inadequacy of relying on a single-reference genome-based approach for evaluating intraspecific variation and the power of combined genomic approaches to elucidate population structure, genetic diversity, and putative ecological drivers of clinically relevant fungi.
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The haustorium as a driving force for speciation in thallus-forming Laboulbeniomycetes. IMA Fungus 2022; 13:1. [PMID: 35101145 PMCID: PMC8805332 DOI: 10.1186/s43008-021-00087-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 12/19/2021] [Indexed: 11/10/2022] Open
Abstract
Laboulbeniomycetes is a class of fungi that have obligate associations with arthropod hosts, either for dispersal (order Pyxidiophorales) or as biotrophic parasites (orders Herpomycetales and Laboulbeniales). Here, we focus on Herpomycetales and Laboulbeniales, which include fungi that form thalli, 3-dimensional, multicellular units of 1000 s of cells. Based on recently published data regarding patterns of speciation, we present the One-Host-One-Parasite model (1H1P) for haustorial thallus-forming Laboulbeniomycetes. We hypothesize that taxa with haustoria, rhizoidal structures that make contact with the host’s body cavity, have very strict host specificity. For taxa without haustoria, the microhabitat—as selected by the host—governs host shifting, presence or absence of the fungus, abundance, effective host range, and geographic distribution. We make suggestions for future research including fluorescent labeling of waxy lipids and mass spectrometry. These techniques have the potential to generate the data necessary to evaluate the here proposed 1H1P hypothesis for Herpomycetales and Laboulbeniales.
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Brackin AP, Shelton JMG, Abdolrasouli A, Fisher MC, Sewell TR. A Low-Cost Tebuconazole-Based Screening Test for Azole-Resistant Aspergillus fumigatus. ACTA ACUST UNITED AC 2021; 58:e112. [PMID: 32857921 DOI: 10.1002/cpmc.112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The global emergence of azole resistance in Aspergillus fumigatus is resulting in health and food security concerns. Rapid diagnostics and environmental surveillance methods are key to understanding the distribution and prevalence of azole resistance. However, such methods are often associated with high costs and are not always applicable to laboratories based in the least-developed countries. Here, we present and validate a low-cost screening protocol that can be used to differentiate between azole-susceptible "wild-type" and azole-resistant A. fumigatus isolates. © 2020 The Authors. Basic Protocol 1: Preparation of Tebucheck multi-well plates Basic Protocol 2: Inoculation of Tebucheck multi-well plates.
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Affiliation(s)
- Amelie P Brackin
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Jennifer M G Shelton
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Alireza Abdolrasouli
- Diagnostic Mycology Service, Department of Medical Microbiology, North West London Pathology, Imperial College Healthcare National Health Service Trust, London, United Kingdom
| | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Thomas R Sewell
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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Hernández-Hernández T, Miller EC, Román-Palacios C, Wiens JJ. Speciation across the Tree of Life. Biol Rev Camb Philos Soc 2021; 96:1205-1242. [PMID: 33768723 DOI: 10.1111/brv.12698] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/13/2021] [Accepted: 02/16/2021] [Indexed: 01/04/2023]
Abstract
Much of what we know about speciation comes from detailed studies of well-known model systems. Although there have been several important syntheses on speciation, few (if any) have explicitly compared speciation among major groups across the Tree of Life. Here, we synthesize and compare what is known about key aspects of speciation across taxa, including bacteria, protists, fungi, plants, and major animal groups. We focus on three main questions. Is allopatric speciation predominant across groups? How common is ecological divergence of sister species (a requirement for ecological speciation), and on what niche axes do species diverge in each group? What are the reproductive isolating barriers in each group? Our review suggests the following patterns. (i) Based on our survey and projected species numbers, the most frequent speciation process across the Tree of Life may be co-speciation between endosymbiotic bacteria and their insect hosts. (ii) Allopatric speciation appears to be present in all major groups, and may be the most common mode in both animals and plants, based on non-overlapping ranges of sister species. (iii) Full sympatry of sister species is also widespread, and may be more common in fungi than allopatry. (iv) Full sympatry of sister species is more common in some marine animals than in terrestrial and freshwater ones. (v) Ecological divergence of sister species is widespread in all groups, including ~70% of surveyed species pairs of plants and insects. (vi) Major axes of ecological divergence involve species interactions (e.g. host-switching) and habitat divergence. (vii) Prezygotic isolation appears to be generally more widespread and important than postzygotic isolation. (viii) Rates of diversification (and presumably speciation) are strikingly different across groups, with the fastest rates in plants, and successively slower rates in animals, fungi, and protists, with the slowest rates in prokaryotes. Overall, our study represents an initial step towards understanding general patterns in speciation across all organisms.
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Affiliation(s)
- Tania Hernández-Hernández
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A.,Catedrática CONACYT asignada a LANGEBIO-UGA Cinvestav, Libramiento Norte Carretera León Km 9.6, 36821, Irapuato, Guanajuato, Mexico
| | - Elizabeth C Miller
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
| | - Cristian Román-Palacios
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
| | - John J Wiens
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
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Mitchell JK, Garrido-Benavent I, Quijada L, Pfister DH. Sareomycetes: more diverse than meets the eye. IMA Fungus 2021; 12:6. [PMID: 33726866 PMCID: PMC7961326 DOI: 10.1186/s43008-021-00056-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 02/16/2021] [Indexed: 01/16/2023] Open
Abstract
Since its resurrection, the resinicolous discomycete genus Sarea has been accepted as containing two species, one with black apothecia and pycnidia, and one with orange. We investigate this hypothesis using three ribosomal (nuITS, nuLSU, mtSSU) regions from and morphological examination of 70 specimens collected primarily in Europe and North America. The results of our analyses support separation of the traditional Sarea difformis s.lat. and Sarea resinae s.lat. into two distinct genera, Sarea and Zythia. Sarea as circumscribed is shown to conservatively comprise three phylospecies, with one corresponding to Sarea difformis s.str. and two, morphologically indistinguishable, corresponding to the newly combined Sarea coeloplata. Zythia is provisionally maintained as monotypic, containing only a genetically and morphologically variable Z. resinae. The new genus Atrozythia is erected for the new species A. klamathica. Arthrographis lignicola is placed in this genus on molecular grounds, expanding the concept of Sareomycetes by inclusion of a previously unknown type of asexual morph. Dating analyses using additional marker regions indicate the emergence of the Sareomycetes was roughly concurrent with the diversification of the genus Pinus, suggesting that this group of fungi emerged to exploit the newly-available resinous ecological niche supplied by Pinus or another, extinct group of conifers. Our phylogeographic studies also permitted us to study the introductions of these fungi to areas where they are not native, including Antarctica, Cape Verde, and New Zealand and are consistent with historical hypotheses of introduction.
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Affiliation(s)
- James K Mitchell
- Farlow Reference Library and Herbarium of Cryptogamic Botany, Harvard University, 22 Divinity Avenue, Cambridge, MA, 02138, USA. .,Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA, 02138, USA.
| | - Isaac Garrido-Benavent
- Institut Cavanilles de Biodiversitat i Biologia Evolutiva (ICBIBE) & Dept. Botànica i Geologia, Universitat de València, C/ Dr. Moliner 50, 46100-Burjassot, València, Spain
| | - Luis Quijada
- Farlow Reference Library and Herbarium of Cryptogamic Botany, Harvard University, 22 Divinity Avenue, Cambridge, MA, 02138, USA.,Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
| | - Donald H Pfister
- Farlow Reference Library and Herbarium of Cryptogamic Botany, Harvard University, 22 Divinity Avenue, Cambridge, MA, 02138, USA.,Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
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8
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van der Torre MH, Shen H, Rautemaa-Richardson R, Richardson MD, Novak-Frazer L. Molecular Epidemiology of Aspergillus fumigatus in Chronic Pulmonary Aspergillosis Patients. J Fungi (Basel) 2021; 7:jof7020152. [PMID: 33672698 PMCID: PMC7924367 DOI: 10.3390/jof7020152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 12/17/2022] Open
Abstract
Molecular fungal genotyping techniques developed and employed for epidemiological studies have understandably concentrated on establishing the genetic diversity of Aspergillus fumigatus in invasive aspergillosis due to its severity, the urgency for treatment, and the need to demonstrate possible sources. Some early studies suggested that these strains were phenotypically, if not genotypically, different from others. However, with improved discrimination and evaluations, incorporating environmental as well as clinical isolates from other Aspergillus conditions (e.g., chronic pulmonary aspergillosis and cystic fibrosis), this premise is no longer upheld. Moreover, with the onset of increased global triazole resistance, there has been a concerted effort to incorporate resistance profiling into genotyping studies and the realisation that the wider population of non-immunocompromised aspergillosis patients are at risk. This review summarises the developments in molecular genotyping studies that incorporate resistance profiling with attention to chronic pulmonary aspergillosis and an example of our UK experience.
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Affiliation(s)
- Mireille H. van der Torre
- Mycology Reference Centre Manchester, ECMM Centre of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK; (M.H.v.d.T.); (R.R.-R.); (M.D.R.)
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
| | - Hongwei Shen
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
| | - Riina Rautemaa-Richardson
- Mycology Reference Centre Manchester, ECMM Centre of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK; (M.H.v.d.T.); (R.R.-R.); (M.D.R.)
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
- Department of Infectious Diseases, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK
| | - Malcolm D. Richardson
- Mycology Reference Centre Manchester, ECMM Centre of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK; (M.H.v.d.T.); (R.R.-R.); (M.D.R.)
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
| | - Lilyann Novak-Frazer
- Mycology Reference Centre Manchester, ECMM Centre of Excellence in Clinical and Laboratory Mycology and Clinical Studies, Manchester University NHS Foundation Trust, Wythenshawe Hospital, Manchester M23 9LT, UK; (M.H.v.d.T.); (R.R.-R.); (M.D.R.)
- Division of Infection, Inflammation and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK;
- Correspondence: ; Tel.: +44-161-2915856
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Extensive Genetic Diversity and Widespread Azole Resistance in Greenhouse Populations of Aspergillus fumigatus in Yunnan, China. mSphere 2021; 6:6/1/e00066-21. [PMID: 33568450 PMCID: PMC8544883 DOI: 10.1128/msphere.00066-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Aspergillus fumigatus is the main cause of invasive aspergillosis (IA) with a high annual global incidence and mortality rate. Recent studies have indicated an increasing prevalence of azole-resistant A. fumigatus (ARAF) strains, with agricultural use of azole fungicides as a potential contributor. China has an extensive agricultural production system and uses a wide array of fungicides for crop production, including in modern growth facilities such as greenhouses. Soils in greenhouses are among the most intensively cultivated. However, little is known about the occurrence and distribution of ARAF in greenhouse soils. Here, we investigated genetic variation and triazole drug susceptibility in A. fumigatus from greenhouses around metropolitan Kunming in Yunnan, southwest China. Abundant allelic and genotypic variations were found among 233 A. fumigatus strains isolated from nine greenhouses in this region. Significantly, ∼80% of the strains were resistant to at least one medical triazole drug, with >30% showing cross-resistance to both itraconazole and voriconazole. Several previously reported mutations associated with triazole resistance in the triazole target gene cyp51A were also found in our strains, with a strong positive correlation between the frequency of mutations at the cyp51A promoter and that of voriconazole resistance. Phylogenetic analyses of cyp51A gene sequences showed evidence for multiple independent origins of azole-resistant genotypes of A. fumigatus in these greenhouses. Evidence for multiple origins of azole resistance and the widespread distributions of genetically very diverse triazole-resistant strains of A. fumigatus in greenhouses calls for significant attention from public health agencies. IMPORTANCE The origin and prevalence of azole-resistant Aspergillus fumigatus have been attracting increasing attention from biologists, clinicians, and public health agencies. Current evidence suggests agricultural fungicide use as a major cause. In southwest China, greenhouses are used to produce large amounts of fruits, flowers, and vegetables for consumers throughout China as well as those in other countries, primarily in southeast Asia. Here, we found a very high frequency (∼80%) of triazole-resistant A. fumigatus in our sample, the highest reported so far, with a significant proportion of these strains resistant to both tested agricultural fungicides and medical triazole drugs. In addition, we found novel allelic and genotypic diversities and evidence for multiple independent origins of azole-resistant genotypes of A. fumigatus in greenhouse populations in this region. Our study calls for a systematic evaluation of the effects of azole fungicide usage in greenhouses on human health.
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Gladieux P, De Bellis F, Hann-Soden C, Svedberg J, Johannesson H, Taylor JW. Neurospora from Natural Populations: Population Genomics Insights into the Life History of a Model Microbial Eukaryote. Methods Mol Biol 2021; 2090:313-336. [PMID: 31975173 DOI: 10.1007/978-1-0716-0199-0_13] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The ascomycete filamentous fungus Neurospora crassa played a historic role in experimental biology and became a model system for genetic research. Stimulated by a systematic effort to collect wild strains initiated by Stanford geneticist David Perkins, the genus Neurospora has also become a basic model for the study of evolutionary processes, speciation, and population biology. In this chapter, we will first trace the history that brought Neurospora into the era of population genomics. We will then cover the major contributions of population genomic investigations using Neurospora to our understanding of microbial biogeography and speciation, and review recent work using population genomics and genome-wide association mapping that illustrates the unique potential of Neurospora as a model for identifying the genetic basis of (potentially adaptive) phenotypes in filamentous fungi. The advent of population genomics has contributed to firmly establish Neurospora as a complete model system and we hope our review will entice biologists to include Neurospora in their research.
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Affiliation(s)
- Pierre Gladieux
- UMR BGPI, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France.
| | - Fabien De Bellis
- UMR AGAP, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Christopher Hann-Soden
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Jesper Svedberg
- Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | - Hanna Johannesson
- Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | - John W Taylor
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
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Abstract
The fungal zinc finger transcription factor NsdC is named after, and is best known for, its essential role in sexual reproduction (never in sexual development). In previous studies with Aspergillus nidulans, it was also shown to have roles in promotion of vegetative growth and suppression of asexual conidiation. In this study, the function of the nsdC homologue in the opportunistic human pathogen A. fumigatus was investigated. NsdC was again found to be essential for sexual development, with deletion of the nsdC gene in both MAT1-1 and MAT1-2 mating partners of a cross leading to complete loss of fertility. However, a functional copy of nsdC in one mating partner was sufficient to allow sexual reproduction. Deletion of nsdC also led to decreased vegetative growth and allowed conidiation in liquid cultures, again consistent with previous findings. However, NsdC in A. fumigatus was shown to have additional biological functions including response to calcium stress, correct organization of cell wall structure, and response to the cell wall stressors. Furthermore, virulence and host immune recognition were affected. Gene expression studies involving chromatin immunoprecipitation (ChIP) of RNA polymerase II (PolII) coupled to next-generation sequencing (Seq) revealed that deletion of nsdC resulted in changes in expression of over 620 genes under basal growth conditions. This demonstrated that this transcription factor mediates the activity of a wide variety of signaling and metabolic pathways and indicates that despite the naming of the gene, the promotion of sexual reproduction is just one among multiple roles of NsdC.IMPORTANCE Aspergillus fumigatus is an opportunistic human fungal pathogen and the main causal agent of invasive aspergillosis, a life-threatening infection especially in immunocompromised patients. A. fumigatus can undergo both asexual and sexual reproductive cycles, and the regulation of both cycles involves several genes and pathways. Here, we have characterized one of these genetic determinants, the NsdC transcription factor, which was initially identified in a screen of transcription factor null mutants showing sensitivity when exposed to high concentrations of calcium. In addition to its known essential roles in sexual reproduction and control of growth rate and asexual reproduction, we have shown in the present study that A. fumigatus NsdC transcription factor has additional previously unrecognized biological functions including calcium tolerance, cell wall stress response, and correct cell wall organization and functions in virulence and host immune recognition. Our results indicate that NsdC can play novel additional biological functions not directly related to its role played during sexual and asexual processes.
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12
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Yu LS, Rodriguez-Manzano J, Moser N, Moniri A, Malpartida-Cardenas K, Miscourides N, Sewell T, Kochina T, Brackin A, Rhodes J, Holmes AH, Fisher MC, Georgiou P. Rapid Detection of Azole-Resistant Aspergillus fumigatus in Clinical and Environmental Isolates by Use of a Lab-on-a-Chip Diagnostic System. J Clin Microbiol 2020; 58:e00843-20. [PMID: 32907990 PMCID: PMC7587087 DOI: 10.1128/jcm.00843-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/27/2020] [Indexed: 12/16/2022] Open
Abstract
Aspergillus fumigatus has widely evolved resistance to the most commonly used class of antifungal chemicals, the azoles. Current methods for identifying azole resistance are time-consuming and depend on specialized laboratories. There is an urgent need for rapid detection of these emerging pathogens at point-of-care to provide the appropriate treatment in the clinic and to improve management of environmental reservoirs to mitigate the spread of antifungal resistance. Our study demonstrates the rapid and portable detection of the two most relevant genetic markers linked to azole resistance, the mutations TR34 and TR46, found in the promoter region of the gene encoding the azole target cyp51A. We developed a lab-on-a-chip platform consisting of: (i) tandem-repeat loop-mediated isothermal amplification; (ii) state-of-the-art complementary metal-oxide-semiconductor microchip technology for nucleic acid amplification detection; and (iii) a smartphone application for data acquisition, visualization, and cloud connectivity. Specific and sensitive detection was validated with isolates from clinical and environmental samples from 6 countries across 5 continents, showing a lower limit of detection of 10 genomic copies per reaction in less than 30 min. When fully integrated with a sample preparation module, this diagnostic system will enable the detection of this ubiquitous fungus at the point-of-care, and could help to improve clinical decision making, infection control, and epidemiological surveillance.
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Affiliation(s)
- Ling-Shan Yu
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Jesus Rodriguez-Manzano
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Nicolas Moser
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Ahmad Moniri
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Kenny Malpartida-Cardenas
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Nicholas Miscourides
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - Thomas Sewell
- MRC Centre for Global Infectious Disease Analysis, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Tatiana Kochina
- MRC Centre for Global Infectious Disease Analysis, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Amelie Brackin
- MRC Centre for Global Infectious Disease Analysis, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Johanna Rhodes
- MRC Centre for Global Infectious Disease Analysis, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Alison H Holmes
- NIHR Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Pantelis Georgiou
- Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Faculty of Engineering, Imperial College London, London, United Kingdom
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13
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Steenwyk JL, Lind AL, Ries LNA, Dos Reis TF, Silva LP, Almeida F, Bastos RW, Fraga da Silva TFDC, Bonato VLD, Pessoni AM, Rodrigues F, Raja HA, Knowles SL, Oberlies NH, Lagrou K, Goldman GH, Rokas A. Pathogenic Allodiploid Hybrids of Aspergillus Fungi. Curr Biol 2020; 30:2495-2507.e7. [PMID: 32502407 PMCID: PMC7343619 DOI: 10.1016/j.cub.2020.04.071] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 02/25/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022]
Abstract
Interspecific hybridization substantially alters genotypes and phenotypes and can give rise to new lineages. Hybrid isolates that differ from their parental species in infection-relevant traits have been observed in several human-pathogenic yeasts and plant-pathogenic filamentous fungi but have yet to be found in human-pathogenic filamentous fungi. We discovered 6 clinical isolates from patients with aspergillosis originally identified as Aspergillus nidulans (section Nidulantes) that are actually allodiploid hybrids formed by the fusion of Aspergillus spinulosporus with an unknown close relative of Aspergillus quadrilineatus, both in section Nidulantes. Evolutionary genomic analyses revealed that these isolates belong to Aspergillus latus, an allodiploid hybrid species. Characterization of diverse infection-relevant traits further showed that A. latus hybrid isolates are genomically and phenotypically heterogeneous but also differ from A. nidulans, A. spinulosporus, and A. quadrilineatus. These results suggest that allodiploid hybridization contributes to the genomic and phenotypic diversity of filamentous fungal pathogens of humans.
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Affiliation(s)
- Jacob L Steenwyk
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN 37235, USA
| | - Abigail L Lind
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, 1211 Medical Center Drive, Nashville, TN 37232, USA; Gladstone Institute of Data Science and Biotechnology, San Francisco, CA 94158, USA
| | - Laure N A Ries
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil; Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil
| | - Thaila F Dos Reis
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil; Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil
| | - Lilian P Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil
| | - Fausto Almeida
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Rafael W Bastos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil
| | - Thais Fernanda de Campos Fraga da Silva
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Vania L D Bonato
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - André Moreira Pessoni
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Avenida Bandeirantes 3900, Vila Monte Alegre, 14049-900 Ribeirão Preto, São Paulo, Brazil
| | - Fernando Rodrigues
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4715-495 Braga, Portugal; ICVS/3B's-PT Government Associate Laboratory, 4715-495 Braga, Portugal
| | - Huzefa A Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 1400 Spring Garden Street, Greensboro, NC 27412, USA
| | - Sonja L Knowles
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 1400 Spring Garden Street, Greensboro, NC 27412, USA
| | - Nicholas H Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 1400 Spring Garden Street, Greensboro, NC 27412, USA
| | - Katrien Lagrou
- Department of Microbiology, Immunology and Transplantation, Katholieke Universiteit Leuven, 3000 Leuven, Belgium; Department of Laboratory Medicine and National Reference Centre for Mycosis, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de São Paulo, Avenida do Café S/N, Ribeirão Preto 14040-903, Brazil.
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, TN 37235, USA; Department of Biomedical Informatics, Vanderbilt University School of Medicine, 1211 Medical Center Drive, Nashville, TN 37232, USA.
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14
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Duarte-Escalante E, Frías-De-León MG, Martínez-Herrera E, Acosta-Altamirano G, Rosas de Paz E, Reséndiz-Sánchez J, Refojo N, Reyes-Montes MDR. Identification of CSP Types and Genotypic Variability of Clinical and Environmental Isolates of Aspergillus fumigatus from Different Geographic Origins. Microorganisms 2020; 8:E688. [PMID: 32397318 PMCID: PMC7284390 DOI: 10.3390/microorganisms8050688] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 11/17/2022] Open
Abstract
The CSP (cell surface protein) microsatellite marker is useful for typing Aspergillus fumigatus isolates and determining relationships at the subpopulation level because it has shown high discriminatory power. In the present study, 90 A. fumigatus isolates from Mexico (MX), Argentina (AR), France (FR), and Peru (PE) were identified through a phylogenetic analysis using the benA gene fragment and were typed with the CSP microsatellite, and the types were identified using the nomenclature recommended in the literature. Genetic variability was analyzed through haplotype diversity, nucleotide diversity, polymorphic sites, and nucleotide differences between pairs of sequences. The population structure was evaluated using the Tajima's D statistic. No new CSP types were recorded in the MX, FR, and PE isolates, while in the AR isolates, two new CSP types were identified (t25 and t26). The most common CSP types in the studied populations were t01, t02, t03, and t04A; these results are consistent with findings in other countries. In addition, the genetic diversity parameters we obtained revealed that the greatest genetic diversity was found in the MX population, followed by AR and FR. No population structure was identified among the isolates studied.
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Affiliation(s)
- Esperanza Duarte-Escalante
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria No. 3000, Mexico Cd. Mx. 04510, Mexico; (E.D.-E.); (E.R.d.P.)
| | - María Guadalupe Frías-De-León
- Hospital Regional de Alta Especialidad de Ixtapaluca, Carretera Federal México-Puebla Km. 34.5, Pueblo de Zoquiapan, Ixtapaluca 56530, Mexico; (M.G.F.-D.-L.); (E.M.-H.); (G.A.-A.)
| | - Erick Martínez-Herrera
- Hospital Regional de Alta Especialidad de Ixtapaluca, Carretera Federal México-Puebla Km. 34.5, Pueblo de Zoquiapan, Ixtapaluca 56530, Mexico; (M.G.F.-D.-L.); (E.M.-H.); (G.A.-A.)
| | - Gustavo Acosta-Altamirano
- Hospital Regional de Alta Especialidad de Ixtapaluca, Carretera Federal México-Puebla Km. 34.5, Pueblo de Zoquiapan, Ixtapaluca 56530, Mexico; (M.G.F.-D.-L.); (E.M.-H.); (G.A.-A.)
| | - Emmanuel Rosas de Paz
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria No. 3000, Mexico Cd. Mx. 04510, Mexico; (E.D.-E.); (E.R.d.P.)
| | - Jesús Reséndiz-Sánchez
- Laboratorio de Micología, Hospital Infantil de México “Federico Gómez”, Doctor Márquez 162, Mexico Cd. Mx. 06720, Mexico;
| | - Nicolás Refojo
- Departamento de Micología, Instituto Nacional de Enfermedades Infecciosas ‘Dr. Carlos G. Malbrán’, Buenos Aires C1282AFF, Argentina;
| | - María del Rocío Reyes-Montes
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria No. 3000, Mexico Cd. Mx. 04510, Mexico; (E.D.-E.); (E.R.d.P.)
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15
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Gutierrez AC, Ordoqui E, Leclerque A, López Lastra C. A new species of Herpomyces (Laboulbeniomycetes: Herpomycetales) on Periplaneta fuliginosa (Blattodea: Blattidae) from Argentina. Mycologia 2020; 112:1184-1191. [PMID: 32297827 DOI: 10.1080/00275514.2020.1726134] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We are becoming increasingly aware of the dazzling diversity of fungi-new taxa are being discovered from poorly sampled habitats and integrative approaches point at (near-)cryptic species in many groups. The class Laboulbeniomycetes, which is composed of three orders (Herpomycetales, Laboulbeniales, Pyxidiophorales), is no exception. However, still, in the orders Herpomycetales and Laboulbeniales, species are predominantly described based on morphology alone. Here, we present a new species of Herpomyces from Argentina parasitic on Periplaneta fuliginosa, the smokybrown cockroach. Herpomyces spegazzinii, sp. nov., is characterized based on morphology and molecular data. Phylogenetic inference based on internal transcribed spacer (ITS, consisting of ITS1-5.8S-ITS2) barcode region supports the status of this fungus as a separate species, sister to the recently described H. shelfordellae.
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Affiliation(s)
- Alejandra C Gutierrez
- Centro de Estudios Parasitológicos y de Vectores, Consejo Nacional de Investigaciones Científicas, Universidad Nacional de La Plata , La Plata 1900, Buenos Aires, Argentina
| | - Eliana Ordoqui
- Centro de Estudios Parasitológicos y de Vectores, Consejo Nacional de Investigaciones Científicas, Universidad Nacional de La Plata , La Plata 1900, Buenos Aires, Argentina.,Comisión de Investigaciones Científicas , La Plata 1900, Buenos Aires, Argentina
| | - Andreas Leclerque
- Institute for Microbiology and Biochemistry, Geisenheim University , 65366 Geisenheim, Germany
| | - Claudia López Lastra
- Centro de Estudios Parasitológicos y de Vectores, Consejo Nacional de Investigaciones Científicas, Universidad Nacional de La Plata , La Plata 1900, Buenos Aires, Argentina
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16
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Sumampow TCP, Shekelle M, Beier P, Walker FM, Hepp CM. Identifying genetic relationships among tarsier populations in the islands of Bunaken National Park and mainland Sulawesi. PLoS One 2020; 15:e0230014. [PMID: 32214331 PMCID: PMC7098592 DOI: 10.1371/journal.pone.0230014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/19/2020] [Indexed: 11/22/2022] Open
Abstract
Eastern tarsiers (Tarsius tarsier complex) are small nocturnal primates endemic to Sulawesi Island and small adjacent islands of Indonesia. In 2004, the hybrid biogeography hypothesis predicted this species complex might contain 16 or more taxa, each corresponding to a region of endemism, based on: 1) geological evidence of the development of the archipelago, 2) biological evidence in the form of concordant distributions of monkeys and toads, and 3) the distribution of tarsier acoustic groups. Since then, 11 tarsier species have been recognized, potentially leaving more to be described. Efforts to identify these cryptic species are urgently needed so that habitat conversion, pet trade, and cultural activities will not render some species extinct before they are recognized. We gathered data to test the hypothesis of cryptic tarsier species on three volcanic islands in Bunaken National Park, North Sulawesi, namely Bunaken, Manadotua, and Mantehage, during May-August 2018. We sequenced individuals at 5 nuclear genes (ABCA1, ADORA3, AXIN1, RAG, and TTR) and made comparisons to existing genotypes at 14 mainland sites. Bayesian phylogenetic analyses revealed that island populations are genetically identical in all 5 genes, and formed a clade separated from the mainland ones. The eastern tarsiers first diverged from the western tarsiers approximately 2.5 MYA. The three island populations diverged from mainland tarsiers approximately 2,000-150,000 YA, due to either human activities or natural rafting. This study provides information for tarsier conservation, advances the understanding of biogeography of Sulawesi, and contributes to Indonesian awareness of biodiversity. Further quantitative genetics research on tarsiers, especially the island populations, will offer significant insights to establish more efficient and strategic tarsier conservation actions.
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Affiliation(s)
| | - Myron Shekelle
- Western Washington University, Bellingham, WA, United States of America
| | - Paul Beier
- School of Forestry, Northern Arizona University, Flagstaff, AZ, United States of America
| | - Faith M. Walker
- School of Forestry, Northern Arizona University, Flagstaff, AZ, United States of America
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States of America
| | - Crystal M. Hepp
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, United States of America
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17
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Abstract
Aspergillus fumigatus is a saprotrophic fungus; its primary habitat is the soil. In its ecological niche, the fungus has learned how to adapt and proliferate in hostile environments. This capacity has helped the fungus to resist and survive against human host defenses and, further, to be responsible for one of the most devastating lung infections in terms of morbidity and mortality. In this review, we will provide (i) a description of the biological cycle of A. fumigatus; (ii) a historical perspective of the spectrum of aspergillus disease and the current epidemiological status of these infections; (iii) an analysis of the modes of immune response against Aspergillus in immunocompetent and immunocompromised patients; (iv) an understanding of the pathways responsible for fungal virulence and their host molecular targets, with a specific focus on the cell wall; (v) the current status of the diagnosis of different clinical syndromes; and (vi) an overview of the available antifungal armamentarium and the therapeutic strategies in the clinical context. In addition, the emergence of new concepts, such as nutritional immunity and the integration and rewiring of multiple fungal metabolic activities occurring during lung invasion, has helped us to redefine the opportunistic pathogenesis of A. fumigatus.
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Affiliation(s)
- Jean-Paul Latgé
- School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Georgios Chamilos
- School of Medicine, University of Crete, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, Crete, Greece
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18
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Cox F, Newsham KK, Robinson CH. Endemic and cosmopolitan fungal taxa exhibit differential abundances in total and active communities of Antarctic soils. Environ Microbiol 2019; 21:1586-1596. [PMID: 30652397 PMCID: PMC6850668 DOI: 10.1111/1462-2920.14533] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 01/13/2019] [Indexed: 01/05/2023]
Abstract
Our understanding of the diversity and community dynamics of soil fungi has increased greatly through the use of DNA-based identification. Community characterization of metabolically active communities via RNA sequencing has previously revealed differences between 'active' and 'total' fungal communities, which may be influenced by the persistence of DNA from nonactive components. However, it is not known how fungal traits influence their prevalence in these contrasting community profiles. In this study, we coextracted DNA and RNA from soil collected from three Antarctic islands to test for differences between total and active soil fungal communities. By matching these geographically isolated fungi against a global dataset of soil fungi, we show that widely dispersed taxa are often more abundant in the total community, whilst taxa restricted to Antarctica are more likely to have higher abundance in the active community. In addition, we find that active communities have lower richness, and show a reduction in the abundance of the most dominant fungi, whilst there are consistent differences in the abundances of certain taxonomic groups between the total and active communities. These results suggest that the views of soil fungal communities offered by DNA- and RNA-based characterization differ in predictable ways.
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Affiliation(s)
- Filipa Cox
- School of Earth & Environmental Sciences, The University of Manchester, Manchester M13 9PL, UK
- NERC British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Kevin K Newsham
- NERC British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Clare H Robinson
- School of Earth & Environmental Sciences, The University of Manchester, Manchester M13 9PL, UK
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19
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Broberg M, Dubey M, Sun MH, Ihrmark K, Schroers HJ, Li SD, Jensen DF, Brandström Durling M, Karlsson M. Out in the Cold: Identification of Genomic Regions Associated With Cold Tolerance in the Biocontrol Fungus Clonostachys rosea Through Genome-Wide Association Mapping. Front Microbiol 2018; 9:2844. [PMID: 30524411 PMCID: PMC6262169 DOI: 10.3389/fmicb.2018.02844] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 11/05/2018] [Indexed: 01/16/2023] Open
Abstract
There is an increasing importance for using biocontrol agents in combating plant diseases sustainably and in the long term. As large scale genomic sequencing becomes economically viable, the impact of single nucleotide polymorphisms (SNPs) on biocontrol-associated phenotypes can be easily studied across entire genomes of fungal populations. Here, we improved a previously reported genome assembly of the biocontrol fungus Clonostachys rosea strain IK726 using the PacBio sequencing platform, which resulted in a total genome size of 70.7 Mbp and 21,246 predicted genes. We further performed whole-genome re-sequencing of 52 additional C. rosea strains isolated globally using Illumina sequencing technology, in order to perform genome-wide association studies in conditions relevant for biocontrol activity. One such condition is the ability to grow at lower temperatures commonly encountered in cryic or frigid soils in temperate regions, as these will be prevalent for protecting growing crops in temperate climates. Growth rates at 10°C on potato dextrose agar of the 53 sequenced strains of C. rosea were measured and ranged between 0.066 and 0.413 mm/day. Performing a genome wide association study, a total of 1,478 SNP markers were significantly associated with the trait and located in 227 scaffolds, within or close to (< 1000 bp distance) 265 different genes. The predicted gene products included several chaperone proteins, membrane transporters, lipases, and proteins involved in chitin metabolism with possible roles in cold tolerance. The data reported in this study provides a foundation for future investigations into the genetic basis for cold tolerance in fungi, with important implications for biocontrol.
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Affiliation(s)
- Martin Broberg
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Mukesh Dubey
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Man-Hong Sun
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Katarina Ihrmark
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | - Shi-Dong Li
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Dan Funck Jensen
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Mikael Brandström Durling
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Magnus Karlsson
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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20
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Haelewaters D, De Kesel A, Pfister DH. Integrative taxonomy reveals hidden species within a common fungal parasite of ladybirds. Sci Rep 2018; 8:15966. [PMID: 30374135 PMCID: PMC6206035 DOI: 10.1038/s41598-018-34319-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 10/08/2018] [Indexed: 11/09/2022] Open
Abstract
Our understanding of fungal diversity is far from complete. Species descriptions generally focus on morphological features, but this approach may underestimate true diversity. Using the morphological species concept, Hesperomyces virescens (Ascomycota, Laboulbeniales) is a single species with global distribution and wide host range. Since its description 120 years ago, this fungal parasite has been reported from 30 species of ladybird hosts on all continents except Antarctica. These host usage patterns suggest that H. virescens could be made up of many different species, each adapted to individual host species. Using sequence data from three gene regions, we found evidence for distinct clades within Hesperomyces virescens, each clade corresponding to isolates from a single host species. We propose that these lineages represent separate species, driven by adaptation to different ladybird hosts. Our combined morphometric, molecular phylogenetic and ecological data provide support for a unified species concept and an integrative taxonomy approach.
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Affiliation(s)
- Danny Haelewaters
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, Massachusetts, 02138, USA.
- Faculty of Science, University of South Bohemia, Branišovská 31, 37005, České Budějovice, Czech Republic.
| | - André De Kesel
- Botanic Garden Meise, Nieuwelaan 38, 1860, Meise, Belgium
| | - Donald H Pfister
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, Massachusetts, 02138, USA
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21
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Cissé OH, Hauser PM. Genomics and evolution of Pneumocystis species. INFECTION GENETICS AND EVOLUTION 2018; 65:308-320. [PMID: 30138710 DOI: 10.1016/j.meegid.2018.08.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 08/15/2018] [Accepted: 08/17/2018] [Indexed: 01/20/2023]
Abstract
The genus Pneumocystis comprises highly diversified fungal species that cause severe pneumonia in individuals with a deficient immune system. These fungi infect exclusively mammals and present a strict host species specificity. These species have co-diverged with their hosts for long periods of time (> 100 MYA). Details of their biology and evolution are fragmentary mainly because of a lack of an established long-term culture system. Recent genomic advances have unlocked new areas of research and allow new hypotheses to be tested. We review here new findings of the genomic studies in relation with the evolutionary trajectory of these fungi and discuss the impact of genomic data analysis in the context of the population genetics. The combination of slow genome decay and limited expansion of specific gene families and introns reflect intimate interactions of these species with their hosts. The evolutionary adaptation of these organisms is profoundly influenced by their population structure, which in turn is determined by intrinsic features such as their self-fertilizing mating system, high host specificity, long generation times, and transmission mode. Essential key questions concerning their adaptation and speciation remain to be answered. The next cornerstone will consist in the establishment of a long-term culture system and genetic manipulation that should allow unravelling the driving forces of Pneumocystis species evolution.
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Affiliation(s)
- Ousmane H Cissé
- Critical Care Medicine Department, NIH Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Philippe M Hauser
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland.
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22
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Silva DN, Várzea V, Paulo OS, Batista D. Population genomic footprints of host adaptation, introgression and recombination in coffee leaf rust. MOLECULAR PLANT PATHOLOGY 2018; 19:1742-1753. [PMID: 29328532 PMCID: PMC6638104 DOI: 10.1111/mpp.12657] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 01/04/2018] [Accepted: 01/09/2018] [Indexed: 05/30/2023]
Abstract
Coffee leaf rust, caused by Hemileia vastatrix (Hv), represents the biggest threat to coffee production worldwide and ranks amongst the most serious fungal diseases in history. Despite a recent series of outbreaks and emergence of hypervirulent strains, the population evolutionary history and potential of this pathogen remain poorly understood. To address this issue, we used restriction site-associated DNA sequencing (RADseq) to generate ∼19 000 single nucleotide polymorphisms (SNPs) across a worldwide collection of 37 Hv samples. Contrary to the long-standing idea that Hv represents a genetically unstructured and cosmopolitan species, our results reveal the existence of a cryptic species complex with marked host tropism. Using phylogenetic and pathological data, we show that one of these lineages (C3) infects almost exclusively the most economically valuable coffee species (tetraploids that include Coffea arabica and interspecific hybrids), whereas the other lineages (C1 and C2) are severely maladapted to these hosts, but successfully infect diploid coffee species. Population dynamic analyses suggest that the C3 group may be a recent 'domesticated' lineage that emerged via host shift from diploid coffee hosts. We also found evidence of recombination occurring within this group, which could explain the high pace of pathotype emergence despite the low genetic variation. Moreover, genomic footprints of introgression between the C3 and C2 groups were discovered and raise the possibility that virulence factors may be quickly exchanged between groups with different pathogenic abilities. This work advances our understanding of the evolutionary strategies used by plant pathogens in agro-ecosystems with direct and far-reaching implications for disease control.
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Affiliation(s)
- Diogo Nuno Silva
- Departamento de Biologia Animal, Centre for Ecology, Evolution and Environmental Changes (cE3c), Computational Biology and Population Genomics Group (CoBiG)Faculdade de Ciências, Universidade de LisboaLisboaPortugal
- Centro de Investigação das Ferrugens do Cafeeiro (CIFC), Instituto Superior de AgronomiaUniversidade de LisboaOeirasPortugal
- Linking Landscape, Environment, Agriculture and Food (LEAF), Instituto Superior de AgronomiaUniversidade de LisboaLisboaPortugal
| | - Vítor Várzea
- Centro de Investigação das Ferrugens do Cafeeiro (CIFC), Instituto Superior de AgronomiaUniversidade de LisboaOeirasPortugal
- Linking Landscape, Environment, Agriculture and Food (LEAF), Instituto Superior de AgronomiaUniversidade de LisboaLisboaPortugal
| | - Octávio Salgueiro Paulo
- Departamento de Biologia Animal, Centre for Ecology, Evolution and Environmental Changes (cE3c), Computational Biology and Population Genomics Group (CoBiG)Faculdade de Ciências, Universidade de LisboaLisboaPortugal
| | - Dora Batista
- Departamento de Biologia Animal, Centre for Ecology, Evolution and Environmental Changes (cE3c), Computational Biology and Population Genomics Group (CoBiG)Faculdade de Ciências, Universidade de LisboaLisboaPortugal
- Centro de Investigação das Ferrugens do Cafeeiro (CIFC), Instituto Superior de AgronomiaUniversidade de LisboaOeirasPortugal
- Linking Landscape, Environment, Agriculture and Food (LEAF), Instituto Superior de AgronomiaUniversidade de LisboaLisboaPortugal
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Banfalvi G. Improved and adopted murine models to combat pulmonary aspergillosis. Appl Microbiol Biotechnol 2018; 102:6865-6875. [DOI: 10.1007/s00253-018-9161-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/05/2018] [Accepted: 06/05/2018] [Indexed: 12/20/2022]
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Lücking R, Hawksworth DL. Formal description of sequence-based voucherless Fungi: promises and pitfalls, and how to resolve them. IMA Fungus 2018; 9:143-166. [PMID: 30018876 PMCID: PMC6048566 DOI: 10.5598/imafungus.2018.09.01.09] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 05/15/2018] [Indexed: 11/25/2022] Open
Abstract
There is urgent need for a formal nomenclature of sequence-based, voucherless Fungi, given that environmental sequencing has accumulated more than one billion fungal ITS reads in the Sequence Read Archive, about 1,000 times as many as fungal ITS sequences in GenBank. These unnamed Fungi could help to bridge the gap between 115,000 to 140,000 currently accepted and 2.2 to 3.8 million predicted species, a gap that cannot realistically be filled using specimen or culture-based inventories. The Code never aimed at placing restrictions on the nature of characters chosen for taxonomy, and the requirement for physical types is now becoming a constraint on the advancement of science. We elaborate on the promises and pitfalls of sequence-based nomenclature and provide potential solutions to major concerns of the mycological community. Types of sequence-based taxa, which by default lack a physical specimen or culture, could be designated in four alternative ways: (1) the underlying sample ('bag' type), (2) the DNA extract, (3) fluorescent in situ hybridization (FISH), or (4) the type sequence itself. Only (4) would require changes to the Code and the latter would be the most straightforward approach, complying with three of the five principal functions of types better than physical specimens. A fifth way, representation of the sequence in an illustration, has been ruled as unacceptable in the Code. Potential flaws in sequence data are analogous to flaws in physical types, and artifacts are manageable if a stringent analytical approach is applied. Conceptual errors such as homoplasy, intragenomic variation, gene duplication, hybridization, and horizontal gene transfer, apply to all molecular approaches and cannot be used as a specific argument against sequence-based nomenclature. The potential impact of these phenomena is manageable, as phylogenetic species delimitation has worked satisfactorily in Fungi. The most serious shortcoming of sequence-based nomenclature is the likelihood of parallel classifications, either by describing taxa that already have names based on physical types, or by using different markers to delimit species within the same lineage. The probability of inadvertently establishing sequence-based species that have names available is between 20.4 % and 1.5 % depending on the number of globally predicted fungal species. This compares favourably to a historical error rate of about 30 % based on physical types, and this rate could be reduced to practically zero by adding specific provisions to this approach in the Code. To avoid parallel classifications based on different markers, sequence-based nomenclature should be limited to a single marker, preferably the fungal ITS barcoding marker; this is possible since sequence-based nomenclature does not aim at accurate species delimitation but at naming lineages to generate a reference database, independent of whether these lineages represent species, closely related species complexes, or infraspecies. We argue that clustering methods are inappropriate for sequence-based nomenclature; this approach must instead use phylogenetic methods based on multiple alignments, combined with quantitative species recognition methods. We outline strategies to obtain higher-level phylogenies for ITS-based, voucherless species, including phylogenetic binning, 'hijacking' species delimitation methods, and temporal banding. We conclude that voucherless, sequence-based nomenclature is not a threat to specimen and culture-based fungal taxonomy, but a complementary approach capable of substantially closing the gap between known and predicted fungal diversity, an approach that requires careful work and high skill levels.
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Affiliation(s)
- Robert Lücking
- Botanischer Garten und Botanisches Museum, Freie Universität Berlin, Königin-Luise-Strasse 6–8, 14195 Berlin, Germany
| | - David L. Hawksworth
- Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK; and Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Surrey TW9 3DS, UK; Jilin Agricultural University, Changchun, Jilin Province,130118 China
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Rama Rao S, Liew TS, Yow YY, Ratnayeke S. Cryptic diversity: Two morphologically similar species of invasive apple snail in Peninsular Malaysia. PLoS One 2018; 13:e0196582. [PMID: 29734361 PMCID: PMC5937749 DOI: 10.1371/journal.pone.0196582] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/16/2018] [Indexed: 11/18/2022] Open
Abstract
Invasive snails in the genus Pomacea have spread across Southeast Asia including Peninsular Malaysia. Their effects on natural and agricultural wetlands are appreciable, but species-specific effects are less clear because of morphological similarity among the species. Our objective was to establish diagnostic characteristics of Pomacea species in Malaysia using genetic and morphological criteria. The mitochondrial COI gene of 52 adult snails from eight localities in Peninsular Malaysia was amplified, sequenced, and analysed to verify species and phylogenetic relationships. Shells were compared using geometric morphometric and covariance analyses. Two monophyletic taxa, P. canaliculata and P. maculata, occurred in our samples. The mean ratio of shell height: aperture height (P = 0.042) and shell height: shell width (P = 0.007) was smaller in P. maculata. P. maculata co-occurred with P. canaliculata in five localities, but samples from three localities contained only P. canaliculata. This study is the first to confirm the presence of two of the most invasive species of Pomacea in Peninsular Malaysia using a molecular technique. P. canaliculata appears to be the more widespread species. Despite statistical differences, both quantitative and qualitative morphological characteristics demonstrated much interspecific overlap and intraspecific variability; thus, shell morphology alone cannot reliably verify species identity. Molecular techniques for distinguishing between these two highly invasive Pomacea species are needed to understand their specific ecological niches and to develop effective protocols for their management.
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Affiliation(s)
- Suganiya Rama Rao
- Department of Biological Sciences, School of Science and Technology, Sunway University, Selangor, Malaysia
| | - Thor-Seng Liew
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Yoon-Yen Yow
- Department of Biological Sciences, School of Science and Technology, Sunway University, Selangor, Malaysia
| | - Shyamala Ratnayeke
- Department of Biological Sciences, School of Science and Technology, Sunway University, Selangor, Malaysia
- * E-mail:
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Abstract
Dispersal is a fundamental biological process, operating at multiple temporal and spatial scales. Despite an increasing understanding of fungal biodiversity, most research on fungal dispersal focuses on only a small fraction of species. Thus, any discussion of the dispersal dynamics of fungi as a whole is problematic. While abundant morphological and biogeographic data are available for hundreds of species, researchers have yet to integrate this information into a unifying paradigm of fungal dispersal, especially in the context of long-distance dispersal (LDD). Fungal LDD is mediated by multiple vectors, including meteorological phenomena (e.g., wind and precipitation), plants (e.g., seeds and senesced leaves), animals (e.g., fur, feathers, and gut microbiomes), and in many cases humans. In addition, fungal LDD is shaped by both physical constraints on travel and the ability of spores to survive harsh environments. Finally, fungal LDD is commonly measured in different ways, including by direct capture of spores, genetic comparisons of disconnected populations, and statistical modeling and simulations of dispersal data. To unify perspectives on fungal LDD, we propose a synthetic three-part definition that includes (i) an identification of the source population and a measure of the concentration of source inoculum and (ii) a measured and/or modeled dispersal kernel. With this information, LDD is defined as (iii) the distance found within the dispersal kernel beyond which only 1% of spores travel.
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Abstract
The question of how many species of Fungi there are has occasioned much speculation, with figures mostly posited from around half a million to 10 million, and in one extreme case even a sizable portion of the spectacular number of 1 trillion. Here we examine new evidence from various sources to derive an updated estimate of global fungal diversity. The rates and patterns in the description of new species from the 1750s show no sign of approaching an asymptote and even accelerated in the 2010s after the advent of molecular approaches to species delimitation. Species recognition studies of (semi-)cryptic species hidden in morpho-species complexes suggest a weighted average ratio of about an order of magnitude for the number of species recognized after and before such studies. New evidence also comes from extrapolations of plant:fungus ratios, with information now being generated from environmental sequence studies, including comparisons of molecular and fieldwork data from the same sites. We further draw attention to undescribed species awaiting discovery in biodiversity hot spots in the tropics, little-explored habitats (such as lichen-inhabiting fungi), and material in collections awaiting study. We conclude that the commonly cited estimate of 1.5 million species is conservative and that the actual range is properly estimated at 2.2 to 3.8 million. With 120,000 currently accepted species, it appears that at best just 8%, and in the worst case scenario just 3%, are named so far. Improved estimates hinge particularly on reliable statistical and phylogenetic approaches to analyze the rapidly increasing amount of environmental sequence data.
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Leavitt SD, Westberg M, Nelsen MP, Elix JA, Timdal E, Sohrabi M, St. Clair LL, Williams L, Wedin M, Lumbsch HT. Multiple, Distinct Intercontinental Lineages but Isolation of Australian Populations in a Cosmopolitan Lichen-Forming Fungal Taxon, Psora decipiens (Psoraceae, Ascomycota). Front Microbiol 2018; 9:283. [PMID: 29527197 PMCID: PMC5829036 DOI: 10.3389/fmicb.2018.00283] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 02/07/2018] [Indexed: 12/12/2022] Open
Abstract
Multiple drivers shape the spatial distribution of species, including dispersal capacity, niche incumbency, climate variability, orographic barriers, and plate tectonics. However, biogeographic patterns of fungi commonly do not fit conventional expectations based on studies of animals and plants. Fungi, in general, are known to occur across exceedingly broad, intercontinental distributions, including some important components of biological soil crust communities (BSCs). However, molecular data often reveal unexpected biogeographic patterns in lichenized fungal species that are assumed to have cosmopolitan distributions. The lichen-forming fungal species Psora decipiens is found on all continents, except Antarctica and occurs in BSCs across diverse habitats, ranging from hot, arid deserts to alpine habitats. In order to better understand factors that shape population structure in cosmopolitan lichen-forming fungal species, we investigated biogeographic patterns in the cosmopolitan taxon P. decipiens, along with the closely related taxa P. crenata and P. saviczii. We generated a multi-locus sequence dataset based on a worldwide sampling of these taxa in order to reconstruct evolutionary relationships and explore phylogeographic patterns. Both P. crenata and P. decipiens were not recovered as monophyletic; and P. saviczii specimens were recovered as a monophyletic clade closely related to a number of lineages comprised of specimens representing P. decipiens. Striking phylogeographic patterns were observed for P. crenata, with populations from distinct geographic regions belonging to well-separated, monophyletic lineages. South African populations of P. crenata were further divided into well-supported sub-clades. While well-supported phylogenetic substructure was also observed for the nominal taxon P. decipiens, nearly all lineages were comprised of specimens collected from intercontinental populations. However, all Australian specimens representing P. decipiens were recovered within a single well-supported monophyletic clade consisting solely of Australian samples. Our study supports up to 10 candidate species-level lineages in P. decipiens, based on genealogical concordance and coalescent-based species delimitation analyses. Our results support the general pattern of the biogeographic isolation of lichen-forming fungal populations in Australia, even in cases where closely related congeners have documented intercontinental distributions. Our study has important implications for understanding factors influencing diversification and distributions of lichens associated with BSC.
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Affiliation(s)
- Steven D. Leavitt
- Department of Biology and Monte L. Bean Life Science Museum, Brigham Young University, Provo, UT, United States
| | | | | | - John A. Elix
- Research School of Chemistry, Australian National University, Canberra, ACT, Australia
| | - Einar Timdal
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Mohammad Sohrabi
- Department of Biotechnology, Iranian Research Organization for Science and Technology, Tehran, Iran
| | - Larry L. St. Clair
- Department of Biology and Monte L. Bean Life Science Museum, Brigham Young University, Provo, UT, United States
| | - Laura Williams
- Plant Ecology and Systematics, Biology Institute, University of Kaiserslautern, Kaiserslautern, Germany
| | - Mats Wedin
- Department of Botany, Swedish Museum of Natural History, Stockholm, Sweden
| | - H. T. Lumbsch
- Science and Education, The Field Museum, Chicago, IL, United States
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29
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Gale SW, Duangjai S, Li J, Ito Y, Watthana S, Termwutthipreecha P, Cheuk ML, Suddee S. Integrative analyses of Nervilia (Orchidaceae) section Linervia reveal further undescribed cryptic diversity in Thailand. SYST BIODIVERS 2018. [DOI: 10.1080/14772000.2017.1415233] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Stephan W. Gale
- Kadoorie Farm and Botanic Garden, Lam Kam Road, Tai Po, New Territories, Hong Kong
| | - Sutee Duangjai
- Department of Forest Biology, Faculty of Forestry, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - Jihong Li
- Kadoorie Farm and Botanic Garden, Lam Kam Road, Tai Po, New Territories, Hong Kong
| | - Yu Ito
- Plant Phylogenetics and Conservation Group, Centre for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China
| | - Santi Watthana
- School of Biology, Institute of Science, Suranaree University of Technology, 111 University Avenue, Muang District, Nakhon Ratchasima 30000, Thailand
| | - Phatsara Termwutthipreecha
- Department of Forest Biology, Faculty of Forestry, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - Mang Lung Cheuk
- Kadoorie Farm and Botanic Garden, Lam Kam Road, Tai Po, New Territories, Hong Kong
| | - Somran Suddee
- Forest Herbarium, Department of National Parks, Wildlife and Plant Conservation, Chatuchak, Bangkok 10900, Thailand
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Savary R, Masclaux FG, Wyss T, Droh G, Cruz Corella J, Machado AP, Morton JB, Sanders IR. A population genomics approach shows widespread geographical distribution of cryptic genomic forms of the symbiotic fungus Rhizophagus irregularis. THE ISME JOURNAL 2018; 12:17-30. [PMID: 29027999 PMCID: PMC5739010 DOI: 10.1038/ismej.2017.153] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 07/20/2017] [Accepted: 08/21/2017] [Indexed: 11/26/2022]
Abstract
Arbuscular mycorrhizal fungi (AMF; phylum Gomeromycota) associate with plants forming one of the most successful microbe-plant associations. The fungi promote plant diversity and have a potentially important role in global agriculture. Plant growth depends on both inter- and intra-specific variation in AMF. It was recently reported that an unusually large number of AMF taxa have an intercontinental distribution, suggesting long-distance gene flow for many AMF species, facilitated by either long-distance natural dispersal mechanisms or human-assisted dispersal. However, the intercontinental distribution of AMF species has been questioned because the use of very low-resolution markers may be unsuitable to detect genetic differences among geographically separated AMF, as seen with some other fungi. This has been untestable because of the lack of population genomic data, with high resolution, for any AMF taxa. Here we use phylogenetics and population genomics to test for intra-specific variation in Rhizophagus irregularis, an AMF species for which genome sequence information already exists. We used ddRAD sequencing to obtain thousands of markers distributed across the genomes of 81 R. irregularis isolates and related species. Based on 6 888 variable positions, we observed significant genetic divergence into four main genetic groups within R. irregularis, highlighting that previous studies have not captured underlying genetic variation. Despite considerable genetic divergence, surprisingly, the variation could not be explained by geographical origin, thus also supporting the hypothesis for at least one AMF species of widely dispersed AMF genotypes at an intercontinental scale. Such information is crucial for understanding AMF ecology, and how these fungi can be used in an environmentally safe way in distant locations.
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Affiliation(s)
- Romain Savary
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - Frédéric G Masclaux
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Tania Wyss
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - Germain Droh
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
- Laboratoire de Génétique, Unité de Formation et de Recherche en Biosciences, Université Félix Houphouet Boigny, Abidjan, Ivory Coast
| | - Joaquim Cruz Corella
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - Ana Paula Machado
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
| | - Joseph B Morton
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA
| | - Ian R Sanders
- Department of Ecology and Evolution, Biophore Building, University of Lausanne, Lausanne, Switzerland
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Santoro K, Matić S, Gisi U, Spadaro D, Pugliese M, Gullino ML. Abundance, genetic diversity and sensitivity to demethylation inhibitor fungicides of Aspergillus fumigatus isolates from organic substrates with special emphasis on compost. PEST MANAGEMENT SCIENCE 2017; 73:2481-2494. [PMID: 28618166 DOI: 10.1002/ps.4642] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 06/10/2017] [Accepted: 06/12/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Aspergillus fumigatus is a widespread fungus that colonizes dead organic substrates but it can also cause fatal human diseases. Aspergilloses are treated with demethylation inhibitor (DMI) fungicides; however, resistant isolates appeared recently in the medical and also environmental area. The present study aims at molecular characterizing and quantifying A. fumigatus in major environmental habitats and determining its sensitivity to medical and agricultural DMI fungicides. RESULTS A. fumigatus was isolated only rarely from soil and meadow/forest organic matter but high concentrations (103 to 107 cfu/g) were detected in substrates subjected to elevated temperatures, such as compost and silage. High genetic diversity of A. fumigatus from compost was found based on SSR markers, distinguishing among fungal isolates even when coming from the same substrate sample, while subclustering was observed based on mutations in cyp51A gene. Several cyp51A amino acid substitutions were found in 15 isolates, although all isolates were fully sensitive to the tested DMI fungicides, with exception of one isolate in combination with one fungicide. CONCLUSION This study suggests that the tested A. fumigatus isolates collected in Italy, Spain and Hungary from the fungus' major living habitats (compost) and commercial growing substrates are not potential carriers for DMI resistance in the environment. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Karin Santoro
- AGROINNOVA - Centre of Competence for the Innovation in the Agro-environmental Sector, Università di Torino, Grugliasco, (TO), Italy
- Dept. Agricultural, Forestry and Food Sciences (DISAFA), Università di Torino, Grugliasco, (TO), Italy
| | - Slavica Matić
- AGROINNOVA - Centre of Competence for the Innovation in the Agro-environmental Sector, Università di Torino, Grugliasco, (TO), Italy
| | - Ulrich Gisi
- AGROINNOVA - Centre of Competence for the Innovation in the Agro-environmental Sector, Università di Torino, Grugliasco, (TO), Italy
| | - Davide Spadaro
- AGROINNOVA - Centre of Competence for the Innovation in the Agro-environmental Sector, Università di Torino, Grugliasco, (TO), Italy
- Dept. Agricultural, Forestry and Food Sciences (DISAFA), Università di Torino, Grugliasco, (TO), Italy
| | - Massimo Pugliese
- AGROINNOVA - Centre of Competence for the Innovation in the Agro-environmental Sector, Università di Torino, Grugliasco, (TO), Italy
- Dept. Agricultural, Forestry and Food Sciences (DISAFA), Università di Torino, Grugliasco, (TO), Italy
- AgriNewTech srl, Torino, (TO), Italy
| | - Maria L Gullino
- AGROINNOVA - Centre of Competence for the Innovation in the Agro-environmental Sector, Università di Torino, Grugliasco, (TO), Italy
- Dept. Agricultural, Forestry and Food Sciences (DISAFA), Università di Torino, Grugliasco, (TO), Italy
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Meis JF, Chowdhary A, Rhodes JL, Fisher MC, Verweij PE. Clinical implications of globally emerging azole resistance in Aspergillus fumigatus. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0460. [PMID: 28080986 DOI: 10.1098/rstb.2015.0460] [Citation(s) in RCA: 209] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/05/2016] [Indexed: 01/23/2023] Open
Abstract
Aspergillus fungi are the cause of an array of diseases affecting humans, animals and plants. The triazole antifungal agents itraconazole, voriconazole, isavuconazole and posaconazole are treatment options against diseases caused by Aspergillus However, resistance to azoles has recently emerged as a new therapeutic challenge in six continents. Although de novo azole resistance occurs occasionally in patients during azole therapy, the main burden is the aquisition of resistance through the environment. In this setting, the evolution of resistance is attributed to the widespread use of azole-based fungicides. Although ubiquitously distributed, A. fumigatus is not a phytopathogen. However, agricultural fungicides deployed against plant pathogenic moulds such as Fusarium, Mycospaerella and A. flavus also show activity against A. fumigatus in the environment and exposure of non-target fungi is inevitable. Further, similarity in molecule structure between azole fungicides and antifungal drugs results in cross-resistance of A. fumigatus to medical azoles. Clinical studies have shown that two-thirds of patients with azole-resistant infections had no previous history of azole therapy and high mortality rates between 50% and 100% are reported in azole-resistant invasive aspergillosis. The resistance phenotype is associated with key mutations in the cyp51A gene, including TR34/L98H, TR53 and TR46/Y121F/T289A resistance mechanisms. Early detection of resistance is of paramount importance and if demonstrated, either with susceptibility testing or through molecular analysis, azole monotherapy should be avoided. Liposomal amphotericin B or a combination of voriconazole and an echinocandin are recomended for azole-resistant aspergillosis.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'.
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Affiliation(s)
- Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius Wihelmina Hospital (CWZ), Nijmegen, The Netherlands .,Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboudumc/CWZ Centre of Excellence in Mycology, Nijmegen, The Netherlands
| | - Anuradha Chowdhary
- Department of Medical Microbiology, Division of Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Johanna L Rhodes
- Department of Infectious Disease Epidemiology, Imperial College School of Public Health, St Mary's Campus, London, UK
| | - Matthew C Fisher
- Department of Infectious Disease Epidemiology, Imperial College School of Public Health, St Mary's Campus, London, UK
| | - Paul E Verweij
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboudumc/CWZ Centre of Excellence in Mycology, Nijmegen, The Netherlands
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Hagen F, Lumbsch HT, Arsic Arsenijevic V, Badali H, Bertout S, Billmyre RB, Bragulat MR, Cabañes FJ, Carbia M, Chakrabarti A, Chaturvedi S, Chaturvedi V, Chen M, Chowdhary A, Colom MF, Cornely OA, Crous PW, Cuétara MS, Diaz MR, Espinel-Ingroff A, Fakhim H, Falk R, Fang W, Herkert PF, Ferrer Rodríguez C, Fraser JA, Gené J, Guarro J, Idnurm A, Illnait-Zaragozi MT, Khan Z, Khayhan K, Kolecka A, Kurtzman CP, Lagrou K, Liao W, Linares C, Meis JF, Nielsen K, Nyazika TK, Pan W, Pekmezovic M, Polacheck I, Posteraro B, de Queiroz Telles F, Romeo O, Sánchez M, Sampaio A, Sanguinetti M, Sriburee P, Sugita T, Taj-Aldeen SJ, Takashima M, Taylor JW, Theelen B, Tomazin R, Verweij PE, Wahyuningsih R, Wang P, Boekhout T. Importance of Resolving Fungal Nomenclature: the Case of Multiple Pathogenic Species in the Cryptococcus Genus. mSphere 2017; 2:e00238-17. [PMID: 28875175 PMCID: PMC5577652 DOI: 10.1128/msphere.00238-17] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. After more than 15 years of molecular genetic and phenotypic studies and much debate, a proposal for a taxonomic revision was made. The two varieties within C. neoformans were raised to species level, and the same was done for five genotypes within C. gattii. In a recent perspective (K. J. Kwon-Chung et al., mSphere 2:e00357-16, 2017, https://doi.org/10.1128/mSphere.00357-16), it was argued that this taxonomic proposal was premature and without consensus in the community. Although the authors of the perspective recognized the existence of genetic diversity, they preferred the use of the informal nomenclature "C. neoformans species complex" and "C. gattii species complex." Here we highlight the advantage of recognizing these seven species, as ignoring these species will impede deciphering further biologically and clinically relevant differences between them, which may in turn delay future clinical advances.
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Affiliation(s)
- Ferry Hagen
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
- Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | | | | | - Hamid Badali
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), Mazandaran University of Medical Sciences, Sari, Iran
| | - Sebastien Bertout
- Unité Mixte Internationale Recherches Translationnelles sur l’Infection à VIH et les Maladies Infectieuses, Laboratoire de Parasitologie et Mycologie Médicale, UFR Pharmacie, Université Montpellier, Montpellier, France
| | - R. Blake Billmyre
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - M. Rosa Bragulat
- Veterinary Mycology Group, Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - F. Javier Cabañes
- Veterinary Mycology Group, Department of Animal Health and Anatomy, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Mauricio Carbia
- Departamento de Parasitología y Micología, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Arunaloke Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sudha Chaturvedi
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Vishnu Chaturvedi
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Min Chen
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
- Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | | | - Oliver A. Cornely
- CECAD Cluster of Excellence, University of Cologne, Cologne, Germany
- Department I for Internal Medicine, University Hospital of Cologne, Cologne, Germany
- Center for Clinical Trials, University Hospital Cologne, Cologne, Germany
| | - Pedro W. Crous
- Phytopathology Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
- Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai, Thailand
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Maria S. Cuétara
- Department of Microbiology, Hospital Severo Ochoa, Madrid, Spain
| | - Mara R. Diaz
- University of Miami, NSF NIEHS Oceans and Human Health Center, Miami, Florida, USA
- Rosentiel School of Marine and Atmospheric Science, Division of Marine Biology and Fisheries, University of Miami, Miami, Florida, USA
| | | | - Hamed Fakhim
- Department of Medical Parasitology and Mycology/Cellular and Molecular Research Center, Urmia University of Medical Sciences, Urmia, Iran
| | - Rama Falk
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel
- Department of Fisheries and Aquaculture, Ministry of Agriculture and Rural Development, Nir-David, Israel
| | - Wenjie Fang
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
- Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Patricia F. Herkert
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
- Postgraduate Program in Microbiology, Parasitology and Pathology, Biological Sciences, Department of Basic Pathology, Federal University of Parana, Curitiba, Brazil
| | | | - James A. Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry & Molecular Biosciences, University of Queensland, Brisbane, Australia
| | - Josepa Gené
- Unitat de Micologia, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain
| | - Josep Guarro
- Unitat de Micologia, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain
| | - Alexander Idnurm
- School of BioSciences, BioSciences 2, University of Melbourne, Melbourne, Australia
| | | | - Ziauddin Khan
- Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| | - Kantarawee Khayhan
- Department of Microbiology and Parasitology, Faculty of Medical Sciences, University of Phayao, Phayao, Thailand
- Yeast Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Anna Kolecka
- Yeast Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Cletus P. Kurtzman
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, USDA-ARS, Peoria, Illinois, USA
| | - Katrien Lagrou
- Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
- Department of Microbiology and Immunology, KU Leuven - University of Leuven, Leuven, Belgium
| | - Wanqing Liao
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
- Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Carlos Linares
- Medical School, Universidad Miguel Hernández, Alicante, Spain
| | - Jacques F. Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
- Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Tinashe K. Nyazika
- Department of Medical Microbiology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe
- Malawi-Liverpool-Wellcome Trust, College of Medicine, University of Malawi, Blantyre, Malawi
- School of Tropical Medicine, Liverpool, United Kingdom
| | - Weihua Pan
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Second Military Medical University, Shanghai, China
- Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | | | - Itzhack Polacheck
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel
| | - Brunella Posteraro
- Institute of Public Health (Section of Hygiene), Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Flavio de Queiroz Telles
- Department of Communitarian Health, Hospital de Clínicas, Federal University of Parana, Curitiba, Brazil
| | - Orazio Romeo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
- IRCCS Centro Neurolesi Bonino-Pulejo, Messina, Italy
| | - Manuel Sánchez
- Medical School, Universidad Miguel Hernández, Alicante, Spain
| | - Ana Sampaio
- Centro de Investigação e de Tecnologias Agro-ambientais e Biológicas (CITAB), Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta dos Prados, Vila Real, Portugal
| | - Maurizio Sanguinetti
- Institute of Microbiology, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Pojana Sriburee
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Takashi Sugita
- Department of Microbiology, Meiji Pharmaceutical University, Noshio, Kiyose, Tokyo, Japan
| | - Saad J. Taj-Aldeen
- Mycology Unit, Microbiology Division, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar
| | - Masako Takashima
- Japan Collection of Microorganisms, RIKEN BioResource Center, Koyadai, Tsukuba, Ibaraki, Japan
| | - John W. Taylor
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, USA
| | - Bart Theelen
- Yeast Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Rok Tomazin
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Paul E. Verweij
- Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Retno Wahyuningsih
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, School of Medicine, Universitas Kristen Indonesia, Jakarta, Indonesia
| | - Ping Wang
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
- Department of Pediatrics, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Teun Boekhout
- Institute of Biodiversity and Ecosystems Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
- Yeast Research, Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
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Invasive Everywhere? Phylogeographic Analysis of the Globally Distributed Tree Pathogen Lasiodiplodia theobromae. FORESTS 2017. [DOI: 10.3390/f8050145] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Global Population Genetic Analysis of Aspergillus fumigatus. mSphere 2017; 2:mSphere00019-17. [PMID: 28168221 PMCID: PMC5288565 DOI: 10.1128/msphere.00019-17] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 01/17/2023] Open
Abstract
The genetic diversity and geographic structure of the human fungal pathogen A. fumigatus have been the subject of many studies. However, most previous studies had relatively limited sample ranges and sizes and/or used genetic markers with low-level polymorphisms. In this paper, we characterize a global collection of strains of A. fumigatus using a panel of 9 highly polymorphic microsatellite markers. Using these markers, we analyze 2,026 isolates, which is ~3 times the number of isolates reported so far in previous studies. Our analyses suggest that A. fumigatus contains historically differentiated genetic populations but that its evolution is significantly impacted by contemporary forces such as widespread gene flow and local antifungal drug pressure. In the wake of a global rise in resistance to azoles in fungal pathogens, our findings should aid in developing management strategies to mitigate current increases to azole resistance. Aspergillus fumigatus is a ubiquitous opportunistic fungal pathogen capable of causing invasive aspergillosis, a globally distributed disease with a mortality rate of up to 90% in high-risk populations. Effective control and prevention of this disease require a thorough understanding of its epidemiology. However, despite significant efforts, the global molecular epidemiology of A. fumigatus remains poorly understood. In this study, we analyzed 2,026 A. fumigatus isolates from 13 countries in four continents using nine highly polymorphic microsatellite markers. Genetic cluster analyses suggest that our global sample of A. fumigatus isolates belonged to eight genetic clusters, with seven of the eight clusters showing broad geographic distributions. We found common signatures of sexual recombination within individual genetic clusters and clear evidence of hybridization between several clusters. Limited but statistically significant genetic differentiations were found among geographic and ecological populations. However, there was abundant evidence for gene flow at the local, regional, and global scales. Interestingly, the triazole-susceptible and triazole-resistant populations showed different population structures, consistent with antifungal drug pressure playing a significant role in local adaptation. Our results suggest that global populations of A. fumigatus are shaped by historical differentiation, contemporary gene flow, sexual reproduction, and the localized antifungal drug selection that is driving clonal expansion of genotypes resistant to multiple triazole drugs. IMPORTANCE The genetic diversity and geographic structure of the human fungal pathogen A. fumigatus have been the subject of many studies. However, most previous studies had relatively limited sample ranges and sizes and/or used genetic markers with low-level polymorphisms. In this paper, we characterize a global collection of strains of A. fumigatus using a panel of 9 highly polymorphic microsatellite markers. Using these markers, we analyze 2,026 isolates, which is ~3 times the number of isolates reported so far in previous studies. Our analyses suggest that A. fumigatus contains historically differentiated genetic populations but that its evolution is significantly impacted by contemporary forces such as widespread gene flow and local antifungal drug pressure. In the wake of a global rise in resistance to azoles in fungal pathogens, our findings should aid in developing management strategies to mitigate current increases to azole resistance.
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Pavlic D, Slippers B, Coutinho TA, Wingfield MJ. Molecular and phenotypic characterization of three phylogenetic species discovered within theNeofusicoccum parvum/N. ribiscomplex. Mycologia 2017; 101:636-47. [DOI: 10.3852/08-193] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Draginja Pavlic
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Centre of Excellence in Tree Health Biotechnology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0002, South Africa
| | - Bernard Slippers
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), Centre of Excellence in Tree Health Biotechnology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0002, South Africa
| | | | - Michael J. Wingfield
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Centre of Excellence in Tree Health Biotechnology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0002, South Africa
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Poulin R, Pérez-Ponce de León G. Global analysis reveals that cryptic diversity is linked with habitat but not mode of life. J Evol Biol 2017; 30:641-649. [DOI: 10.1111/jeb.13034] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 01/23/2023]
Affiliation(s)
- R. Poulin
- Department of Zoology; University of Otago; Dunedin New Zealand
| | - G. Pérez-Ponce de León
- Departamento de Zoología; Instituto de Biología; Universidad Nacional Autónoma de México, Ciudad Universitaria; México D.F. México
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Overview of Phylogenetic Approaches to Mycorrhizal Biogeography, Diversity and Evolution. BIOGEOGRAPHY OF MYCORRHIZAL SYMBIOSIS 2017. [DOI: 10.1007/978-3-319-56363-3_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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McTaggart LR, Brown EM, Richardson SE. Phylogeographic Analysis of Blastomyces dermatitidis and Blastomyces gilchristii Reveals an Association with North American Freshwater Drainage Basins. PLoS One 2016; 11:e0159396. [PMID: 27428521 PMCID: PMC4948877 DOI: 10.1371/journal.pone.0159396] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/03/2016] [Indexed: 11/25/2022] Open
Abstract
Blastomyces dermatitidis and Blastomyces gilchristii are dimorphic fungal pathogens that cause serious pulmonary and systemic infections in humans. Although their natural habitat is in the environment, little is known about their specific ecologic niche(s). Here, we analyzed 25 microsatellite loci from 169 strains collected from various regions throughout their known endemic range in North America, representing the largest and most geographically diverse collection of isolates studied to date. Genetic analysis of multilocus microsatellite data divided the strains into four populations of B. dermatitidis and four populations of B. gilchristii. B. dermatitidis isolates were recovered from areas throughout North America, while the B. gilchristii strains were restricted to Canada and some northern US states. Furthermore, the populations of both species were associated with major freshwater drainage basins. The four B. dermatitidis populations were partitioned among (1) the Nelson River drainage basin, (2) the St. Lawrence River and northeast Atlantic Ocean Seaboard drainage basins, (3) the Mississippi River System drainage basin, and (4) the Gulf of Mexico Seaboard and southeast Atlantic Ocean Seaboard drainage basins. A similar partitioning of the B. gilchristii populations was observed among the more northerly drainage basins only. These associations suggest that the ecologic niche where the sexual reproduction, growth, and dispersal of B. dermatitidis and B. gilchristii occur is intimately linked to freshwater systems. For most populations, sexual reproduction was rare enough to produce significant linkage disequilibrium among loci but frequent enough that mating-type idiomorphic ratios were not skewed from 1:1. Furthermore, the evolutionary divergence of B. dermatitidis and B. gilchristii was estimated at 1.9 MYA during the Pleistocene epoch. We suggest that repeated glaciations during the Pleistocene period and resulting biotic refugia may have provided the impetus for speciation as theorized for other species associated with temperate freshwater systems.
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Affiliation(s)
- Lisa R. McTaggart
- Public Health Laboratories Toronto, Public Health Ontario, Toronto, Ontario, Canada
- * E-mail:
| | - Elizabeth M. Brown
- Public Health Laboratories Toronto, Public Health Ontario, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Susan E. Richardson
- Public Health Laboratories Toronto, Public Health Ontario, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Division of Microbiology, Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
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Lumbsch HT, Kirika PM, Divakar PK, Crespo A, Mugambi G, Orock EA, Leavitt SD, Gatheri GW. Phylogenetic studies uncover a predominantly African lineage in a widely distributed lichen-forming fungal species. MycoKeys 2016. [DOI: 10.3897/mycokeys.14.8971] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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Croft CA, Culibrk L, Moore MM, Tebbutt SJ. Interactions of Aspergillus fumigatus Conidia with Airway Epithelial Cells: A Critical Review. Front Microbiol 2016; 7:472. [PMID: 27092126 PMCID: PMC4823921 DOI: 10.3389/fmicb.2016.00472] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/21/2016] [Indexed: 02/05/2023] Open
Abstract
Aspergillus fumigatus is an environmental filamentous fungus that also acts as an opportunistic pathogen able to cause a variety of symptoms, from an allergic response to a life-threatening disseminated fungal infection. The infectious agents are inhaled conidia whose first point of contact is most likely to be an airway epithelial cell (AEC). The interaction between epithelial cells and conidia is multifaceted and complex, and has implications for later steps in pathogenesis. Increasing evidence has demonstrated a key role for the airway epithelium in the response to respiratory pathogens, particularly at early stages of infection; therefore, elucidating the early stages of interaction of conidia with AECs is essential to understand the establishment of infection in cohorts of at-risk patients. Here, we present a comprehensive review of the early interactions between A. fumigatus and AECs, including bronchial and alveolar epithelial cells. We describe mechanisms of adhesion, internalization of conidia by AECs, the immune response of AECs, as well as the role of fungal virulence factors, and patterns of fungal gene expression characteristic of early infection. A clear understanding of the mechanisms involved in the early establishment of infection by A. fumigatus could point to novel targets for therapy and prophylaxis.
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Affiliation(s)
- Carys A Croft
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver BC, Canada
| | - Luka Culibrk
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, Vancouver BC, Canada
| | - Margo M Moore
- Department of Biological Sciences, Simon Fraser University, Burnaby BC, Canada
| | - Scott J Tebbutt
- Centre for Heart Lung Innovation, St. Paul's Hospital, University of British Columbia, VancouverBC, Canada; Prevention of Organ Failure Centre of Excellence, VancouverBC, Canada; Department of Medicine, Division of Respiratory Medicine, University of British Columbia, VancouverBC, Canada
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Skoracka A, Magalhães S, Rector BG, Kuczyński L. Cryptic speciation in the Acari: a function of species lifestyles or our ability to separate species? EXPERIMENTAL & APPLIED ACAROLOGY 2015; 67:165-82. [PMID: 26209969 PMCID: PMC4559570 DOI: 10.1007/s10493-015-9954-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 07/19/2015] [Indexed: 05/08/2023]
Abstract
There are approximately 55,000 described Acari species, accounting for almost half of all known Arachnida species, but total estimated Acari diversity is reckoned to be far greater. One important source of currently hidden Acari diversity is cryptic speciation, which poses challenges to taxonomists documenting biodiversity assessment as well as to researchers in medicine and agriculture. In this review, we revisit the subject of biodiversity in the Acari and investigate what is currently known about cryptic species within this group. Based on a thorough literature search, we show that the probability of occurrence of cryptic species is mainly related to the number of attempts made to detect them. The use of, both, DNA tools and bioassays significantly increased the probability of cryptic species detection. We did not confirm the generally-accepted idea that species lifestyle (i.e. free-living vs. symbiotic) affects the number of cryptic species. To increase detection of cryptic lineages and to understand the processes leading to cryptic speciation in Acari, integrative approaches including multivariate morphometrics, molecular tools, crossing, ecological assays, intensive sampling, and experimental evolution are recommended. We conclude that there is a demonstrable need for future investigations focusing on potentially hidden mite and tick species and addressing evolutionary mechanisms behind cryptic speciation within Acari.
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Affiliation(s)
- Anna Skoracka
- Department of Animal Taxonomy and Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland,
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Leavitt SD, Divakar PK, Ohmura Y, Wang LS, Esslinger TL, Lumbsch HT. Who’s getting around? Assessing species diversity and phylogeography in the widely distributed lichen-forming fungal genus Montanelia (Parmeliaceae, Ascomycota). Mol Phylogenet Evol 2015; 90:85-96. [DOI: 10.1016/j.ympev.2015.04.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 02/13/2015] [Accepted: 04/30/2015] [Indexed: 10/23/2022]
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Irmer H, Tarazona S, Sasse C, Olbermann P, Loeffler J, Krappmann S, Conesa A, Braus GH. RNAseq analysis of Aspergillus fumigatus in blood reveals a just wait and see resting stage behavior. BMC Genomics 2015; 16:640. [PMID: 26311470 PMCID: PMC4551469 DOI: 10.1186/s12864-015-1853-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 08/17/2015] [Indexed: 12/20/2022] Open
Abstract
Background Invasive aspergillosis is started after germination of Aspergillus fumigatus conidia that are inhaled by susceptible individuals. Fungal hyphae can grow in the lung through the epithelial tissue and disseminate hematogenously to invade into other organs. Low fungaemia indicates that fungal elements do not reside in the bloodstream for long. Results We analyzed whether blood represents a hostile environment to which the physiology of A. fumigatus has to adapt. An in vitro model of A. fumigatus infection was established by incubating mycelium in blood. Our model allowed to discern the changes of the gene expression profile of A. fumigatus at various stages of the infection. The majority of described virulence factors that are connected to pulmonary infections appeared not to be activated during the blood phase. Three active processes were identified that presumably help the fungus to survive the blood environment in an advanced phase of the infection: iron homeostasis, secondary metabolism, and the formation of detoxifying enzymes. Conclusions We propose that A. fumigatus is hardly able to propagate in blood. After an early stage of sensing the environment, virtually all uptake mechanisms and energy-consuming metabolic pathways are shut-down. The fungus appears to adapt by trans-differentiation into a resting mycelial stage. This might reflect the harsh conditions in blood where A. fumigatus cannot take up sufficient nutrients to establish self-defense mechanisms combined with significant growth. Electronic supplementary material The online version of this article (doi10.1186/s12864-015-1853-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Henriette Irmer
- Institut für Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Grisebachstraße 8, D-37077, Göttingen, Germany.
| | - Sonia Tarazona
- Genomics of Gene Expression Lab, Prince Felipe Research Center, Av. Eduardo Primo Yufera 3, 46012, Valencia, Spain.
| | - Christoph Sasse
- Institut für Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Grisebachstraße 8, D-37077, Göttingen, Germany.
| | - Patrick Olbermann
- Research Center for Infectious Diseases, Julius-Maximilians University Würzburg, Würzburg, Germany.
| | - Jürgen Loeffler
- Laboratory WÜ4i, Medical Clinic and Policlinic II, University Clinic Würzburg, Würzburg, Germany.
| | - Sven Krappmann
- Research Center for Infectious Diseases, Julius-Maximilians University Würzburg, Würzburg, Germany. .,Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinik Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
| | - Ana Conesa
- Genomics of Gene Expression Lab, Prince Felipe Research Center, Av. Eduardo Primo Yufera 3, 46012, Valencia, Spain. .,Department of Microbiology and Cell Science, Institute for Food and Agricultura Sciences, University of Florida at Gainesville, Gainesville, FL, USA.
| | - Gerhard H Braus
- Institut für Mikrobiologie und Genetik, Georg-August-Universität Göttingen, Grisebachstraße 8, D-37077, Göttingen, Germany.
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Genomic Context of Azole Resistance Mutations in Aspergillus fumigatus Determined Using Whole-Genome Sequencing. mBio 2015; 6:e00536. [PMID: 26037120 PMCID: PMC4453006 DOI: 10.1128/mbio.00536-15] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A rapid and global emergence of azole resistance has been observed in the pathogenic fungus Aspergillus fumigatus over the past decade. The dominant resistance mechanism appears to be of environmental origin and involves mutations in the cyp51A gene, which encodes a protein targeted by triazole antifungal drugs. Whole-genome sequencing (WGS) was performed for high-resolution single-nucleotide polymorphism (SNP) analysis of 24 A. fumigatus isolates, including azole-resistant and susceptible clinical and environmental strains obtained from India, the Netherlands, and the United Kingdom, in order to assess the utility of WGS for characterizing the alleles causing resistance. WGS analysis confirmed that TR34/L98H (a mutation comprising a tandem repeat [TR] of 34 bases in the promoter of the cyp51A gene and a leucine-to-histidine change at codon 98) is the sole mechanism of azole resistance among the isolates tested in this panel of isolates. We used population genomic analysis and showed that A. fumigatus was panmictic, with as much genetic diversity found within a country as is found between continents. A striking exception to this was shown in India, where isolates are highly related despite being isolated from both clinical and environmental sources across >1,000 km; this broad occurrence suggests a recent selective sweep of a highly fit genotype that is associated with the TR34/L98H allele. We found that these sequenced isolates are all recombining, showing that azole-resistant alleles are segregating into diverse genetic backgrounds. Our analysis delineates the fundamental population genetic parameters that are needed to enable the use of genome-wide association studies to identify the contribution of SNP diversity to the generation and spread of azole resistance in this medically important fungus. Resistance to azoles in the ubiquitous ascomycete fungus A. fumigatus was first reported from clinical isolates collected in the United States during the late 1980s. Over the last decade, an increasing number of A. fumigatus isolates from the clinic and from nature have been found to show resistance to azoles, suggesting that resistance is emerging through selection by the widespread usage of agricultural azole antifungal compounds. Aspergillosis is an emerging clinical problem, with high rates of treatment failures necessitating the development of new techniques for surveillance and for determining the genome-wide basis of azole resistance in A. fumigatus.
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Dumas P, Barbut J, Le Ru B, Silvain JF, Clamens AL, d’Alençon E, Kergoat GJ. Phylogenetic molecular species delimitations unravel potential new species in the pest genus Spodoptera Guenée, 1852 (Lepidoptera, Noctuidae). PLoS One 2015; 10:e0122407. [PMID: 25853412 PMCID: PMC4390195 DOI: 10.1371/journal.pone.0122407] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/20/2015] [Indexed: 02/03/2023] Open
Abstract
Nowadays molecular species delimitation methods promote the identification of species boundaries within complex taxonomic groups by adopting innovative species concepts and theories (e.g. branching patterns, coalescence). As some of them can efficiently deal with large single-locus datasets, they could speed up the process of species discovery compared to more time consuming molecular methods, and benefit from the existence of large public datasets; these methods can also particularly favour scientific research and actions dealing with threatened or economically important taxa. In this study we aim to investigate and clarify the status of economically important moths species belonging to the genus Spodoptera (Lepidoptera, Noctuidae), a complex group in which previous phylogenetic analyses and integrative approaches already suggested the possible occurrence of cryptic species and taxonomic ambiguities. In this work, the effectiveness of innovative (and faster) species delimitation approaches to infer putative species boundaries has been successfully tested in Spodoptera, by processing the most comprehensive dataset (in terms of number of species and specimens) ever achieved; results are congruent and reliable, irrespective of the set of parameters and phylogenetic models applied. Our analyses confirm the existence of three potential new species clusters (for S. exigua (Hübner, 1808), S. frugiperda (J.E. Smith, 1797) and S. mauritia (Boisduval, 1833)) and support the synonymy of S. marima (Schaus, 1904) with S. ornithogalli (Guenée, 1852). They also highlight the ambiguity of the status of S. cosmiodes (Walker, 1858) and S. descoinsi Lalanne-Cassou & Silvain, 1994. This case study highlights the interest of molecular species delimitation methods as valuable tools for species discovery and to emphasize taxonomic ambiguities.
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Affiliation(s)
- Pascaline Dumas
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Jérôme Barbut
- Direction des collections—USM 602, Muséum National d’Histoire Naturelle, Paris, France
| | - Bruno Le Ru
- IRD/CNRS, Laboratoire Evolution Génomes Spéciation, Avenue de la terrasse, Gif-sur-Yvette, France and Université Paris-Sud 11, Orsay, France
- Unité de Recherche IRD 072, African Insect Science for Food and Health (icipe), Nairobi, Kenya
| | - Jean-François Silvain
- IRD/CNRS, Laboratoire Evolution Génomes Spéciation, Avenue de la terrasse, Gif-sur-Yvette, France and Université Paris-Sud 11, Orsay, France
| | - Anne-Laure Clamens
- INRA—UMR 1062 CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Montferrier-sur-Lez, France
| | - Emmanuelle d’Alençon
- UM2—UMR 1333 DGIMI, Université Montpellier 2, Montpellier, France
- INRA—UMR 1333 DGIMI, Université Montpellier 2, Montpellier, France
| | - Gael J. Kergoat
- INRA—UMR 1062 CBGP (INRA, IRD, CIRAD, Montpellier SupAgro), Montferrier-sur-Lez, France
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Yurkov A, Guerreiro MA, Sharma L, Carvalho C, Fonseca Á. Multigene assessment of the species boundaries and sexual status of the basidiomycetous yeasts Cryptococcus flavescens and C. terrestris (Tremellales). PLoS One 2015; 10:e0120400. [PMID: 25811603 PMCID: PMC4374795 DOI: 10.1371/journal.pone.0120400] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 01/21/2015] [Indexed: 02/06/2023] Open
Abstract
Cryptococcus flavescens and C. terrestris are phenotypically indistinguishable sister species that belong to the order Tremellales (Tremellomycetes, Basidiomycota) and which may be mistaken for C. laurentii based on phenotype. Phylogenetic separation between C. flavescens and C. terrestris was based on rDNA sequence analyses, but very little is known on their intraspecific genetic variability or propensity for sexual reproduction. We studied 59 strains from different substrates and geographic locations, and used a multilocus sequencing (MLS) approach complemented with the sequencing of mating type (MAT) genes to assess genetic variation and reexamine the boundaries of the two species, as well as their sexual status. The following five loci were chosen for MLS: the rDNA ITS-LSU region, the rDNA IGS1 spacer, and fragments of the genes encoding the largest subunit of RNA polymerase II (RPB1), the translation elongation factor 1 alpha (TEF1) and the p21-activated protein kinase (STE20). Phylogenetic network analyses confirmed the genetic separation of the two species and revealed two additional cryptic species, for which the names Cryptococcus baii and C. ruineniae are proposed. Further analyses of the data revealed a high degree of genetic heterogeneity within C. flavescens as well as evidence for recombination between lineages detected for this species. Strains of C. terrestris displayed higher levels of similarity in all analysed genes and appear to make up a single recombining group. The two MAT genes (STE3 and SXI1/SXI2) sequenced for C. flavescens strains confirmed the potential for sexual reproduction and suggest the presence of a tetrapolar mating system with a biallelic pheromone/receptor locus and a multiallelic HD locus. In C. terrestris we could only sequence STE3, which revealed a biallelic P/R locus. In spite of the strong evidence for sexual recombination in the two species, attempts at mating compatible strains of both species on culture media were unsuccessful.
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Affiliation(s)
- Andrey Yurkov
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
- * E-mail:
| | - Marco A. Guerreiro
- Centro de Recursos Microbiológicos, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Lav Sharma
- Centro de Recursos Microbiológicos, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Cláudia Carvalho
- Centro de Recursos Microbiológicos, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Álvaro Fonseca
- Centro de Recursos Microbiológicos, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
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Short DPG, Gurung S, Gladieux P, Inderbitzin P, Atallah ZK, Nigro F, Li G, Benlioglu S, Subbarao KV. Globally invading populations of the fungal plant pathogen Verticillium dahliae are dominated by multiple divergent lineages. Environ Microbiol 2015; 17:2824-40. [PMID: 25630463 DOI: 10.1111/1462-2920.12789] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/16/2014] [Accepted: 12/17/2014] [Indexed: 11/28/2022]
Abstract
The spread of aggressive fungal pathogens into previously non-endemic regions is a major threat to plant health and food security. Analyses of the spatial and genetic structure of plant pathogens offer valuable insights into their origin, dispersal mechanisms and evolution, and have been useful to develop successful disease management strategies. Here, we elucidated the genetic diversity, population structure and demographic history of worldwide invasion of the ascomycete Verticillium dahliae, a soil-borne pathogen, using a global collection of 1100 isolates from multiple plant hosts and countries. Seven well-differentiated genetic clusters were revealed through discriminant analysis of principal components (DAPC), but no strong associations between these clusters and host/geographic origin of isolates were found. Analyses of clonal evolutionary relationships among multilocus genotypes with the eBURST algorithm and analyses of genetic distances revealed that genetic clusters represented several ancient evolutionary lineages with broad geographic distribution and wide host range. Comparison of different scenarios of demographic history using approximate Bayesian computations revealed the branching order among the different genetic clusters and lineages. The different lineages may represent incipient species, and this raises questions with respect to their evolutionary origin and the factors allowing their maintenance in the same areas and same hosts without evidence of admixture between them. Based on the above findings and the biology of V. dahliae, we conclude that anthropogenic movement has played an important role in spreading V. dahliae lineages. Our findings have implications for the development of management strategies such as quarantine measures and crop resistance breeding.
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Affiliation(s)
- Dylan P G Short
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Suraj Gurung
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Pierre Gladieux
- Ecologie Systematique Evolution, CNRS, Université Paris Sud, Orsay, F-91405, France
| | - Patrik Inderbitzin
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Zahi K Atallah
- Department of Advanced Technology, Hartnell College, Salinas, CA, 93905, USA
| | - Franco Nigro
- Department of Soil, Plant, and Food Sciences, University of Bari 'Aldo Moro', Bari, 70126, Italy
| | - Guoqing Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China
| | | | - Krishna V Subbarao
- Department of Plant Pathology, University of California, Davis, CA, 95616, USA
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Kathuria S, Sharma C, Singh PK, Agarwal P, Agarwal K, Hagen F, Meis JF, Chowdhary A. Molecular epidemiology and in-vitro antifungal susceptibility of Aspergillus terreus species complex isolates in Delhi, India: evidence of genetic diversity by amplified fragment length polymorphism and microsatellite typing. PLoS One 2015; 10:e0118997. [PMID: 25781896 PMCID: PMC4363790 DOI: 10.1371/journal.pone.0118997] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 01/08/2015] [Indexed: 11/19/2022] Open
Abstract
Aspergillus terreus is emerging as an etiologic agent of invasive aspergillosis in immunocompromised individuals in several medical centers in the world. Infections due to A. terreus are of concern due to its resistance to amphotericin B, in vivo and in vitro, resulting in poor response to antifungal therapy and high mortality. Herein we examined a large collection of molecularly characterized, geographically diverse A. terreus isolates (n = 140) from clinical and environmental sources in India for the occurrence of cryptic A. terreus species. The population structure of the Indian A. terreus isolates and their association with those outside India was determined using microsatellite based typing (STR) technique and Amplified Fragment Length Polymorphism analysis (AFLP). Additionally, in vitro antifungal susceptibility of A. terreus isolates was determined against 7 antifungals. Sequence analyses of the calmodulin locus identified the recently described cryptic species A. hortai, comprising 1.4% of Aspergillus section Terrei isolates cultured from cases of aspergilloma and probable invasive aspergillosis not reported previously. All the nine markers used for STR typing of A. terreus species complex proved to be highly polymorphic. The presence of high genetic diversity revealing 75 distinct genotypes among 101 Indian A. terreus isolates was similar to the marked heterogeneity noticed in the 47 global A. terreus population exhibiting 38 unique genotypes mainly among isolates from North America and Europe. Also, AFLP analysis showed distinct banding patterns for genotypically diverse A. terreus isolates. Furthermore, no correlation between a particular genotype and amphotericin B susceptibility was observed. Overall, 8% of the A. terreus isolates exhibited low MICs of amphotericin B. All the echinocandins and azoles (voriconazole, posaconazole and isavuconazole) demonstrated high potency against all the isolates. The study emphasizes the need of molecular characterization of A. terreus species complex isolates to better understand the ecology, acquisition and transmission of this species.
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Affiliation(s)
- Shallu Kathuria
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Cheshta Sharma
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Pradeep Kumar Singh
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Puneet Agarwal
- Department of Pulmonary Medicine, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Kshitij Agarwal
- Department of Pulmonary Medicine, Rajan Babu Institute of Pulmonary Medicine and Tuberculosis, Delhi, India
| | - Ferry Hagen
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Jacques F. Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
- Department of Medical Microbiology, Radboudumc, Nijmegen, The Netherlands
| | - Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
- * E-mail:
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50
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Hagen F, Khayhan K, Theelen B, Kolecka A, Polacheck I, Sionov E, Falk R, Parnmen S, Lumbsch HT, Boekhout T. Recognition of seven species in the Cryptococcus gattii/Cryptococcus neoformans species complex. Fungal Genet Biol 2015; 78:16-48. [PMID: 25721988 DOI: 10.1016/j.fgb.2015.02.009] [Citation(s) in RCA: 460] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/12/2015] [Accepted: 02/15/2015] [Indexed: 02/08/2023]
Abstract
Phylogenetic analysis of 11 genetic loci and results from many genotyping studies revealed significant genetic diversity with the pathogenic Cryptococcus gattii/Cryptococcus neoformans species complex. Genealogical concordance, coalescence-based, and species tree approaches supported the presence of distinct and concordant lineages within the complex. Consequently, we propose to recognize the current C. neoformans var. grubii and C. neoformans var. neoformans as separate species, and five species within C. gattii. The type strain of C. neoformans CBS132 represents a serotype AD hybrid and is replaced. The newly delimited species differ in aspects of pathogenicity, prevalence for patient groups, as well as biochemical and physiological aspects, such as susceptibility to antifungals. MALDI-TOF mass spectrometry readily distinguishes the newly recognized species.
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Affiliation(s)
- Ferry Hagen
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands; Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Kantarawee Khayhan
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands; Department of Microbiology and Parasitology, Faculty of Medical Sciences, University of Phayao, Phayao, Thailand
| | - Bart Theelen
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands
| | - Anna Kolecka
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands
| | - Itzhack Polacheck
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel
| | - Edward Sionov
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel; Department of Food Quality & Safety, Institute for Postharvest and Food Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Rama Falk
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel; Department of Fisheries and Aquaculture, Ministry of Agriculture and Rural Development, Nir-David, Israel
| | - Sittiporn Parnmen
- Department of Medical Sciences, Ministry of Public Health, Nonthaburi, Thailand
| | | | - Teun Boekhout
- CBS-KNAW Fungal Biodiversity Centre, Basidiomycete and Yeast Research, Utrecht, The Netherlands; Shanghai Key Laboratory of Molecular Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China; Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
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