Journal of Fungi

15 pages, 2261 KiB

Open AccessArticle

Peel Diffusion and Antifungal Efficacy of Different Fungicides in Pear Fruit: Structure-Diffusion-Activity Relationships

by Gui-Yang Zhu, Ying Chen, Su-Yan Wang, Xin-Chi Shi, Daniela D. Herrera-Balandrano, Victor Polo and Pedro Laborda

J. Fungi 2022, 8(5), 547; https://doi.org/10.3390/jof8050547 - 23 May 2022

Cited by 13 | Viewed by 2553

Abstract

Fungal pathogens can invade not only the fruit peel but also the outer part of the fruit mesocarp, limiting the efficacy of fungicides. In this study, the relationships between fungicide structure, diffusion capacity and in vivo efficacy were evaluated for the first time. [...] Read more.

Fungal pathogens can invade not only the fruit peel but also the outer part of the fruit mesocarp, limiting the efficacy of fungicides. In this study, the relationships between fungicide structure, diffusion capacity and in vivo efficacy were evaluated for the first time. The diffusion capacity from pear peel to mesocarp of 11 antifungal compounds, including p-aminobenzoic acid, carbendazim, difenoconazole, dipicolinic acid, flusilazole, gentamicin, kojic acid, prochloraz, quinolinic acid, thiophanate methyl and thiram was screened. The obtained results indicated that size and especially polarity were negatively correlated with the diffusion capacity. Although some antifungal compounds, such as prochloraz and carbendazim, were completely degraded after a few days in peel and mesocarp, other compounds, such as p-aminobenzoic acid and kojic acid, showed high stability. When applying the antifungal compounds at the EC₅₀ concentrations, it was observed that the compounds with high diffusion capacity showed higher in vivo antifungal activity against Alternaria alternata than compounds with low diffusion capacity. In contrast, there was no relationship between stability and in vivo efficacy. Collectively, the obtained results indicated that the diffusion capacity plays an important role in the efficacy of fungicides for the control of pear fruit diseases. Full article

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

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8 pages, 435 KiB

Open AccessArticle

Effect of Household Laundering, Heat Drying, and Freezing on the Survival of Dermatophyte Conidia

by Mohammad Akhoundi, Jade Nasrallah, Anthony Marteau, Dahlia Chebbah, Arezki Izri and Sophie Brun

J. Fungi 2022, 8(5), 546; https://doi.org/10.3390/jof8050546 - 23 May 2022

Cited by 8 | Viewed by 3584

Abstract

Dermatomycoses are one of the most common dermatological infectious diseases. Dermatophytoses, such as tinea pedis (athlete’s foot) in adults and tinea capitis in children, are the most prevalent fungal diseases caused by dermatophytes. The transmission of anthropophilic dermatophytoses occurs almost exclusively through indirect [...] Read more.

Dermatomycoses are one of the most common dermatological infectious diseases. Dermatophytoses, such as tinea pedis (athlete’s foot) in adults and tinea capitis in children, are the most prevalent fungal diseases caused by dermatophytes. The transmission of anthropophilic dermatophytoses occurs almost exclusively through indirect contact with patient-contaminated belongings or environments and, subsequently, facilitates the spread of the infection to others. Hygienic measures were demonstrated to have an important role in removing or reducing the fungal burden. Herein, we evaluated the effectiveness of physical-based methods of laundering, heat drying, and freezing in the elimination of Trichophyton tonsurans, T. rubrum, and T. interdigitale conidia in diverse temperatures and time spectra. Based on our findings, laundering at 60 °C was effective for removing the dermatophyte conidia from contaminated linens. On the contrary, heat drying using domestic or laundromat machines; freezing at −20 °C for 24 h, 48 h, or one week; and direct heat exposure at 60 °C for 10, 30, or 90 min were unable to kill the dermatophytes. These results can be helpful for clinicians, staff of children’s communities, and hygiene practitioners for implementing control management strategies against dermatophytoses caused by mentioned dermatophyte species. Full article

(This article belongs to the Special Issue Epidemiology and Pathogenesis of Dermatophytes)

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17 pages, 1803 KiB

Open AccessArticle

Exposure to Essential and Toxic Elements via Consumption of Agaricaceae, Amanitaceae, Boletaceae, and Russulaceae Mushrooms from Southern Spain and Northern Morocco

by Marta Barea-Sepúlveda, Estrella Espada-Bellido, Marta Ferreiro-González, Hassan Bouziane, José Gerardo López-Castillo, Miguel Palma and Gerardo F. Barbero

J. Fungi 2022, 8(5), 545; https://doi.org/10.3390/jof8050545 - 23 May 2022

Cited by 11 | Viewed by 2741

Abstract

The demand and interest in mushrooms, both cultivated and wild, has increased among consumers in recent years due to a better understanding of the benefits of this food. However, the ability of wild edible mushrooms to accumulate essential and toxic elements is well [...] Read more.

The demand and interest in mushrooms, both cultivated and wild, has increased among consumers in recent years due to a better understanding of the benefits of this food. However, the ability of wild edible mushrooms to accumulate essential and toxic elements is well documented. In this study, a total of eight metallic elements and metalloids (chromium (Cr), arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb), copper (Cu), zinc (Zn), and selenium (Se)) were determined by ICP-MS in five wild edible mushroom species (Agaricus silvicola, Amanita caesarea, Boletus aereus, Boletus edulis, and Russula cyanoxantha) collected in southern Spain and northern Morocco. Overall, Zn was found to be the predominant element among the studied species, followed by Cu and Se. The multivariate analysis suggested that considerable differences exist in the uptake of the essential and toxic elements determined, linked to species-intrinsic factors. Furthermore, the highest Estimated Daily Intake of Metals (EDIM) values obtained were observed for Zn. The Health Risk Index (HRI) assessment for all the mushroom species studied showed a Hg-related cause of concern due to the frequent consumption of around 300 g of fresh mushrooms per day during the mushrooming season. Full article

(This article belongs to the Special Issue Heavy Metals in Mushrooms)

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19 pages, 782 KiB

Open AccessArticle

In Vitro Characterization and Identification of Potential Probiotic Yeasts Isolated from Fermented Dairy and Non-Dairy Food Products

by Nadia S. Alkalbani, Tareq M. Osaili, Anas A. Al-Nabulsi, Reyad S. Obaid, Amin N. Olaimat, Shao-Quan Liu and Mutamed M. Ayyash

J. Fungi 2022, 8(5), 544; https://doi.org/10.3390/jof8050544 - 23 May 2022

Cited by 13 | Viewed by 3654

Abstract

This study is about the isolation of yeast from fermented dairy and non-dairy products as well as the characterization of their survival in in vitro digestion conditions and tolerance to bile salts. Promising strains were selected to further investigate their probiotic properties, including [...] Read more.

This study is about the isolation of yeast from fermented dairy and non-dairy products as well as the characterization of their survival in in vitro digestion conditions and tolerance to bile salts. Promising strains were selected to further investigate their probiotic properties, including cell surface properties (autoaggregation, hydrophobicity and coaggregation), physiological properties (adhesion to the HT-29 cell line and cholesterol lowering), antimicrobial activities, bile salt hydrolysis, exopolysaccharide (EPS) producing capability, heat resistance and resistance to six antibiotics. The selected yeast isolates demonstrated remarkable survivability in an acidic environment. The reduction caused by in vitro digestion conditions ranged from 0.7 to 2.1 Log₁₀. Bile salt tolerance increased with the extension in the incubation period, which ranged from 69.2% to 91.1% after 24 h. The ability of the 12 selected isolates to remove cholesterol varied from 41.6% to 96.5%, and all yeast strains exhibited a capability to hydrolyse screened bile salts. All the selected isolates exhibited heat resistance, hydrophobicity, strong coaggregation, autoaggregation after 24 h, robust antimicrobial activity and EPS production. The ability to adhere to the HT-29 cell line was within an average of 6.3 Log₁₀ CFU/mL after 2 h. Based on ITS/5.8S ribosomal DNA sequencing, 12 yeast isolates were identified as 1 strain for each Candidaalbicans and Saccharomyces cerevisiae and 10 strains for Pichia kudriavzevii. Full article

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10 pages, 1464 KiB

Open AccessArticle

Cytochalasans from the Endophytic Fungus Phomopsis sp. shj2 and Their Antimigratory Activities

by Bing-Chao Yan, Wei-Guang Wang, Ling-Mei Kong, Jian-Wei Tang, Xue Du, Yan Li and Pema-Tenzin Puno

J. Fungi 2022, 8(5), 543; https://doi.org/10.3390/jof8050543 - 23 May 2022

Cited by 4 | Viewed by 2194

Abstract

Cytochalasans from the endophytic fungi featured structure diversity. Our previous study has disclosed that cytochalasans from the endophytic fungus Phomopsis sp. shj2 exhibited an antimigratory effect. Further chemical investigation on Phomopsis sp. shj2 has led to the discovery of seven new cytochalasans ( [...] Read more.

Cytochalasans from the endophytic fungi featured structure diversity. Our previous study has disclosed that cytochalasans from the endophytic fungus Phomopsis sp. shj2 exhibited an antimigratory effect. Further chemical investigation on Phomopsis sp. shj2 has led to the discovery of seven new cytochalasans (1–7), together with four known ones. Their structures were elucidated through extensive spectroscopic data interpretation and single-crystal X-ray diffraction analysis. Compounds 1–3 and 8–11 exhibited antimigratory effects against MDA-MB-231 in vitro with IC₅₀ values in the range of 1.01−10.42 μM. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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16 pages, 1580 KiB

Open AccessArticle

Co-Occurrence Patterns of Ustilago nuda and Pyrenophora graminea and Fungicide Contribution to Yield Gain in Barley under Fluctuating Climatic Conditions in Serbia

by Radivoje Jevtić, Vesna Župunski, Mirjana Lalošević, Ljiljana Brbaklić and Branka Orbović

J. Fungi 2022, 8(5), 542; https://doi.org/10.3390/jof8050542 - 23 May 2022

Cited by 1 | Viewed by 2104

Abstract

The utilization of production systems with reduced chemical input renewed the interest in Ustilago nuda and Pyrenophora graminea. The investigations of seed fungicide treatments are more related to their efficacy than to their contribution to yield gain. The data were collected from [...] Read more.

The utilization of production systems with reduced chemical input renewed the interest in Ustilago nuda and Pyrenophora graminea. The investigations of seed fungicide treatments are more related to their efficacy than to their contribution to yield gain. The data were collected from research and development trials on fungicide efficacy against U. nuda and P. graminea conducted from 2014 to 2020 in Serbia. Partial least squares, multiple stepwise regression and best subset regression were used for statistical modeling. The total number of plants infected with U. nuda and P. graminea per plot differed significantly in the seven-year period. Shifts in the predominance of one pathogen over the other were also shown. Temperature, total rainfall and relative humidity in flowering time (p < 0.001) influenced the occurrence of both pathogens. The strongest impact on yield loss was observed for temperature in the phenological phases of leaf development (p = 0.014), temperature in flowering time (p < 0.001) and total number of plants infected with U. nuda and P. graminea per plot (p < 0.001). Our results indicated that regression models consisting of both biotic and abiotic factors were more precise in estimating regression coefficients. Neither fungicidal treatment had a stable contribution to yield gain in the seven-year period. Full article

(This article belongs to the Special Issue Plant Fungal Pathogenesis 2022)

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13 pages, 764 KiB

Open AccessArticle

Association between Following the ESCMID Guidelines for the Management of Candidemia and Mortality: A Retrospective Cohort Study

by Charles Maurille, Julie Bonhomme, Anaïs R. Briant, Jean-Jacques Parienti, Renaud Verdon and Anna Lucie Fournier

J. Fungi 2022, 8(5), 541; https://doi.org/10.3390/jof8050541 - 23 May 2022

Cited by 4 | Viewed by 2482

Abstract

Objectives: The objective of this study was to evaluate the association between ESCMID adherence and 30-day mortality in candidemia. Methods: We performed a retrospective cohort study in two French tertiary-care hospitals. All patients with at least one positive blood culture (BC) for Candida [...] Read more.

Objectives: The objective of this study was to evaluate the association between ESCMID adherence and 30-day mortality in candidemia. Methods: We performed a retrospective cohort study in two French tertiary-care hospitals. All patients with at least one positive blood culture (BC) for Candida spp. between January 2013 and December 2019 were included. An adherent case was defined as a candidemia case for which the treatment fulfilled a bundle of defined criteria based on the latest ESCMID recommendations. We explored factors associated with adherence to ESCMID recommendations in an unadjusted model, and we used a propensity score method to address potential channeling biases with regard to 30-day mortality. Results: During the study period, 165 cases of candidemia were included. Among the ESCMID criteria, funduscopic examination was not performed in 45% and neither was echocardiography in 31%, while the ESCMID criteria were fully implemented in 44 cases (27%). In the propensity score analysis, the all-cause 30-day mortality rate was significantly lower among adherent cases (3.4/36.6, 9%) than among nonadherent cases (42.4/119.5, 36%) (OR = 5.3 95% CI [1.6–17.1]). Conclusions: In our study, adherence to the bundle of criteria for candidemia management was associated with increased survival, supporting additional efforts to implement these recommendations. Full article

(This article belongs to the Topic Infectious Diseases)

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13 pages, 3792 KiB

Open AccessReview

Molecular Genetics of Anthracnose Resistance in Maize

by Wendi Ma, Xinying Gao, Tongling Han, Magaji Tukur Mohammed, Jun Yang, Junqiang Ding, Wensheng Zhao, You-Liang Peng and Vijai Bhadauria

J. Fungi 2022, 8(5), 540; https://doi.org/10.3390/jof8050540 - 23 May 2022

Cited by 7 | Viewed by 3426

Abstract

Maize (Zea mays), also called corn, is one of the top three staple food crops worldwide and is also utilized as feed (e.g., feed grain and silage) and a source of biofuel (e.g., bioethanol). Maize production is hampered by a myriad [...] Read more.

Maize (Zea mays), also called corn, is one of the top three staple food crops worldwide and is also utilized as feed (e.g., feed grain and silage) and a source of biofuel (e.g., bioethanol). Maize production is hampered by a myriad of factors, including although not limited to fungal diseases, which reduce grain yield and downgrade kernel quality. One such disease is anthracnose leaf blight and stalk rot (ALB and ASR) caused by the hemibiotrophic fungal pathogen Colletotrichum graminicola. The pathogen deploys a biphasic infection strategy to colonize susceptible maize genotypes, comprising latent (symptomless) biotrophic and destructive (symptomatic) necrotrophic phases. However, the resistant maize genotypes restrict the C. graminicola infection and in planta fungal proliferation during the biotrophic phase of the infection. Some studies on the inheritance of ASR resistance in the populations derived from biparental resistant and susceptible genotypes reveal that anthracnose is likely a gene-for-gene disease in which the resistant maize genotypes and C. graminicola recognize each other by their matching pairs of nucleotide-binding leucine-rich repeat resistance (NLR) proteins (whose coding genes are localized in disease QTL) and effectors (1–2 effectors/NLR) during the biotrophic phase of infection. The Z. mays genome encodes approximately 144 NLRs, two of which, RCg1 and RCg1b, located on chromosome 4, were cloned and functionally validated for their role in ASR resistance. Here, we discuss the genetic architecture of anthracnose resistance in the resistant maize genotypes, i.e., disease QTL and underlying resistance genes. In addition, this review also highlights the disease cycle of C. graminicola and molecular factors (e.g., virulence/pathogenicity factors such as effectors and secondary metabolites) that contribute to the pathogen’s virulence on maize. A detailed understanding of molecular genetics underlying the maize—C. graminicola interaction will help devise effective management strategies against ALB and ASR. Full article

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

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12 pages, 3748 KiB

Open AccessArticle

Physiological Response of Saccharomyces cerevisiae to Silver Stress

by Janelle R. Robinson, Omoanghe S. Isikhuemhen, Felicia N. Anike and Kiran Subedi

J. Fungi 2022, 8(5), 539; https://doi.org/10.3390/jof8050539 - 22 May 2022

Cited by 1 | Viewed by 2526

Abstract

Silver nanoparticle (AgNP) production and their use as antimicrobial agents is a current area of active research. Biosynthesis is the most sustainable production method, and fungi have become candidates of interest in AgNP production. However, investigations into the physiological responses of fungi due [...] Read more.

Silver nanoparticle (AgNP) production and their use as antimicrobial agents is a current area of active research. Biosynthesis is the most sustainable production method, and fungi have become candidates of interest in AgNP production. However, investigations into the physiological responses of fungi due to silver exposure are scanty. This present work utilized two strains of Saccharomyces cerevisiae (one used in commercial fermentation and a naturally occurring strain) to determine the physiological consequences of their transient exposure to AgNO₃. The assessments were based on studies involving growth curves, minimal inhibitory concentration assays, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging, and inductively coupled plasma optical emission spectroscopy (ICP-OES). Results indicated (a) the capability of S. cerevisiae to produce silver nanoparticles, even at elevated levels of exposure; (b) strain origin had no significant impact on S. cerevisiae physiological response to AgNO₃; and (c) coexposure to copper and silver significantly increased intracellular copper, silver, and calcium in treated yeast cells. In addition, electron microscopy and ICP-OES results revealed that both strains internalized silver after exposure, resulting in the shrunken and distorted physical appearance visible on SEM micrographs of treated cells. Though a promising candidate for AgNPs biosynthesis, this study analyzed the effects of transient silver exposure on S. cerevisiae growth physiology and morphology. Full article

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

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17 pages, 3240 KiB

Open AccessArticle

Spontaneous Suppressors against Debilitating Transmembrane Mutants of CaMdr1 Disclose Novel Interdomain Communication via Signature Motifs of the Major Facilitator Superfamily

by Suman Sharma, Atanu Banerjee, Alexis Moreno, Archana Kumari Redhu, Pierre Falson and Rajendra Prasad

J. Fungi 2022, 8(5), 538; https://doi.org/10.3390/jof8050538 - 22 May 2022

Viewed by 2004

Abstract

The Major Facilitator Superfamily (MFS) drug:H⁺ antiporter CaMdr1, from Candida albicans, is responsible for the efflux of structurally diverse antifungals. MFS members share a common fold of 12–14 transmembrane helices (TMHs) forming two N- and C-domains. Each domain is arranged [...] Read more.

The Major Facilitator Superfamily (MFS) drug:H⁺ antiporter CaMdr1, from Candida albicans, is responsible for the efflux of structurally diverse antifungals. MFS members share a common fold of 12–14 transmembrane helices (TMHs) forming two N- and C-domains. Each domain is arranged in a pseudo-symmetric fold of two tandems of 3-TMHs that alternatively expose the drug-binding site towards the inside or the outside of the yeast to promote drug binding and release. MFS proteins show great diversity in primary structure and few conserved signature motifs, each thought to have a common function in the superfamily, although not yet clearly established. Here, we provide new information on these motifs by having screened a library of 64 drug transport-deficient mutants and their corresponding suppressors spontaneously addressing the deficiency. We found that five strains recovered the drug-resistance capacity by expressing CaMdr1 with a secondary mutation. The pairs of debilitating/rescuing residues are distributed either in the same TMH (T127A_TMH1- > G140D_TMH1) or 3-TMHs repeat (F216A_TMH4- > G260A_TMH5), at the hinge of 3-TMHs repeats tandems (R184A_TMH3- > D235H_TMH4, L480A_TMH10- > A435T_TMH9), and finally between the N- and C-domains (G230A_TMH4- > P528H_TMH12). Remarkably, most of these mutants belong to the different signature motifs, highlighting a mechanistic role and interplay thought to be conserved among MFS proteins. Results also point to the specific role of TMH11 in the interplay between the N- and C-domains in the inward- to outward-open conformational transition. Full article

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

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30 pages, 2519 KiB

Open AccessReview

Saprolegniosis in Amphibians: An Integrated Overview of a Fluffy Killer Disease

by Sara Costa and Isabel Lopes

J. Fungi 2022, 8(5), 537; https://doi.org/10.3390/jof8050537 - 22 May 2022

Cited by 4 | Viewed by 4127

Abstract

Amphibians constitute the class of vertebrates with the highest proportion of threatened species, with infectious diseases being considered among the greatest causes for their worldwide decline. Aquatic oomycetes, known as “water molds”, are fungus-like microorganisms that are ubiquitous in freshwater ecosystems and are [...] Read more.

Amphibians constitute the class of vertebrates with the highest proportion of threatened species, with infectious diseases being considered among the greatest causes for their worldwide decline. Aquatic oomycetes, known as “water molds”, are fungus-like microorganisms that are ubiquitous in freshwater ecosystems and are capable of causing disease in a broad range of amphibian hosts. Various species of Achlya sp., Leptolegnia sp., Aphanomyces sp., and mainly, Saprolegnia sp., are responsible for mass die-offs in the early developmental stages of a wide range of amphibian populations through a disease known as saprolegniosis, aka, molding or a “Saprolegnia-like infection”. In this context, the main objective of the present review was to bring together updated information about saprolegniosis in amphibians to integrate existing knowledge, identify current knowledge gaps, and suggest future directions within the saprolegniosis–amphibian research field. Based on the available literature and data, an integrated and critical interpretation of the results is discussed. Furthermore, the occurrence of saprolegniosis in natural and laboratory contexts and the factors that influence both pathogen incidence and host susceptibility are also addressed. The focus of this work was the species Saprolegnia sp., due to its ecological importance on amphibian population dynamics and due to the fact that this is the most reported genera to be associated with saprolegniosis in amphibians. In addition, integrated emerging therapies, and their potential application to treat saprolegniosis in amphibians, were evaluated, and future actions are suggested. Full article

(This article belongs to the Special Issue Epidemic Mycoses Devastating Wild Animal Populations)

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11 pages, 1853 KiB

Open AccessArticle

Pulmonary Sporotrichosis Caused by Sporothrix brasiliensis: A 22-Year, Single-Center, Retrospective Cohort Study

by Vivian Fichman, Caroline Graça Mota-Damasceno, Anna Carolina Procópio-Azevedo, Fernando Almeida-Silva, Priscila Marques de Macedo, Denise Machado Medeiros, Guis Saint-Martin Astacio, Rosely Maria Zancopé-Oliveira, Rodrigo Almeida-Paes, Dayvison Francis Saraiva Freitas and Maria Clara Gutierrez-Galhardo

J. Fungi 2022, 8(5), 536; https://doi.org/10.3390/jof8050536 - 21 May 2022

Cited by 11 | Viewed by 3203

Abstract

Pulmonary sporotrichosis is a rare condition. It can present as a primary pulmonary disease, resulting from direct Sporothrix species (spp). conidia inhalation, or as part of multifocal sporotrichosis with multiple organ involvement, mainly in immunocompromised patients. This study aimed to describe the sociodemographic [...] Read more.

Pulmonary sporotrichosis is a rare condition. It can present as a primary pulmonary disease, resulting from direct Sporothrix species (spp). conidia inhalation, or as part of multifocal sporotrichosis with multiple organ involvement, mainly in immunocompromised patients. This study aimed to describe the sociodemographic and epidemiological characteristics and clinical course of patients with positive cultures for Sporothrix spp. from pulmonary specimens (sputum and/or bronchoalveolar lavage) at a reference center in an area hyperendemic for zoonotic sporotrichosis. The clinical records of these patients were reviewed. Fourteen patients were included, and Sporothrix brasiliensis was identified in all cases. Disseminated sporotrichosis was the clinical presentation in 92.9% of cases, and primary pulmonary sporotrichosis accounted for 7.1%. Comorbidities included human immunodeficiency virus infection (78.6%), alcoholism (71.4%), and chronic obstructive pulmonary disease (14.3%). Treatment with amphotericin B followed by itraconazole was the preferred regimen and was prescribed in 92.9% of cases. Sporotrichosis-related death occurred in 42.9% while 35.7% of patients were cured. In five cases there was a probable contamination from upper airway lesions. Despite the significant increase in sporotrichosis cases, pulmonary sporotrichosis remains rare. The treatment of disseminated sporotrichosis is typically difficult. Prompt diagnosis and identification of all affected organs are crucial for better prognosis. Full article

(This article belongs to the Special Issue Sporothrix and Sporotrichosis 2.0)

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18 pages, 2794 KiB

Open AccessArticle

Efficacy of Inhaled N-Chlorotaurine in a Mouse Model of Lichtheimia corymbifera and Aspergillus fumigatus Pneumonia

by Cornelia Speth, Günter Rambach, Andrea Windisch, Magdalena Neurauter, Hans Maier and Markus Nagl

J. Fungi 2022, 8(5), 535; https://doi.org/10.3390/jof8050535 - 20 May 2022

Cited by 3 | Viewed by 2249

Abstract

N-chlorotaurine (NCT) can be used topically as a well-tolerated anti-infective at different body sites. The aim of this study was to investigate the efficacy of inhaled NCT in a mouse model of fungal pneumonia. Specific pathogen-free female C57BL/6JRj seven-week-old mice were immune-suppressed with [...] Read more.

N-chlorotaurine (NCT) can be used topically as a well-tolerated anti-infective at different body sites. The aim of this study was to investigate the efficacy of inhaled NCT in a mouse model of fungal pneumonia. Specific pathogen-free female C57BL/6JRj seven-week-old mice were immune-suppressed with cyclophosphamide. After 4 days, the mice were inoculated intranasally with 1.5 × 10E7 spores of Lichtheimia corymbifera or 1.0 × 10E7 spores of Aspergillus fumigatus. They were randomized and treated three times daily for 10 min with aerosolized 1% NCT or 0.9% sodium chloride starting 1 h after the inoculation. The mice were observed for survival for two weeks, and fungal load, blood inflammation parameters, bronchoalveolar lavage, and histology of organs were evaluated upon their death or at the end of this period. Inhalations were well-tolerated. After challenge with L. corymbifera, seven out of the nine mice (77.8%) survived for 15 days in the test group, which was in strong contrast to one out of the nine mice (11.1%) in the control group (p = 0.0049). The count of colony-forming units in the homogenized lung tissues came to 1.60 (1.30; 1.99; median, quartiles) log₁₀ in the test group and to 4.26 (2.17; 4.53) log₁₀ in the control group (p = 0.0032). Body weight and temperature, white blood count, and haptoglobin significantly improved with NCT treatment. With A. fumigatus, all the mice except for one in the test group died within 4 days without a significant difference from the control group. Inhaled NCT applied early demonstrated a highly significant curative effect in L. corymbifera pneumonia, while this could not be shown in A. fumigatus pneumonia, probably due to a too high inoculum. Nevertheless, this study for the first time disclosed efficacy of NCT in pneumonia in vivo. Full article

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

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14 pages, 2974 KiB

Open AccessArticle

MAPK CcSakA of the HOG Pathway Is Involved in Stipe Elongation during Fruiting Body Development in Coprinopsis cinerea

by Jing Zhao, Jing Yuan, Yating Chen, Yu Wang, Jing Chen, Jingjing Bi, Linna Lyu, Cigang Yu, Sheng Yuan and Zhonghua Liu

J. Fungi 2022, 8(5), 534; https://doi.org/10.3390/jof8050534 - 20 May 2022

Cited by 5 | Viewed by 2167

Abstract

Mitogen-activated protein kinase (MAPK) pathways, such as the high-osmolarity glycerol mitogen-activated protein kinase (HOG) pathway, are evolutionarily conserved signaling modules responsible for transmitting environmental stress signals in eukaryotic organisms. Here, we identified the MAPK homologue in the HOG pathway of Coprinopsis cinerea, which [...] Read more.

Mitogen-activated protein kinase (MAPK) pathways, such as the high-osmolarity glycerol mitogen-activated protein kinase (HOG) pathway, are evolutionarily conserved signaling modules responsible for transmitting environmental stress signals in eukaryotic organisms. Here, we identified the MAPK homologue in the HOG pathway of Coprinopsis cinerea, which was named CcSakA. Furthermore, during the development of the fruiting body, CcSakA was phosphorylated in the fast elongating apical part of the stipe, which meant that CcSakA was activated in the apical elongating stipe region of the fruiting body. The knockdown of CcSakA resulted in a shorter stipe of the fruiting body compared to the control strain, and the expression of phosphomimicking mutant CcSakA led to a longer stipe of the fruiting body compared to the control strain. The chitinase CcChiE1, which plays a key role during stipe elongation, was downregulated in the CcSakA knockdown strains and upregulated in the CcSakA phosphomimicking mutant strains. The results indicated that CcSakA participated in the elongation of stipes in the fruiting body development of C. cinerea by regulating the expression of CcChiE1. Analysis of the H₂O₂ concentration in different parts of the stipe showed that the oxidative stress in the elongating part of the stipe was higher than those in the non-elongating part. The results indicated that CcSakA of the HOG pathway may be activated by oxidative stress. Our results demonstrated that the HOG pathway transmits stress signals and regulates the expression of CcChiE1 during fruiting body development in C. cinerea. Full article

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

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12 pages, 671 KiB

Open AccessArticle

CYP51 Mutations in the Fusarium solani Species Complex: First Clue to Understand the Low Susceptibility to Azoles of the Genus Fusarium

by Pierre Vermeulen, Arnaud Gruez, Anne-Lyse Babin, Jean-Pol Frippiat, Marie Machouart and Anne Debourgogne

J. Fungi 2022, 8(5), 533; https://doi.org/10.3390/jof8050533 - 20 May 2022

Cited by 6 | Viewed by 2653

Abstract

Members of Fusarium solani species complex (FSSC) are cosmopolitan filamentous fungi responsible for invasive fungal infections in immunocompromised patients. Despite the treatment recommendations, many strains show reduced sensitivity to voriconazole. The objective of this work was to investigate the potential relationship between azole [...] Read more.

Members of Fusarium solani species complex (FSSC) are cosmopolitan filamentous fungi responsible for invasive fungal infections in immunocompromised patients. Despite the treatment recommendations, many strains show reduced sensitivity to voriconazole. The objective of this work was to investigate the potential relationship between azole susceptibility and mutations in CYP51 protein sequences. Minimal inhibitory concentrations (MICs) for azole antifungals have been determined using the CLSI (Clinical and Laboratory Standards Institute) microdilution method on a panel of clinical and environmental strains. CYP51A, CYP51B and CYP51C genes for each strain have been sequenced using the Sanger method. Amino acid substitutions described in multiple azole-resistant Aspergillus fumigatus (mtrAf) strains have been sought and compared with other Fusarium complexes’ strains. Our results show that FSSC exhibit point mutations similar to those described in mtrAf. Protein sequence alignments of CYP51A, CYP51B and CYP51C have highlighted different profiles based on sequence similarity. A link between voriconazole MICs and protein sequences was observed, suggesting that these mutations could be an explanation for the intrinsic azole resistance in the genus Fusarium. Thus, this innovative approach provided clues to understand low azole susceptibility in FSSC and may contribute to improving the treatment of FSSC infection. Full article

(This article belongs to the Special Issue Clinically Relevant Fusarium Species)

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28 pages, 7556 KiB

Open AccessArticle

Taxonomic and Phylogenetic Characterizations Reveal Four New Species, Two New Asexual Morph Reports, and Six New Country Records of Bambusicolous Roussoella from China

by Dong-Qin Dai, Nalin N. Wijayawardene, Monika C. Dayarathne, Jaturong Kumla, Li-Su Han, Gui-Qing Zhang, Xian Zhang, Ting-Ting Zhang and Huan-Huan Chen

J. Fungi 2022, 8(5), 532; https://doi.org/10.3390/jof8050532 - 20 May 2022

Cited by 13 | Viewed by 2612

Abstract

During the ongoing investigation of bambusicolous ascomycetous fungi in Yunnan, China, 24 specimens belonging to the family Roussoellaceae were collected and identified based on morphological features and phylogenetic support. Maximum-likelihood (ML) analyses and Bayesian analyses were generated based on the combined data set [...] Read more.

During the ongoing investigation of bambusicolous ascomycetous fungi in Yunnan, China, 24 specimens belonging to the family Roussoellaceae were collected and identified based on morphological features and phylogenetic support. Maximum-likelihood (ML) analyses and Bayesian analyses were generated based on the combined data set of ITS, LSU, tef1, and rpb2 loci. The phylogenetic analyses revealed four novel lineages in Roussoella s. str.; thus, we introduced four new species viz., Roussoella multiloculate sp. nov., R. papillate sp. nov., R. sinensis sp. nov., and R. uniloculata sp. nov. Their morphological characters were compared with the known Roussoella taxa, which lack sequence data in the GenBank. Asexual morphs of R. kunmingensis and R. padinae were recorded from dead bamboo culms in China (from the natural substrates) for the first time. Neoroussoella bambusae, Roussoella japanensis, R. nitidula, R. padinae, R. scabrispora, and R. tuberculate were also reported as the first records from China. All new taxa are described and illustrated in detail. Plates are provided for new reports. Full article

(This article belongs to the Special Issue Holarctic Fungi: Taxonomy, Phylogeny, Ecology, Nutrition Interactions and Distribution)

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15 pages, 5298 KiB

Open AccessArticle

Toolbox for Genetic Transformation of Non-Conventional Saccharomycotina Yeasts: High Efficiency Transformation of Yeasts Belonging to the Schwanniomyces Genus

by Angela Matanović, Kristian Arambašić, Bojan Žunar, Anamarija Štafa, Marina Svetec Miklenić, Božidar Šantek and Ivan-Krešimir Svetec

J. Fungi 2022, 8(5), 531; https://doi.org/10.3390/jof8050531 - 20 May 2022

Cited by 1 | Viewed by 2837

Abstract

Non-conventional yeasts are increasingly being investigated and used as producers in biotechnological processes which often offer advantages in comparison to traditional and well-established systems. Most biotechnologically interesting non-conventional yeasts belong to the Saccharomycotina subphylum, including those already in use (Pichia pastoris, Yarrowia [...] Read more.

Non-conventional yeasts are increasingly being investigated and used as producers in biotechnological processes which often offer advantages in comparison to traditional and well-established systems. Most biotechnologically interesting non-conventional yeasts belong to the Saccharomycotina subphylum, including those already in use (Pichia pastoris, Yarrowia lypolitica, etc.), as well as those that are promising but as yet insufficiently characterized. Moreover, for many of these yeasts the basic tools of genetic engineering needed for strain construction, including a procedure for efficient genetic transformation, heterologous protein expression and precise genetic modification, are lacking. The first aim of this study was to construct a set of integrative and replicative plasmids which can be used in various yeasts across the Saccharomycotina subphylum. Additionally, we demonstrate here that the electroporation procedure we developed earlier for transformation of B. bruxellensis can be applied in various yeasts which, together with the constructed plasmids, makes a solid starting point when approaching a transformation of yeasts form the Saccharomycotina subphylum. To provide a proof of principle, we successfully transformed three species from the Schwanniomyces genus (S. polymorphus var. polymorphus, S. polymorphus var. africanus and S. pseudopolymorphus) with high efficiencies (up to 8 × 10³ in case of illegitimate integration of non-homologous linear DNA and up to 4.7 × 10⁵ in case of replicative plasmid). For the latter two species this is the first reported genetic transformation. Moreover, we found that a plasmid carrying replication origin from Scheffersomyces stipitis can be used as a replicative plasmid for these three Schwanniomyces species. Full article

(This article belongs to the Special Issue Yeast Genetics 2021)

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15 pages, 2174 KiB

Open AccessArticle

Sorbicillinoid Derivatives with the Radical Scavenging Activities from the Marine-Derived Fungus Acremonium chrysogenum C10

by Chengbao Duan, Shiyuan Wang, Ruiyun Huo, Erwei Li, Min Wang, Jinwei Ren, Yuanyuan Pan, Ling Liu and Gang Liu

J. Fungi 2022, 8(5), 530; https://doi.org/10.3390/jof8050530 - 20 May 2022

Cited by 9 | Viewed by 2553

Abstract

Sorbicillinoids are a class of structurally diverse hexaketide metabolites with good biological activities. To explore new structural sorbicillinoids and their bioactivities, the marine-derived fungus Acremonium chrysogenum C10 was studied. Three new sorbicillinoid derivatives, acresorbicillinols A–C (1–3), along with five [...] Read more.

Sorbicillinoids are a class of structurally diverse hexaketide metabolites with good biological activities. To explore new structural sorbicillinoids and their bioactivities, the marine-derived fungus Acremonium chrysogenum C10 was studied. Three new sorbicillinoid derivatives, acresorbicillinols A–C (1–3), along with five known ones, trichotetronine (4), trichodimerol (5), demethyltrichodimerol (6), trichopyrone (7) and oxosorbicillinol (8), were isolated. The structures of new sorbicillinoids were elucidated by analysis of nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy (HRESIMS). The absolute configurations of compounds 1–3 were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Compound 3 exhibited a strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, with the IC₅₀ value ranging from 11.53 ± 1.53 to 60.29 ± 6.28 μM in 24 h. Additionally, compounds 2 and 3 showed moderate activities against Staphylococcus aureus and Cryptococcus neoformans, with IC₅₀ values of 86.93 ± 1.72 and 69.06 ± 10.50 μM, respectively. The boundary of sorbicillinoid biosynthetic gene cluster in A. chrysogenum was confirmed by transcriptional analysis, and the biosynthetic pathway of compounds 1–8 was also proposed. In summary, our results indicated that A. chrysogenum is an important reservoir of sorbicillinoid derivatives, and compound 3 has the potential for new natural agents in DPPH radical scavenging. Full article

(This article belongs to the Special Issue Secondary Metabolites from Fungi—in Honour of Prof. Dr. Ji-Kai Liu's 60th Birthday)

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16 pages, 1508 KiB

Open AccessArticle

The Search for Cryptic L-Rhamnosyltransferases on the Sporothrix schenckii Genome

by Héctor M. Mora-Montes, Karina García-Gutiérrez, Laura C. García-Carnero, Nancy E. Lozoya-Pérez and Jorge H. Ramirez-Prado

J. Fungi 2022, 8(5), 529; https://doi.org/10.3390/jof8050529 - 20 May 2022

Cited by 4 | Viewed by 2416

Abstract

The fungal cell wall is an attractive structure to look for new antifungal drug targets and for understanding the host-fungus interaction. Sporothrix schenckii is one of the main causative agents of both human and animal sporotrichosis and currently is the species most studied [...] Read more.

The fungal cell wall is an attractive structure to look for new antifungal drug targets and for understanding the host-fungus interaction. Sporothrix schenckii is one of the main causative agents of both human and animal sporotrichosis and currently is the species most studied of the Sporothrix genus. The cell wall of this organism has been previously analyzed, and rhamnoconjugates are signature molecules found on the surface of both mycelia and yeast-like cells. Similar to other reactions where sugars are covalently linked to other sugars, lipids, or proteins, the rhamnosylation process in this organism is expected to involve glycosyltransferases with the ability to transfer rhamnose from a sugar donor to the acceptor molecule, i.e., rhamnosyltransferases. However, no obvious rhamnosyltransferase has thus far been identified within the S. schenckii proteome or genome. Here, using a Hidden Markov Model profile strategy, we found within the S. schenckii genome five putative genes encoding for rhamnosyltransferases. Expression analyses indicated that only two of them, named RHT1 and RHT2, were significantly expressed in yeast-like cells and during interaction with the host. These two genes were heterologously expressed in Escherichia coli, and the purified recombinant proteins showed rhamnosyltransferase activity, dependent on the presence of UDP-rhamnose as a sugar donor. To the best of our knowledge, this is the first report about rhamnosyltransferases in S. schenckii. Full article

(This article belongs to the Special Issue Sporothrix and Sporotrichosis 2.0)

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5 pages, 214 KiB

Open AccessEditorial

Special Issue “Signal Transductions in Fungi”

by Ulrich Kück

J. Fungi 2022, 8(5), 528; https://doi.org/10.3390/jof8050528 - 20 May 2022

Cited by 1 | Viewed by 1604

Abstract

In all living organisms, extracellular signals are translated into specific responses through signal transduction processes [...] Full article

(This article belongs to the Special Issue Signal Transductions in Fungi)

17 pages, 11872 KiB

Open AccessArticle

Secretome Profiling by Proteogenomic Analysis Shows Species-Specific, Temperature-Dependent, and Putative Virulence Proteins of Pythium insidiosum

by Theerapong Krajaejun, Thidarat Rujirawat, Tassanee Lohnoo, Wanta Yingyong, Pattarana Sae-Chew, Onrapak Reamtong, Weerayuth Kittichotirat and Preecha Patumcharoenpol

J. Fungi 2022, 8(5), 527; https://doi.org/10.3390/jof8050527 - 20 May 2022

Cited by 3 | Viewed by 2390

Abstract

In contrast to most pathogenic oomycetes, which infect plants, Pythium insidiosum infects both humans and animals, causing a difficult-to-treat condition called pythiosis. Most patients undergo surgical removal of an affected organ, and advanced cases could be fetal. As a successful human/animal pathogen, P. [...] Read more.

In contrast to most pathogenic oomycetes, which infect plants, Pythium insidiosum infects both humans and animals, causing a difficult-to-treat condition called pythiosis. Most patients undergo surgical removal of an affected organ, and advanced cases could be fetal. As a successful human/animal pathogen, P. insidiosum must tolerate body temperature and develop some strategies to survive and cause pathology within hosts. One of the general pathogen strategies is virulence factor secretion. Here, we used proteogenomic analysis to profile and validate the secretome of P. insidiosum, in which its genome contains 14,962 predicted proteins. Shotgun LC–MS/MS analysis of P. insidiosum proteins prepared from liquid cultures incubated at 25 and 37 °C mapped 2980 genome-predicted proteins, 9.4% of which had a predicted signal peptide. P. insidiosum might employ an alternative secretory pathway, as 90.6% of the validated secretory/extracellular proteins lacked the signal peptide. A comparison of 20 oomycete genomes showed 69 P. insidiosum–specific secretory/extracellular proteins, and these may be responsible for the host-specific infection. The differential expression analysis revealed 14 markedly upregulated proteins (particularly cyclophilin and elicitin) at body temperature which could contribute to pathogen fitness and thermotolerance. Our search through a microbial virulence database matched 518 secretory/extracellular proteins, such as urease and chaperones (including heat shock proteins), that might play roles in P. insidiosum virulence. In conclusion, the identification of the secretome promoted a better understanding of P. insidiosum biology and pathogenesis. Cyclophilin, elicitin, chaperone, and urease are top-listed secreted/extracellular proteins with putative pathogenicity properties. Such advances could lead to developing measures for the efficient detection and treatment of pythiosis. Full article

(This article belongs to the Special Issue Novel, Emerging and Neglected Fungal Pathogens for Humans and Animals)

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15 pages, 3211 KiB

Open AccessArticle

Sclerotinia sclerotiorum SsCut1 Modulates Virulence and Cutinase Activity

by Yingdi Gong, Yanping Fu, Jiatao Xie, Bo Li, Tao Chen, Yang Lin, Weidong Chen, Daohong Jiang and Jiasen Cheng

J. Fungi 2022, 8(5), 526; https://doi.org/10.3390/jof8050526 - 20 May 2022

Cited by 14 | Viewed by 2888

Abstract

The plant cuticle is one of the protective layers of the external surface of plant tissues. Plants use the cuticle layer to reduce water loss and resist pathogen infection. Fungi release cell wall-degrading enzymes to destroy the epidermis of plants to achieve the [...] Read more.

The plant cuticle is one of the protective layers of the external surface of plant tissues. Plants use the cuticle layer to reduce water loss and resist pathogen infection. Fungi release cell wall-degrading enzymes to destroy the epidermis of plants to achieve the purpose of infection. Sclerotinia sclerotiorum secretes a large amount of cutinase to disrupt the cuticle layer of plants during the infection process. In order to further understand the role of cutinase in the pathogenic process of S. sclerotiorum, the S. sclerotiorum cutinsae 1 (SsCut1) gene was cloned and analyzed. The protein SsCut1 contains the conserved cutinase domain and a fungal cellulose-binding domain. RT-qPCR results showed that the expression of SsCut1 was significantly upregulated during infection. Split-Marker recombination was utilized for the deletion of the SsCut1 gene, ΔSsCut1 mutants showed reduced cutinase activity and virulence, but the deletion of the SsCut1 gene had no effect on the growth rate, colony morphology, oxalic acid production, infection cushion formation and sclerotial development. Complementation with the wild-type SsCut1 allele restored the cutinase activity and virulence to the wild-type level. Interestingly, expression of SsCut1 in plants can trigger defense responses, but it also enhanced plant susceptibility to SsCut1 gene knock-out mutants. Taken together, our finding demonstrated that the SsCut1 gene promotes the virulence of S. sclerotiorum by enhancing its cutinase activity. Full article

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13 pages, 1733 KiB

Open AccessArticle

Synergistic In Vitro Interaction of Isavuconazole and Isoquercitrin against Candida glabrata

by Petra V. Schwarz, Ilya Nikolskiy, Eric Dannaoui, Frank Sommer, Gert Bange and Patrick Schwarz

J. Fungi 2022, 8(5), 525; https://doi.org/10.3390/jof8050525 - 20 May 2022

Cited by 2 | Viewed by 2025

Abstract

In vitro interactions of broad-spectrum azole isavuconazole with flavonoid isoquercitrin were evaluated by a broth microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference methodology for antifungal susceptibility testing against 60 Candida strains belonging to the species Candida [...] Read more.

In vitro interactions of broad-spectrum azole isavuconazole with flavonoid isoquercitrin were evaluated by a broth microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference methodology for antifungal susceptibility testing against 60 Candida strains belonging to the species Candida albicans (n = 10), Candida glabrata (n = 30), Candida kefyr (n = 6), Candida krusei (n = 5), Candida parapsilosis (n = 4), and Candida tropicalis (n = 5). The results were analyzed with the fractional inhibitory concentration index and by response surface analysis based on the Bliss model. Synergy was found for all C. glabrata strains, when the results were interpreted by the fractional inhibitory concentration index, and for 60% of the strains when response surface analysis was used. Interaction for all other species was indifferent for all strains tested, whatever interpretation model used. Importantly, antagonistic interaction was never observed. Full article

(This article belongs to the Special Issue Antifungal Combinations in Fungal Infections)

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12 pages, 1522 KiB

Open AccessArticle

Ustilago maydis Metabolic Characterization and Growth Quantification with a Genome-Scale Metabolic Model

by Ulf W. Liebal, Lena Ullmann, Christian Lieven, Philipp Kohl, Daniel Wibberg, Thiemo Zambanini and Lars M. Blank

J. Fungi 2022, 8(5), 524; https://doi.org/10.3390/jof8050524 - 20 May 2022

Cited by 9 | Viewed by 3310

Abstract

Ustilago maydis is an important plant pathogen that causes corn smut disease and serves as an effective biotechnological production host. The lack of a comprehensive metabolic overview hinders a full understanding of the organism’s environmental adaptation and a full use of its metabolic [...] Read more.

Ustilago maydis is an important plant pathogen that causes corn smut disease and serves as an effective biotechnological production host. The lack of a comprehensive metabolic overview hinders a full understanding of the organism’s environmental adaptation and a full use of its metabolic potential. Here, we report the first genome-scale metabolic model (GSMM) of Ustilago maydis (iUma22) for the simulation of metabolic activities. iUma22 was reconstructed from sequencing and annotation using PathwayTools, and the biomass equation was derived from literature values and from the codon composition. The final model contains over 25% annotated genes (6909) in the sequenced genome. Substrate utilization was corrected by BIOLOG phenotype arrays, and exponential batch cultivations were used to test growth predictions. The growth data revealed a decrease in glucose uptake rate with rising glucose concentration. A pangenome of four different U. maydis strains highlighted missing metabolic pathways in iUma22. The new model allows for studies of metabolic adaptations to different environmental niches as well as for biotechnological applications. Full article

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

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18 pages, 2124 KiB

Open AccessArticle

Elevated Ozone Concentration and Nitrogen Addition Increase Poplar Rust Severity by Shifting the Phyllosphere Microbial Community

by Siqi Tao, Yunxia Zhang, Chengming Tian, Sébastien Duplessis and Naili Zhang

J. Fungi 2022, 8(5), 523; https://doi.org/10.3390/jof8050523 - 18 May 2022

Cited by 11 | Viewed by 2803

Abstract

Tropospheric ozone and nitrogen deposition are two major environmental pollutants. A great deal of research has focused on the negative impacts of elevated O₃ and the complementary effect of soil N addition on the physiological properties of trees. However, it has been [...] Read more.

Tropospheric ozone and nitrogen deposition are two major environmental pollutants. A great deal of research has focused on the negative impacts of elevated O₃ and the complementary effect of soil N addition on the physiological properties of trees. However, it has been overlooked how elevated O₃ and N addition affect tree immunity in face of pathogen infection, as well as of the important roles of phyllosphere microbiome community in host–pathogen–environment interplay. Here, we examined the effects of elevated O₃ and soil N addition on poplar leaf rust [Melampsora larici-populina] severity of two susceptible hybrid poplars [clone ‘107’: Populus euramericana cv. ‘74/76’; clone ‘546’: P. deltoides Í P. cathayana] in Free-Air-Controlled-Environment plots, in addition, the link between Mlp-susceptibility and changes in microbial community was determined using Miseq amplicon sequencing. Rust severity of clone ‘107’ significantly increased under elevated O₃ or N addition only; however, the negative impact of elevated O₃ could be significantly mitigated when accompanied by N addition, likewise, this trade-off was reflected in its phyllosphere microbial α-diversity responding to elevated O₃ and N addition. However, rust severity of clone ‘546’ did not differ significantly in the cases of elevated O₃ and N addition. Mlp infection altered microbial community composition and increased its sensitivity to elevated O₃, as determined by the markedly different abundance of taxa. Elevated O₃ and N addition reduced the complexity of microbial community, which may explain the increased severity of poplar rust. These findings suggest that poplars require a changing phyllosphere microbial associations to optimize plant immunity in response to environmental changes. Full article

(This article belongs to the Topic Infectious Diseases)

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21 pages, 2999 KiB

Open AccessArticle

Heme Oxygenase-1 (HMX1) Loss of Function Increases the In-Host Fitness of the Saccharomyces ‘boulardii’ Probiotic Yeast in a Mouse Fungemia Model

by Alexandra Imre, Renátó Kovács, Zoltán Tóth, László Majoros, Zsigmond Benkő, Walter P. Pfliegler and István Pócsi

J. Fungi 2022, 8(5), 522; https://doi.org/10.3390/jof8050522 - 18 May 2022

Viewed by 3528

Abstract

The use of yeast-containing probiotics is on the rise; however, these products occasionally cause fungal infections and possibly even fungemia among susceptible probiotic-treated patients. The incidence of such cases is probably underestimated, which is why it is important to delve deeper into the [...] Read more.

The use of yeast-containing probiotics is on the rise; however, these products occasionally cause fungal infections and possibly even fungemia among susceptible probiotic-treated patients. The incidence of such cases is probably underestimated, which is why it is important to delve deeper into the pathomechanism and the adaptive features of S. ‘boulardii’. Here in this study, the potential role of the gene heme oxygenase-1 (HMX1) in probiotic yeast bloodstream-derived infections was studied by generating marker-free HMX1 deletion mutants with CRISPR/Cas9 technology from both commercial and clinical S. ‘boulardii’ isolates. The six commercial and clinical yeasts used here represented closely related but different genetic backgrounds as revealed by comparative genomic analysis. We compared the wild-type isolates against deletion mutants for their tolerance of iron starvation, hemolytic activity, as well as kidney burden in immunosuppressed BALB/c mice after lateral tail vein injection. Our results reveal that the lack of HMX1 in S. ‘boulardii’ significantly (p < 0.0001) increases the kidney burden of the mice in most genetic backgrounds, while at the same time causes decreased growth in iron-deprived media in vitro. These findings indicate that even a single-gene loss-of-function mutation can, surprisingly, cause elevated fitness in the host during an opportunistic systemic infection. Our findings indicate that the safety assessment of S. ‘boulardii’ strains should not only take strain-to-strain variation into account, but also avoid extrapolating in vitro results to in vivo virulence factor determination. Full article

(This article belongs to the Topic Infectious Diseases)

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21 pages, 7872 KiB

Open AccessArticle

Encephalartos villosus Lem. Displays a Strong In Vivo and In Vitro Antifungal Potential against Candida glabrata Clinical Isolates

by Moneerah J. Alqahtani, Engy Elekhnawy, Walaa A. Negm, Sebaey Mahgoub and Ismail A. Hussein

J. Fungi 2022, 8(5), 521; https://doi.org/10.3390/jof8050521 - 18 May 2022

Cited by 18 | Viewed by 2541

Abstract

Recently, Candida glabrata has been recognized as one of the most common fungal species that is highly associated with invasive candidiasis. Its spread could be attributed to its increasing resistance to antifungal drugs. Thus, there is a high need for safer and more [...] Read more.

Recently, Candida glabrata has been recognized as one of the most common fungal species that is highly associated with invasive candidiasis. Its spread could be attributed to its increasing resistance to antifungal drugs. Thus, there is a high need for safer and more efficient therapeutic alternatives such as plant extracts. Here, we investigated the antifungal potential of Encephalartos villosus leaves methanol extract (EVME) against C. glabrata clinical isolates. Tentative phytochemical identification of 51 metabolites was conducted in EVME using LC–MS/MS. EVME demonstrated antifungal activity with minimum inhibitory concentrations that ranged from 32 to 256 µg/mL. The mechanism of the antifungal action was studied by investigating the impact of EVME on nucleotide leakage. Additionally, a sorbitol bioassay was performed, and we found that EVME affected the fungal cell wall. In addition, the effect of EVME was elucidated on the efflux activity of C. glabrata isolates using acridine orange assay and quantitative real-time PCR. EVME resulted in downregulation of the expression of the efflux pump genes CDR1, CDR2, and ERG11 in the tested isolates with percentages of 33.33%, 41.67%, and 33.33%, respectively. Moreover, we investigated the in vivo antifungal activity of EVME using a murine model with systemic infection. The fungal burden was determined in the kidney tissues. Histological and immunohistochemical studies were carried out to investigate the effect of EVME. We noticed that EVME reduced the congestion of the glomeruli and tubules of the kidney tissues of the rats infected with C. glabrata. Furthermore, it decreased both the proinflammatory cytokine tumor necrosis factor-alpha and the abnormal collagen fibers. Our results reveal, for the first time, the potential in vitro (by inhibition of the efflux activity) and in vivo (by decreasing the congestion and inflammation of the kidney tissues) antifungal activity of EVME against C. glabrata isolates. Full article

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

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20 pages, 12051 KiB

Open AccessArticle

Taxonomy, Phylogenetic and Ancestral Area Reconstruction in Phyllachora, with Four Novel Species from Northwestern China

by Jin-Chen Li, Hai-Xia Wu, Yuying Li, Xin-Hao Li, Jia-Yu Song, Nakarin Suwannarach and Nalin N. Wijayawardene

J. Fungi 2022, 8(5), 520; https://doi.org/10.3390/jof8050520 - 18 May 2022

Cited by 5 | Viewed by 3249

Abstract

The members of Phyllachora are biotrophic, obligate plant parasitic fungi featuring a high degree of host specificity. This genus also features a high degree of species richness and worldwide distribution. In this study, four species occurring on leaf and stem of two different [...] Read more.

The members of Phyllachora are biotrophic, obligate plant parasitic fungi featuring a high degree of host specificity. This genus also features a high degree of species richness and worldwide distribution. In this study, four species occurring on leaf and stem of two different species of grass were collected from Shanxi and Shaanxi Provinces, China. Based on morphological analysis, multigene (combined data set of LSU, SSU, and ITS) phylogenetic analyses (maximum likelihood and Bayesian analysis), and host relationship, we introduce herein four new taxa of Phyllachora. Ancestral area reconstruction analysis showed that the ancestral area of Phyllachora occurred in Latin America about 194 Mya. Novel taxa are compared with the related Phyllachora species. Detailed descriptions, illustrations, and notes are provided for each species. Full article

(This article belongs to the Special Issue Women in Mycology)

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17 pages, 1369 KiB

Open AccessArticle

Metabolomics Analysis and Antioxidant Potential of Endophytic Diaporthe fraxini ED2 Grown in Different Culture Media

by Wen-Nee Tan, Kashvintha Nagarajan, Vuanghao Lim, Juzaili Azizi, Kooi-Yeong Khaw, Woei-Yenn Tong, Chean-Ring Leong and Nelson Jeng-Yeou Chear

J. Fungi 2022, 8(5), 519; https://doi.org/10.3390/jof8050519 - 18 May 2022

Cited by 13 | Viewed by 2732

Abstract

Endophytic fungi are a promising source of bioactive metabolites with a wide range of pharmacological activities. In the present study, MS-based metabolomics was conducted to study the metabolomes variations of endophytic Diaporthe fraxini ED2 grown in different culture media. Total phenolic content (TPC), [...] Read more.

Endophytic fungi are a promising source of bioactive metabolites with a wide range of pharmacological activities. In the present study, MS-based metabolomics was conducted to study the metabolomes variations of endophytic Diaporthe fraxini ED2 grown in different culture media. Total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP) assays were conducted to assess the antioxidant potential of the fungal extracts. Multivariate data analysis (MVDA) was employed in data analysis and interpretation to elucidate the complex metabolite profile. The supplemented culture medium of D. fraxini fungal extract stimulated the production of metabolites not occurring in the normal culture medium. Antioxidant activity studies revealed the potential of supplemented cultured fungal extract of D. fraxini as a source of antioxidants. The present findings highlight that fungal culture medium supplementation is an effective approach to unravelling the hidden metabolome in plant-associated fungal diversity. Full article

(This article belongs to the Special Issue Fungi: What Have We Learned from Omics?)

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14 pages, 2378 KiB

Open AccessArticle

Stemphylium lycopersici Nep1-like Protein (NLP) Is a Key Virulence Factor in Tomato Gray Leaf Spot Disease

by Jiajie Lian, Hongyu Han, Xizhan Chen, Qian Chen, Jiuhai Zhao and Chuanyou Li

J. Fungi 2022, 8(5), 518; https://doi.org/10.3390/jof8050518 - 18 May 2022

Cited by 6 | Viewed by 2832

Abstract

The fungus Stemphylium lycopersici (S. lycopersici) is an economically important plant pathogen that causes grey leaf spot disease in tomato. However, functional genomic studies in S. lycopersici are lacking, and the factors influencing its pathogenicity remain largely unknown. Here, we present [...] Read more.

The fungus Stemphylium lycopersici (S. lycopersici) is an economically important plant pathogen that causes grey leaf spot disease in tomato. However, functional genomic studies in S. lycopersici are lacking, and the factors influencing its pathogenicity remain largely unknown. Here, we present the first example of genetic transformation and targeted gene replacement in S. lycopersici. We functionally analyzed the NLP gene, which encodes a necrosis- and ethylene-inducing peptide 1 (Nep1)-like protein (NLP). We found that targeted disruption of the NLP gene in S. lycopersici significantly compromised its virulence on tomato. Moreover, our data suggest that NLP affects S. lycopersici conidiospore production and weakly affects its adaptation to osmotic and oxidative stress. Interestingly, we found that NLP suppressed the production of reactive oxygen species (ROS) in tomato leaves during S. lycopersici infection. Further, expressing the fungal NLP in tomato resulted in constitutive transcription of immune-responsive genes and inhibited plant growth. Through gene manipulation, we demonstrated the function of NLP in S. lycopersici virulence and development. Our work provides a paradigm for functional genomics studies in a non-model fungal pathogen system. Full article

(This article belongs to the Special Issue Emergent Fungal Models for Genetics and Cell Biology)

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J. Fungi, Volume 8, Issue 5 (May 2022) – 132 articles

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