1
|
Wang C, Miller N, Vines D, Severns PM, Momany M, Brewer MT. Azole resistance mechanisms and population structure of the human pathogen Aspergillus fumigatus on retail plant products. Appl Environ Microbiol 2024; 90:e0205623. [PMID: 38651929 PMCID: PMC11107156 DOI: 10.1128/aem.02056-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/30/2024] [Indexed: 04/25/2024] Open
Abstract
Aspergillus fumigatus is a ubiquitous saprotroph and human-pathogenic fungus that is life-threatening to the immunocompromised. Triazole-resistant A. fumigatus was found in patients without prior treatment with azoles, leading researchers to conclude that resistance had developed in agricultural environments where azoles are used against plant pathogens. Previous studies have documented azole-resistant A. fumigatus across agricultural environments, but few have looked at retail plant products. Our objectives were to determine if azole-resistant A. fumigatus is prevalent in retail plant products produced in the United States (U.S.), as well as to identify the resistance mechanism(s) and population genetic structure of these isolates. Five hundred twenty-five isolates were collected from retail plant products and screened for azole resistance. Twenty-four isolates collected from compost, soil, flower bulbs, and raw peanuts were pan-azole resistant. These isolates had the TR34/L98H, TR46/Y121F/T289A, G448S, and H147Y cyp51A alleles, all known to underly pan-azole resistance, as well as WT alleles, suggesting that non-cyp51A mechanisms contribute to pan-azole resistance in these isolates. Minimum spanning networks showed two lineages containing isolates with TR alleles or the F46Y/M172V/E427K allele, and discriminant analysis of principle components identified three primary clusters. This is consistent with previous studies detecting three clades of A. fumigatus and identifying pan-azole-resistant isolates with TR alleles in a single clade. We found pan-azole resistance in U.S. retail plant products, particularly compost and flower bulbs, which indicates a risk of exposure to these products for susceptible populations and that highly resistant isolates are likely distributed worldwide on these products.IMPORTANCEAspergillus fumigatus has recently been designated as a critical fungal pathogen by the World Health Organization. It is most deadly to people with compromised immune systems, and with the emergence of antifungal resistance to multiple azole drugs, this disease carries a nearly 100% fatality rate without treatment or if isolates are resistant to the drugs used to treat the disease. It is important to determine the relatedness and origins of resistant A. fumigatus isolates in the environment, including plant-based retail products, so that factors promoting the development and propagation of resistant isolates can be identified.
Collapse
Affiliation(s)
- Caroline Wang
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| | - Natalie Miller
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| | - Douglas Vines
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| | - Paul M. Severns
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| | - Michelle Momany
- Fungal Biology Group, Plant Biology Department, University of Georgia, Athens, Georgia, USA
| | - Marin T. Brewer
- Fungal Biology Group, Plant Pathology Department, University of Georgia, Athens, Georgia, USA
| |
Collapse
|
2
|
White KH, Keepers K, Kane N, Lendemer JC. Discovery of New Genomic Configuration of Mating-Type Loci in the Largest Lineage of Lichen-Forming Fungi. Genome Biol Evol 2024; 16:evae094. [PMID: 38686438 PMCID: PMC11126327 DOI: 10.1093/gbe/evae094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 05/02/2024] Open
Abstract
The genetic architecture of mating-type loci in lichen-forming fungi has been characterized in very few taxa. Despite the limited data, and in contrast to all other major fungal lineages, arrangements that have both mating-type alleles in a single haploid genome have been hypothesized to be absent from the largest lineage of lichen-forming fungi, the Lecanoromycetes. We report the discovery of both mating-type alleles from the haploid genomes of three species within this group. Our results demonstrate that Lecanoromycetes are not an outlier among Ascomycetes.
Collapse
Affiliation(s)
- Kristin H White
- Department of Ecology and Evolution, University of Colorado, Boulder, CO 80309, USA
| | - Kyle Keepers
- Department of Ecology and Evolution, University of Colorado, Boulder, CO 80309, USA
| | - Nolan Kane
- Department of Ecology and Evolution, University of Colorado, Boulder, CO 80309, USA
| | - James C Lendemer
- Department of Botany, Research and Collections, CEC 3148, The New York State Museum, Albany, NY 12230, USA
| |
Collapse
|
3
|
Verweij PE, Song Y, Buil JB, Zhang J, Melchers WJG. Antifungal Resistance in Pulmonary Aspergillosis. Semin Respir Crit Care Med 2024; 45:32-40. [PMID: 38196063 DOI: 10.1055/s-0043-1776997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Aspergilli may cause various pulmonary diseases in humans, including allergic bronchopulmonary aspergillosis (ABPA), chronic pulmonary aspergillosis (CPA), and acute invasive pulmonary aspergillosis (IPA). In addition, chronic colonization may occur in cystic fibrosis (CF). Aspergillus fumigatus represents the main pathogen, which may employ different morphotypes, for example, conidia, hyphal growth, and asexual sporulation, in the various Aspergillus diseases. These morphotypes determine the ease by which A. fumigatus can adapt to stress by antifungal drug exposure, usually resulting in one or more resistance mutations. Key factors that enable the emergence of resistance include genetic variation and selection. The ability to create genetic variation depends on the reproduction mode, including, sexual, parasexual, and asexual, and the population size. These reproduction cycles may take place in the host and/or in the environment, usually when specific conditions are present. Environmental resistance is commonly characterized by tandem repeat (TR)-mediated mutations, while in-host resistance selection results in single-resistance mutations. Reported cases from the literature indicate that environmental resistance mutations are almost exclusively present in patients with IA indicating that the risk for in-host resistance selection is very low. In aspergilloma, single-point mutations are the dominant resistance genotype, while in other chronic Aspergillus diseases, for example, ABPA, CPA, and CF, both TR-mediated and single-resistance mutations are reported. Insights into the pathogenesis of resistance selection in various Aspergillus diseases may help to improve diagnostic and therapeutic strategies.
Collapse
Affiliation(s)
- Paul E Verweij
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboudumc-CWZ Center of Expertise for Mycology, Nijmegen, the Netherlands
- Center for Infectious Disease Research, Diagnostics and Laboratory Surveillance, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Yinggai Song
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Dermatology and Venerology, Peking University First Hospital, 8 Xishiku Street, Xicheng District, Beijing, China
- National Clinical Research Center For Skin and Immune Diseases, Beijing, China
- Research Center for Medical Mycology, Peking University, Beijing, China
| | - Jochem B Buil
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboudumc-CWZ Center of Expertise for Mycology, Nijmegen, the Netherlands
| | - Jianhua Zhang
- Center for Infectious Disease Research, Diagnostics and Laboratory Surveillance, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Willem J G Melchers
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboudumc-CWZ Center of Expertise for Mycology, Nijmegen, the Netherlands
| |
Collapse
|
4
|
Yang XT, Wang J, Jiang YH, Zhang L, Du L, Li J, Liu F. Insight into the mechanism of gallstone disease by proteomic and metaproteomic characterization of human bile. Front Microbiol 2023; 14:1276951. [PMID: 38111640 PMCID: PMC10726133 DOI: 10.3389/fmicb.2023.1276951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 11/16/2023] [Indexed: 12/20/2023] Open
Abstract
Introduction Cholesterol gallstone disease is a prevalent condition that has a significant economic impact. However, the role of the bile microbiome in its development and the host's responses to it remain poorly understood. Methods In this study, we conducted a comprehensive analysis of microbial and human bile proteins in 40 individuals with either gallstone disease or gallbladder polyps. We employed a combined proteomic and metaproteomic approach, as well as meta-taxonomic analysis, functional pathway enrichment, and Western blot analyses. Results Our metaproteomic analysis, utilizing the lowest common ancestor algorithm, identified 158 microbial taxa in the bile samples. We discovered microbial taxa that may contribute to gallstone formation, including β-glucuronidase-producing bacteria such as Streptococcus, Staphylococcus, and Clostridium, as well as those involved in biofilm formation like Helicobacter, Cyanobacteria, Pseudomonas, Escherichia coli, and Clostridium. Furthermore, we identified 2,749 human proteins and 87 microbial proteins with a protein false discovery rate (FDR) of 1% and at least 2 distinct peptides. Among these proteins, we found microbial proteins crucial to biofilm formation, such as QDR3, ompA, ndk, pstS, nanA, pfIB, and dnaK. Notably, QDR3 showed a gradual upregulation from chronic to acute cholesterol gallstone disease when compared to polyp samples. Additionally, we discovered other microbial proteins that enhance bacterial virulence and gallstone formation by counteracting host oxidative stress, including sodB, katG, rbr, htrA, and ahpC. We also identified microbial proteins like lepA, rtxA, pckA, tuf, and tpiA that are linked to bacterial virulence and potential gallstone formation, with lepA being upregulated in gallstone bile compared to polyp bile. Furthermore, our analysis of the host proteome in gallstone bile revealed enhanced inflammatory molecular profiles, including innate immune molecules against microbial infections. Gallstone bile exhibited overrepresented pathways related to blood coagulation, folate metabolism, and the IL-17 pathway. However, we observed suppressed metabolic activities, particularly catabolic metabolism and transport activities, in gallstone bile compared to polyp bile. Notably, acute cholelithiasis bile demonstrated significantly impaired metabolic activities compared to chronic cholelithiasis bile. Conclusion Our study provides a comprehensive metaproteomic analysis of bile samples related to gallstone disease, offering new insights into the microbiome-host interaction and gallstone formation mechanism.
Collapse
Affiliation(s)
- Xue-Ting Yang
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| | - Jie Wang
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| | - Ying-Hua Jiang
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| | - Lei Zhang
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| | - Ling Du
- Key Laboratory of Digestive Cancer Full Cycle Monitoring and Precise Intervention of Shanghai Municipal Health Commission, Minhang Hospital, Fudan University, Shanghai, China
| | - Jun Li
- Department of Surgery, Tongren Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Feng Liu
- Minhang Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical of Sciences, Fudan University, Shanghai, China
| |
Collapse
|
5
|
Afifi HAM, Mansour MMA, Hassan AGAI, Salem MZM. Biodeterioration effects of three Aspergillus species on stucco supported on a wooden panel modeled from Sultan al-Ashraf Qaytbay Mausoleum, Egypt. Sci Rep 2023; 13:15241. [PMID: 37709813 PMCID: PMC10502143 DOI: 10.1038/s41598-023-42028-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 09/04/2023] [Indexed: 09/16/2023] Open
Abstract
This study focuses on the magnificent decoration of a painted and gilded wooden panel with signs of fungal biodeterioration caused by Aspergillus species in the Mausoleum of Sultan al-Ashraf Qaytbay, Cairo, Egypt. Numerous spectroscopic analyses and investigation techniques, including Scanning Electron Microscope Equipped with Energy Dispersive X-ray analysis (SEM-EDX), Fourier Transform Infrared analysis (FTIR), and X-Ray Diffraction (XRD) have been used to study the materials that comprise this painted and gilded wooden panel composition. Aspergillus niger, A. flavus, and A. terreus were recognized as isolated fungi, and their accession numbers are OQ820164, OQ820163, and OQ820160, respectively. The findings showed that the wooden support is of pinewood (Pinus halepensis), the white priming layer on top of the wooden support was identified as gypsum, the blue paint layer has been proposed to be Azurite, Au (gold) was the primary composition of the gilding layer, while Pb (lead) was detected in some spots, suggesting the use an alloy of gold with lead, and finally, animal glue was the bonding medium. Based on these findings, mimic samples with identical substrates and structural components have been designed, and the biodeterioration signs by the growing of the three Aspergillus species-A. niger, A. flavus and A. terreus were evaluated via SEM and color change. However, A. niger was discovered with density growth on surfaces of pinewood, gypsum, and Azurite and with less growth on the gilding layer after 6-month incubation. This contrasts with A. terreus and A. flavus, which had greater density growth on Azurite and stucco than on pinewood and less growth on the gilding layer. The used analytical methods with detailed analyses revealed the novelty and significant future aspects of the conservation of the painted and gilded wooden panel. Particularly given that this location is used for prayer and is crowded with people five times a day, which increases the accumulation of fungi and negatively affects both the historic Mosque and the worshippers' health.
Collapse
Affiliation(s)
- Hala A M Afifi
- Conservation Department, Faculty of Archaeology, Cairo University, Giza, 12613, Egypt.
| | - Maisa M A Mansour
- Conservation Department, Faculty of Archaeology, Cairo University, Giza, 12613, Egypt.
| | - Alyaa G A I Hassan
- Conservation Department, Faculty of Archaeology, Cairo University, Giza, 12613, Egypt
| | - Mohamed Z M Salem
- Forestry and Wood Technology Department, Faculty of Agriculture (El-Shatby), Alexandria University, Alexandria, 21545, Egypt.
| |
Collapse
|
6
|
Auxier B, Debets AJM, Stanford FA, Rhodes J, Becker FM, Reyes Marquez F, Nijland R, Dyer PS, Fisher MC, van den Heuvel J, Snelders E. The human fungal pathogen Aspergillus fumigatus can produce the highest known number of meiotic crossovers. PLoS Biol 2023; 21:e3002278. [PMID: 37708139 PMCID: PMC10501685 DOI: 10.1371/journal.pbio.3002278] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/27/2023] [Indexed: 09/16/2023] Open
Abstract
Sexual reproduction involving meiosis is essential in most eukaryotes. This produces offspring with novel genotypes, both by segregation of parental chromosomes as well as crossovers between homologous chromosomes. A sexual cycle for the opportunistic human pathogenic fungus Aspergillus fumigatus is known, but the genetic consequences of meiosis have remained unknown. Among other Aspergilli, it is known that A. flavus has a moderately high recombination rate with an average of 4.2 crossovers per chromosome pair, whereas A. nidulans has in contrast a higher rate with 9.3 crossovers per chromosome pair. Here, we show in a cross between A. fumigatus strains that they produce an average of 29.9 crossovers per chromosome pair and large variation in total map length across additional strain crosses. This rate of crossovers per chromosome is more than twice that seen for any known organism, which we discuss in relation to other genetic model systems. We validate this high rate of crossovers through mapping of resistance to the laboratory antifungal acriflavine by using standing variation in an undescribed ABC efflux transporter. We then demonstrate that this rate of crossovers is sufficient to produce one of the common multidrug resistant haplotypes found in the cyp51A gene (TR34/L98H) in crosses among parents harboring either of 2 nearby genetic variants, possibly explaining the early spread of such haplotypes. Our results suggest that genomic studies in this species should reassess common assumptions about linkage between genetic regions. The finding of an unparalleled crossover rate in A. fumigatus provides opportunities to understand why these rates are not generally higher in other eukaryotes.
Collapse
Affiliation(s)
- Ben Auxier
- Laboratory of Genetics, Wageningen University; Wageningen, the Netherlands
| | | | | | - Johanna Rhodes
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom
| | - Frank M. Becker
- Laboratory of Genetics, Wageningen University; Wageningen, the Netherlands
| | | | - Reindert Nijland
- Marine Animal Ecology, Wageningen University, Wageningen, the Netherlands
| | - Paul S. Dyer
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Matthew C. Fisher
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom
| | | | - Eveline Snelders
- Laboratory of Genetics, Wageningen University; Wageningen, the Netherlands
| |
Collapse
|
7
|
Nji QN, Babalola OO, Mwanza M. Soil Aspergillus Species, Pathogenicity and Control Perspectives. J Fungi (Basel) 2023; 9:766. [PMID: 37504754 PMCID: PMC10381279 DOI: 10.3390/jof9070766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/05/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023] Open
Abstract
Five Aspergillus sections have members that are established agricultural pests and producers of different metabolites, threatening global food safety. Most of these pathogenic Aspergillus species have been isolated from almost all major biomes. The soil remains the primary habitat for most of these cryptic fungi. This review explored some of the ecological attributes that have contributed immensely to the success of the pathogenicity of some members of the genus Aspergillus over time. Hence, the virulence factors of the genus Aspergillus, their ecology and others were reviewed. Furthermore, some biological control techniques were recommended. Pathogenic effects of Aspergillus species are entirely accidental; therefore, the virulence evolution prediction model in such species becomes a challenge, unlike their obligate parasite counterparts. In all, differences in virulence among organisms involved both conserved and species-specific genetic factors. If the impacts of climate change continue, new cryptic Aspergillus species will emerge and mycotoxin contamination risks will increase in all ecosystems, as these species can metabolically adjust to nutritional and biophysical challenges. As most of their gene clusters are silent, fungi continue to be a source of underexplored bioactive compounds. The World Soil Charter recognizes the relevance of soil biodiversity in supporting healthy soil functions. The question of how a balance may be struck between supporting healthy soil biodiversity and the control of toxic fungi species in the field to ensure food security is therefore pertinent. Numerous advanced strategies and biocontrol methods so far remain the most environmentally sustainable solution to the control of toxigenic fungi in the field.
Collapse
Affiliation(s)
- Queenta Ngum Nji
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Mulunda Mwanza
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
- Department of Animal Health, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| |
Collapse
|
8
|
Gares M, Benaissa A, Hiligsmann S, Cherfia R, Flahaut S, Alloun W, Djelid H, Chaoua S, Kacem Chaouche N. Box-Behnken design optimization of xylanase and cellulase production by Aspergillus fumigatus on Stipa tenacissima biomass. Mycologia 2023:1-19. [PMID: 37216583 DOI: 10.1080/00275514.2023.2205331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 04/18/2023] [Indexed: 05/24/2023]
Abstract
Optimization of xylanase and cellulase production by a newly isolated Aspergillus fumigatus strain grown on Stipa tenacissima (alfa grass) biomass without pretreatment was carried out using a Box-Behnken design. First, the polysaccharides of dried and ground alfa grass were characterized using chemical methods (strong and diluted acid). The effect of substrate particle size on xylanase and carboxymethylcellulase (CMCase) production by the selected and identified strain was then investigated. Thereafter, experiments were statistically planned with a Box-Behnken design to optimize initial pH, cultivation temperature, moisture content, and incubation period using alfa as sole carbon source. The effect of these parameters on the two enzyme production was evaluated using the response surface method. Analysis of variance was also carried out, and production of the enzymes was expressed using a mathematical equation depending on the influencing factors. The effects of individual, interaction, and square terms on production of both enzymes were represented using the nonlinear regression equations with significant R2 and P-values. Xylanase and CMCase production levels were enhanced by 25% and 27%, respectively. Thus, this study demonstrated for the first time the potential of alfa as a raw material to produce enzymes without any pretreatment. A set of parameter combinations was found to be effective for the production of xylanase and CMCase by A. fumigatus in an alfa-based solid-state fermentation.
Collapse
Affiliation(s)
- Maroua Gares
- Laboratory of Mycology, Biotechnology and Microbial Activity, Department of Applied Biology, Faculty of Natural and Life Sciences, University of Brothers Mentouri, Constantine 25017, Algeria
| | - Akila Benaissa
- Drug and Sustainable Development Laboratory, Faculty of Process Engineering, University Salah Boubnider-Constantine 3, Constantine 25000, Algeria
| | - Serge Hiligsmann
- 3BIO-BioTech, Université Libre de Bruxelles, Av. F. Roosevelt 50, CP 165/61, Brussels 1050, Belgium
| | - Radia Cherfia
- Laboratory of Mycology, Biotechnology and Microbial Activity, Department of Applied Biology, Faculty of Natural and Life Sciences, University of Brothers Mentouri, Constantine 25017, Algeria
| | - Sigrid Flahaut
- Applied Microbiology Laboratory, Interfaculty School of Bioengineers, Université Libre de Bruxelles, Brussels 1050, Belgium
| | - Wiem Alloun
- Laboratory of Mycology, Biotechnology and Microbial Activity, Department of Applied Biology, Faculty of Natural and Life Sciences, University of Brothers Mentouri, Constantine 25017, Algeria
| | - Hadjer Djelid
- Laboratory of Mycology, Biotechnology and Microbial Activity, Department of Applied Biology, Faculty of Natural and Life Sciences, University of Brothers Mentouri, Constantine 25017, Algeria
| | - Samah Chaoua
- Laboratory of Mycology, Biotechnology and Microbial Activity, Department of Applied Biology, Faculty of Natural and Life Sciences, University of Brothers Mentouri, Constantine 25017, Algeria
- Applied Microbiology Laboratory, Interfaculty School of Bioengineers, Université Libre de Bruxelles, Brussels 1050, Belgium
| | - Noreddine Kacem Chaouche
- Laboratory of Mycology, Biotechnology and Microbial Activity, Department of Applied Biology, Faculty of Natural and Life Sciences, University of Brothers Mentouri, Constantine 25017, Algeria
| |
Collapse
|
9
|
Sklar J. QnAs with Joseph Heitman. Proc Natl Acad Sci U S A 2023; 120:e2305474120. [PMID: 37130150 PMCID: PMC10175810 DOI: 10.1073/pnas.2305474120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
|
10
|
Kolařík M, Hulcr J. Geosmithia—widespread and abundant but long ignored bark beetle symbionts. Mycol Prog 2023. [DOI: 10.1007/s11557-023-01880-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
|
11
|
Korfanty G, Heifetz E, Xu J. Assessing thermal adaptation of a global sample of Aspergillus fumigatus: Implications for climate change effects. Front Public Health 2023; 11:1059238. [PMID: 36875405 PMCID: PMC9978374 DOI: 10.3389/fpubh.2023.1059238] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Aspergillus fumigatus is a common environmental mold and a major cause of opportunistic infections in humans. It's distributed among many ecological niches across the globe. A major virulence factor of A. fumigatus is its ability to grow at high temperature. However, at present, little is known about variations among strains in their growth at different temperatures and how their geographic origins may impact such variations. In this study, we analyzed 89 strains from 12 countries (Cameroon, Canada, China, Costa Rica, France, India, Iceland, Ireland, New Zealand, Peru, Saudi Arabia, and USA) representing diverse geographic locations and temperature environments. Each strain was grown at four temperatures and genotyped at nine microsatellite loci. Our analyses revealed a range of growth profiles, with significant variations among strains within individual geographic populations in their growths across the temperatures. No statistically significant association was observed between strain genotypes and their thermal growth profiles. Similarly geographic separation contributed little to differences in thermal adaptations among strains and populations. The combined analyses among genotypes and growth rates at different temperatures in the global sample suggest that most natural populations of A. fumigatus are capable of rapid adaptation to temperature changes. We discuss the implications of our results to the evolution and epidemiology of A. fumigatus under increasing climate change.
Collapse
Affiliation(s)
- Greg Korfanty
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Erin Heifetz
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
12
|
Abstract
Oral microbial dysbiosis contributes to the development of oral squamous cell carcinoma (OSCC). Numerous studies have focused on variations in the oral bacterial microbiota of patients with OSCC. However, similar studies on fungal microbiota, another integral component of the oral microbiota, are scarce. Moreover, there is an evidence gap regarding the role that microecosystems play in different niches of the oral cavity at different stages of oral carcinogenesis. Here, we catalogued the microbial communities in the human oral cavity by profiling saliva, gingival plaque, and mucosal samples at different stages of oral carcinogenesis. We analyzed the oral bacteriome and mycobiome along the health-premalignancy-carcinoma sequence. Some species, including Prevotella intermedia, Porphyromonas endodontalis, Acremonium exuviarum, and Aspergillus fumigatus, were enriched, whereas others, such as Streptococcus salivarius subsp. salivarius, Scapharca broughtonii, Mortierella echinula, and Morchella septimelata, were depleted in OSCC. These findings suggest that an array of signature species, including bacteria and fungi, are closely associated with oral carcinogenesis. OSCC-associated diversity differences, species distinction, and functional alterations were most remarkable in mucosal samples, not in gingival plaque or saliva samples, suggesting an urgent need to define oral carcinogenesis-associated microbial dysbiosis based on the spatial microbiome. IMPORTANCE Abundant oral microorganisms constitute a complex microecosystem within the oral environment of the host, which plays a critical role in the adjustment of various physiological and pathological states of the oral cavity. In this study, we demonstrated that variations in the "core microbiome" may be used to predict carcinogenesis. In addition, sample data collected from multiple oral sites along the health-premalignancy-carcinoma sequence increase our understanding of the microecosystems of different oral niches and their specific changes during oral carcinogenesis. This work provides insight into the roles of bacteria and fungi in OSCC and may contribute to the development of early diagnostic assays and novel treatments.
Collapse
|
13
|
Punia A, Choudhary P, Sharma N, Dahiya S, Gulia P, Chhillar AK. Therapeutic Approaches for Combating Aspergillus Associated Infection. Curr Drug Targets 2022; 23:1465-1488. [PMID: 35748549 DOI: 10.2174/1389450123666220623164548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 02/12/2022] [Accepted: 02/16/2022] [Indexed: 01/25/2023]
Abstract
Now-a-days fungal infection emerges as a significant problem to healthcare management systems due to high frequency of associated morbidity, mortality toxicity, drug-drug interactions, and resistance of the antifungal agents. Aspergillus is the most common mold that cause infection in immunocompromised hosts. It's a hyaline mold that is cosmopolitan and ubiquitous in nature. Aspergillus infects around 10 million population each year with a mortality rate of 30-90%. Clinically available antifungal formulations are restricted to four classes (i.e., polyene, triazole, echinocandin, and allylamine), and each of them have their own limitations associated with the activity spectrum, the emergence of resistance, and toxicity. Consequently, novel antifungal agents with modified and altered chemical structures are required to combat these invasive fungal infections. To overcome these limitations, there is an urgent need for new antifungal agents that can act as potent drugs in near future. Currently, some compounds have shown effective antifungal activity. In this review article, we have discussed all potential antifungal therapies that contain old antifungal drugs, combination therapies, and recent novel antifungal formulations, with a focus on the Aspergillus associated infections.
Collapse
Affiliation(s)
- Aruna Punia
- Department of Biotechnology, Maharishi Dayanand University, Rohtak, Haryana 124001, India
| | - Pooja Choudhary
- Department of Biotechnology, Maharishi Dayanand University, Rohtak, Haryana 124001, India
| | - Namita Sharma
- Department of Biotechnology, Maharishi Dayanand University, Rohtak, Haryana 124001, India
| | - Sweety Dahiya
- Department of Biotechnology, Maharishi Dayanand University, Rohtak, Haryana 124001, India
| | - Prity Gulia
- Department of Biotechnology, Maharishi Dayanand University, Rohtak, Haryana 124001, India
| | - Anil K Chhillar
- Department of Biotechnology, Maharishi Dayanand University, Rohtak, Haryana 124001, India
| |
Collapse
|
14
|
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.
Collapse
|
15
|
Novel Treatment Approach for Aspergilloses by Targeting Germination. J Fungi (Basel) 2022; 8:jof8080758. [PMID: 35893126 PMCID: PMC9331470 DOI: 10.3390/jof8080758] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/03/2022] [Accepted: 07/19/2022] [Indexed: 12/24/2022] Open
Abstract
Germination of conidia is an essential process within the Aspergillus life cycle and plays a major role during the infection of hosts. Conidia are able to avoid detection by the majority of leukocytes when dormant. Germination can cause severe health problems, specifically in immunocompromised people. Aspergillosis is most often caused by Aspergillus fumigatus (A. fumigatus) and affects neutropenic patients, as well as people with cystic fibrosis (CF). These patients are often unable to effectively detect and clear the conidia or hyphae and can develop chronic non-invasive and/or invasive infections or allergic inflammatory responses. Current treatments with (tri)azoles can be very effective to combat a variety of fungal infections. However, resistance against current azoles has emerged and has been increasing since 1998. As a consequence, patients infected with resistant A. fumigatus have a reported mortality rate of 88% to 100%. Especially with the growing number of patients that harbor azole-resistant Aspergilli, novel antifungals could provide an alternative. Aspergilloses differ in defining characteristics, but germination of conidia is one of the few common denominators. By specifically targeting conidial germination with novel antifungals, early intervention might be possible. In this review, we propose several morphotypes to disrupt conidial germination, as well as potential targets. Hopefully, new antifungals against such targets could contribute to disturbing the ability of Aspergilli to germinate and grow, resulting in a decreased fungal burden on patients.
Collapse
|
16
|
Zhou D, Wang R, Li X, Peng B, Yang G, Zhang KQ, Zhang Y, Xu J. Genetic Diversity and Azole Resistance Among Natural Aspergillus fumigatus Populations in Yunnan, China. MICROBIAL ECOLOGY 2022; 83:869-885. [PMID: 34279697 DOI: 10.1007/s00248-021-01804-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
The emergence and spread of azole resistance alleles in clinical and environmental isolates of Aspergillus fumigatus is a global human health concern and endangers the "One Health" approach in our fight against antifungal resistance (AFR) in this pathogen. A major challenge to combat AFR in A. fumigatus is the massive aerial dispersal ability of its asexual spores. Our recent fine-scale survey of greenhouse populations of A. fumigatus near Kunming, Yunnan, China, suggested that the use of azole fungicides for plant protection was likely a major driver of the high-frequency azole-resistant A. fumigatus (ARAF) in greenhouses. Here, we investigated the potential spread of those ARAF and the structure of geographic populations of A. fumigatus by analyzing 452 isolates from 19 geographic locations across Yunnan. We found lower frequencies of ARAF in these outdoor populations than those in greenhouses near Kunming, but there were abundant new alleles and new genotypes, including those associated with azole resistance, consistent with multiple independent origins of ARAF across Yunnan. Interestingly, among the four ecological niches, the sediments of a large lake near Kunming were found to have the highest frequency of ARAF (~ 43%). While most genetic variations were observed within the 19 local populations, statistically significant genetic differentiations were found between many subpopulations within Yunnan. Furthermore, similar to greenhouse populations, these outdoor populations of A. fumigatus in Yunnan were significantly different from those in other parts of the world. Our results call for increased attention to local and regional studies of this fungal pathogen to help develop targeted control strategies against ARAF.
Collapse
Affiliation(s)
- Duanyong Zhou
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- School of Biology and Chemistry, Xingyi Normal University for Nationalities, Xingyi, 562400, Guizhou, People's Republic of China
| | - Ruirui Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Xiao Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Bin Peng
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Guangzhu Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
- College of Life Science, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China
| | - Ying Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China.
| | - Jianping Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, and Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming, 650032, Yunnan, People's Republic of China.
- Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1, Canada.
| |
Collapse
|
17
|
Ashton GD, Sang F, Blythe M, Zadik D, Holmes N, Malla S, Camps SMT, Wright V, Melchers WJG, Verweij PE, Dyer PS. Use of Bulk Segregant Analysis for Determining the Genetic Basis of Azole Resistance in the Opportunistic Pathogen Aspergillus fumigatus. Front Cell Infect Microbiol 2022; 12:841138. [PMID: 35531335 PMCID: PMC9069965 DOI: 10.3389/fcimb.2022.841138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/03/2022] [Indexed: 12/19/2022] Open
Abstract
A sexual cycle was described in 2009 for the opportunistic fungal pathogen Aspergillus fumigatus, opening up for the first time the possibility of using techniques reliant on sexual crossing for genetic analysis. The present study was undertaken to evaluate whether the technique 'bulk segregant analysis' (BSA), which involves detection of differences between pools of progeny varying in a particular trait, could be applied in conjunction with next-generation sequencing to investigate the underlying basis of monogenic traits in A. fumigatus. Resistance to the azole antifungal itraconazole was chosen as a model, with a dedicated bioinformatic pipeline developed to allow identification of SNPs that differed between the resistant progeny pool and resistant parent compared to the sensitive progeny pool and parent. A clinical isolate exhibiting monogenic resistance to itraconazole of unknown basis was crossed to a sensitive parent and F1 progeny used in BSA. In addition, the use of backcrossing and increasing the number in progeny pools was evaluated as ways to enhance the efficiency of BSA. Use of F1 pools of 40 progeny led to the identification of 123 candidate genes with SNPs distributed over several contigs when aligned to an A1163 reference genome. Successive rounds of backcrossing enhanced the ability to identify specific genes and a genomic region, with BSA of progeny (using 40 per pool) from a third backcross identifying 46 genes with SNPs, and BSA of progeny from a sixth backcross identifying 20 genes with SNPs in a single 292 kb region of the genome. The use of an increased number of 80 progeny per pool also increased the resolution of BSA, with 29 genes demonstrating SNPs between the different sensitive and resistant groupings detected using progeny from just the second backcross with the majority of variants located on the same 292 kb region. Further bioinformatic analysis of the 292 kb region identified the presence of a cyp51A gene variant resulting in a methionine to lysine (M220K) change in the CYP51A protein, which was concluded to be the causal basis of the observed resistance to itraconazole. The future use of BSA in genetic analysis of A. fumigatus is discussed.
Collapse
Affiliation(s)
- George D. Ashton
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Fei Sang
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Martin Blythe
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Daniel Zadik
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Nadine Holmes
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Sunir Malla
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Simone M. T. Camps
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Victoria Wright
- DeepSeq, Centre for Genetics and Genomics, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Willem J. G. Melchers
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Paul E. Verweij
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Paul S. Dyer
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| |
Collapse
|
18
|
Cai Y, Nie Y, Gao Y, Huang B. Natural populations of the entomopathogenic fungus Beauveria bassiana in Chinese forest ecosystems are diverse and reveal equal frequencies of mating types within phylogenetic species. FUNGAL ECOL 2022. [DOI: 10.1016/j.funeco.2021.101139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
19
|
Senanayake IC, Pem D, Rathnayaka AR, Wijesinghe SN, Tibpromma S, Wanasinghe DN, Phookamsak R, Kularathnage ND, Gomdola D, Harishchandra D, Dissanayake LS, Xiang MM, Ekanayaka AH, McKenzie EHC, Hyde KD, Zhang HX, Xie N. Predicting global numbers of teleomorphic ascomycetes. FUNGAL DIVERS 2022. [DOI: 10.1007/s13225-022-00498-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AbstractSexual reproduction is the basic way to form high genetic diversity and it is beneficial in evolution and speciation of fungi. The global diversity of teleomorphic species in Ascomycota has not been estimated. This paper estimates the species number for sexual ascomycetes based on five different estimation approaches, viz. by numbers of described fungi, by fungus:substrate ratio, by ecological distribution, by meta-DNA barcoding or culture-independent studies and by previous estimates of species in Ascomycota. The assumptions were made with the currently most accepted, “2.2–3.8 million” species estimate and results of previous studies concluding that 90% of the described ascomycetes reproduce sexually. The Catalogue of Life, Species Fungorum and published research were used for data procurement. The average value of teleomorphic species in Ascomycota from all methods is 1.86 million, ranging from 1.37 to 2.56 million. However, only around 83,000 teleomorphic species have been described in Ascomycota and deposited in data repositories. The ratio between described teleomorphic ascomycetes to predicted teleomorphic ascomycetes is 1:22. Therefore, where are the undiscovered teleomorphic ascomycetes? The undescribed species are no doubt to be found in biodiversity hot spots, poorly-studied areas and species complexes. Other poorly studied niches include extremophiles, lichenicolous fungi, human pathogens, marine fungi, and fungicolous fungi. Undescribed species are present in unexamined collections in specimen repositories or incompletely described earlier species. Nomenclatural issues, such as the use of separate names for teleomorph and anamorphs, synonyms, conspecific names, illegitimate and invalid names also affect the number of described species. Interspecies introgression results in new species, while species numbers are reduced by extinctions.
Collapse
|
20
|
Zhang J, Verweij PE, Rijs AJMM, Debets AJM, Snelders E. Flower Bulb Waste Material Is a Natural Niche for the Sexual Cycle in Aspergillus fumigatus. Front Cell Infect Microbiol 2022; 11:785157. [PMID: 35145921 PMCID: PMC8823264 DOI: 10.3389/fcimb.2021.785157] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/29/2021] [Indexed: 12/18/2022] Open
Abstract
With population genetic evidence of recombination ongoing in the natural Aspergillus fumigatus population and a sexual cycle demonstrated in the laboratory the question remained what the natural niche for A. fumigatus sex is. Composting plant-waste material is a known substrate of A. fumigatus to thrive and withstand temperatures even up to 70°C. Previous studies have shown indirect evidence for sexual reproduction in these heaps but never directly demonstrated the sexual structures due to technical limitations. Here, we show that flower bulb waste material from stockpiles undergoing composting can provide the conditions for sexual reproduction. Direct detection of ascospore structures was shown in agricultural flower bulb waste material by using a grid-based detection assay. Furthermore, we demonstrate that ascospores can germinate after exposure to 70°C for up to several days in contrast to asexual conidia that are unable to survive a two-hour heat shock. This indicates a sufficient time frame for ascospores to survive and escape composting stockpiles. Finally, sexual crosses with cleistothecium and viable ascospore formation could successfully be performed on flower bulb waste material. Recombination of A. fumigatus can now be explained by active sexual reproduction in nature as we show in this study that flower bulb waste material provides an environmental niche for sex.
Collapse
Affiliation(s)
- Jianhua Zhang
- Laboratory of Genetics, Wageningen University & Research, Wageningen, Netherlands
- *Correspondence: Jianhua Zhang,
| | - Paul E. Verweij
- Radboud University Medical Center (Radboudumc), Nijmegen, Netherlands
- Canisius-Wilhelmina Ziekenhuis (CWZ) Center of Expertise for Mycology, Radboud University Medical Center (Radboudumc), Nijmegen, Netherlands
| | - Antonius J. M. M. Rijs
- Radboud University Medical Center (Radboudumc), Nijmegen, Netherlands
- Canisius-Wilhelmina Ziekenhuis (CWZ) Center of Expertise for Mycology, Radboud University Medical Center (Radboudumc), Nijmegen, Netherlands
| | - Alfons J. M. Debets
- Laboratory of Genetics, Wageningen University & Research, Wageningen, Netherlands
| | - Eveline Snelders
- Laboratory of Genetics, Wageningen University & Research, Wageningen, Netherlands
| |
Collapse
|
21
|
The Gβ-like Protein AfCpcB Affects Sexual Development, Response to Oxidative Stress and Phagocytosis by Alveolar Macrophages in Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8010056. [PMID: 35049996 PMCID: PMC8777951 DOI: 10.3390/jof8010056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/26/2021] [Accepted: 01/04/2022] [Indexed: 12/17/2022] Open
Abstract
G-protein signaling is important for signal transduction, allowing various stimuli that are external to a cell to affect its internal molecules. In Aspergillus fumigatus, the roles of Gβ-like protein CpcB on growth, asexual development, drug sensitivity, and virulence in a mouse model have been previously reported. To gain a deeper insight into Aspergillus fumigatus sexual development, the ΔAfcpcB strain was generated using the supermater AFB62 strain and crossed with AFIR928. This cross yields a decreased number of cleistothecia, including few ascospores. The sexual reproductive organ-specific transcriptional analysis using RNAs from the cleistothecia (sexual fruiting bodies) indicated that the CpcB is essential for the completion of sexual development by regulating the transcription of sexual genes, such as veA, steA, and vosA. The ΔAfcpcB strain revealed increased resistance to oxidative stress by regulating genes for catalase, peroxiredoxin, and ergosterol biosynthesis. The ΔAfcpcB strain showed decreased uptake by alveolar macrophages in vitro, decreased sensitivity to Congo red, decreased expression of cell wall genes, and increased expression of the hydrophobin genes. Taken together, these findings indicate that AfCpcB plays important roles in sexual development, phagocytosis by alveolar macrophages, biosynthesis of the cell wall, and oxidative stress response.
Collapse
|
22
|
Screening and Identification of Trichoderma Strains isolated from Natural Habitats in China with Potential Agricultural Applications. BIOMED RESEARCH INTERNATIONAL 2022; 2021:7913950. [PMID: 34970627 PMCID: PMC8714372 DOI: 10.1155/2021/7913950] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/09/2021] [Accepted: 11/18/2021] [Indexed: 01/21/2023]
Abstract
Trichoderma spp. are widely distributed in natural habitats and have been evaluated as a potential biocontrol agent (BCA) for disease control and plant growth promotion. In this study, 1308 Trichoderma strains were obtained from the plant rhizosphere soil, above-ground plants, and decaying wood from natural habitats in China. Among them, 49 Trichoderma strains showed a good inhibitory effect, especially against Botrytis cinerea, Fusarium oxysporum, and Colletotrichum gloeosporioides with inhibition rate above 85% in the dual culture test. Among these 49 strains, the 13 strains with broad-spectrum inhibitory effects also significantly promoted the seed germination of five crops (rice, cucumber, tomato, melon, and pakchoi) and root growth of four crop seedlings (watermelon, tomato, eggplant, and chili). Furthermore, these strains showed effective colonization in the rhizosphere and root of cucumber. Trichoderma strains SC012 and NX043 showed the highest chitinase and β-1,3-glucanase activity among all strains. Based on the morphological characterization and phylogenetic analysis of the nuclear ribosomal internal transcribed spacer (ITS) and translation elongation factor 1 (tef1), twelve Trichoderma strains were identified as Trichoderma asperellum and one as Trichoderma afroharzianum. This study suggests that the 13 Trichoderma strains are promising BCAs and could be developed as biofertilizers and biological pesticides for agricultural applications.
Collapse
|
23
|
Colabardini AC, Wang F, Miao Z, Pardeshi L, Valero C, de Castro PA, Akiyama DY, Tan K, Nora LC, Silva-Rocha R, Marcet-Houben M, Gabaldón T, Fill T, Wong KH, Goldman GH. Chromatin profiling reveals heterogeneity in clinical isolates of the human pathogen Aspergillus fumigatus. PLoS Genet 2022; 18:e1010001. [PMID: 35007279 PMCID: PMC8782537 DOI: 10.1371/journal.pgen.1010001] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 01/21/2022] [Accepted: 12/17/2021] [Indexed: 12/21/2022] Open
Abstract
Invasive Pulmonary Aspergillosis, which is caused by the filamentous fungus Aspergillus fumigatus, is a life-threatening infection for immunosuppressed patients. Chromatin structure regulation is important for genome stability maintenance and has the potential to drive genome rearrangements and affect virulence and pathogenesis of pathogens. Here, we performed the first A. fumigatus global chromatin profiling of two histone modifications, H3K4me3 and H3K9me3, focusing on the two most investigated A. fumigatus clinical isolates, Af293 and CEA17. In eukaryotes, H3K4me3 is associated with active transcription, while H3K9me3 often marks silent genes, DNA repeats, and transposons. We found that H3K4me3 deposition is similar between the two isolates, while H3K9me3 is more variable and does not always represent transcriptional silencing. Our work uncovered striking differences in the number, locations, and expression of transposable elements between Af293 and CEA17, and the differences are correlated with H3K9me3 modifications and higher genomic variations among strains of Af293 background. Moreover, we further showed that the Af293 strains from different laboratories actually differ in their genome contents and found a frequently lost region in chromosome VIII. For one such Af293 variant, we identified the chromosomal changes and demonstrated their impacts on its secondary metabolites production, growth and virulence. Overall, our findings not only emphasize the influence of genome heterogeneity on A. fumigatus fitness, but also caution about unnoticed chromosomal variations among common laboratory strains.
Collapse
Affiliation(s)
- Ana Cristina Colabardini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
- Faculty of Health Sciences, University of Macau, Macau SAR of China
| | - Fang Wang
- Faculty of Health Sciences, University of Macau, Macau SAR of China
- Intensive Care Unit, Biomedical Research Center, Shenzhen Institute of Translational Medicine, Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Zhengqiang Miao
- Faculty of Health Sciences, University of Macau, Macau SAR of China
| | - Lakhansing Pardeshi
- Faculty of Health Sciences, University of Macau, Macau SAR of China
- Genomics, Bioinformatics and Single Cell Analysis Core, Faculty of Health Sciences, University of Macau, Macau SAR of China
| | - Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Daniel Yuri Akiyama
- Instituto de Química, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Kaeling Tan
- Faculty of Health Sciences, University of Macau, Macau SAR of China
- Genomics, Bioinformatics and Single Cell Analysis Core, Faculty of Health Sciences, University of Macau, Macau SAR of China
| | - Luisa Czamanski Nora
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Rafael Silva-Rocha
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Marina Marcet-Houben
- Barcelona Supercomputing Centre (BSC-CNS). Jordi Girona, Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, Barcelona, Spain
| | - Toni Gabaldón
- Barcelona Supercomputing Centre (BSC-CNS). Jordi Girona, Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Taicia Fill
- Instituto de Química, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Koon Ho Wong
- Faculty of Health Sciences, University of Macau, Macau SAR of China
- Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau SAR of China
- MoE Frontiers Science Center for Precision Oncology, University of Macau, Macau SAR of China
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| |
Collapse
|
24
|
Bader O. Phylogenetic Distribution of csp1 Types in Aspergillus fumigatus and Their Correlates to Azole Antifungal Drug Resistance. Microbiol Spectr 2021; 9:e0121421. [PMID: 34787484 PMCID: PMC8597649 DOI: 10.1128/spectrum.01214-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 09/22/2021] [Indexed: 11/20/2022] Open
Abstract
In Aspergillus fumigatus, the repetitive region of the csp1 gene is one of the most frequently used loci for intraspecies typing of this human pathogenic mold. Using PCR amplification and Sanger sequencing of only a single marker, csp1 typing is readily available to most laboratories and highly reproducible. Here, I evaluate the usefulness of the csp1 marker for resistance detection and epidemiologic stratification among A. fumigatus isolates. After resolving nomenclature conflicts from published studies and adding novel csp1 types, the number of known types now adds up to 38. Their distribution mostly correlates with A. fumigatus population structure, and they are also meaningful for narrowly defined cases of azole resistance phenotypes. Isolates carrying the pandemic resistance allele TR34/L98H show signs of interclade crossing of strains with t02 or t04A, into the t11 clade. Furthermore, absolute differences in voriconazole MIC values between t02/t04B versus t11 TR34/L98H isolates indicate that the genetic background of resistance mutations may have a pivotal role in cross-resistance phenotypes and, thus, clinical outcome and environmental selection. Despite the general genetic similarity of isolates with identical csp1 types, outcrossing into other clades is also observed. The csp1 type alone, therefore, does not sufficiently discriminate genetic clades to be used as the sole marker in epidemiologic studies. IMPORTANCE Aspergillus fumigatus is a ubiquitously distributed saprophytic mold and a leading cause of invasive aspergillosis in human hosts. Pandemic azole-resistant strains have emerged on a global scale, which are thought to be propagated through use of azole-based fungicides in agriculture. To perform epidemiologic studies, genetic typing of large cohorts is key. Here, I evaluate the usefulness of the frequently used csp1 marker for resistance detection and epidemiologic stratification among A. fumigatus isolates. The phylogenetic distribution of csp1 types mostly correlates with A. fumigatus population structure and is also meaningful for narrowly defined cases of azole resistance phenotypes. Nevertheless, outcrossing of csp1 into other clades is also observed. The csp1 type alone, therefore, does not sufficiently discriminate genetic clades and should not be used as the sole marker in epidemiologic studies.
Collapse
Affiliation(s)
- Oliver Bader
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
25
|
Rivelli Zea SM, Toyotome T. Azole-resistant Aspergillus fumigatus as an emerging worldwide pathogen. Microbiol Immunol 2021; 66:135-144. [PMID: 34870333 DOI: 10.1111/1348-0421.12957] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 12/19/2022]
Abstract
Aspergillus fumigatus, a ubiquitous pathogen, causes aspergillosis in humans, especially in immunodeficient patients. Azoles are frontline antifungal drugs for treating aspergillosis. The recent global emergence of azole resistance in A. fumigatus has become a serious problem worldwide. It has arisen through two routes: long-term azole medical therapy, called the patient route, and the use of azole fungicides in its habitats especially for agricultural activities, called the environmental route. Resistant strains developed through the latter route show cross-resistance to medical azoles because of the identical molecular target Cyp51A between azole compounds used for medical treatment and agricultural disease control. In azole-resistant strains arising through the environmental route, A. fumigatus is observed frequently possessing mutations in the cyp51A gene linked to tandem repeats in the promoter region such as TR34 /L98H and TR46 /Y121F/T289A. Results of microsatellite genotyping analyses of resistant A. fumigatus strains have suggested a transboundary spread of this microorganism in many countries. Diverse actors are involved in the global highway of transmission. Therefore, the matter must be addressed as a "One Health" issue. This review presents a background of azole resistance in A. fumigatus and introduces newly discovered difficulties generated as this pathogen spreads worldwide. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
| | - Takahito Toyotome
- Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine.,Diagnostic Center for Animal Health and Food Safety, Obihiro University of Agriculture and Veterinary Medicine.,Medical Mycology Research Center, Chiba University
| |
Collapse
|
26
|
Genome sequencing of the neotype strain CBS 554.65 reveals the MAT1-2 locus of Aspergillus niger. BMC Genomics 2021; 22:679. [PMID: 34548025 PMCID: PMC8454179 DOI: 10.1186/s12864-021-07990-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 09/03/2021] [Indexed: 12/05/2022] Open
Abstract
Background Aspergillus niger is a ubiquitous filamentous fungus widely employed as a cell factory thanks to its abilities to produce a wide range of organic acids and enzymes. Its genome was one of the first Aspergillus genomes to be sequenced in 2007, due to its economic importance and its role as model organism to study fungal fermentation. Nowadays, the genome sequences of more than 20 A. niger strains are available. These, however, do not include the neotype strain CBS 554.65. Results The genome of CBS 554.65 was sequenced with PacBio. A high-quality nuclear genome sequence consisting of 17 contigs with a N50 value of 4.07 Mbp was obtained. The assembly covered all the 8 centromeric regions of the chromosomes. In addition, a complete circular mitochondrial DNA assembly was obtained. Bioinformatic analyses revealed the presence of a MAT1-2-1 gene in this genome, contrary to the most commonly used A. niger strains, such as ATCC 1015 and CBS 513.88, which contain a MAT1-1-1 gene. A nucleotide alignment showed a different orientation of the MAT1–1 locus of ATCC 1015 compared to the MAT1–2 locus of CBS 554.65, relative to conserved genes flanking the MAT locus. Within 24 newly sequenced isolates of A. niger half of them had a MAT1–1 locus and the other half a MAT1–2 locus. The genomic organization of the MAT1–2 locus in CBS 554.65 is similar to other Aspergillus species. In contrast, the region comprising the MAT1–1 locus is flipped in all sequenced strains of A. niger. Conclusions This study, besides providing a high-quality genome sequence of an important A. niger strain, suggests the occurrence of genetic flipping or switching events at the MAT1–1 locus of A. niger. These results provide new insights in the mating system of A. niger and could contribute to the investigation and potential discovery of sexuality in this species long thought to be asexual. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07990-8.
Collapse
|
27
|
Arastehfar A, Carvalho A, Houbraken J, Lombardi L, Garcia-Rubio R, Jenks J, Rivero-Menendez O, Aljohani R, Jacobsen I, Berman J, Osherov N, Hedayati M, Ilkit M, Armstrong-James D, Gabaldón T, Meletiadis J, Kostrzewa M, Pan W, Lass-Flörl C, Perlin D, Hoenigl M. Aspergillus fumigatus and aspergillosis: From basics to clinics. Stud Mycol 2021; 100:100115. [PMID: 34035866 PMCID: PMC8131930 DOI: 10.1016/j.simyco.2021.100115] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.
Collapse
Affiliation(s)
- A. Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - A. Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - J. Houbraken
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands
| | - L. Lombardi
- UCD Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland
| | - R. Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - J.D. Jenks
- Department of Medicine, University of California San Diego, San Diego, CA, 92103, USA
- Clinical and Translational Fungal-Working Group, University of California San Diego, La Jolla, CA, 92093, USA
| | - O. Rivero-Menendez
- Medical Mycology Reference Laboratory, National Center for Microbiology, Instituto de Salud Carlos III, Madrid, 28222, Spain
| | - R. Aljohani
- Department of Infectious Diseases, Imperial College London, London, UK
| | - I.D. Jacobsen
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Jena, Germany
- Institute for Microbiology, Friedrich Schiller University, Jena, Germany
| | - J. Berman
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Jena, Germany
| | - N. Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, 69978, Israel
| | - M.T. Hedayati
- Invasive Fungi Research Center/Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - M. Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, Çukurova University, 01330, Adana, Turkey
| | | | - T. Gabaldón
- Life Sciences Programme, Supercomputing Center (BSC-CNS), Jordi Girona, Barcelona, 08034, Spain
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), Barcelona, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010, Barcelona, Spain
| | - J. Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | - W. Pan
- Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - C. Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - D.S. Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - M. Hoenigl
- Department of Medicine, University of California San Diego, San Diego, CA, 92103, USA
- Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, 8036, Graz, Austria
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, San Diego, CA 92093, USA
| |
Collapse
|
28
|
Takahashi H, Oiki S, Kusuya Y, Urayama SI, Hagiwara D. Intimate genetic relationships and fungicide resistance in multiple strains of Aspergillus fumigatus isolated from a plant bulb. Environ Microbiol 2021; 23:5621-5638. [PMID: 34464008 PMCID: PMC9292267 DOI: 10.1111/1462-2920.15724] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 12/12/2022]
Abstract
Fungal infections are increasingly dangerous because of environmentally dispersed resistance to antifungal drugs. Azoles are commonly used antifungal drugs, but they are also used as fungicides in agriculture, which may enable enrichment of azole‐resistant strains of the human pathogen Aspergillus fumigatus in the environment. Understanding of environmental dissemination and enrichment of genetic variation associated with azole resistance in A. fumigatus is required to suppress resistant strains. Here, we focused on eight strains of azole‐resistant A. fumigatus isolated from a single tulip bulb for sale in Japan. This set includes strains with TR34/L98H/T289A/I364V/G448S and TR46/Y121F/T289A/S363P/I364V/G448S mutations in the cyp51A gene, which showed higher tolerance to several azoles than strains harbouring TR46/Y121F/T289A mutation. The strains were typed by microsatellite typing, single nucleotide polymorphism profiles, and mitochondrial and nuclear genome analyses. The strains grouped differently using each typing method, suggesting historical genetic recombination among the strains. Our data also revealed that some strains isolated from the tulip bulb showed tolerance to other classes of fungicides, such as QoI and carbendazim, followed by related amino acid alterations in the target proteins. Considering spatial–temporal factors, plant bulbs are an excellent environmental niche for fungal strains to encounter partners, and to obtain and spread resistance‐associated mutations.
Collapse
Affiliation(s)
- Hiroki Takahashi
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan.,Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.,Plant Molecular Science Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8675, Japan
| | - Sayoko Oiki
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Yoko Kusuya
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
| | - Syun-Ichi Urayama
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Daisuke Hagiwara
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan.,Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| |
Collapse
|
29
|
Etienne KA, Berkow EL, Gade L, Nunnally N, Lockhart SR, Beer K, Jordan IK, Rishishwar L, Litvintseva AP. Genomic Diversity of Azole-Resistant Aspergillus fumigatus in the United States. mBio 2021; 12:e0180321. [PMID: 34372699 PMCID: PMC8406307 DOI: 10.1128/mbio.01803-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 12/19/2022] Open
Abstract
Azole resistance in pathogenic Aspergillus fumigatus has become a global public health issue threatening the use of medical azoles. The environmentally occurring resistance mutations, TR34/L98H (TR34) and TR46/Y121F/T289A (TR46), are widespread across multiple continents and emerging in the United States. We used whole-genome single nucleotide polymorphism (SNP) analysis on 179 nationally represented clinical and environmental A. fumigatus genomes from the United States along with 18 non-U.S. genomes to evaluate the genetic diversity and foundation of the emergence of azole resistance in the United States. We demonstrated the presence of clades of A. fumigatus isolates: clade A (17%) comprised a global collection of clinical and environmental azole-resistant strains, including all strains with the TR34/L98H allele from India, The Netherlands, the United Kingdom, and the United States, and clade B (83%) consisted of isolates without this marker mainly from the United States. The TR34/L98H polymorphism was shared among azole-resistant A. fumigatus strains from India, The Netherlands, the United Kingdom, and the United States, suggesting the common origin of this resistance mechanism. Six percent of azole-resistant A. fumigatus isolates from the United States with the TR34 resistance marker had a mixture of clade A and clade B alleles, suggestive of recombination. Additionally, the presence of equal proportions of both mating types further suggests the ongoing presence of recombination. This study demonstrates the genetic background for the emergence of azole resistance in the United States, supporting a single introduction and subsequent propagation, possibly through recombination of environmentally driven resistance mutations. IMPORTANCE Aspergillus fumigatus is one of the most common causes of invasive mold infections in patients with immune deficiencies and has also been reported in patients with severe influenza and severe acute respiratory syndrome coronavirus 2 (SARs-CoV-2). Triazole drugs are the first line of therapy for this infection; however, their efficacy has been compromised by the emergence of azole resistance in A. fumigatus, which was proposed to be selected for by exposure to azole fungicides in the environment [P. E. Verweij, E. Snelders, G. H. J. Kema, E. Mellado, et al., Lancet Infect Dis 9:789-795, 2009, https://doi.org/10.1016/S1473-3099(09)70265-8]. Isolates with environmentally driven resistance mutations, TR34/L98H (TR34) and TR46/Y121F/T289A (TR46), have been reported worldwide. Here, we used genomic analysis of a large sample of resistant and susceptible A. fumigatus isolates to demonstrate a single introduction of TR34 in the United States and suggest its ability to spread into the susceptible population is through recombination between resistant and susceptible isolates.
Collapse
Affiliation(s)
- Kizee A. Etienne
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Elizabeth L. Berkow
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Lalitha Gade
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Natalie Nunnally
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Shawn R. Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - Karlyn Beer
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| | - I. King Jordan
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Lavanya Rishishwar
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Anastasia P. Litvintseva
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, Georgia, USA
| |
Collapse
|
30
|
Chen JY, Klosterman SJ, Hu XP, Dai XF, Subbarao KV. Key Insights and Research Prospects at the Dawn of the Population Genomics Era for Verticillium dahliae. ANNUAL REVIEW OF PHYTOPATHOLOGY 2021; 59:31-51. [PMID: 33891830 DOI: 10.1146/annurev-phyto-020620-121925] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The genomics era has ushered in exciting possibilities to examine the genetic bases that undergird the characteristic features of Verticillium dahliae and other plant pathogens. In this review, we provide historical perspectives on some of the salient biological characteristics of V. dahliae, including its morphology, microsclerotia formation, host range, disease symptoms, vascular niche, reproduction, and population structure. The kaleidoscopic population structure of this pathogen is summarized, including different races of the pathogen, defoliating and nondefoliating phenotypes, vegetative compatibility groupings, and clonal populations. Where possible, we place the characteristic differences in the context of comparative and functional genomics analyses that have offered insights into population divergence within V. dahliae and the related species.Current challenges are highlighted along with some suggested future population genomics studies that will contribute to advancing our understanding of the population divergence in V. dahliae.
Collapse
Affiliation(s)
- Jie-Yin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; ,
| | - Steven J Klosterman
- Agricultural Research Service, United States Department of Agriculture, Salinas, California 93905, USA;
| | - Xiao-Ping Hu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, China;
| | - Xiao-Feng Dai
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; ,
| | - Krishna V Subbarao
- Department of Plant Pathology, University of California, Davis, California 93905, USA;
| |
Collapse
|
31
|
Azole-Resistance Development; How the Aspergillus fumigatus Lifecycle Defines the Potential for Adaptation. J Fungi (Basel) 2021; 7:jof7080599. [PMID: 34436138 PMCID: PMC8397044 DOI: 10.3390/jof7080599] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/16/2021] [Accepted: 07/20/2021] [Indexed: 01/15/2023] Open
Abstract
In order to successfully infect or colonize human hosts or survive changing environments, Aspergillus fumigatus needs to adapt through genetic changes or phenotypic plasticity. The genomic changes are based on the capacity of the fungus to produce genetic variation, followed by selection of the genotypes that are most fit to the new environment. Much scientific work has focused on the metabolic plasticity, biofilm formation or the particular genetic changes themselves leading to adaptation, such as antifungal resistance in the host. Recent scientific work has shown advances made in understanding the natural relevance of parasex and how both the asexual and sexual reproduction can lead to tandem repeat elongation in the target gene of the azoles: the cyp51A gene. In this review, we will explain how the fungus can generate genetic variation that can lead to adaptation. We will discuss recent advances that have been made in the understanding of the lifecycle of A. fumigatus to explain the differences observed in speed and type of mutations that are generated under different environments and how this can facilitate adaptation, such as azole-resistance selection.
Collapse
|
32
|
Ramšak B, Markau J, Pazen T, Dahlmann TA, Krappmann S, Kück U. The master regulator MAT1-1-1 of fungal mating binds to its targets via a conserved motif in the human pathogen Aspergillus fumigatus. G3-GENES GENOMES GENETICS 2021; 11:6026963. [PMID: 33598704 PMCID: PMC8022922 DOI: 10.1093/g3journal/jkaa012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/23/2020] [Indexed: 12/18/2022]
Abstract
Mating-type transcription factors are master regulators of sexually related signal transduction pathways in fungi; however, their recognition of specific DNA sequences from target genes is widely undetermined. Here, we identified and characterized the DNA-binding sequence of the MAT1-1-1 alpha-box domain transcription factor from the human pathogen Aspergillus fumigatus. In order to explore MAT1-1-1 DNA-binding targets, we used the previously reported MAT1-1-1 binding motif from Penicillium chrysogenum, in a bioinformatics approach. We identified 18 A. fumigatus genes carrying the MAT1.1 sequence in their upstream region, among them genes for the α-pheromone precursor (PpgA), G-protein-coupled pheromone receptor (PreA), and for TomA, an unidentified protein. To validate our prediction further, quantification of transcript levels showed a decrease in expression of ppgA, tomA, and others in a MAT1-1 deletion strain. For a functional analysis of the binding sites, truncated variants of the A. fumigatus MAT1-1-1 gene were introduced into Escherichia coli for heterologous expression. The yield of recombinant protein was further optimized for the AfMAT1-1-178-235 variant that harbors an extended alpha-box domain. AfMAT1-1-178-235 bound to a subset of the most strongly upregulated genes: ppgA, preA, and tomA. The DNA-binding specificity was confirmed by testing mutated binding sequences, as well as performing competition experiments with specific and non-specific sequences. Finally, equilibrium dissociation constants of 1.83 ± 0.1 and 1.45 ± 0.26 µM were determined for AfMAT1-1-178-235 and fusion protein GST-AfMAT1-1-178-235. Collectively, these findings provide further insights into AfMAT1-1-1-mediated gene expression and imply that alpha-box domain regulators from other members of Eurotiales control fungal development in a conserved manner.
Collapse
Affiliation(s)
- Barbara Ramšak
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Jessica Markau
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Tobias Pazen
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen und Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Tim A Dahlmann
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Sven Krappmann
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen und Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Ulrich Kück
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780 Bochum, Germany
| |
Collapse
|
33
|
Turning Inside Out: Filamentous Fungal Secretion and Its Applications in Biotechnology, Agriculture, and the Clinic. J Fungi (Basel) 2021; 7:jof7070535. [PMID: 34356914 PMCID: PMC8307877 DOI: 10.3390/jof7070535] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/14/2021] [Accepted: 06/25/2021] [Indexed: 12/15/2022] Open
Abstract
Filamentous fungi are found in virtually every marine and terrestrial habitat. Vital to this success is their ability to secrete a diverse range of molecules, including hydrolytic enzymes, organic acids, and small molecular weight natural products. Industrial biotechnologists have successfully harnessed and re-engineered the secretory capacity of dozens of filamentous fungal species to make a diverse portfolio of useful molecules. The study of fungal secretion outside fermenters, e.g., during host infection or in mixed microbial communities, has also led to the development of novel and emerging technological breakthroughs, ranging from ultra-sensitive biosensors of fungal disease to the efficient bioremediation of polluted environments. In this review, we consider filamentous fungal secretion across multiple disciplinary boundaries (e.g., white, green, and red biotechnology) and product classes (protein, organic acid, and secondary metabolite). We summarize the mechanistic understanding for how various molecules are secreted and present numerous applications for extracellular products. Additionally, we discuss how the control of secretory pathways and the polar growth of filamentous hyphae can be utilized in diverse settings, including industrial biotechnology, agriculture, and the clinic.
Collapse
|
34
|
Biological Characteristics of Verticillium dahliae MAT1-1 and MAT1-2 Strains. Int J Mol Sci 2021; 22:ijms22137148. [PMID: 34281204 PMCID: PMC8269371 DOI: 10.3390/ijms22137148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 12/17/2022] Open
Abstract
Verticillium dahliae is a soil-borne plant pathogenic fungus that causes Verticillium wilt on hundreds of dicotyledonous plant species. V. dahliae is considered an asexually (clonal) reproducing fungus, although both mating type idiomorphs (MAT1-1 and MAT1-2) are present, and is heterothallic. Most of the available information on V. dahliae strains, including their biology, pathology, and genomics comes from studies on isolates with the MAT1-2 idiomorph, and thus little information is available on the MAT1-1 V. dahliae strains in the literature. We therefore evaluated the growth responses of MAT1-1 and MAT1-2 V. dahliae strains to various stimuli. Growth rates and melanin production in response to increased temperature, alkaline pH, light, and H2O2 stress were higher in the MAT1-2 strains than in the MAT1-1 strains. In addition, the MAT1-2 strains showed an enhanced ability to degrade complex polysaccharides, especially starch, pectin, and cellulose. Furthermore, several MAT1-2 strains from both potato and sunflower showed increased virulence on their original hosts, relative to their MAT1-1 counterparts. Thus, compared to MAT1-1 strains, MAT1-2 strains derive their potentially greater fitness from an increased capacity to adapt to their environment and exhibit higher virulence. These competitive advantages might explain the current abundance of MAT1-2 strains relative to MAT1-1 strains in the agricultural and sylvicultural ecosystems, and this study provides the baseline information on the two mating idiomorphs to study sexual reproduction in V. dahliae under natural and laboratory conditions.
Collapse
|
35
|
Cadena J, Thompson GR, Patterson TF. Aspergillosis: Epidemiology, Diagnosis, and Treatment. Infect Dis Clin North Am 2021; 35:415-434. [PMID: 34016284 DOI: 10.1016/j.idc.2021.03.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The spectrum of disease produced by Aspergillus species ranges from allergic syndromes to chronic pulmonary conditions and invasive infections. Invasive aspergillosis is a major cause of morbidity and mortality in immunocompromised patients. Risk factors continue to evolve and include newer biological agents that target the immune system and postinfluenza infection; and it has been observed following COVID-19 infection. Diagnosis remains a challenge but non-culture-based methods are available. Antifungal resistance has emerged. Voriconazole remains the treatment of choice but isavuconazole and posaconazole have similar efficacy with less toxicity. Combination therapy is used with extensive infection and in severe immunosuppression.
Collapse
Affiliation(s)
- Jose Cadena
- Department of Medicine, Division of Infectious Diseases, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive - MSC 7881, San Antonio, TX 78229-3900, USA
| | - George R Thompson
- Department of Internal Medicine, Division of Infectious Diseases, University of California - Davis Health; Department of Medical Microbiology and Immunology, University of California - Davis Health.
| | - Thomas F Patterson
- Department of Medicine, Division of Infectious Diseases, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive - MSC 7881, San Antonio, TX 78229-3900, USA
| |
Collapse
|
36
|
Abundant Small Protein ICARUS Inside the Cell Wall of Stress-Resistant Ascospores of Talaromyces macrosporus Suggests a Novel Mechanism of Constitutive Dormancy. J Fungi (Basel) 2021; 7:jof7030216. [PMID: 33802751 PMCID: PMC8002430 DOI: 10.3390/jof7030216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/08/2021] [Accepted: 03/10/2021] [Indexed: 01/01/2023] Open
Abstract
Ascospores of Talaromyces.macrosporus belong to the most stress resistant eukaryotic cells and show a constitutive dormancy, i.e., no germination occurs in the presence of rich growth medium. Only an extreme trigger as very high temperature or pressure is able to evoke synchronized germination. In this study, several changes within the thick cell wall of these cells are observed after a heat treatment: (i.) a change in its structure as shown with EPR and X-ray diffraction; (ii.) a release of an abundant protein into the supernatant, which is proportional to the extent of heat activation; (iii.) a change in the permeability of the cell wall as judged by fluorescence studies in which staining of the interior of the cell wall correlates with germination of individual ascospores. The gene encoding the protein, dubbed ICARUS, was studied in detail and was expressed under growth conditions that showed intense ascomata (fruit body) and ascospore formation. It encodes a small 7–14 kD protein. Blast search exhibits that different Talaromyces species show a similar sequence, indicating that the protein also occurs in other species of the genus. Deletion strains show delayed ascomata formation, release of pigments into the growth medium, higher permeability of the cell wall and a markedly shorter heat activation needed for activation. Further, wild type ascospores are more heat-resistant. All these observations suggest that the protein plays a role in dormancy and is related to the structure and permeability of the ascospore cell wall. However, more research on this topic is needed to study constitutive dormancy in other fungal species that form stress-resistant ascospores.
Collapse
|
37
|
Huang C, Feng Y, Patel G, Xu XQ, Qian J, Liu Q, Kai GY. Production, immobilization and characterization of beta-glucosidase for application in cellulose degradation from a novel Aspergillus versicolor. Int J Biol Macromol 2021; 177:437-446. [PMID: 33636259 DOI: 10.1016/j.ijbiomac.2021.02.154] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/16/2021] [Accepted: 02/20/2021] [Indexed: 01/19/2023]
Abstract
Beta-glucosidase (EC 3.2.1.21) catalyzes the hydrolysis of cellobiose and cellooligosaccharides containing (1 → 4)-beta-glycosidic bonds to glucose, which is crucial in cellulosic ethanol production. In this study, Aspergillus versicolor, a novel highly productive beta-glucosidase strain, was first isolated from Camptotheca acuminata seeds. The highest beta-glucosidase activity with 812.86 U/mL was obtained by using the response surface methodology, and a 14.4-fold has increased compared to the control. The beta-glucosidase was then purified to homogeneity with recovery yield and specific activity of 25.98% and 499.15 U/mg, respectively. To enhance its stability and recyclability, the purified beta-glucosidase was first immobilized onto magnetic MnO2 by electrostatic adsorption. The immobilized materials were characterized by FR-IT, TEM and FE-SEM. Compared with the free beta-glucosidase, the immobilized enzyme exhibited enhanced thermal stability (1.5-fold raise in half-life at 50 °C), and reusability (holding over 60% activity after eight cycles), besides, the optimum pH has increased to 6.0. Substrate specificity research suggested that the enzyme had high hydrolytic activity on cellobiose. It also had a hydrolysis effect on (1 → 3) and (1 → 6)-beta-glycosidic linkages. Application trials in cellulose hydrolysis revealed that the immobilized enzyme was comparatively more effective. Our results suggested this novel immobilized beta-glucosidase makes a promising alternative for the cellulosic ethanol production.
Collapse
Affiliation(s)
- Chao Huang
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Yue Feng
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Gopal Patel
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Xiao-Qian Xu
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Jun Qian
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Qun Liu
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Guo-Yin Kai
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China.
| |
Collapse
|
38
|
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.
Collapse
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
| |
Collapse
|
39
|
Reinhardt D, Roux C, Corradi N, Di Pietro A. Lineage-Specific Genes and Cryptic Sex: Parallels and Differences between Arbuscular Mycorrhizal Fungi and Fungal Pathogens. TRENDS IN PLANT SCIENCE 2021; 26:111-123. [PMID: 33011084 DOI: 10.1016/j.tplants.2020.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/29/2020] [Accepted: 09/08/2020] [Indexed: 05/25/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) live as obligate root symbionts on almost all land plants. They have long been regarded as ancient asexuals that have propagated clonally for millions of years. However, genomic studies in Rhizophagus irregularis and other AMF revealed many features indicative of sex. Surprisingly, comparative genomics of conspecific isolates of R. irregularis revealed an unexpected interstrain diversity, suggesting that AMF carry a high number of lineage-specific (LS) genes. Intriguingly, cryptic sex and LS genomic regions have previously been reported in a number of fungal pathogens of plants and humans. Here, we discuss these genomic similarities and highlight their potential relevance for AMF adaptation to the environment and for symbiotic functioning.
Collapse
Affiliation(s)
- Didier Reinhardt
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
| | - Christophe Roux
- Laboratoire de Recherche en Sciences Végétales, UPS, CNRS, Université de Toulouse, Castanet-Tolosan 31326, France
| | - Nicolas Corradi
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Antonio Di Pietro
- Departamento de Genética, Universidad de Cordoba, 14071 Cordoba, Spain
| |
Collapse
|
40
|
Moore GG. Practical considerations will ensure the continued success of pre-harvest biocontrol using non-aflatoxigenic Aspergillus flavus strains. Crit Rev Food Sci Nutr 2021; 62:4208-4225. [PMID: 33506687 DOI: 10.1080/10408398.2021.1873731] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
There is an important reason for the accelerated use of non-aflatoxigenic Aspergillus flavus to mitigate pre-harvest aflatoxin contamination… it effectively addresses the imperative need for safer food and feed. Now that we have decades of proof of the effectiveness of A. flavus as biocontrol, it is time to improve several aspects of this strategy. If we are to continue relying heavily on this form of aflatoxin mitigation, there are considerations we must acknowledge, and actions we must take, to ensure that we are best wielding this strategy to our advantage. These include its: (1) potential to produce other mycotoxins, (2) persistence in the field in light of several ecological factors, (3) its reproductive and genetic stability, (4) the mechanism(s) employed that allow it to elicit control over aflatoxigenic strains and species of agricultural importance and (5) supplemental alternatives that increase its effectiveness. There is a need to be consistent, practical and thoughtful when it comes to implementing this method of mycotoxin mitigation since these fungi are living organisms that have been adapting, evolving and surviving on this planet for tens-of-millions of years. This document will serve as a critical review of the literature regarding pre-harvest A. flavus biocontrol and will discuss opportunities for improvements.
Collapse
Affiliation(s)
- Geromy G Moore
- United States Department of Agriculture, Agricultural Research Service, New Orleans, USA
| |
Collapse
|
41
|
Li Y, Dai M, Zhang Y, Lu L. The sterol C-14 reductase Erg24 is responsible for ergosterol biosynthesis and ion homeostasis in Aspergillus fumigatus. Appl Microbiol Biotechnol 2021; 105:1253-1268. [PMID: 33475797 DOI: 10.1007/s00253-021-11104-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/10/2020] [Accepted: 01/05/2021] [Indexed: 11/26/2022]
Abstract
Ergosterol, a major lipid present in the fungal cell membrane, is considered as an effective antifungal drug target. A rational strategy for increasing drug reservoir relies on functionally validation of essential enzymes involved in fungal key biological pathway. Current knowledge regarding the essential genes in the ergosterol biosynthesis pathway is still limited in the opportunistic human pathogen Aspergillus fumigatus. In this study, we characterized two endoplasmic reticulum-localized sterol C-14 reductases encoded by both erg24A and erg24B homologs that are essential for the viability of A. fumigatus despite the fact that neither paralog is essential individually. Loss of one homolog of Erg24 impairs hyphal growth, conidiation, and virulence but has no effect on ergosterol biosynthesis. To investigate the functional significance of erg24, a conditional double mutant (Δerg24B niiA::erg24A) was constructed in the Δerg24B background. Strikingly, the conditional erg24 double mutant exhibited severe growth defects and accumulation of sterol intermediate. Moreover, the addition of metal ions and the overexpression of the corresponding ion transporters could rescue the growth defects of the erg24 double mutant in A. fumigatus, implying that the defective phenotype of the erg24 double mutant is tightly associated with dysregulation of ion homeostasis. Taken together, our results demonstrate the critical role of Erg24 in ergosterol biosynthesis and ion homeostasis in A. fumigatus, which may have important implications for antifungal discovery. KEY POINTS: • We characterized two endoplasmic reticulum-localized sterol C-14 reductases Erg24A and Erg24B in A. fumigatus. • Erg24A and Erg24B in combination, but not individually, are required for the viability of A. fumigatus. • Inactivation of Erg24 leads to the disruption of ion homeostasis and affects ergosterol biosynthesis.
Collapse
Affiliation(s)
- Yeqi Li
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Mengyao Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Yuanwei Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
| |
Collapse
|
42
|
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.
Collapse
|
43
|
Dynamics of Aspergillus fumigatus in Azole Fungicide-Containing Plant Waste in the Netherlands (2016-2017). Appl Environ Microbiol 2021; 87:AEM.02295-20. [PMID: 33127811 PMCID: PMC7783342 DOI: 10.1128/aem.02295-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/20/2020] [Indexed: 01/24/2023] Open
Abstract
The treatment of patients suffering from Aspergillus diseases is hampered due to infections with Aspergillus fumigatus that are already resistant to medical azoles. Previous work has suggested that A. fumigatus likely gains resistance through environmental azole exposure in so-called hot spots. Here, we investigated A. fumigatus resistance dynamics over time at three sites at which farmers used azole fungicides for crop protection. Over 16 months, 114 samples were taken from stockpiles of decaying plant waste. A. fumigatus and azole fungicide residues were ubiquitously present in the plant waste. On average, 105 A. fumigatus CFU/g was recovered, of which roughly half were itraconazole and tebuconazole resistant. Similar tandem repeat-mediated resistance mechanisms were found in colonies cultured from plant waste as reported in clinical azole-resistant isolates. Our results show a consistent high burden of azole-resistant A. fumigatus in azole-containing plant waste and underscores the need to further investigate resistance-reducing interventions and transmission routes.IMPORTANCE Aspergillus fumigatus is consistently present independently on season at a high abundance in plant waste material throughout the sampling period. Our study confirmed that long-term storage sites of azole-containing decaying plant material can indeed be considered hot spots, which can sustain resistance development and maintenance in A. fumigatus Roughly half of individual isolates were azole resistant and carried genetic mutations that are highly similar to those found in patients with azole-resistant invasive aspergillosis. Our work suggests that environmental sources of azole resistance in A. fumigatus may be important, underscoring the need for further studies on environment-to-patient transmission routes.
Collapse
|
44
|
Ellena V, Sauer M, Steiger MG. The fungal sexual revolution continues: discovery of sexual development in members of the genus Aspergillus and its consequences. Fungal Biol Biotechnol 2020; 7:17. [PMID: 33357234 PMCID: PMC7761153 DOI: 10.1186/s40694-020-00107-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/15/2020] [Indexed: 12/24/2022] Open
Abstract
Asexuality was considered to be a common feature of a large part of fungi, including those of the genus Aspergillus. However, recent advances and the available genomic and genetic engineering technologies allowed to gather more and more indications of a hidden sexuality in fungi previously considered asexual. In parallel, the acquired knowledge of the most suitable conditions for crossings was shown to be crucial to effectively promote sexual reproduction in the laboratory. These discoveries not only have consequences on our knowledge of the biological processes ongoing in nature, questioning if truly asexual fungal species exist, but they also have important implications on other research areas. For instance, the presence of sexuality in certain fungi can have effects on their pathogenicity or on shaping the ecosystem that they normally colonize. For these reasons, further investigations of the sexual potential of Aspergillus species, such as the industrially important A. niger, will be carried on.
Collapse
Affiliation(s)
- Valeria Ellena
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Muthgasse 18, Vienna, Austria. .,Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria.
| | - Michael Sauer
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Muthgasse 18, Vienna, Austria.,Institute of Microbiology and Microbial Biotechnology, BOKU-VIBT, University of Natural Resources and Life Sciences, Muthgasse 18, Vienna, Austria.,CD Laboratory for Biotechnology of Glycerol, Muthgasse 18, Vienna, Austria
| | - Matthias G Steiger
- Austrian Centre of Industrial Biotechnology (ACIB GmbH), Muthgasse 18, Vienna, Austria.,Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| |
Collapse
|
45
|
Verweij PE, Lucas JA, Arendrup MC, Bowyer P, Brinkmann AJ, Denning DW, Dyer PS, Fisher MC, Geenen PL, Gisi U, Hermann D, Hoogendijk A, Kiers E, Lagrou K, Melchers WJ, Rhodes J, Rietveld AG, Schoustra SE, Stenzel K, Zwaan BJ, Fraaije BA. The one health problem of azole resistance in Aspergillus fumigatus: current insights and future research agenda. FUNGAL BIOL REV 2020. [DOI: 10.1016/j.fbr.2020.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
46
|
Korfanty G, Stanley K, Lammers K, Fan Y, Xu J. Variations in sexual fitness among natural strains of the opportunistic human fungal pathogen Aspergillus fumigatus. INFECTION GENETICS AND EVOLUTION 2020; 87:104640. [PMID: 33246083 DOI: 10.1016/j.meegid.2020.104640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 10/05/2020] [Accepted: 11/21/2020] [Indexed: 10/22/2022]
Abstract
Aspergillus fumigatus is a ubiquitous ascomycete fungus, naturally inhabiting the soil and compost piles. Its conidia readily disperse into the atmosphere and cause opportunistic infections known as aspergillosis. With the emerging resistance to many antifungal drugs, our understanding of A. fumigatus epidemiology has become increasingly important for developing effective control and treatment strategies. As a pathogen capable of both sexual and asexual reproduction, mutations causing drug resistance and increased virulence could be spread rapidly in A. fumigatus populations. However, relatively little is known about the distributions of sexual reproductive fitness among natural strains of A. fumigatus. Here we investigated the formation of sexual reproductive structure (i.e. cleistothecia) and sexual spore viability among 60 natural strains of A. fumigatus. These strains were from six geographically distant countries (India, China, Canada, Cameroon, Saudi Arabia, and New Zealand), with 10 strains (including five MAT1-1 strains and five MAT1-2 strains) from each country. These strains were crossed in all combinations with strains of the opposite mating type. In addition, all 60 strains were crossed with either AFB62-1 (MAT1-1) or AFIR928 (MAT1-2), two reference supermater strains. Of the 900 crosses among the 60 natural strains, 136 crosses (15.1%) produced cleistothecia. Our analyses revealed that strains from China had the highest average ability to form cleistothecia, followed by those from New Zealand, Saudi Arabia, India, Canada, and Cameroon. Among the crosses that produced cleistothecia, about 40% produced viable ascospores, with the rate of ascospore germination varied significantly among crosses. Interestingly, neither the ability to form cleistothecia nor ascospore germination rate showed any distinct relationships with either geographic or genetic distance between parental strains. Our results suggest that genetic exchange among geographically and genetically divergent strains of A. fumigatus are possible. However, the rates of genetic exchange likely vary among strains and populations in nature.
Collapse
Affiliation(s)
- Greg Korfanty
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Kaitlin Stanley
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Kaitlyn Lammers
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - YuYing Fan
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, Ontario, Canada.
| |
Collapse
|
47
|
Ma LG, Geng Y. Determination of the reference genes for qRT-PCR normalization and expression levels of MAT genes under various conditions in Ulocladium. PeerJ 2020; 8:e10379. [PMID: 33282558 PMCID: PMC7690293 DOI: 10.7717/peerj.10379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 10/26/2020] [Indexed: 11/20/2022] Open
Abstract
The genus Ulocladium is thought to be strictly asexual. One of the possible reasons for the lack of sexuality in Ulocladium species is the absence of the stimulus of environmental factors. Sexual reproduction in ascomycetes is controlled by a specific region in the genome referred to as mating-type locus (MAT) that consists of two dissimilar DNA sequences in the mating partners, termed MAT1-1 and MAT1-2 idiomorphs. To identify the response of MAT loci to environmental conditions, the mRNA transcription level of MAT1-1-1 and MAT1-2-1 genes was tested using qRT-PCR under different temperatures (−20 °C, −10 °C, 0 °C, 10 °C, 20 °C, 30 °C and 40 °C), culture medias (CM, OA, HAY, PCA, PDA and V8), photoperiods (24 h light, 24 h dark, 12 h light/12 h dark, 10 h light/14 h dark and 8 h light/16 h dark), and CO2 concentrations (0.03%, 0.5%, 1%, 5%, 10%, 15% and 20%). For obtaining reliable results from qRT-PCR, the most stable internal control gene and optimal number of reference genes for normalization were determined under different treatments. The results showed that there is no universal internal control gene that is expressed at a constant level under different experimental treatments. In comparison to various incubation conditions, the relative expression levels of both MAT genes were significantly increased when fungal mycelia were grown on HAY culture media at 0–10 °C with a light/dark cycle, indicating that temperature, culture media, and light might be the key environmental factors for regulating the sexuality in Ulocladium. Moreover, MAT1-1-1 and MAT1-2-1 genes showed similar expression patterns under different treatments, suggesting that the two MAT genes might play an equally important role in the sexual evolutionary process.
Collapse
Affiliation(s)
- Li-Guo Ma
- Shandong Key Laboratory of Plant Virology, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Yun Geng
- Biotechnology Research Center, Shandong Academy of Agricultural Sciences, Jinan, China
| |
Collapse
|
48
|
Swilaiman SS, O’Gorman CM, Du W, Sugui JA, Del Buono J, Brock M, Kwon-Chung KJ, Szakacs G, Dyer PS. Global Sexual Fertility in the Opportunistic Pathogen Aspergillus fumigatus and Identification of New Supermater Strains. J Fungi (Basel) 2020; 6:E258. [PMID: 33143051 PMCID: PMC7712211 DOI: 10.3390/jof6040258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 12/26/2022] Open
Abstract
A sexual cycle in Aspergillus fumigatus was first described in 2009 with isolates from Dublin, Ireland. However, the extent to which worldwide isolates can undergo sexual reproduction has remained unclear. In this study a global collection of 131 isolates was established with a near 1:1 ratio of mating types. All isolates were crossed to MAT1-1 or MAT1-2 Irish strains, and a subset of isolates from different continents were crossed together. Ninety seven percent of isolates were found to produce cleistothecia with at least one mating partner, showing that sexual fertility is not limited to the Irish population but is a characteristic of global A. fumigatus. However, large variation was seen in numbers of cleistothecia produced per cross, suggesting differences in the possibility for genetic exchange between strains in nature. The majority of crosses produced ascospores with >50% germination rates, but with wide variation evident. A high temperature heat shock was required to induce ascospore germination. Finally, a new set of highly fertile MAT1-1 and MAT1-2 supermater strains were identified and pyrimidine auxotrophs generated for community use. Results provide insights into the potential for the A. fumigatus sexual cycle to generate genetic variation and allow gene flow of medically important traits.
Collapse
Affiliation(s)
- Sameira S. Swilaiman
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Céline M. O’Gorman
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Wenyue Du
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Janyce A. Sugui
- Molecular Microbiology Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20825, USA; (J.A.S.); (K.J.K.-C.)
| | - Joanne Del Buono
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Matthias Brock
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Kyung J. Kwon-Chung
- Molecular Microbiology Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20825, USA; (J.A.S.); (K.J.K.-C.)
| | - George Szakacs
- Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Szent Gellert ter 4, 1111 Budapest, Hungary;
| | - Paul S. Dyer
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| |
Collapse
|
49
|
Maroc L, Zhou-Li Y, Boisnard S, Fairhead C. A single Ho-induced double-strand break at the MAT locus is lethal in Candida glabrata. PLoS Genet 2020; 16:e1008627. [PMID: 33057400 PMCID: PMC7591073 DOI: 10.1371/journal.pgen.1008627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 10/27/2020] [Accepted: 09/12/2020] [Indexed: 01/24/2023] Open
Abstract
Mating-type switching is a complex mechanism that promotes sexual reproduction in Saccharomycotina. In the model species Saccharomyces cerevisiae, mating-type switching is initiated by the Ho endonuclease that performs a site-specific double-strand break (DSB) at MAT, repaired by homologous recombination (HR) using one of the two silent mating-type loci, HMLalpha and HMRa. The reasons why all the elements of the mating-type switching system have been conserved in some Saccharomycotina, that do not show a sexual cycle nor mating-type switching, remain unknown. To gain insight on this phenomenon, we used the yeast Candida glabrata, phylogenetically close to S. cerevisiae, and for which no spontaneous and efficient mating-type switching has been observed. We have previously shown that expression of S. cerevisiae’s Ho (ScHo) gene triggers mating-type switching in C. glabrata, but this leads to massive cell death. In addition, we unexpectedly found, that not only MAT but also HML was cut in this species, suggesting the formation of multiple chromosomal DSBs upon HO induction. We now report that HMR is also cut by ScHo in wild-type strains of C. glabrata. To understand the link between mating-type switching and cell death in C. glabrata, we constructed strains mutated precisely at the Ho recognition sites. We find that even when HML and HMR are protected from the Ho-cut, introducing a DSB at MAT is sufficient to induce cell death, whereas one DSB at HML or HMR is not. We demonstrate that mating-type switching in C. glabrata can be triggered using CRISPR-Cas9, without high lethality. We also show that switching is Rad51-dependent, as in S. cerevisiae, but that donor preference is not conserved in C. glabrata. Altogether, these results suggest that a DSB at MAT can be repaired by HR in C. glabrata, but that repair is prevented by ScHo. Mating-type switching is one of the strategies developed by fungi to promote sexual reproduction and propagation. This mechanism enables one haploid cell to give rise to a cell of the opposite mating-type so that they can mate. It has been extensively studied in the yeast S. cerevisiae in which it relies on a programmed double-strand break performed by the Ho endonuclease at the MAT locus which determines sexual identity. Little is known about why the mating-type switching components have been conserved in species like C. glabrata, in which neither sexual reproduction nor mating-type switching is observed. We have previously shown that mating-type switching can be triggered, in C. glabrata, by expression of the HO gene from S. cerevisiae but this leads to massive cell death. In this work, we show that mating-type switching in C. glabrata can be triggered by CRISPR-Cas9 and without any high lethality. We demonstrate that the cut at MAT is only lethal when the Ho endonuclease performs the break, a situation unique to C. glabrata. Our work points to a degeneration of the mating-type switching system in C. glabrata. Further studies of this phenomenon should shed light on the evolution of mating systems in asexual yeasts.
Collapse
Affiliation(s)
- Laetitia Maroc
- Université Paris-Saclay, INRAE, CNRS, AgroParisTech, GQE—Le Moulon, Gif-sur-Yvette, France
| | - Youfang Zhou-Li
- Université Paris-Saclay, INRAE, CNRS, AgroParisTech, GQE—Le Moulon, Gif-sur-Yvette, France
| | - Stéphanie Boisnard
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Cécile Fairhead
- Université Paris-Saclay, INRAE, CNRS, AgroParisTech, GQE—Le Moulon, Gif-sur-Yvette, France
- * E-mail:
| |
Collapse
|
50
|
Naranjo‐Ortiz MA, Gabaldón T. Fungal evolution: cellular, genomic and metabolic complexity. Biol Rev Camb Philos Soc 2020; 95:1198-1232. [PMID: 32301582 PMCID: PMC7539958 DOI: 10.1111/brv.12605] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 12/13/2022]
Abstract
The question of how phenotypic and genomic complexity are inter-related and how they are shaped through evolution is a central question in biology that historically has been approached from the perspective of animals and plants. In recent years, however, fungi have emerged as a promising alternative system to address such questions. Key to their ecological success, fungi present a broad and diverse range of phenotypic traits. Fungal cells can adopt many different shapes, often within a single species, providing them with great adaptive potential. Fungal cellular organizations span from unicellular forms to complex, macroscopic multicellularity, with multiple transitions to higher or lower levels of cellular complexity occurring throughout the evolutionary history of fungi. Similarly, fungal genomes are very diverse in their architecture. Deep changes in genome organization can occur very quickly, and these phenomena are known to mediate rapid adaptations to environmental changes. Finally, the biochemical complexity of fungi is huge, particularly with regard to their secondary metabolites, chemical products that mediate many aspects of fungal biology, including ecological interactions. Herein, we explore how the interplay of these cellular, genomic and metabolic traits mediates the emergence of complex phenotypes, and how this complexity is shaped throughout the evolutionary history of Fungi.
Collapse
Affiliation(s)
- Miguel A. Naranjo‐Ortiz
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyDr. Aiguader 88, Barcelona08003Spain
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyDr. Aiguader 88, Barcelona08003Spain
- Department of Experimental Sciences, Universitat Pompeu Fabra (UPF)Dr. Aiguader 88, 08003BarcelonaSpain
- ICREAPg. Lluís Companys 23, 08010BarcelonaSpain
| |
Collapse
|