Journal of Fungi

11 pages, 663 KiB

Open AccessArticle

Characteristics and Outcomes of Cryptococcosis among Patients with and without COVID-19

by Daniel B. Chastain, Vanessa M. Kung, Lilian Vargas Barahona, Brittany T. Jackson, Sahand Golpayegany, Carlos Franco-Paredes, George R. Thompson III and Andrés F. Henao-Martínez

J. Fungi 2022, 8(11), 1234; https://doi.org/10.3390/jof8111234 - 21 Nov 2022

Cited by 2 | Viewed by 1892

Abstract

The effect of COVID-19 on the risk and prognosis of cryptococcosis is unclear. We compared the characteristics and outcomes of cryptococcosis in patients with and without COVID-19. Patients 18 years and older with cryptococcosis were identified from TriNetX and separated into two cohorts [...] Read more.

The effect of COVID-19 on the risk and prognosis of cryptococcosis is unclear. We compared the characteristics and outcomes of cryptococcosis in patients with and without COVID-19. Patients 18 years and older with cryptococcosis were identified from TriNetX and separated into two cohorts based on a diagnosis of COVID-19 within 3 months of the index diagnosis of cryptococcosis. Differences examined between groups included comorbidities, immunosuppressive medications, ED visits, hospitalizations, ICU admissions, mechanical ventilation, and deaths. The propensity score matching was performed based on demographics and comorbidities. Of the 6998 patients with cryptococcosis included, 4.4% (n = 306) had COVID-19 prior to cryptococcosis. Mortality was higher in patients with COVID-19 compared to those without COVID-19 (14% vs. 11%, p = 0.032). Additionally, those with COVID-19 were older (55.2 ± 14.4 vs. 51.9 ± 15.2 years, p < 0.001) with higher rates of transplant (29% vs. 13%, p < 0.001), neoplastic disease (37% vs. 21%, p < 0.001), chronic kidney disease (42% vs. 18%, p < 0.001), or diabetes (35% vs. 19%, p < 0.001) but not HIV (30% vs. 31%, p = 0.618). Glucocorticoid use was more common in those with COVID-19 (52% vs. 27%, p < 0.001). More patients with COVID-19 required ED visits (29% vs. 23%, p = 0.025) and ICU admission (18% vs. 11%, p < 0.001). After propensity score matching, patients with COVID-19 had higher rates of neoplastic disease, heart failure, chronic kidney disease, and glucocorticoid use but did not experience worse outcomes compared to those without COVID-19. Patients with COVID-19 who developed cryptococcosis had independently higher rates of comorbidities and glucocorticoid use but similar outcomes, including death, versus those without COVID-19. Full article

(This article belongs to the Special Issue The Fungal Threat to Public Health)

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25 pages, 3575 KiB

Open AccessArticle

The Lipid Profile of the Endomyces magnusii Yeast upon the Assimilation of the Substrates of Different Types and upon Calorie Restriction

by Yulia I. Deryabina, Anastasia S. Kokoreva, Olga I. Klein, Natalya N. Gessler and Elena P. Isakova

J. Fungi 2022, 8(11), 1233; https://doi.org/10.3390/jof8111233 - 21 Nov 2022

Cited by 1 | Viewed by 1453

Abstract

The study analyzes the dynamics in the lipid profile of the Endomyces magnusii yeast during the long-lasting cultivation using the substrates of “enzymatic” or “oxidative” type. Moreover, we studied its changes upon calorie restriction (CR) (0.5% glucose) and glucose depletion (0.2% glucose). Di-(DAGs), [...] Read more.

The study analyzes the dynamics in the lipid profile of the Endomyces magnusii yeast during the long-lasting cultivation using the substrates of “enzymatic” or “oxidative” type. Moreover, we studied its changes upon calorie restriction (CR) (0.5% glucose) and glucose depletion (0.2% glucose). Di-(DAGs), triacylglycerides (TAGs) and free fatty acids (FFAs) dominate in the storage lipid fractions. The TAG level was high in all the cultures tested and reached 80% of the total lipid amount. While being cultured on 2% substrates, the level of storage lipids decreased at the four-week stage, whereas upon CR their initially low amount doubled. Phosphatidylethanolamines (PE), sterols (St) (up to 62% of total lipids), phosphatidylcholines (PC), and phosphatidic acids (PA) (more than 40% of total lipids) were dominating in the membrane lipids of E magnusii. Upon CR at the late stationary growth stages (3–4 weeks), the total level of membrane lipid was two-fold higher than those on glycerol and 2% glucose. The palmitic acid C16:0 (from 10 to 23%), the palmitoleic acid C16:1 (from 4.3 to 15.9%), the oleic acid C18:1 (from 23.4 to 59.2%), and the linoleic acid C18:2 (from 10.8 to 49.2%) were the dominant fatty acids (FAs) of phospholipids. Upon glucose depletion (0.2% glucose), the total amount of storage and membrane lipids in the cells was comparable to that in the cells both on 2% and 0.5% glucose. High levels of PC and sphingolipids (SL) at the late stationary growth stages and an increased PA level throughout the whole experiment were typical for the membrane lipids composition upon the substrate depletion. There was shown a crucial role of St, PA, and a high share of the unsaturated FAs in the membrane phospholipids upon the adaptation of the E. magnusii yeast to the long-lasting cultivation upon the substrate restriction is shown. The autophagic processes in some fractions of the cell population provide the support of high level of lipid components at the late stages of cultivation upon substrate depletion under the CR conditions. CR is supposed to play the key role in regulating the lipid synthesis and risen resistance to oxidative stress, as well as its possible biotechnological application. Full article

(This article belongs to the Section Fungal Cell Biology, Metabolism and Physiology)

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13 pages, 2460 KiB

Open AccessArticle

Microalgae Harvesting after Tertiary Wastewater Treatment with White-Rot Fungi

by Anna Civzele and Linda Mezule

J. Fungi 2022, 8(11), 1232; https://doi.org/10.3390/jof8111232 - 21 Nov 2022

Cited by 3 | Viewed by 2102

Abstract

Tertiary wastewater treatment with microalgae incorporates environmental sustainability with future technologies and high exploitation costs. Despite the apparent ecological benefits of microalgae-assisted wastewater treatment/biomass-based resource production, technological improvements are still essential to compete with other technologies. Bio-flocculation instead of mechanical harvesting has been [...] Read more.

Tertiary wastewater treatment with microalgae incorporates environmental sustainability with future technologies and high exploitation costs. Despite the apparent ecological benefits of microalgae-assisted wastewater treatment/biomass-based resource production, technological improvements are still essential to compete with other technologies. Bio-flocculation instead of mechanical harvesting has been demonstrated as an alternative cost-effective approach. So far, mostly filamentous fungi of genus Aspergillus have been used for this purpose. Within this study, we demonstrate a novel approach of using white-rot fungi, with especially high potential of algae—Irpex lacteus complex that demonstrates efficiency with various microalgae species at a broad range of temperatures (5–20 °C) and various pH levels. Harvesting of microalgae from primary and secondary wastewater resulted in 73–93% removal efficiencies within the first 24 h and up to 95% after 48 h. The apparent reuse potential of the algae—I. lacteus pellets further complements the reduced operating costs and environmental sustainability of bio-flocculation technology. Full article

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13 pages, 2244 KiB

Open AccessArticle

The Toxicity of Salicylhydroxamic Acid and Its Effect on the Sensitivity of Ustilaginoidea virens to Azoxystrobin and Pyraclostrobin

by Jiehui Song, Zhiying Wang, Sijie Zhang, Yan Wang, You Liang, Qigen Dai, Zhongyang Huo and Ke Xu

J. Fungi 2022, 8(11), 1231; https://doi.org/10.3390/jof8111231 - 21 Nov 2022

Cited by 2 | Viewed by 1367

Abstract

Rice false smut (RFS) caused by Ustilaginoidea virens has been one of the most severe rice diseases. Fungicide-based chemical control is a significant measure to control RFS. In the sensitivity determination of quinone outside inhibitor (QoI) fungicide in vitro, salicylhydroxamic acid (SHAM) has [...] Read more.

Rice false smut (RFS) caused by Ustilaginoidea virens has been one of the most severe rice diseases. Fungicide-based chemical control is a significant measure to control RFS. In the sensitivity determination of quinone outside inhibitor (QoI) fungicide in vitro, salicylhydroxamic acid (SHAM) has been commonly added to artificial culture media in order to inhibit alternative oxidase of phytopathogenic fungi. However, some studies showed that artificial media should not include SHAM due to its toxicity. Whether SHAM should be added in the assay of U. virens sensitivity to QoI fungicide remains unknown. In this study, two appropriate media, potato sucrose agar (PSA) and minimal medium (MM), were selected to test SHAM toxicity and sensitivity of U. virens to azoxystrobin and pyraclostrobin. The mycelial growth and sensitivity to azoxystrobin and pyraclostrobin had no significant difference between on PSA and MM. SHAM could significantly inhibit mycelial growth, conidial germination, peroxidase (POD) and esterase activity of U. virens. Average effective concentration for inhibiting 50% (EC₅₀) values of SHAM against mycelial growth of ten U. virens were 27.41 and 12.75 μg/mL on PSA and MM, respectively. The EC₅₀ values of SHAM against conidial germination of isolates HWD and JS60 were 70.36 and 44.69 μg/mL, respectively. SHAM at 30 μg/mL significantly inhibited POD and esterase activity of isolates HWD and JS60, and even SHAM at 10 μg/mL significantly inhibited POD activity of isolate HWD. In addition, SHAM significantly reduced EC₅₀ values and EC₉₀ values of azoxystrobin and pyraclostrobin on both PSA and MM. Even in the presence of SHAM at 10 μg/mL, average EC₅₀ values of ten U. virens isolates for azoxystrobin decreased 1.7-fold on PSA and 4.8-fold on MM, and for pyraclostrobin that decreased 2.8-fold on PSA and 4.8-fold on MM. Therefore, these results suggest that SHAM should not be included in artificial media in the assay of U. virens sensitivity to QoI fungicides. Full article

(This article belongs to the Special Issue Smut Fungi 2.0)

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31 pages, 19249 KiB

Open AccessArticle

Geo-Distribution Patterns of Soil Fungal Community of Pennisetum flaccidum in Tibet

by Guangyu Zhang, Zhenxi Shen and Gang Fu

J. Fungi 2022, 8(11), 1230; https://doi.org/10.3390/jof8111230 - 21 Nov 2022

Cited by 7 | Viewed by 1299

Abstract

Pennisetum flaccidum can be used as a pioneer species for the restoration of degraded grasslands and as a high-quality forage for local yak and sheep in alpine regions. The geographical distribution pattern of soil fungal community can modify that of P. flaccidum. [...] Read more.

Pennisetum flaccidum can be used as a pioneer species for the restoration of degraded grasslands and as a high-quality forage for local yak and sheep in alpine regions. The geographical distribution pattern of soil fungal community can modify that of P. flaccidum. A field survey along 32 sampling sites was conducted to explore the geo-distribution patterns of soil fungal community of P. flaccidum in Tibet. Soil fungal species, phylogenetic and function diversity generally had a closer correlation with longitude/elevation than latitude. The geo-distribution patterns of soil fungal species, phylogenetic and function diversity varied with soil depth. Soil fungal species, phylogenetic and function diversity had dissimilar geo-distribution patterns. Precipitation had stronger impacts on total abundance, species α-diversity, phylogenetic α-diversity, and function β-diversity than temperature for both topsoil (0–10 cm depth) and subtopsoil (10–20 cm depth). Furthermore, precipitation had stronger impacts on function α-diversity for topsoil, species β-diversity for topsoil, and phylogenetic β-diversity for subtopsoil than temperature. The combination of species, phylogenetic and function diversity can better reflect geo-distribution patterns of soil fungal community. Compared to global warming, the impact of precipitation change on the variation in soil fungal community of P. flaccidum should be given more attention. Full article

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20 pages, 6089 KiB

Open AccessArticle

Taxonomy and Phylogeny of Cystostereaceae (Agaricales, Basidiomycota): A New Genus, Five New Species, and Three New Combinations

by Yue Li, Karen K. Nakasone, Che-Chih Chen, Chang-Lin Zhao, Ting Cao, Hai-Sheng Yuan and Shuang-Hui He

J. Fungi 2022, 8(11), 1229; https://doi.org/10.3390/jof8111229 - 21 Nov 2022

Cited by 6 | Viewed by 1792

Abstract

This paper aims to understand the species diversity, taxonomy, and phylogeny of Cystostereaceae (Agaricales), which is based primarily on material from East and Southeast Asia. Cystostereaceae is a small, understudied family of saprobes of woody plants with a worldwide distribution. Phylogenetic analyses of [...] Read more.

This paper aims to understand the species diversity, taxonomy, and phylogeny of Cystostereaceae (Agaricales), which is based primarily on material from East and Southeast Asia. Cystostereaceae is a small, understudied family of saprobes of woody plants with a worldwide distribution. Phylogenetic analyses of the LSU and ITS sequences revealed four distinct clades in the Cystostereaceae, representing the genera Crustomyces, Cystostereum, Effusomyces gen. nov., and Parvodontia. In addition, phylogenetic analyses showed that Cystidiodontia and Rigidotubus are synonyms of Crustomyces for their type of species nested within the Crustomyces clade. The new monotypic genus Effusomyces, based on specimens from Thailand, lacks any distinctive morphological features. Parvodontia, originally erected for a species from South America, is reported for the first time from Asia. The widely distributed and morphologically well-characterized Cystostereum is represented in East Asia by two new species: Cystostereum crassisporum and C. submurrayi. In addition, three new species, viz., Crustomyces albidus, Effusomyces thailandicus, and Parvodontia austrosinensis, are described and illustrated. Finally, three new combinations are proposed: Crustomyces isabellinus, C. laminiferus, and C. tephroleucus. A key to the genera and species of Cystostereaceae is provided. Our results proved that the species diversity of wood-decaying fungi in East and Southeast Asia is rich and suggested that more investigations and studies should be carried out in the future. Full article

(This article belongs to the Special Issue Phylogeny and Diversity of Forestry Fungi)

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12 pages, 1618 KiB

Open AccessArticle

Candida Genotyping of Blood Culture Isolates from Patients Admitted to 16 Hospitals in Madrid: Genotype Spreading during the COVID-19 Pandemic Driven by Fluconazole-Resistant C. parapsilosis

by Judith Díaz-García, Ana Gómez, Marina Machado, Luis Alcalá, Elena Reigadas, Carlos Sánchez-Carrillo, Ana Pérez-Ayala, Elia Gómez-García de la Pedrosa, Fernando González-Romo, María Soledad Cuétara, Coral García-Esteban, Inmaculada Quiles-Melero, Nelly Daniela Zurita, María Muñoz Algarra, María Teresa Durán-Valle, Aída Sánchez-García, Patricia Muñoz, Pilar Escribano, Jesús Guinea and on behalf of the CANDIMAD Study Group

J. Fungi 2022, 8(11), 1228; https://doi.org/10.3390/jof8111228 - 21 Nov 2022

Cited by 8 | Viewed by 1571 | Correction

Abstract

Background: Candidaemia and invasive candidiasis are typically hospital-acquired. Genotyping isolates from patients admitted to different hospitals may be helpful in tracking clones spreading across hospitals, especially those showing antifungal resistance. Methods: We characterized Candida clusters by studying Candida isolates (C. albicans, [...] Read more.

Background: Candidaemia and invasive candidiasis are typically hospital-acquired. Genotyping isolates from patients admitted to different hospitals may be helpful in tracking clones spreading across hospitals, especially those showing antifungal resistance. Methods: We characterized Candida clusters by studying Candida isolates (C. albicans, n = 1041; C. parapsilosis, n = 354, and C. tropicalis, n = 125) from blood cultures (53.8%) and intra-abdominal samples (46.2%) collected as part of the CANDIMAD (Candida in Madrid) study in Madrid (2019–2021). Species-specific microsatellite markers were used to define the genotypes of Candida spp. found in a single patient (singleton) or several patients (cluster) from a single hospital (intra-hospital cluster) or different hospitals (widespread cluster). Results: We found 83 clusters, of which 20 were intra-hospital, 49 were widespread, and 14 were intra-hospital and widespread. Some intra-hospital clusters were first detected before the onset of the COVID-19 pandemic, but the number of clusters increased during the pandemic, especially for C. parapsilosis. The proportion of widespread clusters was significantly higher for genotypes found in both compartments than those exclusively found in either the blood cultures or intra-abdominal samples. Most C. albicans- and C. tropicalis-resistant genotypes were singleton and presented exclusively in either blood cultures or intra-abdominal samples. Fluconazole-resistant C. parapsilosis isolates belonged to intra-hospital clusters harboring either the Y132F or G458S ERG11p substitutions; the dominant genotype was also widespread. Conclusions: the number of clusters—and patients involved—increased during the COVID-19 pandemic mainly due to the emergence of fluconazole-resistant C. parapsilosis genotypes. Full article

(This article belongs to the Special Issue Fungal Diseases in Europe)

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23 pages, 13078 KiB

Open AccessArticle

Four New Wood-Inhabiting Fungal Species of Peniophoraceae (Russulales, Basidiomycota) from the Yunnan-Guizhou Plateau, China

by Lei Zou, Xiaolu Zhang, Yinglian Deng and Changlin Zhao

J. Fungi 2022, 8(11), 1227; https://doi.org/10.3390/jof8111227 - 21 Nov 2022

Cited by 5 | Viewed by 1571

Abstract

Four new fungi of the family Peniophoraceae, viz., Peniophora roseoalba, P. yunnanensis, Vararia daweishanensis, and V. fragilis are herein proposed, based on a combination of morphological features and molecular evidence. Peniophora roseoalba is characterized by resupinate, membranaceous basidiomata with a [...] Read more.

Four new fungi of the family Peniophoraceae, viz., Peniophora roseoalba, P. yunnanensis, Vararia daweishanensis, and V. fragilis are herein proposed, based on a combination of morphological features and molecular evidence. Peniophora roseoalba is characterized by resupinate, membranaceous basidiomata with a rose pink to pale pinkish grey hymenophore, a monomitic hyphal system with clamped generative hyphae, the presence of cystidia, and ellipsoid basidiospores. However, P. yunnanensis differs in being tuberculate, with a pale cream to cream hymenial surface, small lamprocystidia (18–29 × 4.5–7 µm), and subcylindrical basidiospores. Vararia daweishanensis is characterized by resupinate, membranous basidiomata with a pale yellowish hymenial surface, a dimitic hyphal system with clamped generative hyphae, strongly dextrinoid dichohyphae, and allantoid basidiospores; V. fragilis is characterized by resupinate, brittle basidiomata, with a buff to ochraceous hymenial surface and small ellipsoid basidiospores measuring 3.5–5.5 × 2.5–3.5 µm. Sequences of the ITS and nLSU rRNA markers of the studied samples were generated, and phylogenetic analyses were performed with the maximum likelihood, maximum parsimony, and Bayesian inference methods. The nLSU analysis revealed that the four new species can be clustered into the family Peniophoraceae (Russulales), in the genera Peniophora and Vararia. Further studies based on the ITS dataset showed that four fungi of the family Peniophoraceae were new to science. Full article

(This article belongs to the Special Issue Fungal Diversity in Various Environments)

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19 pages, 2612 KiB

Open AccessArticle

Stress Responses Elicited by Glucose Withdrawal in Aspergillus fumigatus

by Tamás Emri, Károly Antal, Barnabás Gila, Andrea P. Jónás and István Pócsi

J. Fungi 2022, 8(11), 1226; https://doi.org/10.3390/jof8111226 - 21 Nov 2022

Cited by 1 | Viewed by 1462

Abstract

Glucose is a widely used carbon source in laboratory practice to culture Aspergillus fumigatus, however, glucose availability is often low in its “natural habitats”, including the human body. We used a physiological–transcriptomical approach to reveal differences between A. fumigatus Af293 cultures incubated on [...] Read more.

Glucose is a widely used carbon source in laboratory practice to culture Aspergillus fumigatus, however, glucose availability is often low in its “natural habitats”, including the human body. We used a physiological–transcriptomical approach to reveal differences between A. fumigatus Af293 cultures incubated on glucose, glucose and peptone, peptone (carbon limitation), or without any carbon source (carbon starvation). Autolytic cell wall degradation was upregulated by both carbon starvation and limitation. The importance of autolytic cell wall degradation in the adaptation to carbon stress was also highlighted by approximately 12.4% of the A. fumigatus genomes harboring duplication of genes involved in N-acetyl glucosamine utilization. Glucose withdrawal increased redox imbalance, altered both the transcription of antioxidative enzyme genes and oxidative stress tolerance, and downregulated iron acquisition, but upregulated heme protein genes. Transcriptional activity of the Gliotoxin cluster was low in all experiments, while the Fumagillin cluster showed substantial activity both on glucose and under carbon starvation, and the Hexadehydro-astechrome cluster only on glucose. We concluded that glucose withdrawal substantially modified the physiology of A. fumigatus, including processes that contribute to virulence. This may explain the challenge of predicting the in vivo behavior of A. fumigatus based on data from glucose rich cultures. Full article

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17 pages, 3014 KiB

Open AccessArticle

The Role of Phialocephala fortinii in Improving Plants’ Phosphorus Nutrition: New Puzzle Pieces

by Vyacheslav S. Mikheev, Irina V. Struchkova, Maria N. Ageyeva, Anna A. Brilkina and Ekaterina V. Berezina

J. Fungi 2022, 8(11), 1225; https://doi.org/10.3390/jof8111225 - 21 Nov 2022

Cited by 7 | Viewed by 2223

Abstract

Plants’ mineral nutrition in acidic soils can be facilitated by phosphate solubilizing fungi inhabiting the root systems of these plants. We attempt to find dark septate endophyte (DSE) isolates in the roots of wild-heather plants, which are capable of improving plants’ phosphorus nutrition [...] Read more.

Plants’ mineral nutrition in acidic soils can be facilitated by phosphate solubilizing fungi inhabiting the root systems of these plants. We attempt to find dark septate endophyte (DSE) isolates in the roots of wild-heather plants, which are capable of improving plants’ phosphorus nutrition levels. Bright-field and confocal laser scanning microscopy were used for the visualization of endophytes. A model system of co-cultivation with Vaccinium macrocarpon Ait. was used to study a fungal isolate’s ability to supply plants with phosphorus. Fungal phytase activity and phosphorus content in plants were estimated spectrophotometrically. In V. vitis-idaea L. roots, we obtained a Phialocephala fortinii Wang, Wilcox DSE2 isolate with acid phytase activity (maximum 6.91 ± 0.17 U on 21st day of cultivation on potato-dextrose broth medium) and the ability to accumulate polyphosphates in hyphae cells. The ability of the isolate to increase both phosphorus accumulation and biomass in V. macrocarpon is also shown. The data obtained for the same isolate, as puzzle pieces put together, indicate the possible mediation of P. fortinii DSE2 isolate in the process of phosphorus intake from inorganic soil reserves to plants. Full article

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16 pages, 4347 KiB

Open AccessArticle

Pb Transfer Preference of Arbuscular Mycorrhizal Fungus Rhizophagus irregularis in Morus alba under Different Light Intensities

by Wei Ren, Haoqiang Zhang, Xiaoxia Jin, Hongchao Huang, Linxi Zhou, Tingying Xu and Ming Tang

J. Fungi 2022, 8(11), 1224; https://doi.org/10.3390/jof8111224 - 20 Nov 2022

Cited by 2 | Viewed by 1396

Abstract

Arbuscular mycorrhizal (AM) fungi can improve the lead (Pb) tolerance of host plants and accumulate intensive Pb in mycorrhizal roots. However, the detailed contribution of AM fungal extraradical hyphae to the plants’ Pb uptake remains unknown. In this study, mulberry (Morus alba [...] Read more.

Arbuscular mycorrhizal (AM) fungi can improve the lead (Pb) tolerance of host plants and accumulate intensive Pb in mycorrhizal roots. However, the detailed contribution of AM fungal extraradical hyphae to the plants’ Pb uptake remains unknown. In this study, mulberry (Morus alba) colonized by the AM fungus (Rhizophagus irregularis) with light treatments were linked by fungal extraradical hyphae using a three-compartment system (pot test), and their differences in responding to Pb application were compared. Shading inhibited mulberry photosynthesis and the growth of mulberry. In this study, Pb application did not affect the colonization of R. irregularis when symbiosis had already formed as the root was not exposed to Pb during the colonization and formation of the AM fungal hyphae network. The R. irregularis preferred to transfer more Pb to the unshaded mulberry than to the shaded mulberry, a condition capable of providing more C supply for fungal survival than to low-light mulberry. The Pb transferred through the mycorrhizal pathway to mulberry had low mobility and might be compartmented in the root by R. irregularis until exceeding a threshold. The relatively high expressions of MaABCG16 with high Pb concentrations in plants suggest that MaABCG16 might play an important role in Pb translocation. Full article

(This article belongs to the Section Environmental and Ecological Interactions of Fungi)

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17 pages, 2501 KiB

Open AccessArticle

Screening, and Optimization of Fermentation Medium to Produce Secondary Metabolites from Bacillus amyloliquefaciens, for the Biocontrol of Early Leaf Spot Disease, and Growth Promoting Effects on Peanut (Arachis hypogaea L.)

by Taswar Ahsan, Chaoqun Zang, Shuyi Yu, Xue Pei, Jinhui Xie, Ying Lin, Xiaozhou Liu and Chunhao Liang

J. Fungi 2022, 8(11), 1223; https://doi.org/10.3390/jof8111223 - 20 Nov 2022

Cited by 3 | Viewed by 2033

Abstract

A novel Bacillus amyloliquefaciens BAM strain, with novel fermentation nutrient mediums and compositions, could produce potent antifungal secondary metabolites, as the existing strains face resistance from fungus pathogens. In the current study, we introduced two novel nutrient mediums for the fermentation process, semolina [...] Read more.

A novel Bacillus amyloliquefaciens BAM strain, with novel fermentation nutrient mediums and compositions, could produce potent antifungal secondary metabolites, as the existing strains face resistance from fungus pathogens. In the current study, we introduced two novel nutrient mediums for the fermentation process, semolina and peanut root extract, as carbon and nitrogen sources in order to maximize the antifungal effects of B. amyloliquefaciens against Cercaspora arachidichola to control early leaf spot disease in peanuts. Based on a single-factor test and the central composite design of response surface methodology, the optimum fermentation medium for Bacillus amyloliquefaciens antagonistic substance was determined, containing 15 gm/L of semolina flour, 12.5 gm/L of beef extract, and 0.5 gm/L of magnesium sulfate, which inhibited the fungal growth by 91%. In vitro, antagonistic activity showed that the fermentation broth of B. amyloliquefaciens BAM with the optimized medium formulation had an inhibition rate of (92.62 ± 2.07)% on the growth of C. arachidichola. Disease control effects in pot experiments show that the pre-infection spray of B. amyloliquefaciens BAM broth had significant efficiency of (92.00 ± 3.79)% in comparison to post-infection spray. B. amyloliquefaciens BAM broth significantly promoted peanut plant growth and physiological parameters and reduced the biotic stress of C. archidechola. Studies revealed that B. amyloliquefaciens BAM with a novel fermentation formulation could be an ideal biocontrol and biofertilizer agent and help in early disease management of early leaf spots in peanuts. Full article

(This article belongs to the Special Issue Antifungal Discovery of Natural Products)

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16 pages, 3161 KiB

Open AccessArticle

First Record of Aspergillus fijiensis as an Entomopathogenic Fungus against Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae)

by Jianquan Yan, Hao Liu, Atif Idrees, Fenghao Chen, Huilin Lu, Gecheng Ouyang and Xiang Meng

J. Fungi 2022, 8(11), 1222; https://doi.org/10.3390/jof8111222 - 19 Nov 2022

Cited by 7 | Viewed by 2164

Abstract

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the most widespread and devastating pest species in citrus orchards and is the natural vector of the phloem-limited bacterium that causes Huanglongbing (HLB) disease. Thus, reducing the population of D. citri is an [...] Read more.

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the most widespread and devastating pest species in citrus orchards and is the natural vector of the phloem-limited bacterium that causes Huanglongbing (HLB) disease. Thus, reducing the population of D. citri is an important means to prevent the spread of HLB disease. Due to the long-term use of chemical control, biological control has become the most promising strategy. In this study, a novel highly pathogenic fungal strain was isolated from naturally infected cadavers of adult D. citri. The species was identified as Aspergillus fijiensis using morphological identification and phylogenetic analysis and assigned the strain name GDIZM-1. Tests to detect aflatoxin B₁ demonstrated that A. fijiensis GDIZM-1 is a non-aflatoxin B₁ producer. The pathogenicity of the strain against D. citri was determined under laboratory and greenhouse conditions. The results of the laboratory study indicated that nymphs from the 1st to 5th instar and adults of D. citri were infected by A. fijiensis GDIZM-1. The mortality of nymphs and adults of D. citri caused by infection with A. fijiensis increased with the concentration of the conidial suspension and exposure time, and the median lethal concentration (LC₅₀) and median lethal time (LT₅₀) values gradually decreased. The mortality of D. citri for all instars was higher than 70%, with high pathogenicity at the 7th day post treatment with 1 × 10⁸ conidia/mL. The results of the greenhouse pathogenicity tests showed that the survival of D. citri adults was 3.33% on the 14th day post-treatment with 1 × 10⁸ conidia/mL, which was significantly lower than that after treatment with the Metarhizium anisopliae GDIZMMa-3 strain and sterile water. The results of the present study revealed that the isolate of A. fijiensis GDIZM-1 was effective against D. citri and it provides a basis for the development of a new microbial pesticide against D. citri after validation of these results in the field. Full article

(This article belongs to the Special Issue Plant Fungi: Impact on Agricultural Production)

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14 pages, 2581 KiB

Open AccessArticle

The Mitochondrial Alternative Oxidase in Ustilago maydis Is Not Involved in Response to Oxidative Stress Induced by Paraquat

by Lucero Romero-Aguilar, Héctor Vázquez-Meza, Guadalupe Guerra-Sánchez, Oscar Ivan Luqueño-Bocardo and Juan Pablo Pardo

J. Fungi 2022, 8(11), 1221; https://doi.org/10.3390/jof8111221 - 19 Nov 2022

Cited by 2 | Viewed by 1448

Abstract

It has been shown that the alternative oxidase in mitochondria of fungi and plants has important functions in the response against stress conditions, although their role in some organisms is still unknown. This is the case of Ustilago maydis. There is no [...] Read more.

It has been shown that the alternative oxidase in mitochondria of fungi and plants has important functions in the response against stress conditions, although their role in some organisms is still unknown. This is the case of Ustilago maydis. There is no evidence of the participation of the U. maydis Aox1 in stressful conditions such as desiccation, high or low temperature, and low pH, among others. Therefore, in this work, we studied the role of the U. maydis Aox1 in cells exposed to oxidative stress induced by methyl viologen (paraquat). To gain insights into the role of this enzyme, we took advantage of four strains: the FB2 wild-type, a strain without the alternative oxidase (FB2aox1Δ), other with the Aox1 fused to the Gfp under the control of the original promoter (FB2aox1-Gfp), and one expressing constitutively de Aox1-Gfp (FB2Potef:aox1-Gfp). Cells were incubated for various times in the presence of 1 mM paraquat and growth, replicative capacities, mitochondrial respiratory activity, Aox1 capacity, and the activities of several antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase, and superoxide dismutase) were assayed. The results show that (1) the response of U. maydis against oxidative stress was the same in the presence or absence of the Aox1; (2) the activities of the antioxidant enzymes remained constant despite the oxidative stress; and (3) there was a decrease in the GSH/GSSG ratio in U. maydis cells incubated with paraquat. Full article

(This article belongs to the Special Issue Fungal Metabolism in Filamentous Fungi)

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23 pages, 2457 KiB

Open AccessArticle

Silencing of ROT2, the Encoding Gene of the Endoplasmic Reticulum Glucosidase II, Affects the Cell Wall and the Sporothrix schenckii–Host Interaction

by Luz A. López-Ramírez, Iván Martínez-Duncker, Anayeli Márquez-Márquez, Ana P. Vargas-Macías and Héctor M. Mora-Montes

J. Fungi 2022, 8(11), 1220; https://doi.org/10.3390/jof8111220 - 18 Nov 2022

Cited by 2 | Viewed by 1553

Abstract

Sporothrix schenckii is a member of the Sporothrix pathogenic clade and one of the most common etiological agents of sporotrichosis, a subcutaneous fungal infection that affects both animal and human beings. Like other fungal pathogens, the Sporothrix cell wall is composed of structural [...] Read more.

Sporothrix schenckii is a member of the Sporothrix pathogenic clade and one of the most common etiological agents of sporotrichosis, a subcutaneous fungal infection that affects both animal and human beings. Like other fungal pathogens, the Sporothrix cell wall is composed of structural polysaccharides and glycoproteins that are covalently modified with both N-linked and O-linked glycans. Thus far, little is known about the N-linked glycosylation pathway in this organism or its contribution to cell wall composition and interaction with the host. Here, we silenced ROT2, which encodes the catalytic subunit of the endoplasmic reticulum α-glucosidase II, a processing enzyme key for the N-linked glycan core processing. Silencing of ROT2 led to the accumulation of the Glc₂Man₉GlcNAC₂ glycan core at the cell wall and a reduction in the total content of N-linked glycans found in the wall. However, the highly silenced mutants showed a compensatory mechanism with increased content of cell wall O-linked glycans. The phenotype of mutants with intermediate levels of ROT2 silencing was more informative, as they showed changes in the cell wall composition and exposure of β-1.3-glucans and chitin at the cell surface. Furthermore, the ability to stimulate cytokine production by human mononuclear cells was affected, along with the phagocytosis by human monocyte-derived macrophages, in a mannose receptor-, complement receptor 3-, and TLR4-dependent stimulation. In an insect model of experimental sporotrichosis, these mutant cells showed virulence attenuation. In conclusion, S. schenckii ROT2 is required for proper N-linked glycosylation, cell wall organization and composition, and interaction with the host. Full article

(This article belongs to the Special Issue Sporothrix Emerging Investigators)

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17 pages, 3563 KiB

Open AccessArticle

Subunit C of V-ATPase-VmaC Is Required for Hyphal Growth and Conidiation in A. fumigatus by Affecting Vacuolar Calcium Homeostasis and Cell Wall Integration

by Congcong Sun, Xingyue Li, Yuanwei Zhang and Ling Lu

J. Fungi 2022, 8(11), 1219; https://doi.org/10.3390/jof8111219 - 17 Nov 2022

Cited by 2 | Viewed by 1281

Abstract

Aspergillus fumigatus is a widespread airborne fungal pathogen in humans. However, the functional genes in A. fumigatus that may contribute to its pathogenesis have not yet been fully identified. Vacuolar H⁺-ATPase is universal in eukaryotic organisms but exhibits specific roles in [...] Read more.

Aspergillus fumigatus is a widespread airborne fungal pathogen in humans. However, the functional genes in A. fumigatus that may contribute to its pathogenesis have not yet been fully identified. Vacuolar H⁺-ATPase is universal in eukaryotic organisms but exhibits specific roles in various species. Here, we identified VmaC as a putative subunit of vacuolar H⁺-ATPase in A. fumigatus that is widely conserved through evolution. The C-terminal hydrophobic domain of VmaC plays a critical role in its vacuolar localization and growth and conidiation. Deletion or turn-off of VmaC encoding gene-AfvmaC expression is not lethal but leads to a very sick and tiny colony phenotype, which is different from that of yeast with conditional ScvmaC defects. Furthermore, we found that AfvmaC not only participates in maintaining calcium homeostasis and vacuolar acidity but is also involved in cell wall integration pathway regulation, highlighting the importance of the vacuole as a storage organelle associated with many aspects of cellular homeostasis. This study indicates that fungal VmaC is relatively conserved. When compared to that in model yeasts, VmaC in A. fumigatus is required for hyphal growth and conidiation, suggesting that specific motifs in VmaC might be functioned in Aspergilli. Full article

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11 pages, 1635 KiB

Open AccessArticle

Bioactive Alkaloids from the Marine-Derived Fungus Metarhizium sp. P2100

by Guang-Shan Yao, Zhong-Lian Ma, Yao-Yao Zheng, Ling Lv, Jun-Qiu Mao and Chang-Yun Wang

J. Fungi 2022, 8(11), 1218; https://doi.org/10.3390/jof8111218 - 17 Nov 2022

Cited by 7 | Viewed by 1791

Abstract

The Metarhizium fungal species are considered the prolific producers of bioactive secondary metabolites with a variety of chemical structures. In this study, the biosynthetic potential of marine-derived fungus Metarhizium sp. P2100 to produce bioactive alkaloids was explored by using the one strain many [...] Read more.

The Metarhizium fungal species are considered the prolific producers of bioactive secondary metabolites with a variety of chemical structures. In this study, the biosynthetic potential of marine-derived fungus Metarhizium sp. P2100 to produce bioactive alkaloids was explored by using the one strain many compounds (OSMAC) strategy. From the rice solid medium (mixed with glucose peptone and yeast broth (GPY)), wheat solid medium (mixed with Czapek) and GPY liquid medium, one rare N-butenone spiroquinazoline alkaloid, N-butenonelapatin A (1), together with nine known compounds (2–10), were isolated and identified. Their structures were elucidated by analysis of the comprehensive spectroscopic data, including 1D and 2D NMR and HRESIMS, and the absolute configuration of 1 was determined by a single-crystal X-ray crystallographic experiment. N-butenonelapatin A (1) represents the first example of N-butenone spiroquinazoline with a rare α, β-unsaturated ketone side chain in the family of spiroquinazoline alkaloids. Compound 4 displayed antibacterial activity against Vibrio vulnificus MCCC E1758 with a minimum inhibitory concentration (MIC) value of 6.25 µg/mL. Compound 7 exhibited antibacterial activities against three aquatic pathogenic bacteria, including V. vulnificus MCCC E1758, V. rotiferianus MCCC E385 and V. campbellii MCCC E333 with the MIC values of 12.5, 12.5 and 6.25 μg/mL, respectively. Compounds 3 and 6 demonstrated anti-inflammatory activity against NO production induced by lipopolysaccharide (LPS) with the IC₅₀ values of 37.08 and 37.48 μM, respectively. In addition, compound 1 showed weak inhibitory activity against the proliferation of tumor cell lines A-375 and HCT 116. These findings further demonstrated that fungi of the Metarhizium species harbor great potentials in the synthesis of a variety of bioactive alkaloids. Full article

(This article belongs to the Special Issue Diversity and Secondary Metabolites of Marine Fungi)

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13 pages, 1313 KiB

Open AccessArticle

Increased Rice Susceptibility to Rice Blast Is Related to Post-Flowering Nitrogen Assimilation Efficiency

by Mathias Frontini, Jean-Benoit Morel, Antoine Gravot, Tanguy Lafarge and Elsa Ballini

J. Fungi 2022, 8(11), 1217; https://doi.org/10.3390/jof8111217 - 17 Nov 2022

Viewed by 1280

Abstract

Reducing nitrogen leaching and nitrous oxide emissions with the goal of more sustainability in agriculture implies better identification and characterization of the different patterns in nitrogen use efficiency by crops. However, a change in the ability of varieties to use nitrogen resources could [...] Read more.

Reducing nitrogen leaching and nitrous oxide emissions with the goal of more sustainability in agriculture implies better identification and characterization of the different patterns in nitrogen use efficiency by crops. However, a change in the ability of varieties to use nitrogen resources could also change the access to nutrient resources for a foliar pathogen such as rice blast and lead to an increase in the susceptibility of these varieties. This study focuses on the pre- and post-floral biomass accumulation and nitrogen uptake and utilization of ten temperate japonica rice genotypes grown in controlled conditions, and the relationship of these traits with molecular markers and susceptibility to rice blast disease. After flowering, the ten varieties displayed diversity in nitrogen uptake and remobilization. Surprisingly, post-floral nitrogen uptake was correlated with higher susceptibility to rice blast, particularly in plants fertilized with nitrogen. This increase in susceptibility is associated with a particular metabolite profile in the upper leavers of these varieties. Full article

(This article belongs to the Special Issue Roles of Soil and Roots Biotic and Abiotic Conditions in Fungal-Plant Interactions and Plant Performance)

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15 pages, 4330 KiB

Open AccessArticle

Efficacy of Propolis Gel on Mature Biofilm Formed by Neocosmospora keratoplastica Isolated from Onychomycosis

by Polyana de Souza Costa, Elton Cruz, Flávia Veiga, Isabelle Carrilho Jarros, Melyssa Negri and Terezinha Inez Estivalet Svidzinski

J. Fungi 2022, 8(11), 1216; https://doi.org/10.3390/jof8111216 - 17 Nov 2022

Cited by 1 | Viewed by 1671

Abstract

This article describes Neocosmospora keratoplastica as an etiological onychomycosis agent. Ex vivo studies were initially performed to demonstrate the ability of this species to grow and form a well-organized characteristic biofilm on sterilized healthy nails. Based on the history of excellent results, both [...] Read more.

This article describes Neocosmospora keratoplastica as an etiological onychomycosis agent. Ex vivo studies were initially performed to demonstrate the ability of this species to grow and form a well-organized characteristic biofilm on sterilized healthy nails. Based on the history of excellent results, both for antifungal and antibiofilm, of propolis resin gum, we evaluated its activity using artificially formed biofilm. In vitro, the minimal biofilm eradication concentration of the propolis extract (PE) was 375 µg of total polyphenol content (TPC) per mL, while for the propolis gel (PG) it was 450 µg of TPC per mL. In biofilm exposed to the propolis products, a decrease in hyphae and conidia was evident, accompanied by a disorganization of the extracellular matrix. Additionally, this low concentration of PE was able to significantly reduce the number of colony-forming units and the metabolic activity. Furthermore, the treatment of a 15-year nail infection due to N. keratoplastica was carried out exclusively using a topical treatment with a gel containing propolis (30%) with a daily dosage. This treatment achieved complete remission of the onychomycosis in 12 months. It is important to point out that some inconveniences previously reported by other patients treated with propolis extract were eliminated, increasing adherence to treatment. Full article

(This article belongs to the Special Issue Onychomycosis Emerging Investigators)

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15 pages, 2558 KiB

Open AccessArticle

Recombinant Expression in Pichia pastoris System of Three Potent Kv1.3 Channel Blockers: Vm24, Anuroctoxin, and Ts6

by Jesús Borrego, Muhammad Umair Naseem, Al Nasar Ahmed Sehgal, Lipsa Rani Panda, Kashmala Shakeel, Attila Gaspar, Cynthia Nagy, Zoltan Varga and Gyorgy Panyi

J. Fungi 2022, 8(11), 1215; https://doi.org/10.3390/jof8111215 - 17 Nov 2022

Cited by 2 | Viewed by 2126

Abstract

The Kv1.3 channel has become a therapeutic target for the treatment of various diseases. Several Kv1.3 channel blockers have been characterized from scorpion venom; however, extensive studies require amounts of toxin that cannot be readily obtained directly from venoms. The Pichia pastoris expression system [...] Read more.

The Kv1.3 channel has become a therapeutic target for the treatment of various diseases. Several Kv1.3 channel blockers have been characterized from scorpion venom; however, extensive studies require amounts of toxin that cannot be readily obtained directly from venoms. The Pichia pastoris expression system provides a cost-effective approach to overcoming the limitations of chemical synthesis and E. coli recombinant expression. In this work, we developed an efficient system for the production of three potent Kv1.3 channel blockers from different scorpion venoms: Vm24, AnTx, and Ts6. Using the Pichia system, these toxins could be obtained in sufficient quantities (Vm24 1.6 mg/L, AnTx 46 mg/L, and Ts6 7.5 mg/L) to characterize their biological activity. A comparison was made between the activity of tagged and untagged recombinant peptides. Tagged Vm24 and untagged AnTx are nearly equivalent to native toxins in blocking Kv1.3 (Kd = 4.4 pM and Kd = 0.72 nM, respectively), whereas untagged Ts6 exhibits a 53-fold increase in Kd (Kd = 29.1 nM) as compared to the native peptide. The approach described here provides a method that can be optimized for toxin production to develop more selective and effective Kv1.3 blockers with therapeutic potential. Full article

(This article belongs to the Special Issue Protein Engineering of Yeast)

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17 pages, 2341 KiB

Open AccessArticle

Identification and Characterization of a QTL for Growth of Fusarium circinatum on Pine-Based Medium

by Benedicta S. Swalarsk-Parry, Emma T. Steenkamp, Stephanie van Wyk, Quentin C. Santana, Magriet A. van der Nest, Almuth Hammerbacher, Brenda D. Wingfield and Lieschen De Vos

J. Fungi 2022, 8(11), 1214; https://doi.org/10.3390/jof8111214 - 16 Nov 2022

Cited by 2 | Viewed by 1584

Abstract

Fusarium circinatum is an economically important pathogen of pine and resides in the Fusarium fujikuroi species complex. Here we investigated the molecular processes underlying growth in F. circinatum by exploring the association between growth and the nutritional environment provided by the pine host. [...] Read more.

Fusarium circinatum is an economically important pathogen of pine and resides in the Fusarium fujikuroi species complex. Here we investigated the molecular processes underlying growth in F. circinatum by exploring the association between growth and the nutritional environment provided by the pine host. For this purpose, we subjected a mapping population consisting of F. circinatum X F. temperatum hybrid progeny to an analysis of growth rate on a pine-tissue derived medium. These data, together with the available genetic linkage map for F. circinatum, were then used to identify Quantitative Trait Loci (QTLs) associated with growth. The single significant QTL identified was then characterized using the available genome sequences for the hybrid progeny’s parental isolates. This revealed that the QTL localized to two non-homologous regions in the F. circinatum and F. temperatum genomes. For one of these, the F. circinatum parent contained a two-gene deletion relative to the F. temperatum parent. For the other region, the two parental isolates encoded different protein products. Analysis of repeats, G+C content, and repeat-induced point (RIP) mutations further suggested a retrotransposon origin for the two-gene deletion in F. circinatum. Nevertheless, subsequent genome and PCR-based analyses showed that both regions were similarly polymorphic within a collection of diverse F. circinatum. However, we observed no clear correlation between the respective polymorphism patterns and growth rate in culture. These findings support the notion that growth is a complex multilocus trait and raise the possibility that the identified QTL contains multiple small-effect QTLs, of which some might be dependent on the genetic backgrounds. This study improved our current knowledge of the genetic determinants of vegetative growth in F. circinatum and provided an important foundation for determining the genes and processes underpinning its ability to colonize its host environment. Full article

(This article belongs to the Section Fungal Genomics, Genetics and Molecular Biology)

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11 pages, 2031 KiB

Open AccessArticle

Preliminary Investigation about Aspergillus spp. Spread in Umbrian Avian Farms

by Deborah Cruciani, Silvia Crotti, Carmen Maresca, Ivan Pecorelli, Emanuela Verdini, Marinella Rodolfi, Eleonora Scoccia, Sara Spina, Andrea Valentini and Francesco Agnetti

J. Fungi 2022, 8(11), 1213; https://doi.org/10.3390/jof8111213 - 16 Nov 2022

Cited by 2 | Viewed by 1889

Abstract

Among the fungi responsible for deep mycosis, the genus Aspergillus plays a predominant role both in human and veterinary medicine. From a “One Health” perspective, infections by Aspergillus spp. often represent a public health problem linked to specific occupational categories that could have [...] Read more.

Among the fungi responsible for deep mycosis, the genus Aspergillus plays a predominant role both in human and veterinary medicine. From a “One Health” perspective, infections by Aspergillus spp. often represent a public health problem linked to specific occupational categories that could have a greater risk of inhaling spores and developing any respiratory disease. This preliminary investigation allowed to acquire information about the spread of Aspergillus spp. in avian livestock of the Umbria region (Central Italy), their sensitivity to antifungals, and the presence of mycotoxins in the considered farms. Environmental, feed, animal, and human samples were collected for mycological investigations; chemical analyses were also performed in feed samples. Moreover, prevalence estimated of the fungal isolates were provided for each individual farm sampled. Direct fungal identification was possible in 298 out of the 559 total samples; 162 of the samples were positive for Aspergillus spp. Mycotoxins were detected in 5 out of the 21 feed samples collected. All the aspergilli tested for antifungal susceptibility were resistant to fluconazole. The results obtained show how much the genus Aspergillus is widespread in the investigated farms; therefore, the poultry livestock represents a favorable environment for the maintenance and spread of fungal spores and their potential transmission to animals and humans. Full article

(This article belongs to the Special Issue Fungal Diseases in Animals)

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16 pages, 3869 KiB

Open AccessArticle

Fungal Strains with Identical Genomes Were Found at a Distance of 2000 Kilometers after 40 Years

by Qili Zhu, Yang Lin, Xueliang Lyu, Zheng Qu, Ziyang Lu, Yanping Fu, Jiasen Cheng, Jiatao Xie, Tao Chen, Bo Li, Hui Cheng, Weidong Chen and Daohong Jiang

J. Fungi 2022, 8(11), 1212; https://doi.org/10.3390/jof8111212 - 16 Nov 2022

Cited by 1 | Viewed by 1570

Abstract

Heredity and variation are inherent characteristics of species and are mainly reflected in the stability and variation of the genome; the former is relative, while the latter is continuous. However, whether life has both stable genomes and extremely diverse genomes at the same [...] Read more.

Heredity and variation are inherent characteristics of species and are mainly reflected in the stability and variation of the genome; the former is relative, while the latter is continuous. However, whether life has both stable genomes and extremely diverse genomes at the same time is unknown. In this study, we isolated Sclerotinia sclerotiorum strains from sclerotium samples in Quincy, Washington State, USA, and found that four single-sclerotium-isolation strains (PB4, PB273, PB615, and PB623) had almost identical genomes to the reference strain 1980 isolated in the west of Nebraska 40 years ago. The genome of strain PB4 sequenced by the next-generation sequencing (NGS) and Pacific Biosciences (PacBio) sequencing carried only 135 single nucleotide polymorphisms (SNPs) and 18 structural variations (SVs) compared with the genome of strain 1980 and 48 SNPs were distributed on Contig_20. Based on data generated by NGS, three other strains, PB273, PB615, and PB623, had 256, 275, and 262 SNPs, respectively, against strain 1980, which were much less than in strain PB4 (532 SNPs) and none of them occurred on Contig_20, suggesting much closer genomes to strain 1980 than to strain PB4. All other strains from America and China are rich in SNPs with a range of 34,391–77,618 when compared with strain 1980. We also found that there were 39–79 SNPs between strain PB4 and its sexual offspring, 53.1% of which also occurred on Contig_20. Our discoveries show that there are two types of genomes in S. sclerotiorum, one is very stable and the other tends to change constantly. Investigating the mechanism of such genome stability will enhance our understanding of heredity and variation. Full article

(This article belongs to the Section Fungal Evolution, Biodiversity and Systematics)

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13 pages, 2756 KiB

Open AccessArticle

Flavonoids Modulate Aspergillus flavus Proliferation and Aflatoxin Production

by Lina Castano-Duque, Matthew D. Lebar, Carol Carter-Wientjes, David Ambrogio and Kanniah Rajasekaran

J. Fungi 2022, 8(11), 1211; https://doi.org/10.3390/jof8111211 - 16 Nov 2022

Cited by 5 | Viewed by 2081

Abstract

Aflatoxins are carcinogenic mycotoxins produced by Aspergillus flavus. They contaminate major food crops, particularly corn, and pose a worldwide health concern. Flavonoid production has been correlated to resistance to aflatoxin accumulation in corn. The effects of flavonoids on fungal proliferation and aflatoxin [...] Read more.

Aflatoxins are carcinogenic mycotoxins produced by Aspergillus flavus. They contaminate major food crops, particularly corn, and pose a worldwide health concern. Flavonoid production has been correlated to resistance to aflatoxin accumulation in corn. The effects of flavonoids on fungal proliferation and aflatoxin production are not well understood. In this study, we performed bioassays, fluorescence and scanning electron microscopy, and total antioxidant analysis to determine the effects of three flavonoids (apigenin, luteolin, and quercetin) on proliferation and aflatoxin production in A. flavus NRRL 3357. Results showed that concentrations of apigenin and luteolin modulated fungal proliferation and aflatoxin production in a dose-dependent manner, leading to inhibition or promotion of proliferation and toxin production. Microscopy studies of fungi exposed to flavonoids showed mycelial cell wall disruption, abnormal cell wall invaginations, and tears. Fluorescent enhancement of apigenin and luteolin using Naturstoff reagent A showed that these chemicals localized in sphere-like structures on the mycelia surface. Fungi exposed to low concentrations of apigenin, luteolin, and quercetin lowered the total antioxidant capacity in the environment compared to controls. Our results indicate that flavonoids disrupt cell wall integrity and may localize in vesicle-like structures. We hypothesize that flavonoids could act as potential signaling molecules at low concentrations and change the oxidative state of the microenvironment, either or both of which may lead to reduction of fungal proliferation and aflatoxin production. Full article

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16 pages, 4505 KiB

Open AccessArticle

Variation in Community Structure of the Root-Associated Fungi of Cinnamomum camphora Forest

by Deqiang Chen, Jiaoyan Zeng, Xiaohui Wan, Yonglong Wang, Siren Lan, Shuangquan Zou and Xin Qian

J. Fungi 2022, 8(11), 1210; https://doi.org/10.3390/jof8111210 - 15 Nov 2022

Cited by 2 | Viewed by 1745

Abstract

Plant-associated microbial communities play essential roles in the vegetative cycle, growth, and development of plants. Cinnamomum camphora is an evergreen tree species of the Lauraceae family with high ornamental, medicinal, and economic values. The present study analyzed the composition, diversity, and functions of [...] Read more.

Plant-associated microbial communities play essential roles in the vegetative cycle, growth, and development of plants. Cinnamomum camphora is an evergreen tree species of the Lauraceae family with high ornamental, medicinal, and economic values. The present study analyzed the composition, diversity, and functions of the fungal communities in the bulk soil, rhizosphere, and root endosphere of C. camphora at different slope positions by high-throughput sequencing. The results showed that the alpha diversity of the fungal communities in the bulk soil and rhizosphere of the downhill plots was relatively higher than those uphill. A further analysis revealed that Mucoromycota, the dominant fungus at the phylum level, was positively correlated with soil bulk density, total soil porosity, mass water content, alkaline-hydrolyzable nitrogen, maximum field capacity, and least field capacity. Meanwhile, the prevalent fungus at the class level, Mortierellomycetes, was positively correlated with total phosphorus and available and total potassium, but negatively with alkaline-hydrolyzable nitrogen. Finally, the assignment of the functional guilds to the fungal operational taxonomic units (OTUs) revealed that the OTUs highly enriched in the downhill samples compared with the uphill samples, which were saprotrophs. Thus, this study is the first to report differences in the fungal community among the different soil/root samples and between C. camphora forests grown at different slope positions. We also identified the factors favoring the root-associated beneficial fungi in these forests, providing theoretical guidance for managing C. camphora forests. Full article

(This article belongs to the Special Issue Roles of Soil and Roots Biotic and Abiotic Conditions in Fungal-Plant Interactions and Plant Performance, 2nd Edition)

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9 pages, 549 KiB

Open AccessArticle

In Vitro Biofilm Formation by Malassezia pachydermatis Isolates and Its Susceptibility to Azole Antifungals

by Eva Čonková, Martina Proškovcová, Peter Váczi and Zuzana Malinovská

J. Fungi 2022, 8(11), 1209; https://doi.org/10.3390/jof8111209 - 15 Nov 2022

Cited by 5 | Viewed by 1443

Abstract

The yeast Malassezia pachydermatis, an opportunistic pathogen that inhabits the skin of various domestic and wild animals, is capable of producing a biofilm that plays an important role in antifungal resistance. The aim of this research study was to find the intensity [...] Read more.

The yeast Malassezia pachydermatis, an opportunistic pathogen that inhabits the skin of various domestic and wild animals, is capable of producing a biofilm that plays an important role in antifungal resistance. The aim of this research study was to find the intensity of biofilm production by M. pachydermatis strains isolated from the ear canal of healthy dogs, and to determine the susceptibility of planktonic, adhered and biofilm-forming cells to three azole antifungals—itraco-nazole, voriconazole and posaconazole—that are most commonly used to treat Malassezia infections. Out of 52 isolates, 43 M. pachydermatis strains (82.7%) were biofilm producers with varying levels of intensity. For planktonic cells, the minimum inhibitory concentration (MIC) range was 0.125–2 µg/mL for itraconazole, 0.03–1 µg/mL for voriconazole and 0.03–0.25 µg/mL for posaconazole. Only two isolates (4.7%) were resistant to itraconazole, one strain (2.3%) to voriconazole and none to posaconazole. For adhered cells and the mature biofilm, the following MIC ranges were found: 0.25–16 µg/mL and 4–16 µg/mL for itraconazole, 0.125–8 µg/mL and 0.25–26 µg/mL for voriconazole, and 0.03–4 µg/mL and 0.25–16 µg/mL for posaconazole, respectively. The least resistance for adhered cells was observed for posaconazole (55.8%), followed by voriconazole (62.8%) and itraconazole (88.4%). The mature biofilm of M. pachydermatis showed 100% resistance to itraconazole, 95.3% to posaconazole and 83.7% to voriconazole. The results of this study show that higher concentrations of commonly used antifungal agents are needed to control infections caused by biofilm-forming strains of M. pachydermatis. Full article

(This article belongs to the Section Fungal Pathogenesis and Disease Control)

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20 pages, 5491 KiB

Open AccessArticle

Differential Metabolomics Reveals Pathogenesis of Pestalotiopsis kenyana Causing Leaf Spot Disease of Zanthoxylum schinifolium

by Chang Liu, Haiyao Guo, Han Liu, Jiawen Yu, Shuying Li, Tianhui Zhu, Adjei Mark Owusu and Shujiang Li

J. Fungi 2022, 8(11), 1208; https://doi.org/10.3390/jof8111208 - 15 Nov 2022

Cited by 4 | Viewed by 2054

Abstract

Pepper leaf spot is a common disease of Zanthoxylum schinifolium. When it is serious, it directly affects the growth of Z. schinifolium, making the plant unable to blossom and bear fruit, which seriously restricts the development of the Z. schinifolium industry. [...] Read more.

Pepper leaf spot is a common disease of Zanthoxylum schinifolium. When it is serious, it directly affects the growth of Z. schinifolium, making the plant unable to blossom and bear fruit, which seriously restricts the development of the Z. schinifolium industry. Therefore, the pathogenic mechanism of leaf spots should be explored to provide a basis for a comprehensive understanding of the disease. Using liquid chromatography–mass spectrometry (LC–MS) technology combined with the data-dependent acquisition, the full spectrum analysis of pathogen mycelium samples was carried out. Partial least squares discriminant analysis (PLS-DA) was used to reveal the differences in metabolic patterns among different groups. Hierarchical clustering analysis (HCA) and PLS-DA were used to reveal the relationship between samples and metabolites, which reflected the metabolomics changes of Pestalotiopsis kenyana in the logarithmic growth phase of mycelia, the stable growth phase of mycelia, the massive spore stage, the induction culture conditions of PDA and Z. schinifolium leaves, and the possible pathogenic substances were selected for pathogenicity detection. PLS-DA had a strong predictive ability, indicating a clear analysis trend between different groups. The results of the metabolomics analysis showed that the differential metabolites of pathogenic bacteria were abundant at different stages and under different medium conditions, and the content of metabolites changed significantly. There were 3922 differential metabolites in nine groups under positive and negative ion modes, including lipids and lipid molecules, organic acids and their derivatives, organic heterocyclic compounds, organic oxygen compounds, carbohydrate polyketides, nucleosides, nucleotides, and analogs. The results of the pathogenicity test showed that the leaves treated with 3,5-dimethoxy benzoic acid, S-(5-adenosy)-l-homocysteine, 2-(1H-indol-3-yl) acetic acid, l-glutamic acid, and 2-(2-acetyl-3,5-dihydroxy phenyl) acetic acid showed different degrees of yellowish-brown lesions. This indicated that these substances may be related to the pathogenicity of P. kenyana, and the incidence was more serious when treated with 3,5-dimethoxybenzoic acid and S-(5-adenosy)- l -homocysteine. This study provides a basis for further analysis of differential metabolites and provides a theoretical reference for the prevention and treatment of Z. schinifolium leaf spot. Full article

(This article belongs to the Section Fungal Pathogenesis and Disease Control)

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14 pages, 8774 KiB

Open AccessArticle

Spatial Distribution of Canine Sporotrichosis in Rio de Janeiro, Brazil (1998–2018) and Its Correlation with Socioeconomic Conditions

by Anna Barreto Fernandes Figueiredo, Mônica de Avelar Figueiredo Mafra Magalhães, Wagner de Souza Tassinari, Isabella Dib Ferreira Gremião, Luisa Helena Monteiro de Miranda, Rodrigo Caldas Menezes and Sandro Antonio Pereira

J. Fungi 2022, 8(11), 1207; https://doi.org/10.3390/jof8111207 - 15 Nov 2022

Cited by 1 | Viewed by 1582

Abstract

Canine sporotrichosis is a poorly described global disease and a spatial approach has not yet been used to assess the disease in dogs. Therefore, this study aimed to describe the occurrence of canine sporotrichosis in the state of Rio de Janeiro, Brazil, from [...] Read more.

Canine sporotrichosis is a poorly described global disease and a spatial approach has not yet been used to assess the disease in dogs. Therefore, this study aimed to describe the occurrence of canine sporotrichosis in the state of Rio de Janeiro, Brazil, from 1998 to 2018 and its correlation with socioeconomic characteristics using exploratory spatial data analysis. A total of 295 cases of canine sporotrichosis were identified and 249 were georeferenced. There was a higher concentration of cases in the municipality of Rio de Janeiro, as well as along the border of the city and the adjacent municipalities in the great metropolitan area. The cases occurred in areas where most of the dwellings are houses. Moreover, no focus of disease density was found in the southern part of Rio de Janeiro city over the period studied, possibly due to better socioeconomic conditions. Areas with a high concentration of canine sporotrichosis cases coincided with regions that possessed a low proportion of households without paving, suggesting that the disease is not necessarily linked to extreme poverty. The mapping of areas with a greater density of cases is fundamental to formulate targeted and strategic plans in order to implement effective public health prevention and control measures. Full article

(This article belongs to the Special Issue Fungal Diseases in Animals)

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13 pages, 3445 KiB

Open AccessArticle

The Effect of Dekkera bruxellensis Concentration and Inoculation Time on Biochemical Changes and Cellulose Biosynthesis by Komagataeibacter intermedius

by Putu Virgina Partha Devanthi, Ferren Pratama, Katherine Kho, Mohammad J. Taherzadeh and Solmaz Aslanzadeh

J. Fungi 2022, 8(11), 1206; https://doi.org/10.3390/jof8111206 - 15 Nov 2022

Cited by 4 | Viewed by 1665

Abstract

Bacterial Cellulose (BC) is a biopolymer with numerous applications. The growth of BC-producing bacteria, Komagataeibacter intermedius, could be stimulated by Dekkera bruxellensis, however, the effect on BC yield needs further investigation. This study investigates BC production and biochemical changes in the [...] Read more.

Bacterial Cellulose (BC) is a biopolymer with numerous applications. The growth of BC-producing bacteria, Komagataeibacter intermedius, could be stimulated by Dekkera bruxellensis, however, the effect on BC yield needs further investigation. This study investigates BC production and biochemical changes in the K. intermedius-D. bruxellensis co-culture system. D. bruxellensis was introduced at various concentrations (10³ and 10⁶ CFU/mL) and inoculation times (days 0 and 3). BC yield was ~24% lower when D. bruxellensis was added at 10³ CFU/mL compared to K. intermedius alone (0.63 ± 0.11 g/L). The lowest BC yield was observed when 10³ CFU/mL yeast was added on day 0, which could be compromised by higher gluconic acid production (10.08 g/L). In contrast, BC yields increased by ~88% when 10⁶ CFU/mL D. bruxellensis was added, regardless of inoculation time. High BC yield might correlate with faster sugar consumption or increased ethanol production when 10⁶ CFU/mL D. bruxellensis was added on day 0. These results suggest that cell concentration and inoculation time have crucial impacts on species interactions in the co-culture system and product yield. Full article

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18 pages, 5200 KiB

Open AccessArticle

Four New Species of Aspergillus Subgenus Nidulantes from China

by Bingda Sun, Chunling Luo, Gerald F. Bills, Jibing Li, Panpan Huang, Lin Wang, Xianzhi Jiang and Amanda Juan Chen

J. Fungi 2022, 8(11), 1205; https://doi.org/10.3390/jof8111205 - 15 Nov 2022

Cited by 5 | Viewed by 1847

Abstract

Aspergillus subgenus Nidulantes includes species with emericella-like ascomata and asexual species. Subgenus Nidulantes is the second largest subgenus of Aspergillus and consists of nine sections. In this study, agricultural soils were sampled from 12 provinces and autonomous regions in China. Based on primary [...] Read more.

Aspergillus subgenus Nidulantes includes species with emericella-like ascomata and asexual species. Subgenus Nidulantes is the second largest subgenus of Aspergillus and consists of nine sections. In this study, agricultural soils were sampled from 12 provinces and autonomous regions in China. Based on primary BLAST analyses, seven of 445 Aspergillus isolates showed low similarity with existing species. A polyphasic investigation, including phylogenetic analysis of partial ITS, β-tubulin, calmodulin, and RNA polymerase II second largest subunit genes, provided evidence that these isolates were distributed among four new species (Aspergillus guangdongensis, A. guangxiensis, A. sichuanensis and A. tibetensis) in sections Aenei, Ochraceorosei, and Sparsi of subgenus Nidulantes. Illustrated morphological descriptions are provided for each new taxon. Full article

(This article belongs to the Special Issue Diversity, Classification and Taxonomy of Aspergillus, Penicillium, Talaromyces and related genera (Eurotiales))

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J. Fungi, Volume 8, Issue 11 (November 2022) – 120 articles

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