Rare Fungus Research Articles

Influence of light regulation on growth and enzyme production in rare endolichenic fungi.

The influence of light regulation on the growth and enzyme production of three endolichenic fungal isolates, i.e. Pseudopestalotiopsis theae (EF13), Fusarium solani (EF5), and Xylaria venustula (PH22), was determined. The isolates were exposed to blue, red, green, yellow, white fluorescent light (12h light-12h dark photoperiod) (test), and 24h dark (control) conditions. Results revealed that the alternating light-dark conditions resulted in the formation of dark rings in most fungal isolates but was absent in PH22. Red light induced sporulation while yellow light elicited higher biomass in all isolates (0.19 ± 0.01g, 0.07 ± 0.00g, and 0.11 ± 0.00g, for EF13, PH22, and EF5, respectively) as compared to incubation in the dark. Results also showed that blue light induced higher amylase activity in PH22 (15.31 ± 0.45 U/mL) and L-asparaginase activity in all isolates (0.45 ± 0.01 U/mL, 0.55 ± 0.39 U/mL, and 0.38 ± 0.01 U/mL, for EF13, PH22, and EF5, respectively) compared to both control conditions. Green light enhanced the production of xylanase (6.57 ± 0.42 U/mL, 10.64 ± 0.12 U/mL, and 7.55 ± 0.56 U/mL for EF13, PH22, and EF5, respectively) and cellulase (6.49 ± 0.48 U/mL, 9.57 ± 0.25 U/mL, and 7.28 ± 0.63 U/mL, for EF13, PH22, and EF5, respectively). In contrast, red light was the least effective light treatment as production of enzymes was the least, with lower levels of amylase, cellulase, xylanase, and L-asparaginase detected. To conclude, all three endolichenic fungi are light-responsive, with fungal growth regulated with the use of red light and yellow light, and manipulation of enzyme production via blue and green light.

Real-life epidemiology and current outcomes of hospitalized adults with invasive fungal infections.

We aimed to describe the current epidemiology of both hosts with invasive fungal infections (IFIs) and causative fungi. And, detail outcomes of these infections at 12 weeks in a real-life cohort of hospitalized patients. The study was retrospective and observational to describe IFI diagnosed in a tertiary hospital (February 2017-December 2021). We included all consecutive patients meeting criteria for proven or probable IFI according to EORTC-MSG and other criteria. A total of 367 IFIs were diagnosed. 11.7% were breakthrough infections, and 56.4% were diagnosed in the intensive care unit. Corticosteroid use (41.4%) and prior viral infection (31.3%) were the most common risk factors for IFI. Lymphoma and pneumocystis pneumonia were the most common baseline and fungal diseases. Only 12% of IFI occurred in patients with neutropenia. Fungal cultures were the most important diagnostic tests (85.8%). The most frequent IFIs were candidemia (42.2%) and invasive aspergillosis (26.7%). Azole-resistant Candida strains and non-fumigatus Aspergillus infections represented 36.1% and 44.5% of the cases, respectively. Pneumocystosis (16.9%), cryptococcosis (4.6%), and mucormycosis (2.7%) were also frequent, as well as mixed infections (3.4%). Rare fungi accounted for 9.5% of infections. Overall, IFI mortality at 12 weeks was 32.2%; higher rates were observed for Mucorales (55.6%), Fusarium (50%), and mixed infections (60%). We documented emerging changes in both hosts and real-life IFI epidemiology. Physicians should be aware of these changes to suspect infections and be aggressive in diagnoses and treatments. Currently, outcomes for such clinical scenarios remain extremely poor.

Large-scale analysis of the genome of the rare alkaline-halophilic Stachybotrys microspora reveals 46 cellulase genes.

Fungi are of great importance in biotechnology, for example in the production of enzymes and metabolites. The main goal of this study was to obtain a high-coverage draft of the Stachybotrys microspora genome and to annotate and analyze the genome sequence data. The rare fungus S.microspora N1 strain is distinguished by its ability to grow in an alkaline halophilic environment and to efficiently secrete cellulolytic enzymes. Here we report the draft genome sequence composed of 3715 contigs, a genome size of 35 343 854 bp, with a GC content of 53.31% and a coverage around 20.5×. The identification of cellulolytic genes and of their corresponding functions was carried out through analysis and annotation of the whole genome sequence. Forty-six cellulases were identified using the fungicompanion bioinformatic tool. Interestingly, an S.microspora endoglucanase selected from those with a low isoelectric point was predicted to have a halophilic profile and share significant homology with a well-known bacterial halophilic cellulase. These results confirm previous biochemical studies revealing a halophilic character, which is a very rare feature among fungal cellulases. All these properties suggest that cellulases of S.microspora may have potential for use in the biofuel, textile, and detergent industries.

Isolation, Purification, and Antitumor Activity of a Novel Active Protein from Antrodia cinnamomea Liquid Fermentation Mycelia

Antrodia cinnamomea, a rare medicinal fungus endemic to Taiwan, contains numerous active components and displays strong antitumor and anti-inflammatory effects. We isolated and purified a novel A. cinnamomea active protein (termed ACAP) from liquid fermentation mycelia and evaluated its antitumor activity. A homogeneous protein-eluted fraction was obtained by anion exchange chromatography and gel filtration chromatography, and ACAP was identified based on the antitumor activity screening of this fraction. An in vitro assay of three tumor cell lines (HeLa, Hep G2, and Hepa 1-6) revealed significant antiproliferative effects of ACAP at low concentrations, with IC50 values of 13.10, 10.70, and 18.69 µg/mL, respectively. Flow cytometric analysis showed that ACAP induced late apoptosis of Hep G2 cells. The apoptosis rate of 50 µg/mL ACAP-treated cells (60%) was significantly (p < 0.01) more than that of the control. A Western blotting assay of apoptotic pathway proteins showed that ACAP significantly upregulated p53 and downregulated caspase-3 expression levels. Our findings indicate that ACAP has strong antitumor activity and the potential for development as a therapeutic agent and/or functional food.

Identifying Bioactive Ingredients and Antioxidant Activities of Wild Sanghuangporus Species of Medicinal Fungi.

Sanghuangporus refers to a group of rare medicinal fungi with remarkable therapeutic properties. However, current knowledge on the bioactive ingredients and antioxidant activities of different species of this genus is limited. In this study, a total of 15 wild strains from 8 species of Sanghuangporus were selected as the experimental materials for identification of the bioactive components (polysaccharide, polyphenol, flavonoid, triterpenoid, and ascorbic acid) and antioxidant activities (scavenging activities against hydroxyl, superoxide, DPPH, and ABTS radicals; superoxide dismutase activity; and ferric reducing ability of plasma). Notably, individual strains contained different levels of various indicators, among which Sanghuangporus baumii Cui 3573, S. sanghuang Cui 14419 and Cui 14441, S. vaninii Dai 9061, and S. zonatus Dai 10841 displayed the strongest activities. The correlation analysis of bioactive ingredients and antioxidant activities revealed that the antioxidant capacity of Sanghuangporus is mainly associated with the contents of flavonoid and ascorbic acid, followed by polyphenol and triterpenoid, and finally, polysaccharide. Together, the results obtained from the comprehensive and systematic comparative analyses contribute further potential resources and critical guidance for the separation, purification, and further development and utilization of bioactive agents from wild Sanghuangporus species, as well as the optimization of their artificial cultivation conditions.

Zeta diversity differentiates factors driving community assembly of rare and common ectomycorrhizal fungi.

A fundamental goal in community ecology is to understand what factors drive community assembly processes. The factors affecting ectomycorrhizal fungal communities are unknown in many regions, particularly in the southern hemisphere. We investigate community assembly using ITS2 metabarcoding of ectomycorrhizal fungi sampled from 3943 hyphal ingrowth bags buried in 81 Nothofagus forests across New Zealand's South Island. By applying zeta diversity analysis and multisite generalized dissimilarity modelling (MS-GDM) we quantify the effects of 43 biotic and environmental variables on community turnover. Unlike traditional beta diversity analyses that are heavily influenced by rare species, the zeta diversity framework differentiates between factors driving turnover of rare and common species, providing a more complete picture of community dynamics. We found that community assembly was dominated by deterministic rather than stochastic processes and identified ecological factors affecting all taxa, as well as others that were specifically important to rare or common taxa. Soil variables were important drivers of turnover for all species, whereas ground cover variables, forest patch size, precipitation and host tree identity had greater effects on rarer species, and tree size and temperature effects were specific to more common species. Interestingly, the effect of temperature on common species is in line with recent evidence from other Kingdoms, pointing to possible generality, and highlighting the importance of considering common species. Applying these methods to fungi has allowed us to identify the distinct ecological processes that structure rare and common taxa during community assembly. This has important implications for understanding the functional effects of community responses to environmental change.

The history of research of fungi and fungi-like organisms on the territory of the Hutsulshchyna NNP and the role of security, protection and the environmental measures by in situ, ex situ, re situ in conserving their diversity

The chronology of researches the fungi and fungi-like organisms on the territory of the Hutsulshchyna National Nature Park is described. Information is bases on the Chronicles of Nature of the Park since the time of it creation. The contribution of researchers in the study of the fungal biodiversion of the Park is noted. 1.01.2022 List of fungi of the Park counts 1214 species, of which 23 species are included in the Red Book of Ukraine. The information about in situ, ex situ and re situ methods are represented. In situ method aims the preservation of fungi and their localities. Ex situ method is expressed by introduction into artificial culture of fungi and maintenance of viability of fungal mycelium in collections of pure cultures. Re situ method is expressed by reproduction of aboriginal strains species of fungi in their natural conditions, involving in situ and ex situ practice. The environmental effect of using in situ, ex situ and re situ measures on the territory of Hutsulshchyna National Park is described. The development of growing methods for rare species of fungi in laboratory conditions is pointed. Reducing the threat of extinction of rare fungi due to re-situ technology and systematic fruiting of fungi at the mycological reproductive areas is explained. Certain legal aspects of protection of fungi and mushroom-like organisms are described within the "Program of protection, preservation and reproduction of rare species of fungi", approved by the Scientific and Technical Council of NNP "Hutsulshchyna". The question of creating the protection zones for rare species of fungi is outlined. The collections of macromycetes of Hutsulshchyna National Park are briefly described. The collection of pure cultures numbers 7 species of 13 strains, the collection of herbarium and wet preparations numbers 175 specimens. The important scientific and educational role of the collections is noted, the main purpose of their further operation is marked, as well as the methods and results of popularization of scientific researches among children, youth and adults. The connection of scientific achievements with the creation of a favorable economic climate for the community is indicated. Probably positive results of introduction of new recreational services - fungi therapy routes and commercial cultivation of new species of edible, rare, pharmaceutically popular species of fungi are marked.

Plant Community Associates with Rare Rather than Abundant Fungal Taxa in Alpine Grassland Soils.

The importance of the rare microbial biosphere in maintaining biodiversity and ecological functions has been highlighted recently. However, the current understanding of the spatial distribution of rare microbial taxa is still limited, with only a few investigations for rare prokaryotes and virtually none for rare fungi. Here, we investigated the spatial patterns of rare and abundant fungal taxa in alpine grassland soils across 2,000 km of the Qinghai-Tibetan plateau. We found that most locally rare fungal taxa remained rare (13.07%) or were absent (82.85%) in other sites, whereas only a small proportion (4.06%) shifted between rare and abundant among sites. Although they differed in terms of diversity levels and compositions, the distance decay relationships of both the rare and the abundant fungal taxa were valid and displayed similar turnover rates. Moreover, the community assemblies of both rare and abundant fungal taxa were predominantly controlled by deterministic rather than stochastic processes. Notably, the community composition of rare rather than abundant fungal taxa associated with the plant community composition. In summary, this study advances our understanding of the biogeographic features of rare fungal taxa in alpine grasslands and highlights the concordance between plant communities and rare fungal subcommunities in soil. IMPORTANCE Our current understanding of the ecology and functions of rare microbial taxa largely relies on research conducted on prokaryotes. Despite the key ecological roles of soil fungi, little is known about the biogeographic patterns and drivers of rare and abundant fungi in soils. In this study, we investigated the spatial patterns of rare and abundant fungal taxa in Qinghai-Tibetan plateau (QTP) alpine grassland soils across 2,000 km, with a special concentration on the importance of the plant communities in shaping rare fungal taxa. We showed that rare fungal taxa generally had a biogeographic pattern that was similar to that of abundant fungal taxa in alpine grassland soils on the QTP. Furthermore, the plant community composition was strongly related to the community composition of rare taxa but not abundant taxa. In summary, this study significantly increases our biogeographic and ecological knowledge of rare fungal taxa in alpine grassland soils.

Molecular Identification of Fungi Causing Tissue Mycoses From Formalin Fixed Paraffin Embedded (FFPE) Archive Specimens

Introduction: Isolation of fungi from tissue specimens using conventional methods is time consuming. However, in some cases, the histopathological examination (HPE) of tissue alone is unable to provide a definite identity of the fungus. Alternatively, a non-culture method, such as polymerase chain reaction (PCR) detecting the internal transcribed spacer (ITS) rRNA genes of the fungi, is a promising diagnostic tool for rapid and accurate diagnosis of tissue mycoses. Methods: This work investigated the utility of panfungal PCR in identifying agents of tissue mycoses in 87 FFPE archive specimens. Deoxyribonucleic acid (DNA) extraction was performed on FFPE specimens by using QIAamp DNA FFPE Tissue Kit. The ITS2 region was amplified using ITS3/ITS4 primers. The PCR products were sequenced using the same primers and compared to the NCBI nucleotide database for species identification. Results: Fungal DNA was successfully amplified in 52 (59.8%) specimens, from which only 23 (44.0%) fungi were consistent with clinical/HPE findings. The identified fungi were Aspergillus spp., Candida spp., Penicillium spp., Cryptococcus neoformans, Talaromyces marneffei, and Rhizopus oryzae. A few rare fungi were also identified, such as Diaporthe longicolla and fungus-like oomycete such as Pythium insidiosum that are commonly associated with plant pathogens. Conclusion: Although PCR was able to offer accurate genus/species identification, utilising this method on paraffinised tissue specimens must be evaluated by considering many factors that will reduce its sensitivity and specificity. Therefore, it is important to correlate the PCR results with clinical and HPE findings to obtain a correct diagnosis and adequate treatment for tissue mycoses.

58. A rare fungi, Candida Krusei implicated in Ludwig’s angina and deep neck necrotising infection- a case report and review of literature

Ludwig's angina is potentially life-threatening, polymicrobial infection of bilateral submandibular and sublingual spaces. Most common organisms isolated from deep neck infections are viridans streptococci, streptococcus anginosus group of oral flora.

Construction of nucleus-directed fluorescent reporter systems and its application to verification of heterokaryon formation in Morchella importuna.

Morchella importuna (M. importuna) is a rare fungus with high nutrition value and distinct flavor. Despite the successful artificial cultivation, its genetic characteristics and biological processes such as life cycle, reproductive system, and trophic mode remain poorly understood. Considering this, we constructed pEH2B and pMH2B vectors by fusing M. importuna endogenous histone protein H2B with fluorescent proteins eGFP or mCherry, respectively. Based on the constructed pEH2B and pMH2B vectors, nuclear fluorescence localization was performed via Agrobacterium tumefaciens-mediated transformation (ATMT). These two vectors were both driven by two endogenous promoters glyceraldehyde 3-phosphate dehydrogenase (GPD) and ubiquitin (UBI). The vector-based reporter systems were tested by the paired culture of two genetically modified strains pEH2B-labeled M04M24 (24e, MAT1-1-1) and pMH2B-abeled M04M26 (26m, MAT1-2-1). The fluorescence observation and molecular identification results indicated the successful hyphal fusion and heterokaryon formation. We found that the expression of the reporter genes was stable, and it did not interfere with the growth of the fungus. Our constructed nucleus-directed fluorescent systems in M. importuna can be used for monitoring the dynamic development and reproductive processes in living cells and also for monitoring the interaction between morels and plant roots. Therefore, morels exhibit the potential to be a candidate organism used for the research on basic biology and genetics of ascomycetes.

Both abundant and rare fungi colonizing Fagus sylvatica ectomycorrhizal root-tips shape associated bacterial communities

Ectomycorrhizal fungi live in close association with their host plants and form complex interactions with bacterial/archaeal communities in soil. We investigated whether abundant or rare ectomycorrhizal fungi on root-tips of young beech trees (Fagus sylvatica) shape bacterial/archaeal communities. We sequenced 16S rRNA genes and fungal internal transcribed spacer regions of individual root-tips and used ecological networks to detect the tendency of certain assemblies of fungal and bacterial/archaeal taxa to inhabit the same root-tip (i.e. modularity). Individual ectomycorrhizal root-tips hosted distinct fungal communities associated with unique bacterial/archaeal communities. The structure of the fungal-bacterial/archaeal association was determined by both, dominant and rare fungi. Integrating our data in a conceptual framework suggests that the effect of rare fungi on the bacterial/archaeal communities of ectomycorrhizal root-tips contributes to assemblages of bacteria/archaea on root-tips. This highlights the potential impact of complex fine-scale interactions between root-tip associated fungi and other soil microorganisms for the ectomycorrhizal symbiosis.

Red-listed plants, lichens and fungi of the Teriberka Nature Park and its surroundings, Murmansk Region

The article presents a brief background of the botanical study of the Teriberka Village environs and the studies for substantiating the establishment of a protected area - Teriberka Nature Park. The information on the locations of rare and protected species of plants, fungi and lichens in the Teriberka Nature Park and its surroundings was summarized based on the analysis of herbarium and archival materials, literature sources and fieldwork in 2020. Overall, 22 species of plants, lichens and fungi from the Red Data Book of the Murmansk Region and four species from the Red Data Book of the Russian Federation were identified inside the park and in its immediate vicinities. There are 13 regionally red-listed species within the boundaries of the Teriberka Nature Park, two of them listed also in the Red Data Book of the Russian Federation. The most valuable habitats in terms of protecting rare plants, lichens and fungi were identified.

First Report of Lecanicillium aphanocladii causing rot of Morchella sextelata in China.

Morel mushroom (Morchella spp.) is a rare edible fungus with high nutritional and medicinal value. In China they are cultivated in sandy soils in greenhouses and production of fresh mushrooms reached 10,000 tons in 2019. However, from 2019 to 2020, a serious rot disease with 30% natural incidence was observed on M. sextelata at a mushroom farm in Pinghu (N30°39', E121°2'), Zhejiang province of China. The symptoms mainly occurred after the first flush in the early February. First, a small white mold-like symptoms appeared on the surface or the pinnacle of pileus. Then the lesion developed to encircle the pileus and spread gradually to the stipe. The lesions expanded rapidly at high temperature (>20 °C) and humidity (>70%). In the final stages of infection, the fruiting bodies became soft with white molds. The pathogen was isolated from the margin of the lesions by plating onto potato dextrose agar (PDA) and incubated at 25 °C in the dark. Colonies on PDA grew fast, reaching 60 mm in 7 days at 25 °C, and were white to cream in color, while the back of colonies appeared red to brick-red gradually. Conidiogenous cell was solitary or in whorls of 2-4, flask-shaped in the beginning, and tapered into a thread-like neck. Conidia were borne at the tips of conidiogenous cells, were oval to sub-globose, and ranged from 1.2-2.0 µm in width and 3.2-4.3 µm in length. All these characteristics were consistent with those of Lecanicillium aphanocladii (Zare R and Gams W. 2001). To confirm the identity of the pathogen (L. aphanocladii strain G1), the genomic fragments for the internal transcribed spacer (ITS) and RNA polymerase II second largest subunit (RPB2) gene of the isolate were amplified by PCR (White et al. 1990; Zhou et al. 2020). The resulting sequence was deposited in GenBank with accession No. OL629617 and No. ON005041, respectively. BLAST results showed >99% identity with those of L. aphanocladii (MG593981.1 and KM283853.1, respectively). Concatenated sequences of the two genes in L. aphanocladii strain G1 were used to conduct a phylogenetic analysis using Bayesian inference (BI) and maxium likelihood (ML) methods in MEGA6 (Tamura et al. 2013). The pathogen was grown in PDB medium at 25 °C, 200 r/min for 14 days, and after which conidial suspension (1×107conidia/mL) was prepared by filtration with four layers of sterile gauze. A pathogenicity test was performed by spraying on ten fruit bodies of M. sextelata and cultured in 20 °C and 90 to 95% relative humidity for 7 days. The test results showed that the pathogen infected the pileus and developed into white mold-like lesion, gradually spread to the stipe, and eventually the whole fruiting body became soft with white molds. The pathogen was re-isolated from infected fruiting bodies and was confirmed to be L. aphanocladii, based on morphological characteristics and the ITS, RPB2 sequence. Meanwhile,the control M. sextelata was sprayed with PDB medium and grew normally without any symptoms. L. aphanocladii has been reported on cultivated fungi such as Agaricus bisporus and A. bitorquis in Europe (Zare & Gams 2001) as well as more recently on Tremella fuciformis in China (Liu et al 2018). To our knowledge, this is the first report of L. aphanocladii causing rot of M. sextelata. According to the disease observation in the farm of Pinghu, this rot disease breaks out and spreads fast, and is getting worse ever year, resulting in a huge loss of yield and commodity value. It is a big concern to producers of this edible fungus.

The first find of Naohidea sebacea (Naohideales, Basidiomycota) in Ukraine

The article provides information about a rare fungicolous fungus Naohidea sebacea first recorded in Ukraine in Roztochchia Nature Reserve. It was found to parasitize Dothiorella iberica (Botryosphaeriaceae, Botryosphaeriales, Dothideomycetes, Ascomycota). This host is reported for N. sebacea for the first time. Light microscopy, cultural studies, and nucleotide sequence analysis of the ITS-region of the ribosomal DNA were used to identify specimens. The resulting sequences were uploaded to the GenBank database. Based on the analysis of literature sources and personal data, information on morphological features, distribution, and substrate specialization of the fungus is provided.

The rare fungicolous fungus Pseudotrichia mutabilis (Pers.) Wehm.: new data and a historical perspective

The paper reports two new records of a rare fungicolous fungus Pseudotrichia mutabilis (Melanommataceae, Pleosporales) from Ukraine. Both specimens were collected within protected areas in association with two xylariaceous species, Hypoxylon crocopeplum and Rosellinia corticium. The paper provides descriptions, nomenclatural data, and original illustrations of the reported species. Information on substrate specialization and nutritional strategies of Pseudotrichia mutabilis, as well as general distribution of the species and known localities in Ukraine are specified and summarized.

Microbial spectrum and risk factors of endogenous endophthalmitis in a tertiary center of Northern China.

To study the clinical features, microbial spectrum, associated factors and prognosis of endogenous endophthalmitis (EE) in a group of Chinese patients. The medical records from 32 eyes of 29 patients diagnosed with EE in Peking Union Medical College Hospital from January 2009 to October 2019 were reviewed. The initial visual acuity (VA) of 30 eyes in this study was worse than 20/400. Twenty-three eyes were diagnosed with fungal endophthalmitis and nine with bacterial endophthalmitis. The most common fungal and bacterial isolates were Candida and Klebsiella pneumoniae, respectively. Several rare fungi and bacteria species were also isolated from our patients, including Cryptococcus, Paecilomyces, Brucella, and Bacillus licheniformis. The leading risk factor for EE was diabetes. The most common extraocular infection locus was genitourinary tract. Vitrectomy was performed on twenty-nine eyes. Eight eyes achieved final VA of 20/400 or better. EE caused by Candida had a better prognosis. The visual outcome of EE is based on pathogens and prompt intervention. Early vitrectomy and antimicrobial treatment are beneficial for EE.

Plant traits and community composition drive the assembly processes of abundant and rare fungi across deserts.

The difference in community assembly mechanisms between rare and abundant fungi in deserts remains unknown. Hence, we compared the distribution patterns of abundant and rare fungi, and assessed the factors driving their assembly mechanisms across major vegetation types (shrubby desert, semi-shrubby and dwarf semi-shrubby desert, dwarf semi-arboreous desert, and shrubby steppe desert) of Chinese deserts. We assessed abundant and rare fungal subcommunities base on the sequencing data of fungal ITS data. Abundant fungal assembly was more affected by neutral processes than the rare. Null model and VPA analysis indicated that heterogeneous selection dominated rare sub-communities, whereas abundant fungal assembly was mainly determined by heterogeneous selection, dispersal limitation and other, unknown processes together. As a result, abundant sub-communities exhibited a higher species turnover rate than the rare. Hierarchical partitioning analysis indicated that soil conditions and plant attributes drove the assembly processes of abundant and rare fungi, respectively. Meanwhile, the relative strength of different assembly processes differed significantly among four vegetation types. In addition, we found that plant functional traits and composition played more critical roles in shaping the assembly processes of rare fungi than those of abundant fungi. Taken together, our findings collectively suggest that rare and abundant fungi exhibit differential ecological patterns that are driven by distinct assembly processes in deserts. We emphasize that the assembly processes of abundant and rare fungi are dependent on different abiotic and biotic factors in desert ecosystems.

Dispersal limitation dominates the community assembly of abundant and rare fungi in dryland montane forests.

The assembly mechanisms and drivers of abundant and rare fungi in dryland montane forest soils remain underexplored. Therefore, in this study, we compared the distribution patterns of abundant and rare fungi and explored the factors determining their assembly processes in a dryland montane forest in China. Stronger distance-decay relationships (DDRs) were found in abundant sub-communities than in rare sub-communities. In addition, abundant fungi exhibited greater presence and wider habitat niche breadth than rare fungi. Both the null model and variation partitioning analysis indicated that dispersal limitation and environmental selection work together to govern both abundant and rare fungal assembly, while dispersal limitation plays a dominant role. Meanwhile, the relative influence of dispersal limitation and environmental selection varied between abundant and rare sub-communities, where dispersal limitation showed greater dominance in abundant fungal assembly. Mantel tests demonstrated that soil pH and phosphorus played critical roles in mediating abundant and rare fungi assembly processes, respectively. Our findings highlight that the distinct biogeographic patterns of abundant and rare fungi are driven by different assembly mechanisms, and the assembly processes of abundant and rare fungi are determined by diverse ecological drivers in dryland montane forest soils.

P276 Molecular epidemiology of clinical filamentous fungi in Qatar beyond Aspergillus and Fusarium

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM ObjectivesDue to an increasing number of patients at risk, (ie, with a highly compromised immune system and/or receiving aggressive chemotherapy treatment), invasive fungal infections (IFI) are increasingly being reported. They are associated with significantly high mortality rates. Aspergillus spp., particularly A. fumigatus, is the major cause of mold-related IFI around the world followed by Fusarium spp., however, other molds are emerging as human pathogens. The aim of this study was to explore the epidemiology and prevalence of the non-Aspergillus and non-Fusarium molds in human clinical samples over 11 years period in Qatar based tertiary hospital using molecular techniques.MethodsA total of 91 clinical specimens positive for molds belonging to 90 patients were recorded in about 11 years (September 2003 to November 2014). The isolates were identified based on morphological characteristics and by sequencing the internal transcribed spacer (ITS) gene. To confirm the identifications, a phylogenetic tree based on ITS sequences was constructed.ResultsMost patients were males (72%), 6% were immunocompromised, 12% had IFI, and 7% died within 30 days of diagnosis. The fungal isolates were recovered from a variety of clinical samples, including nails, skin, hair, scalp, nasal cavity, wounds, respiratory samples, body fluids, eye, ear, tissue, abscess, and blood specimens. Dematiaceous fungi were overall the most isolated (33/91, 36%), followed by dermatophytes (25/91, 27%), Mucorales (16/91, 18%), and other hyaline molds (17/91, 19%) (Fig. 1). Curvularia was the most isolated genus (22/91, 24%) and Mucorales were the major cause of IF (5/11, 45.5%) (Table 1). Superficial mycoses were caused by dermatophytes (66%) and non-dermatophytes (34%). Furthermore, rare fungi that are not commonly known to cause human disease were recovered such as Rhytidhysteron rufulum, Subramaniula asteroids, Dothichiza pimprina, and Quambalaria cyanescens.ConclusionThe current study highlights the epidemiology and spectrum of mold genera, other than Aspergillus and Fusarium, recovered from human clinical samples in Qatar, which can aid in surveillance of uncommon and emerging mycoses other than aspergillosis and fusuriosis.