J. Fungi, Volume 8, Issue 4 (April 2022) – 93 articles

Patients with coronavirus disease 19 (COVID-19) admitted to the intensive care unit (ICU) often develop respiratory fungal infections. The most frequent diseases are the COVID-19 associated pulmonary aspergillosis (CAPA), COVID-19 associated pulmonary mucormycosis (CAPM) and the Pneumocystis jirovecii pneumonia (PCP), the latter mostly found in patients with both COVID-19 and underlying HIV infection. Furthermore, co-infections due to less common mold pathogens have been also described. Respiratory fungal infections in critically ill patients are promoted by multiple risk factors, including epithelial damage caused by COVID-19 infection, mechanical ventilation and immunosuppression, mainly induced by corticosteroids and immunomodulators. In COVID-19 patients, a correct discrimination between fungal colonization and infection is challenging, further hampered by sampling difficulties and by the low reliability of diagnostic approaches, frequently needing an integration of clinical, radiological and microbiological features. Several antifungal drugs are currently available, but the development of new molecules with reduced toxicity, less drug-interactions and potentially active on difficult to treat strains, is highly warranted. Finally, the role of prophylaxis in certain COVID-19 populations is still controversial and must be further investigated. Full article

Few data are published from Morocco on fungal disease, although numerous case reports attest to a wide range of conditions in the country. Here, we estimate for the first time the incidence and prevalence of serious fungal diseases in the country. Detailed literature searches in English and French were conducted for all serious fungal infections. Demographic and individual underlying condition prevalence or annual incidence were obtained from UNAIDS (HIV), WHO (TB) and other international sources. Deterministic modelling was then applied to estimate fungal disease burden. Morocco’s population in 2021 was 36,561,800. Multiple publications describe various fungal diseases, but epidemiological studies are rare. The most frequent serious fungal infections were tinea capitis (7258/100,000) and recurrent vulvovaginal candidiasis (2794/100,000 females). Chronic pulmonary aspergillosis is also common at a prevalence of 19,290 (53/100,000) because of the relatively high rate of tuberculosis. The prevalence of asthma in adults exceeds one million, of whom fungal asthma (including allergic bronchopulmonary aspergillosis (ABPA)) probably affects 42,150 (115/100,000). Data are scant on candidaemia (estimated at 5/100,000), invasive aspergillosis (estimated at 4.1/100,000), HIV-related complications such as cryptococcal meningitis and Pneumocystis pneumonia and mucormycosis. Fungal keratitis is estimated at 14/100,000). Mycetoma and chromoblastomycosis are probably rare. Fungal disease is probably common in Morocco and diagnostic capacity is good in the teaching hospitals. These estimates need confirmation with methodologically robust epidemiological studies. Full article

Coccidioidomycosis, also known as Valley fever, is an endemic fungal infection commonly found in the southwestern parts of the United States. However, the disease has seen an increase in both in its area of residency and its prevalence. This review compiles some of the latest information on the epidemiology, current and in-development pharmaceutical approaches to treat the disease, trends and projections, diagnostic concerns, and the overlapping dynamics of coccidioidomycosis and COVID-19, including in special populations. This review provides an overview of the current diagnostic and therapeutic strategies and identifies areas of future development. Full article

Nanoparticles (NPs) have attracted great interest in various fields owing to their antimicrobial activity; however, the use of NPs as fungicides on plants has not been sufficiently investigated. In this study, the antifungal activities of sulfur nanoparticles (S-NPs) and copper nanoparticles (Cu-NPs) prepared by a green method were evaluated against Botrytis cinerea and Sclerotinia sclerotiorum. The formation of NPs was confirmed by transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). The antifungal activities of NPs (5–100 µg/mL), CuSO₄ (4000 µg/mL), and micro sulfur (MS) were compared to those of the recommended chemical fungicide Topsin-M 70 WP at a dose of 1000 µg/mL. They were evaluated in vitro and then in vivo at different temperatures (10 and 20 °C) on cucumber (Cucumis sativus) fruits. The total phenolic content (TPC) and total soluble solids (TSS) were determined to study the effects of various treatments on the shelf life of cucumber fruits, compared to untreated cucumber as a positive control. The diameters of S-NPs and Cu-NPs ranged from 10 to 50 nm, and 2 to 12 nm, respectively. The results revealed that S-NPs exhibited the highest antifungal activity, followed by Cu-NPs. However, CuSO₄ showed the lowest antifungal activity among all treatments. The antifungal activity of the prepared NPs increased with the increase in NP concentration, while the fungal growth was less at low temperature. The cytotoxicity of the prepared NPs was evaluated against the WI-38 and Vero cell lines in order to assess their applicability and sustainability. S-NPs caused less cytotoxicity than Cu-NPs. Full article

Cryptic species of Aspergillus have rapidly increased in the last few decades. Chronic pulmonary aspergillosis (CPA) is a debilitating fungal infection frequently affecting patients with previous TB. The identification and antifungal susceptibility profiles of different species of Aspergillus are important to support the management of CPA. The aim of this study was to describe the molecular and susceptibility profiles of Aspergillus isolated from CPA patients. The species identity of isolates was determined by combined DNA analyses of internal transcribed space (ITS), partial β-tubulin genes, and part of the calmodulin gene. We revealed a high (27%) prevalence of cryptic species among previous tuberculosis patients with persistent symptoms. Twenty-nine (49%) patients met the criteria for diagnosis of CPA with 24% containing Aspergillus cryptic species. This is the first report of five cryptic Aspergillus species from clinical isolates in Indonesia: A. aculea tus, A. neoniger, A. brunneoviolacues, A. welwitschiae, and A. tubingensis. Significantly, there was decreased sensitivity against itraconazole in the CPA group (66% susceptible to itraconazole) compared to the non-CPA group (90% susceptible to itraconazole) (p = 0.003). The species-level characterisation of Aspergillus and its antifungal susceptibility tests demands greater attention to better the management of CPA patients. Full article

Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi is recognized as the dioecious parental generation of today’s cultivars. Climatic change and the arrival of pathogens and pests in Europe led it to be included on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species in 1997. The present work focused on the study of culturable yeast occurrence and diversity of grape berries collected from wild vines. Sampling was performed in 29 locations of Azerbaijan, Georgia, Italy, Romania, and Spain. In total, 3431 yeast colonies were isolated and identified as belonging to 49 species, including Saccharomyces cerevisiae, by 26S rDNA D1/D2 domains and ITS region sequencing. Isolates of S. cerevisiae were also analyzed by SSR–PCR obtaining 185 different genotypes. Classical ecology indices were used to obtain the richness (S), the biodiversity (H’), and the dominance (D) of the species studied. This study highlights the biodiversity potential of natural environments that still represent a fascinating source of solutions to common problems in winemaking. Full article

Botryosphaeria dieback (BD) is a grapevine trunk disease (GTD) causing significant yield losses and limiting the lifespan of vineyards worldwide. Fungi responsible for BD infect grapevines primarily through pruning wounds, and thus pruning wound protection, using either synthetic chemicals or biological control agents (BCAs), is the main available management strategy. However, no products to control GTDs are currently registered in Canada. With a focus on more sustainable grapevine production, there is an increasing demand for alternatives to chemical products to manage GTDs. Accordingly, the objective of this study was to identify Trichoderma species from grapevines in British Columbia (BC) and evaluate their potential biocontrol activity against BD fungi Diplodia seriata and Neofusicoccum parvum. Phylogenetic analyses identified seven species, including T. asperelloides, T. atroviride, T. harzianum, T. koningii, T. tomentosum, and two novel species, T. canadense and T. viticola. In vitro dual culture antagonistic assays showed several isolates to inhibit fungal pathogen mycelial growth by up to 75%. In planta detached cane assays under controlled greenhouse conditions identified T. asperelloides, T. atroviride and T. canadense isolates from BC as providing 70% to 100% pruning wound protection against BD fungi for up to 21 days after treatment. In addition, these isolates were shown to provide similar or better control when compared against commercial chemical and biocontrol products. This study demonstrates the potential that locally sourced Trichoderma species can have for pruning wound protection against BD fungi, and further supports the evaluation of these isolates under natural field conditions. Full article

Infection is a major complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT) especially cytomegalovirus (CMV) infection and invasive fungal infection (IFI). Taiwan is a high CMV seroprevalence area. Our study aimed to evaluate the incidence, risk factors, the impact on survival of CMV infection (including reactivation and disease) and the association of CMV infection and IFI in recipients after allo-HSCT during the first 100 days after transplantation. This was a retrospective study including 180 recipients of allo-HSCT. A total of 99 patients had CMV reactivation, and nine patients had CMV diseases. There were more mismatched donors, more ATG usage and more transplantation from CMV IgG-negative donor in patients with CMV reactivation. There was no survival difference in patients with or without CMV reactivation. A total of 34 patients had IFIs, and IFI after allo-HSCT was associated with significantly inferior survival. Patients with CMV reactivation did not increase the incidence of overall IFI, but they did result in more late-onset (>40 days) IFI (p = 0.056). In this study, we demonstrated real-world data of CMV infection and IFI from a high CMV seroprevalence area. Full article

Monacolin J (MJ), a key precursor of Lovastatin, could synthesize important statin drug simvastatin by hydrolyzing lovastatin and adding different side chains. In this study, to reduce the cumbersome hydrolysis of lovastatin to produce MJ in the native strain Aspergillus terreus, the MJ biosynthetic pathway genes (lovB, lovC, lovG, and lovA) were heterologously integrated into the genome of Aspergillus. niger CBS513.88 with strong promoters and suitable integration sites, via yeast 2μ homologous recombination to construct expression cassettes of long-length genes and CRISPR/Cas9 homology-directed recombination (CRISPR-HDR) to integrate MJ genes in the genome of A. niger. RT-PCR results proved that pathway synthesis-related genes could be heterologously expressed in A. niger. Finally, we constructed an engineered strain that could produce monacolin J, detected by LC-HR-ESIMS (MJ, 339.22 [M-H]⁺). The yield of MJ reached 92.90 mg/L after 7-day cultivation. By optimizing the cultivation conditions and adding precursor, the final titer of MJ was 142.61 mg/L on the fourth day of fed-batch cultivation, which was increased by 53.5% compared to the original growth conditions. Due to the wide application of A. niger in industrial fermentation for food and medicine, the following work will be dedicated to optimizing the metabolic network to improve the MJ production in the engineered strain. Full article

Nematode-trapping (NT) fungi play a significant role in the biological control of plant- parasitic nematodes. NT fungi, as a predator, can differentiate into specialized structures called “traps” to capture, kill, and consume nematodes at a nutrient-deprived condition. Therefore, trap formation is also an important indicator that NT fungi transition from a saprophytic to a predacious lifestyle. With the development of gene knockout and multiple omics such as genomics, transcriptomics, and metabolomics, increasing studies have tried to investigate the regulation mechanism of trap formation in NT fungi. This review summarizes the potential regulatory mechanism of trap formation in NT fungi based on the latest findings in this field. Signaling pathways have been confirmed to play an especially vital role in trap formation based on phenotypes of various mutants and multi-omics analysis, and the involvement of small molecule compounds, woronin body, peroxisome, autophagy, and pH-sensing receptors in the formation of traps are also discussed. In addition, we also highlight the research focus for elucidating the mechanism underlying trap formation of NT fungi in the future. Full article

Wood-inhabiting fungi are a cosmopolitan group and show a rich diversity, growing in the vegetation of boreal, temperate, subtropical, and tropical regions. Xylodon grandineus, X. punctus, and X. wenshanensis spp. nov. were found in the Yunnan–Guizhou Plateau, China, suggested here to be new fungal species in light of their morphology and phylogeny. Xylodon grandineus is characterized by a grandinioid hymenophore and ellipsoid basidiospores; X. punctus has a membranous hymenophore, a smooth hymenial surface with a speckled distribution, and absent cystidia; X. wenshanensis has a grandinioid hymenophore with a cream to slightly buff hymenial surface and cystidia of two types. Sequences of the ITS and nLSU rRNA markers of the studied samples were generated, and phylogenetic analyses were performed using the maximum likelihood, maximum parsimony, and Bayesian inference methods. After a series of phylogenetic studies, the ITS+nLSU analysis of the order Hymenochaetales indicated that, at the generic level, six genera (i.e., Fasciodontia, Hastodontia, Hyphodontia, Lyomyces, Kneiffiella, and Xylodon) should be accepted to accommodate the members of Hyphodontia sensu lato. According to a further analysis of the ITS dataset, X. grandineus was retrieved as a sister to X. nesporii; X. punctus formed a monophyletic lineage and then grouped with X. filicinus, X. hastifer, X. hyphodontinus, and X. tropicus; and X. wenshanensis was a sister to X. xinpingensis. Full article

Mucor lusitanicus and some other members of the fungal order Mucorales display the phenomenon of morphological dimorphism. This means that these fungi aerobically produce filamentous hyphae, developing a coenocytic mycelium, but they grow in a multipolar yeast-like form under anaerobiosis. Revealing the molecular mechanism of the reversible yeast-hyphal transition can be interesting for both the biotechnological application and in the understanding of the pathomechanism of mucormycosis. In the present study, transcriptomic analyses were carried out after cultivating the fungus either aerobically or anaerobically revealing significant changes in gene expression under the two conditions. In total, 539 differentially expressed genes (FDR < 0.05, |log₂FC| ≥ 3) were identified, including 190 upregulated and 349 downregulated transcripts. Within the metabolism-related genes, carbohydrate metabolism was proven to be especially affected. Anaerobiosis also affected the transcription of transporters: among the 14 up- and 42 downregulated transporters, several putative sugar transporters were detected. Moreover, a considerable number of transcripts related to amino acid transport and metabolism, lipid transport and metabolism, and energy production and conversion were proven to be downregulated when the culture had been transferred into an anaerobic atmosphere. Full article

Colletotrichum gloeosporioides is a phytopathogenic fungus that causes devastating losses in strawberries without effective countermeasures. Members of the genus Photorhabdus exhibit antimicrobial capability and have been found to have the potential for use as biocontrol agents against C. gloeosporioides. Photorhabdus species exhibit two phase variations with a differentiated composition of secondary metabolites designated to each phase. In this study, Photorhabdus akhurstii sp. nov. 0813-124 exhibited phase I (PL1) and phase II (PL2); however, only PL1 displayed distinct inhibition of C. gloeosporioides in the confrontation assay. We identified the bioactive ingredients of P. akhurstii sp. nov. 0813-124 to be glidobactin A and cepafungin I, with MIC values lower than 1.5 and 2.0 µg/mL, respectively. Furthermore, we revealed the biosynthetic gene cluster (BGC) of corresponding bioactive molecules through genomics analysis and determined its expression level in PL1 and PL2. The expression of glidobactin BGC in PL1 increased rapidly within 24 h, while PL2 was eventually stimulated after 60 h. In summary, we demonstrated that P. akhurstii sp. nov. 0813-124 could potentially be used as a biocontrol agent or part of a natural product repertoire for combating C. gloeosporioides. Full article

Microsclerotia (MS) produced by some species of Metarhizium can be used as active ingredients in mycoinsecticides for the control of soil-dwelling stages of geophilic pests. In this study, the MS production potential of two Metarhizium brunneum strains and one M. robertsii strain was evaluated. The three strains were able to produce MS in liquid fermentation, yielding between 4.0 × 10⁶ (M. robertsii EAMa 01/158-Su strain) and 1.0 × 10⁷ (M. brunneum EAMa 01/58-Su strain) infective propagules (CFU) per gram of MS. The EAMa 01/58-Su strain was selected for further investigation into the effects of key abiotic factors on their survival and conidial yield. The MS were demonstrated to be stable at different storage temperatures (−80, −18, and 4 °C), with a shelf-life up to one year. The best temperature for MS storage was −80 °C, ensuring good viability of MS for up to one year (4.9 × 10¹⁰ CFU/g MS). Moreover, soil texture significantly affected CFU production by MS; sandy soils were the best driver of infective propagule production. Finally, the best combination of soil temperature and humidity for MS germination was 22.7 °C and 7.3% (wt./wt.), with no significant effect of UV-B exposure time on MS viability. These results provide key insights into the handling and storage of MS, and for decision making on MS dosage and timing of application. Full article

Flammulina filiformis is a popular mushroom which has been regarded as a potential model fungus for mycelium growth, fruiting body development, and stress response studies. Based on a genome-wide search, four genes encoding heterotrimeric G protein α subunits were identified in F. filiformis. The data of conserved domain analysis showed that these genes contain only one subgroup I of Gα subunit (Gαi), similar to many other fungi. To explore the function of Gαi, FfGa1 over-expression (OE) and RNA interference (RNAi) strains were generated using the Agrobacterium tumefaciens-mediated transformation (ATMT) approach. RNAi transformant strains showed remarkably reduced growth on PDA medium and added sensitivity to cell wall-enforcing agents with maximum growth inhibition, but showed better growth in response to hypertonic stress-causing agents, while OE strains exhibited more resistance to thermal stress and mycoparasite Trichoderma as compared to the wild-type and RNAi strains. Taken together, our results indicated that FfGa1 positively regulates hyphal extension, and is crucial for the maintenance of cell wall integrity and protection against biotic and abiotic (hypertonic and thermal) stress. Full article

Background: The diagnosis of CPA relies on the detection of the IgG Aspergillus antibody, which is not freely available, especially in resource-poor settings. Point-of-care tests like LDBio Aspergillus ICT lateral flow assay, evaluated in only a few studies, have shown promising results for the diagnosis of CPA. However, no study has compared the diagnostic performances of LDBio LFA in setting of tuberculosis endemic countries and have compared it with that of IgG Aspergillus. Objectives: This study aimed to evaluate the diagnostic performances of LDBio LFA in CPA and compare it with existing the diagnostic algorithm utilising ImmunoCAP IgG Aspergillus. Methods: Serial patients presenting with respiratory symptoms (cough, haemoptysis, fever, etc.) for >4 weeks were screened for eligibility. Relevant investigations, including direct microscopy and culture of respiratory secretions, IgG Aspergillus, chest imaging, etc., were done according to existing algorithm. Serums of all patients were tested by LDBio LFA and IgG Aspergillus (ImmunoCAP Asp IgG) and their diagnostic performances were compared. Results: A total of 174 patients were included in the study with ~66.7% patients having past history of tuberculosis. A diagnosis of CPA was made in 74 (42.5%) of patients. The estimated sensitivity and specificity of LDBio LFA was 67.6% (95% CI: 55.7–78%) and 81% (95% CI: 71.9–88.2%), respectively, which increased to 73.3% (95% CI: 60.3–83.9%) and 83.9% (95% CI: 71.7–92.4%), respectively, in patients with a past history of tuberculosis. The sensitivity and specificity of IgG Aspergillus was 82.4% (95% CI: 71.8–90.3%) and 82% (95% CI: 73.1–89%); 86.7% (95% CI: 75.4–94.1%) and 80.4% (95% CI: 67.6–89.8%), in the whole group and those with past history of tuberculosis, respectively. Conclusions: LDBio LFA is a point-of-care test with reasonable sensitivity and specificity. However, further tests may have to be done to rule-in or rule-out the diagnosis of CPA in the appropriate setting. Full article

Different strategies have been used to degrade the molecular structure of lignins in natural fibers. Both chemical and biological processes can obtain different types of lignins for industrial use. In this study, a variation of the spectral intensity of the thermo-mechanical and fungi-modified Bambusa oldhamii (giant bamboo) and Guadua angustifolia Kunt fibers were examined via Fouriertransform infrared spectroscopy. The giant bamboo and Guadua angustifolia Kunt specimens were modified using a non-chemical alternative steam pressure method for degrading lignins, followed by mechanical sieving to obtain fibers of different lengths. The obtained fibers were treated with the Fusarium incarnatum-equiseti MF18MH45591 strain in a 21 d degradation process. The samples were subjected to Fouriertransform infrared spectroscopy before and after the strain treatment. The intensity variation was found to be in the spectral range of 1200 cm⁻¹ to 1800 cm⁻¹, in which lignin components are commonly found in most plant species. A multivariate analysis of the principal components of the treated and untreated control samples confirmed the changes in the spectral region of interest, which were associated with the thermo-mechanical and fungal treatment. Full article

Nine collections of gymnopoid fungi were studied based on morpho-molecular characteristics. The macromorphology was made according to the photograph of fresh basidiomata and field notes, while the micromorphology was examined via an optical microscope. Simultaneously, the phylogenetic analyses were performed by maximum likelihood and Bayesian inference methods based on a combined dataset of nrITS1-nr5.8S-nrITS2-nrLSU sequences. Integrated analysis of these results was therefore, G. efibulatus belonging to sect. Androsacei, G. iodes and G. sinopolyphyllus belonging to sect. Impudicae and G. strigosipes belonging to sect. Levipedes are proposed as new to science. The detailed descriptions, colour photos of basidiomata and line-drawings of microscopic structures are provided. The comparisons with closely related species and a key to known species of Gymnopus s. str. reported with morpho-molecular evidence in China is also given. Full article

Introns are usually non-coding sequences interrupting open reading frames in pre-mRNAs [D1,2]. Stwintrons are nested spliceosomal introns, where an internal intron splits a second donor sequence into two consecutive splicing reactions leading to mature mRNA. In Hypoxylon sp. CO27-5, 36 highly sequence-similar [D1,2] stwintrons are extant (sister stwintrons). An additional 81 [D1,2] sequence-unrelated stwintrons are described here. Most of them are located at conserved gene positions rooted deep in the Hypoxylaceae. Absence of exonic sequence bias at the exon–stwintron junctions and a very similar phase distribution were noted for both groups. The presence of an underlying sequence symmetry in all 117 stwintrons was striking. This symmetry, more pronounced near the termini of most of the full-length sister stwintrons, may lead to a secondary structure that brings into close proximity the most distal splice sites, the donor of the internal and the acceptor of the external intron. The Hypoxylon stwintrons were overwhelmingly excised by consecutive splicing reactions precisely removing the whole intervening sequence, whereas one excision involving the distal splice sites led to a frameshift. Alternative (mis)splicing took place for both sister and uniquely occurring stwintrons. The extraordinary symmetry of the sister stwintrons thus seems dispensable for the infrequent, direct utilisation of the distal splice sites. Full article

Herein, silver nanoparticles (Ag-NPs) were synthesized using an environmentally friendly approach by harnessing the metabolites of Aspergillus niger F2. The successful formation of Ag-NPs was checked by a color change to yellowish-brown, followed by UV-Vis spectroscopy, Fourier transforms infrared (FT-IR), Transmission electron microscopy (TEM), and X-ray diffraction (XRD). Data showed the successful formation of crystalline Ag-NPs with a spherical shape at the maximum surface plasmon resonance of 420 nm with a size range of 3–13 nm. The Ag-NPs showed high toxicity against I, II, III, and IV instar larvae and pupae of Aedes aegypti with LC50 and LC90 values of 12.4–22.9 ppm and 22.4–41.4 ppm, respectively under laboratory conditions. The field assay exhibited the highest reduction in larval density due to treatment with Ag-NPs (10× LC50) with values of 59.6%, 74.7%, and 100% after 24, 48, and 72 h, respectively. The exposure of A. aegypti adults to the vapor of burning Ag-NPs-based coils caused a reduction of unfed individuals with a percentage of 81.6 ± 0.5% compared with the positive control, pyrethrin-based coils (86.1 ± 1.1%). The ovicidal activity of biosynthesized Ag-NPs caused the hatching of the eggs with percentages of 50.1 ± 0.9, 33.5 ± 1.1, 22.9 ± 1.1, and 13.7 ± 1.2% for concentrations of 5, 10, 15, and 20 ppm, whereas Ag-NPs at a concentration of 25 and 30 ppm caused complete egg mortality (100%). The obtained data confirmed the applicability of biosynthesized Ag-NPs to the biocontrol of A. aegypti at low concentrations. Full article

Concerns about fossil fuel depletion and the environmental effects of greenhouse gas emissions have led to widespread fermentation-based production of bioethanol from corn starch or sugarcane. However, competition for arable land with food production has led to the extensive investigation of lignocellulosic sources and waste products of the food industry as alternative sources of fermentable sugars. In particular, whey, a lactose-rich, inexpensive byproduct of dairy production, is available in stable, high quantities worldwide. This review summarizes strategies and specific factors essential for efficient lactose/whey fermentation to ethanol. In particular, we cover the most commonly used strains and approaches for developing high-performance strains that tolerate fermentation conditions. The relevant genes and regulatory systems controlling lactose utilization and sources of new genes are also discussed in detail. Moreover, this review covers the optimal conditions, various feedstocks that can be coupled with whey substrates, and enzyme supplements for increasing efficiency and yield. In addition to the historical advances in bioethanol production from whey, this review explores the future of yeast-based fermentation of lactose or whey products for beverage or fuel ethanol as a fertile research area for advanced, environmentally friendly uses of industrial waste products. Full article

The small GTPase Cdc42 acts as a molecular switch essential for cell cycles and polar growth in model yeast, but has not been explored in Beaurveria bassiana, an insect-pathogenic fungus serving as a main source of fungal formulations against arthropod pests. Here, we show the indispensability of Cdc42 for fungal insecticidal activity. Deletion of cdc42 in B. bassiana resulted in a great loss of virulence to Galleria mellonella, a model insect, via normal cuticle infection as well as defects in conidial germination, radial growth, aerial conidiation, and conidial tolerance to heat and UVB irradiation. The deleted mutant’s hyphae formed fewer or more septa and produced unicellular blastospores with disturbed cell cycles under submerged-culture conditions. Transcriptomic analysis revealed differential expression of 746 genes and dysregulation of pyruvate metabolism and related pathways, which were validated by marked changes in intracellular pyruvate content, ATP content, related enzyme activities, and in extracellular beauvericin content and Pr1 protease activity vital for fungal virulence. These findings uncover a novel role for Cdc42 in the pathways of pyruvate metabolism and the pyruvate-involved tricarboxylic acid cycle (TCA cycle) and a linkage of the novel role with its indispensability for the biological control potential of B. bassiana against arthropod pests. Full article

Cryptococcus spp. are human pathogens that cause 181,000 deaths per year. In this work, we systematically investigated the virulence attributes of Cryptococcus spp. clinical isolates and correlated them with patient data to better understand cryptococcosis. We collected 66 C. neoformans and 19 C. gattii clinical isolates and analyzed multiple virulence phenotypes and host–pathogen interaction outcomes. C. neoformans isolates tended to melanize faster and more intensely and produce thinner capsules in comparison with C. gattii. We also observed correlations that match previous studies, such as that between secreted laccase and disease outcome in patients. We measured Cryptococcus colony melanization kinetics, which followed a sigmoidal curve for most isolates, and showed that faster melanization correlated positively with LC3-associated phagocytosis evasion, virulence in Galleria mellonella and worse prognosis in humans. These results suggest that the speed of melanization, more than the total amount of melanin Cryptococcus spp. produces, is crucial for virulence. Full article

Psoroglaena humidosilvae Lee is described as a new lichen species from a wetland forest in South Korea. The new species is distinct from P. stigonemoides (Orange) Henssen by little projections locally present on the thallus; smaller, paler, and globose perithecia; smaller asci; and smaller ascospores generally 3-septate. Molecular analyses employing internal transcribed spacer (ITS), mitochondrial small subunit (mtSSU), and nuclear large subunit ribosomal RNA (LSU) sequences strongly support P. humidosilvae as a nonidentical species in the genus Psoroglaena. A surrogate key is provided to assist in the identification of all 22 species of Psoroglaena. Full article

The soil-borne vascular fungus Verticillium dahliae infects hundreds of dicotyledonous plants, causing severe wilt diseases. During the initial colonization, V. dahliae develops a penetration peg to enable infection of cotton roots. In some phytopathogenic fungi, vacuoles play a critical role in normal formation of the infection structure. Kinesin 2 protein is associated with vacuole formation in Ustilago maydis. To identify the function of vacuoles in the V. dahliae infection structure, we identified VdKin2, an ortholog of kinesin 2, in V. dahliae and investigated its function through gene knockout. VdKin2 mutants showed severe defects in virulence and were suppressed during initial infection and root colonization based on observation of green fluorescent protein-labeled V. dahliae. We also found that deletion of VdKin2 compromised penetration peg formation and the derived septin neck. Disruption strains were viable and showed normal microsclerotia formation, whereas mycelium growth and conidial production were reduced, with shorter and more branched hyphae. Furthermore, the VdKin2 mutant, unlike wild-type V. dahliae, lacked a large basal vacuole, accompanied by a failure to generate concentrated lipid droplets. Taken together, VdKin2 regulates vacuole formation by V. dahliae, which is required for conidiation, mycelium growth, and penetration structure formation during initial plant root infection. Full article

First reports of cases and case series of COVID-19-associated pulmonary aspergillosis (CAPA) emerged during the first months of the pandemic. Prevalence rates varied widely due to the fact that CAPA was, and still remains, challenging to diagnose in patients with COVID-19-associated acute respiratory failure (ARF). The clinical picture and radiological findings of CAPA are unspecific and can resemble those of severe COVID-19. Hence, mycological evidence became a key component in establishing a diagnosis. However, blood tests lack sensitivity in early treatable phases of CAPA and once positive, mortality has been shown to exceed 80% despite systemic antifungal therapy. The primarily airway invasive growth in non-neutropenic patients and the late occurrence of angioinvasion in the course of disease may mainly account for these diagnostic obstacles. Testing of bronchoalveolar lavage (BAL) is therefore crucial in the diagnostic process, but was rarely performed during the early phase of the pandemic, which potentially interfered with the accuracy of reported prevalence. Current guidelines recommend treatment of CAPA during its early airway invasive phase, which may result in some overtreatment (i.e., treatment in patients that may not develop angioinvasive infection) and adverse drug events, yet there is no viable alternative approach. Timely treatment of cases needs to be ensured for patients with mycological evidence of CAPA in the lower respiratory tract given the independent contribution of CAPA to devastating mortality rates of around 50% that have been shown in multiple studies. Here, we review the evolution of reported CAPA prevalence and the role of CAPA as an important opportunistic infection affecting COVID-19 patients in intensive care units (ICUs). Full article

Fungi in the Entomophthorales order can cause insect disease and epizootics in nature, contributing to biological pest control in agriculture and forestry. Most Entomophthorales have narrow host ranges, limited to the arthropod family level; however, rare genomic information about host-specific fungi has been reported. Conidiation is crucial for entomopathogenic fungi to explore insect resources owing to the important roles of conidia in the infection cycle, such as dispersal, adhesion, germination, and penetration into the host hemocoel. In this study, we analyzed the whole genome sequence of the aphid-obligate pathogen Conidiobolus obscurus strain ARSEF 7217 (Entomophthoromycotina), using Nanopore technology from Biomarker Technologies (Beijing, China). The genome size was 37.6 Mb, and encoded 10,262 predicted genes, wherein 21.3% genes were putatively associated to the pathogen–host interaction. In particular, the serine protease repertoire in C. obscurus exhibited expansions in the trypsin and subtilisin classes, which play vital roles in the fungus’ pathogenicity. Differentially expressed transcriptomic patterns were analyzed in three conidiation stages (pre-conidiation, emerging conidiation, and post-conidiation), and 2915 differentially expressed genes were found to be associated with the conidiation process. Furthermore, a weighted gene co-expression network analysis showed that 772 hub genes in conidiation are mainly involved in insect cuticular component degradation, cell wall/membrane biosynthesis, MAPK signaling pathway, and transcription regulation. Our findings of the genomic and transcriptomic features of C. obscurus help reveal the molecular mechanism of the Entomophthorales pathogenicity, which will contribute to improving fungal applications in pest control. Full article

A major citrus postharvest pathogen, Penicillium italicum (P. italicum), causes substantial economic losses in citrus. In this study, a citral nanoemulsion containing polymethoxylated flavonoids (PMFs), the antimicrobial compounds from citrus, was prepared. The antifungal activity and potential antifungal mechanisms of the nanoemulsion against P. italicum were evaluated. The results showed that the growth of P. italicum was effectively inhibited by the nanoemulsion, with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 62.5 and 250 mg L⁻¹, respectively. The nanoemulsion significantly inhibited spore germination and mycelial growth, and it altered the morphology of P. italicum. In addition, the permeability of the cell membrane increased with increasing nanoemulsion concentrations, as evidenced by a rapid rise in extracellular electric conductivity and stronger red fluorescence from mycelia (propidium iodide staining). Compared with the control, the nanoemulsion treatment induced a decrease in total lipid and ergosterol contents in P. italicum cells by 64.61% and 60.58%, respectively, demonstrating that membrane integrity had been disrupted. The results indicated that the PMFs-loaded nanoemulsion exerted antifungal activity against P. italicum by disrupting cell membrane integrity and permeability; such a nanoemulsion may be used as a potential fungicide substitute for preservation in citrus fruits. Full article

Invasive Fusarium species infections in immunocompromised patients occur predominantly in those with hematological malignancies. Survival rates of 20–40% were reported in adults, but data in children are limited. Our retrospective, nationwide multicenter study of invasive fusariosis in pediatric hematology/oncology and stem cell transplant (SCT) patients identified twenty-two cases. Underlying conditions included hematological malignancies (n = 16; 73%), solid tumors (n = 2), and non-malignant hematological conditions (n = 4). Nineteen patients (86%) were neutropenic, nine (41%) were SCT recipients, and seven (32%) received corticosteroids. Sixteen patients (73%) had disseminated fusariosis, five had local infection, and one had isolated fungemia. Fifteen patients (68%) had skin involvement and eight (36%) had a bloodstream infection. Four patients (18%) presented with osteoarticular involvement and four with pulmonary involvement. Nineteen patients (86%) received combination antifungal therapy upfront and three (14%) received single-agent treatment. Ninety-day probability of survival was 77%: four of the five deaths were attributed to fusariosis, all in patients with relapsed/refractory acute leukemias. Ninety-day probability of survival for patients with relapsed/refractory underlying malignancy was 33% vs. 94% in others (p < 0.001). Survival rates in this largest pediatric population-based study were strikingly higher than those reported in adults, demonstrating that invasive fusariosis is a life-threatening but salvageable condition in immunosuppressed children. Full article

Candidiasis may affect the central nervous system (CNS), and although Candida albicans is predominant, non-albicans Candida species can also be associated with CNS infections. Some studies have suggested that Candida infections could increase the odds of multiple sclerosis (MS) development. In this context, we investigated whether systemic infection by non-albicans Candida species would affect, clinically or immunologically, the severity of experimental autoimmune encephalomyelitis (EAE), which is an animal model used to study MS. For this, a strain of C. glabrata, C. krusei, and C. parapsilosis was selected and characterized using different in vitro and in vivo models. In these analysis, all the strains exhibited the ability to form biofilms, produce proteolytic enzymes, and cause systemic infections in Galleria mellonella, with C. glabrata being the most virulent species. Next, C57BL/6 mice were infected with strains of C. glabrata, C. krusei, or C. parapsilosis, and 3 days later were immunized with myelin oligodendrocyte glycoprotein to develop EAE. Mice from EAE groups previously infected with C. glabrata and C. krusei developed more severe and more prevalent paralysis, while mice from the EAE group infected with C. parapsilosis developed a disease comparable to non-infected EAE mice. Disease aggravation by C. glabrata and C. krusei strains was concomitant to increased IL-17 and IFN-γ production by splenic cells stimulated with fungi-derived antigens and with increased percentage of T lymphocytes and myeloid cells in the CNS. Analysis of interaction with BV-2 microglial cell line also revealed differences among these strains, in which C. krusei was the strongest activator of microglia concerning the expression of MHC II and CD40 and pro-inflammatory cytokine production. Altogether, these results indicated that the three non-albicans Candida strains were similarly able to reach the CNS but distinct in terms of their effect over EAE development. Whereas C. glabrata and C. Krusei aggravated the development of EAE, C. parapsilosis did not affect its severity. Disease worsening was partially associated to virulence factors in C. glabrata and to a strong activation of microglia in C. krusei infection. In conclusion, systemic infections by non-albicans Candida strains exerted influence on the experimental autoimmune encephalomyelitis in both immunological and clinical aspects, emphasizing their possible relevance in MS development. Full article