Journal of Fungi

25 pages, 3050 KiB

Open AccessArticle

Unprecedented Antimicrobial and Cytotoxic Polyketides from Cultures of Diaporthe africana sp. nov.

by Blondelle Matio Kemkuignou, Christopher Lambert, Marc Stadler, Simeon Kouam Fogue and Yasmina Marin-Felix

J. Fungi 2023, 9(7), 781; https://doi.org/10.3390/jof9070781 - 24 Jul 2023

Cited by 4 | Viewed by 2326

Abstract

Four unprecedented polyketides named isoprenylisobenzofuran B (2), isoprenylisobenzofuran C₁/C₂ (3), diaporisoindole F₁/F₂ (4), and isochromophilonol A₁/A₂ (7) were isolated from ethyl acetate extracts of the newly [...] Read more.

Four unprecedented polyketides named isoprenylisobenzofuran B (2), isoprenylisobenzofuran C₁/C₂ (3), diaporisoindole F₁/F₂ (4), and isochromophilonol A₁/A₂ (7) were isolated from ethyl acetate extracts of the newly described endophytic fungus Diaporthe africana. Additionally, the previously reported cyclic depsipeptide eucalactam B (1) was also identified, along with the known compounds diaporisoindole A/B (5), tenellone B (6) and beauvericin (8). The taxonomic identification of the fungus was accomplished using a polyphasic approach combining multi-gene phylogenetic analysis and microscopic morphological characters. The structures 1–8 were determined by a detailed analysis of their spectral data, namely high-resolution electrospray ionization mass spectrometry (HR-ESIMS), 1D/2D nuclear magnetic resonance (NMR) spectroscopy, as well as electronic circular dichroism (ECD) spectra. In addition, chemical methods such as Marfey’s analysis were also employed to determine the stereochemistry in compound 1. All the compounds obtained were evaluated for antimicrobial and in vitro cytotoxic properties. Compounds 3–8 were active against certain fungi and Gram-positive bacteria with MIC values of 8.3 to 66.6 µg/mL. In addition, 3–5 displayed cytotoxic effects (22.0 ≤ IC₅₀ ≤ 59.2 µM) against KB3.1 and L929 cell lines, whereas compounds 6–8 inhibited the growth of seven mammalian cancer cell lines with IC₅₀ ranging from 17.7 to 49.5 µM (6), 0.9 to 12.9 µM (7) and 1.9 to 4.3 µM (8). Full article

(This article belongs to the Special Issue Emerging Investigators in Bioactive Fungal Metabolites, 2nd Edition)

► Show Figures

Figure 1

13 pages, 8815 KiB

Open AccessArticle

Fungal Ligninolytic Enzymes and Their Application in Biomass Lignin Pretreatment

by Anna Civzele, Alise Anna Stipniece-Jekimova and Linda Mezule

J. Fungi 2023, 9(7), 780; https://doi.org/10.3390/jof9070780 - 24 Jul 2023

Cited by 14 | Viewed by 2946

Abstract

Lignocellulosic biomass is a significant source of sustainable fuel and high-value chemical production. However, due to the complex cross-linked three-dimensional network structure, lignin is highly rigid to degradation. In natural environments, the degradation is performed by wood-rotting fungi. The process is slow, and [...] Read more.

Lignocellulosic biomass is a significant source of sustainable fuel and high-value chemical production. However, due to the complex cross-linked three-dimensional network structure, lignin is highly rigid to degradation. In natural environments, the degradation is performed by wood-rotting fungi. The process is slow, and thus, the use of lignin degradation by fungi has not been regarded as a feasible technology in the industrial lignocellulose treatment. Fungi produce a wide variety of ligninolytic enzymes that can be directly introduced in industrial processing of lignocellulose. Within this study, screening of ligninolytic enzyme production using decolorization of ABTS and Azure B dyes was performed for 10 fungal strains with potentially high enzyme production abilities. In addition to standard screening methods, media containing lignin and hay biomass as carbon sources were used to determine the change in enzyme production depending on the substrate. All selected fungi demonstrated the ability to adapt to a carbon source limitation; however, four strains indicated the ability to secrete ligninolytic enzymes in all experimental conditions—Irpex lacteus, Pleurotus dryinus, Bjerkandera adusta, and Trametes versicolor—respectively displayed a 100%, 82.7%, 82.7%, and 55% oxidation of ABTS on lignin-containing media and 100%, 87.9%, 78%, and 70% oxidation of ABTS on hay-containing media after 168 h of incubation. As a result, the most potent strains of fungi were selected to produce lignocellulose-degrading enzymes and to demonstrate their potential application in biological lignocellulose pretreatment. Full article

(This article belongs to the Section Fungi in Agriculture and Biotechnology)

► Show Figures

Figure 1

20 pages, 7662 KiB

Open AccessArticle

A Symbiotic Fungus Sistotrema Benefits Blueberry Rejuvenation and Abiotic Stress Tolerance

by Yu Ye, Xufang Zhan, Kai Wang, Jingya Zhong, Fanglei Liao, Wenrong Chen and Weidong Guo

J. Fungi 2023, 9(7), 779; https://doi.org/10.3390/jof9070779 - 24 Jul 2023

Cited by 1 | Viewed by 1638

Abstract

Blueberry (Vaccinium spp.) rhizosphere microorganisms can significantly increase the absorption area and improve the efficiency of rhizospheric nutrient uptake. However, there has been little research on blueberry rhizosphere microorganisms, especially those that can complement root function deficiency. In this study, we analyzed [...] Read more.

Blueberry (Vaccinium spp.) rhizosphere microorganisms can significantly increase the absorption area and improve the efficiency of rhizospheric nutrient uptake. However, there has been little research on blueberry rhizosphere microorganisms, especially those that can complement root function deficiency. In this study, we analyzed the rhizosphere fungi of ‘O’Neal,’ ‘Sharpblue,’ and ‘Premier’ blueberry cultivars and found that ‘Premier’ blueberries showed strong growth potential and relatively high root regulation ability. The dominant symbiotic fungus Sistotrema was correlated with the strong growth of ‘Premier’ and was directionally screened and isolated based on conserved gene structures and COG function analysis. This fungus was reinoculated onto the roots of ‘Gulfcoast’ and ‘Star’ blueberry cultivars. Sistotrema promoted the growth of blueberries and improved their ability to resist stress and grow under adverse conditions, as indicated by maintained or increased chlorophyll content under such conditions. Further analyses showed that Sistotrema has certain functional characteristics such as the ability to dissolve iron in its insoluble form and then release it, to fix nitrogen, and to inhibit nitrification in soil. Thus, it effectively doubled the soil nitrogen content and increased the soluble iron content in soil by 50%. This investigation indicates sistotrema inoculation as an approach to increase blueberry stress tolerance and complete their root nutrition deficiency. Full article

(This article belongs to the Special Issue Plant and Fungal Interactions, 2nd Edition)

► Show Figures

Figure 1

10 pages, 2073 KiB

Open AccessCommunication

Tacrolimus (FK506) Exhibits Fungicidal Effects against Candida parapsilosis Sensu Stricto via Inducing Apoptosis

by Otomi Cho, Shintaro Takada, Takahiro Odaka, Satoshi Futamura, Sanae Kurakado and Takashi Sugita

J. Fungi 2023, 9(7), 778; https://doi.org/10.3390/jof9070778 - 24 Jul 2023

Cited by 2 | Viewed by 1866

Abstract

Tacrolimus (FK506), an immunosuppressant and calcineurin inhibitor, has fungicidal effects. However, its fungicidal effect is thought to be limited to basidiomycetes, such as Cryptococcus and Malassezia, and not to ascomycetes. FK506 had no fungicidal effect on Candida albicans, C. auris, [...] Read more.

Tacrolimus (FK506), an immunosuppressant and calcineurin inhibitor, has fungicidal effects. However, its fungicidal effect is thought to be limited to basidiomycetes, such as Cryptococcus and Malassezia, and not to ascomycetes. FK506 had no fungicidal effect on Candida albicans, C. auris, C. glabrata, C. guilliermondii, C. kefyr, C. krusei, and C. tropicalis (>8 µg/mL); however, C. parapsilosis was susceptible to it at low concentrations of 0.125–0.5 µg/mL. C. metapsilosis and C. orthopsils, previously classified as C. parapsilosis, are molecularly and phylogenetically closely related to C. parapsilosis, but neither species was sensitive to FK506. FK506 increased the mitochondrial reactive oxygen species production and cytoplasmic and mitochondrial calcium concentration and activated metacaspases, nuclear condensation, and DNA fragmentation, suggesting that it induced mitochondria-mediated apoptosis in C. parapsilosis. Elucidating why FK506 exhibits fungicidal activity only against C. parapsilosis will provide new information for developing novel antifungal drugs. Full article

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

► Show Figures

Figure 1

15 pages, 3657 KiB

Open AccessArticle

Effect of Potato Glycoside Alkaloids on Energy Metabolism of Fusarium solani

by Chongqing Zhang, Dedong Ding, Bin Wang, Yupeng Wang, Nan Li, Ruiyun Li, Yuke Yan and Jing He

J. Fungi 2023, 9(7), 777; https://doi.org/10.3390/jof9070777 - 24 Jul 2023

Cited by 6 | Viewed by 1335

Abstract

Fusarium solani is one of the primary pathogens causing root rot of wolfberry. The aims of this study were to investigate the inhibitory effect of potato glycoside alkaloids (PGA) on F. solani and its energy metabolism. In this study, the effects of PGA [...] Read more.

Fusarium solani is one of the primary pathogens causing root rot of wolfberry. The aims of this study were to investigate the inhibitory effect of potato glycoside alkaloids (PGA) on F. solani and its energy metabolism. In this study, the effects of PGA treatment on the growth and development of F. solani were investigated and the changes in the glycolytic pathway (EMP), ATPase activity, mitochondrial complex activity, mitochondrial structure, and energy charge level were analyzed to elucidate the possible antifungal mechanism of PGA on F. solani. The results showed that PGA treatment inhibited the colony growth, biomass, and spore germination of F. solani. PGA treatment reduced the glucose content and Hexokinase (HK) activity of F. solani, but increased the activity of Fructose-6-Phosphate Kinase (PFK) and Pyruvate Kinase (PK) and promoted the accumulation of pyruvic acid. In addition, PGA treatment inhibited the activities of H⁺-ATPase, Ca²⁺-ATPase, and mitochondrial complex IV, increased the mitochondrial inner membrane Ca²⁺ content and mitochondrial membrane permeability transition pore, and decreased the contents of ATP, ADP, and AMP as well as the energy charge. These results indicate that PGA treatment inhibits the growth and development of F. solani, activates the glycolysis pathway, inhibits ATPase activity and mitochondrial complex activity, and destroys the structure and function of mitochondrial membrane, resulting in a lower energy charge level. Full article

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

► Show Figures

Figure 1

10 pages, 1543 KiB

Open AccessArticle

Genetic Variation of Magnaporthe oryzae Population in Hunan Province

by Zhirong Peng, Yuefeng Fu, Fan Wang, Qiqi Liu, Yi Li, Zhengbing Zhang, Li Yin, Xiao-Lin Chen, Jingbo Xu, Huafeng Deng and Junjie Xing

J. Fungi 2023, 9(7), 776; https://doi.org/10.3390/jof9070776 - 23 Jul 2023

Viewed by 1439

Abstract

Studies on the population structure and variation of Magnaporthe oryzae in fields are of great significance for the control of rice blast disease. In this study, a total of 462 isolates isolated from different areas of Hunan Province in 2016 and 2018 were [...] Read more.

Studies on the population structure and variation of Magnaporthe oryzae in fields are of great significance for the control of rice blast disease. In this study, a total of 462 isolates isolated from different areas of Hunan Province in 2016 and 2018 were analyzed for their population structure and variation tendency. The results showed that from 2016 to 2018, the concentration of fungal races of M. oryzae increased and the diversity decreased; furthermore, 218 isolates in 2016 belonged to ZA, ZB, ZC, ZE, ZF and ZG, with a total of 6 groups and 29 races, in which the dominant-population ZB group accounted for 66.2%; meanwhile, in 2018, 244 isolates were classified into 4 groups and 21 races, including ZA, ZB, ZC and ZG, in which the dominant-population ZB group accounted for 72.54%. In 2018, isolates of ZD, ZE and ZF populations were absent, and the number of total races and isolates of the ZA and ZC groups decreased. Fungal pathogenicity was identified, with 24 monogenic lines (MLs) carrying 24 major R genes. The resistance frequency of R genes to fungal isolates in 2018 decreased significantly, in which except Pikm was 64.5%, the other monogenic lines were less than 50%. Rep-PCR analysis for isolates of Guidong in Hunan also showed that fungal diversity decreased gradually. The influence of R genes on fungal variation was analyzed. The pathogenicity of isolates purified from Xiangwanxian 11 planted with monogenic lines was significantly more enhanced than those without monogenic lines. All the results indicated that in recent years, the fungal abundance in Hunan has decreased while fungal pathogenicity has increased significantly. This study will greatly benefit rice-resistance breeding and the control of rice blast disease in Hunan Province. Full article

(This article belongs to the Special Issue Pathogenic Mechanism and Control of Rice Blast Fungus)

► Show Figures

Figure 1

14 pages, 2900 KiB

Open AccessArticle

Additions to the Genus Helicosporium (Tubeufiaceae, Tubeufiales) from China with an Identification Key for Helicosporium Taxa

by Xing-Juan Xiao, Jian Ma, Li-Juan Zhang, Ning-Guo Liu, Yuan-Pin Xiao, Xing-Guo Tian, Zong-Long Luo and Yong-Zhong Lu

J. Fungi 2023, 9(7), 775; https://doi.org/10.3390/jof9070775 - 22 Jul 2023

Cited by 3 | Viewed by 1667

Abstract

Helicosporous hyphomycetes is a group of filamentous fungi that shows promising application prospects in metabolizing bioactive natural compounds. During a study of helicosporous fungi in China, six new helicosporous taxa were collected and isolated from decaying wood in Guangxi Zhuang Autonomous Region, China. [...] Read more.

Helicosporous hyphomycetes is a group of filamentous fungi that shows promising application prospects in metabolizing bioactive natural compounds. During a study of helicosporous fungi in China, six new helicosporous taxa were collected and isolated from decaying wood in Guangxi Zhuang Autonomous Region, China. Morphological comparisons with multi-gene phylogenetic analyses revealed that these six taxa belong to Helicosporium (Tubeufiaceae, Tubeufiales), and they were recognized as three novel species and were named Helicosporium liuzhouense, H. multidentatum, and H. nanningense. Detailed descriptions and illustrations of the newly discovered taxa and comparisons with similar fungi are provided. In addition, a list and a key to accepted Helicosporium species are provided. Full article

(This article belongs to the Special Issue Polyphasic Identification of Fungi 3.0)

► Show Figures

Figure 1

18 pages, 890 KiB

Open AccessReview

Germination of Microsporidian Spores: The Known and Unknown

by Qingyuan Huang, Jie Chen, Qing Lv, Mengxian Long, Guoqing Pan and Zeyang Zhou

J. Fungi 2023, 9(7), 774; https://doi.org/10.3390/jof9070774 - 22 Jul 2023

Cited by 9 | Viewed by 2798

Abstract

Microsporidia are a large group of mysterious obligate intracellular eukaryotic parasites. The microsporidian spore can survive in the absence of nutrients for years under harsh conditions and germinate within seconds under the stimulation of environmental changes like pH and ions. During germination, microsporidia [...] Read more.

Microsporidia are a large group of mysterious obligate intracellular eukaryotic parasites. The microsporidian spore can survive in the absence of nutrients for years under harsh conditions and germinate within seconds under the stimulation of environmental changes like pH and ions. During germination, microsporidia experience an increase in intrasporal osmotic pressure, which leads to an influx of water into the spore, followed by swelling of the polaroplasts and posterior vacuole, which eventually fires the polar filament (PF). Infectious sporoplasm was transported through the extruded polar tube (PT) and delivered into the host cell. Despite much that has been learned about the germination of microsporidia, there are still several major questions that remain unanswered, including: (i) There is still a lack of knowledge about the signaling pathways involved in spore germination. (ii) The germination of spores is not well understood in terms of its specific energetics. (iii) Limited understanding of how spores germinate and how the nucleus and membranes are rearranged during germination. (iv) Only a few proteins in the invasion organelles have been identified; many more are likely undiscovered. This review summarizes the major resolved and unresolved issues concerning the process of microsporidian spore germination. Full article

► Show Figures

Figure 1

11 pages, 8921 KiB

Open AccessArticle

Bioherbicidal Activity of Albifimbria verrucaria (Formerly Myrothecium verrucaria) on Glyphosate-Resistant Conyza canadensis

by Robert E. Hoagland, C. Douglas Boyette and Kenneth C. Stetina

J. Fungi 2023, 9(7), 773; https://doi.org/10.3390/jof9070773 - 22 Jul 2023

Cited by 2 | Viewed by 1555

Abstract

The effects of the bioherbicidal activity of the fungal phytopathogen, Albifimbria verrucaria (AV), formerly Myrothecium verrucaria, on glyphosate-resistant and –susceptible Conyza canadensis (horseweed) were examined in greenhouse and field studies. Spray applications of mycelial formulations of AV infected both glyphosate-resistant and -susceptible [...] Read more.

The effects of the bioherbicidal activity of the fungal phytopathogen, Albifimbria verrucaria (AV), formerly Myrothecium verrucaria, on glyphosate-resistant and –susceptible Conyza canadensis (horseweed) were examined in greenhouse and field studies. Spray applications of mycelial formulations of AV infected both glyphosate-resistant and -susceptible C. canadensis plants at various growth stages. Young plants in the rosette leaf stage of growth were controlled more efficaciously than were older plants that had bolted or that were in the inflorescence stage; nevertheless, severe injury and mortality also occurred in mature plants. The results indicate that this bioherbicidal fungus can infect and control C. canadensis, thereby demonstrating the potential of this fungus as a bioherbicidal agent against this troublesome weed, which has become resistant to various herbicides. Full article

(This article belongs to the Topic Interaction between Plants and Fungi and Oomycetes)

► Show Figures

Figure 1

15 pages, 3742 KiB

Open AccessArticle

Antifungal Effect of Vitamin D₃ against Cryptococcus neoformans Coincides with Reduced Biofilm Formation, Compromised Cell Wall Integrity, and Increased Generation of Reactive Oxygen Species

by Jian Huang, Junwen Lei, Anni Ge, Wei Xiao, Caiyan Xin, Zhangyong Song and Jinping Zhang

J. Fungi 2023, 9(7), 772; https://doi.org/10.3390/jof9070772 - 21 Jul 2023

Cited by 4 | Viewed by 2440

Abstract

Cryptococcus neoformans is an invasive fungus that causes both acute and chronic infections, especially in immunocompromised patients. Owing to the increase in the prevalence of drug-resistant pathogenic fungi and the limitations of current treatment strategies, drug repositioning has become a feasible strategy to [...] Read more.

Cryptococcus neoformans is an invasive fungus that causes both acute and chronic infections, especially in immunocompromised patients. Owing to the increase in the prevalence of drug-resistant pathogenic fungi and the limitations of current treatment strategies, drug repositioning has become a feasible strategy to accelerate the development of new drugs. In this study, the minimum inhibitory concentration of vitamin D₃ (VD₃) against C. neoformans was found to be 0.4 mg/mL by broth microdilution assay. The antifungal activities of VD₃ were further verified by solid dilution assays and “time-kill” curves. The results showed that VD₃ reduced fungal cell adhesion and hydrophobicity and inhibited biofilm formation at various developmental stages, as confirmed by crystal violet staining and the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assay. Fluorescence staining of cellular components and a stress susceptibility assay indicated that VD₃ compromised cell integrity. Reverse transcription quantitative PCR demonstrated that VD₃ treatment upregulated the expression of fungal genes related to cell wall synthesis (i.e., CDA3, CHS3, FKS1, and AGS1). Moreover, VD₃ enhanced cell membrane permeability and caused the accumulation of intracellular reactive oxygen species. Finally, VD₃ significantly reduced the tissue fungal burden and prolonged the survival of Galleria mellonella larvae infected with C. neoformans. These results showed that VD₃ could exert significant antifungal activities both in vitro and in vivo, demonstrating its potential application in the treatment of cryptococcal infections. Full article

(This article belongs to the Special Issue Pathogenesis in Human Fungal Pathogens)

► Show Figures

Figure 1

22 pages, 4661 KiB

Open AccessReview

Suppression of Chitin-Triggered Immunity by Plant Fungal Pathogens: A Case Study of the Cucurbit Powdery Mildew Fungus Podosphaera xanthii

by Nisrine Bakhat, Alejandra Vielba-Fernández, Isabel Padilla-Roji, Jesús Martínez-Cruz, Álvaro Polonio, Dolores Fernández-Ortuño and Alejandro Pérez-García

J. Fungi 2023, 9(7), 771; https://doi.org/10.3390/jof9070771 - 21 Jul 2023

Cited by 10 | Viewed by 3700

Abstract

Fungal pathogens are significant plant-destroying microorganisms that present an increasing threat to the world’s crop production. Chitin is a crucial component of fungal cell walls and a conserved MAMP (microbe-associated molecular pattern) that can be recognized by specific plant receptors, activating chitin-triggered immunity. [...] Read more.

Fungal pathogens are significant plant-destroying microorganisms that present an increasing threat to the world’s crop production. Chitin is a crucial component of fungal cell walls and a conserved MAMP (microbe-associated molecular pattern) that can be recognized by specific plant receptors, activating chitin-triggered immunity. The molecular mechanisms underlying the perception of chitin by specific receptors are well known in plants such as rice and Arabidopsis thaliana and are believed to function similarly in many other plants. To become a plant pathogen, fungi have to suppress the activation of chitin-triggered immunity. Therefore, fungal pathogens have evolved various strategies, such as prevention of chitin digestion or interference with plant chitin receptors or chitin signaling, which involve the secretion of fungal proteins in most cases. Since chitin immunity is a very effective defensive response, these fungal mechanisms are believed to work in close coordination. In this review, we first provide an overview of the current understanding of chitin-triggered immune signaling and the fungal proteins developed for its suppression. Second, as an example, we discuss the mechanisms operating in fungal biotrophs such as powdery mildew fungi, particularly in the model species Podosphaera xanthii, the main causal agent of powdery mildew in cucurbits. The key role of fungal effector proteins involved in the modification, degradation, or sequestration of immunogenic chitin oligomers is discussed in the context of fungal pathogenesis and the promotion of powdery mildew disease. Finally, the use of this fundamental knowledge for the development of intervention strategies against powdery mildew fungi is also discussed. Full article

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

► Show Figures

Figure 1

14 pages, 1286 KiB

Open AccessArticle

Candida palmioleophila: A New Emerging Threat in Brazil?

by Gisela Lara da Costa, Melyssa Negri, Rodrigo Prado Rodrigues de Miranda, Danielly Corrêa-Moreira, Tatiana Castro Abreu Pinto, Livia de Souza Ramos, Deisiany Gomes Ferreira, Bruna Salomão, Tulio Machado Fumian, Camille Ferreira Mannarino, Tatiana Prado, Marise Pereira Miagostovich, André Luis Souza dos Santos and Manoel Marques Evangelista Oliveira

J. Fungi 2023, 9(7), 770; https://doi.org/10.3390/jof9070770 - 21 Jul 2023

Cited by 3 | Viewed by 2150

Abstract

Human activity directly or indirectly causes climate change, promoting changes in the composition of the atmosphere. This change is beyond the variation of the natural climate. In this manner, climate change could create an environmental pressure which is enough to trigger new fungal [...] Read more.

Human activity directly or indirectly causes climate change, promoting changes in the composition of the atmosphere. This change is beyond the variation of the natural climate. In this manner, climate change could create an environmental pressure which is enough to trigger new fungal diseases. In addition to climate alterations, the onset of the COVID-19 pandemic has also been associated with the emergence of fungal pathogens. Fungi showed that an inability to grow at high temperatures limits the capacity of fungi to infect mammals. However, fungi can develop thermotolerance, gradually adapting to rising temperatures due to climate change, and generating a greater number of disease-causing organisms. In the present study, we reported the detection and identification of Candida palmioleophila isolates recovered from raw sewage samples in Niteroi city, Rio de Janeiro State, Brazil, during a monitoring program for measuring SARS-CoV-2 presence and concentration. Using polyphasic taxonomy to identify the species and evaluating some virulence aspects of this species, such as biofilm formation and extracellular enzyme production, our data highlight this species as a possible emerging pathogen in Brazil, especially in the pandemic context. Full article

(This article belongs to the Special Issue Young Investigators of Human Pathogenic Fungi)

► Show Figures

Figure 1

13 pages, 644 KiB

Open AccessArticle

The Impact of COVID-19 on the Epidemiology and Outcomes of Candidemia: A Retrospective Study from a Tertiary Care Center in Lebanon

by Aline El Zakhem, Omar Mahmoud, Johnny Zakhour, Sarah B. Nahhal, Nour El Ghawi, Nadine Omran, Walaa G. El Sheikh, Hani Tamim and Souha S. Kanj

J. Fungi 2023, 9(7), 769; https://doi.org/10.3390/jof9070769 - 21 Jul 2023

Cited by 3 | Viewed by 1952

Abstract

Invasive fungal infections, notably candidemia, have been associated with COVID-19. The epidemiology of candidemia has significantly changed during the COVID-19 pandemic. We aim to identify the microbiological profile, resistance rates, and outcomes of COVID-19-associated candidemia (CAC) compared to patients with candidemia not associated [...] Read more.

Invasive fungal infections, notably candidemia, have been associated with COVID-19. The epidemiology of candidemia has significantly changed during the COVID-19 pandemic. We aim to identify the microbiological profile, resistance rates, and outcomes of COVID-19-associated candidemia (CAC) compared to patients with candidemia not associated with COVID-19. We retrospectively collected data on patients with candidemia admitted to the American University of Beirut Medical Center between 2004 and 2022. We compared the epidemiology of candidemia during and prior to the COVID-19 pandemic. Additionally, we compared the outcomes of critically ill patients with CAC to those with candidemia without COVID-19 from March 2020 till March 2022. Among 245 candidemia episodes, 156 occurred prior to the pandemic and 89 during the pandemic. Of the latter, 39 (43.8%) were CAC, most of which (82%) were reported from intensive care units (ICU). Non-albicans Candida (NAC) spp. were predominant throughout the study period (67.7%). Candida auris infection was the most common cause of NAC spp. in CAC. C. glabrata had decreased susceptibility rates to fluconazole and caspofungin during the pandemic period (46.1% and 38.4%, respectively). The mortality rate in the overall ICU population during the pandemic was 76.6%, much higher than the previously reported candidemia mortality rate observed in studies involving ICU patients. There was no significant difference in 30-day mortality between CAC and non-CAC (75.0% vs. 78.1%; p = 0.76). Performing ophthalmic examination (p = 0.002), CVC removal during the 48 h following the candidemia (p = 0.008) and speciation (p = 0.028) were significantly associated with a lower case-fatality rate. The epidemiology of candidemia has been significantly affected by the COVID-19 pandemic at our center. Rigorous infection control measures and proper antifungal stewardship are essential to combat highly resistant species such as C. auris. Full article

(This article belongs to the Special Issue Invasive Candidiasis)

► Show Figures

Figure 1

21 pages, 4732 KiB

Open AccessArticle

Quantifying Isoprenoids in the Ergosterol Biosynthesis by Gas Chromatography–Mass Spectrometry

by Maximilian Liebl, Ludwig Huber, Hesham Elsaman, Petra Merschak, Johannes Wagener, Fabio Gsaller and Christoph Müller

J. Fungi 2023, 9(7), 768; https://doi.org/10.3390/jof9070768 - 20 Jul 2023

Cited by 2 | Viewed by 2032

Abstract

The ergosterol pathway is a promising target for the development of new antifungals since its enzymes are essential for fungal cell growth. Appropriate screening assays are therefore needed that allow the identification of potential inhibitors. We developed a whole-cell screening method, which can [...] Read more.

The ergosterol pathway is a promising target for the development of new antifungals since its enzymes are essential for fungal cell growth. Appropriate screening assays are therefore needed that allow the identification of potential inhibitors. We developed a whole-cell screening method, which can be used to identify compounds interacting with the enzymes of isoprenoid biosynthesis, an important part of the ergosterol biosynthesis pathway. The method was validated according to the EMEA guideline on bioanalytical method validation. Aspergillus fumigatus hyphae and Saccharomyces cerevisiae cells were lysed mechanically in an aqueous buffer optimized for the enzymatic deconjugation of isoprenoid pyrophosphates. The residual alcohols were extracted, silylated and analyzed by GC-MS. The obtained isoprenoid pattern provides an indication of the inhibited enzyme, due to the accumulation of specific substrates. By analyzing terbinafine-treated A. fumigatus and mutant strains containing tunable gene copies of erg9 or erg1, respectively, the method was verified. Downregulation of erg9 resulted in a high accumulation of intracellular farnesol as well as elevated levels of geranylgeraniol and isoprenol. The decreased expression of erg1 as well as terbinafine treatment led to an increased squalene content. Additional analysis of growth medium revealed high farnesyl pyrophosphate levels extruded during erg9 downregulation. Full article

(This article belongs to the Special Issue Young Investigators of Human Pathogenic Fungi)

► Show Figures

Figure 1

18 pages, 6390 KiB

Open AccessArticle

Preparation of High Water-Soluble Trichoderma Co-Culture Metabolite Powder and Its Effects on Seedling Emergence Rate and Growth of Crops

by Lusheng Chen, Dazhi Hao, Kai Dou, Bo Lang, Xinhua Wang, Yaqian Li and Jie Chen

J. Fungi 2023, 9(7), 767; https://doi.org/10.3390/jof9070767 - 20 Jul 2023

Cited by 3 | Viewed by 2054

Abstract

Trichoderma spp. are widely used beneficial microbes in agricultural production; however, the improper carrier choice for Trichoderma agent preparation can alter the effectiveness of Trichoderma fungicides. In this study, the co-culture of four Trichoderma strains produced a large amount of free amino acids, [...] Read more.

Trichoderma spp. are widely used beneficial microbes in agricultural production; however, the improper carrier choice for Trichoderma agent preparation can alter the effectiveness of Trichoderma fungicides. In this study, the co-culture of four Trichoderma strains produced a large amount of free amino acids, with a content of 392.8414 ug/mL, and significantly improved the production level of γ-aminobutyric acid. A greenhouse experiment further showed that the co-culture of Trichoderma synergistically improved the female flower development and bacterial angular leaf spot resistance. The effects of ten kinds of carriers were compared in terms of water absorption and heat generation, as well as their effects on the seedling emergence rate and the plant growth promotion of maize, cucumber, and pakchoi cabbage. Each carrier was screened to mix with four strains of co-culture metabolites to prepare highly soluble and quality powders. The results showed that there were different effects of the carriers themselves and Trichoderma strain co-culture metabolite powder prepared with the carriers on seedling emergence rate and seedling growth. Β-cyclodextrin performed best in high solubility and low heat generation upon absorbing water and in easy drying in processing operations. Trichoderma strains co-culture metabolite powder with β-cyclodextrin as a carrier provided the most obvious promotion effects on seedling emergence rate and seedling growth. Therefore, β-cyclodextrin was determined to be an ideal carrier to prepare a highly water-soluble Trichoderma agent. Taken together, the study successfully developed a new type of highly soluble powder containing Trichoderma co-culture metabolites that is expected to benefit farming drip irrigation and spraying systems for the promotion of crop growth and disease control. Full article

(This article belongs to the Special Issue Application of Trichoderma Strains and Their Metabolites in Agriculture)

► Show Figures

Figure 1

16 pages, 746 KiB

Open AccessReview

Soil Aspergillus Species, Pathogenicity and Control Perspectives

by Queenta Ngum Nji, Olubukola Oluranti Babalola and Mulunda Mwanza

J. Fungi 2023, 9(7), 766; https://doi.org/10.3390/jof9070766 - 20 Jul 2023

Cited by 15 | Viewed by 3797

Abstract

Five Aspergillus sections have members that are established agricultural pests and producers of different metabolites, threatening global food safety. Most of these pathogenic Aspergillus species have been isolated from almost all major biomes. The soil remains the primary habitat for most of these [...] Read more.

Five Aspergillus sections have members that are established agricultural pests and producers of different metabolites, threatening global food safety. Most of these pathogenic Aspergillus species have been isolated from almost all major biomes. The soil remains the primary habitat for most of these cryptic fungi. This review explored some of the ecological attributes that have contributed immensely to the success of the pathogenicity of some members of the genus Aspergillus over time. Hence, the virulence factors of the genus Aspergillus, their ecology and others were reviewed. Furthermore, some biological control techniques were recommended. Pathogenic effects of Aspergillus species are entirely accidental; therefore, the virulence evolution prediction model in such species becomes a challenge, unlike their obligate parasite counterparts. In all, differences in virulence among organisms involved both conserved and species-specific genetic factors. If the impacts of climate change continue, new cryptic Aspergillus species will emerge and mycotoxin contamination risks will increase in all ecosystems, as these species can metabolically adjust to nutritional and biophysical challenges. As most of their gene clusters are silent, fungi continue to be a source of underexplored bioactive compounds. The World Soil Charter recognizes the relevance of soil biodiversity in supporting healthy soil functions. The question of how a balance may be struck between supporting healthy soil biodiversity and the control of toxic fungi species in the field to ensure food security is therefore pertinent. Numerous advanced strategies and biocontrol methods so far remain the most environmentally sustainable solution to the control of toxigenic fungi in the field. Full article

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

► Show Figures

Figure 1

19 pages, 1969 KiB

Open AccessReview

Safe Production Strategies for Soil-Covered Cultivation of Morel in Heavy Metal-Contaminated Soils

by Xue Li, Tianhong Fu, Hongzhao Li, Bangxi Zhang, Wendi Li, Baige Zhang, Xiaomin Wang, Jie Wang, Qing Chen, Xuehan He, Hao Chen, Qinyu Zhang, Yujin Zhang, Rende Yang and Yutao Peng

J. Fungi 2023, 9(7), 765; https://doi.org/10.3390/jof9070765 - 20 Jul 2023

Cited by 3 | Viewed by 2849

Abstract

Morel is a popular edible mushroom with considerable medicinal and economic value which has garnered global popularity. However, the increasing heavy metal (HM) pollution in the soil presents a significant challenge to morels cultivation. Given the susceptibility of morels to HM accumulation, the [...] Read more.

Morel is a popular edible mushroom with considerable medicinal and economic value which has garnered global popularity. However, the increasing heavy metal (HM) pollution in the soil presents a significant challenge to morels cultivation. Given the susceptibility of morels to HM accumulation, the quality and output of morels are at risk, posing a serious food safety concern that hinders the development of the morel industry. Nonetheless, research on the mechanism of HM enrichment and mitigation strategies in morel remains scarce. The morel, being cultivated in soil, shows a positive correlation between HM content in its fruiting body and the HM content in the soil. Therefore, soil remediation emerges as the most practical and effective approach to tackle HM pollution. Compared to physical and chemical remediation, bioremediation is a low-cost and eco-friendly approach that poses minimal threats to soil composition and structure. HMs easily enriched during morels cultivation were examined, including Cd, Cu, Hg, and Pb, and we assessed soil passivation technology, microbial remediation, strain screening and cultivation, and agronomic measures as potential approaches for HM pollution prevention. The current review underscores the importance of establishing a comprehensive system for preventing HM pollution in morels. Full article

► Show Figures

Figure 1

17 pages, 5131 KiB

Open AccessArticle

Glucose-6-phosphate 1-Epimerase CrGlu6 Contributes to Development and Biocontrol Efficiency in Clonostachys chloroleuca

by Binna Lv, Yan Guo, Xue Zhao, Shidong Li and Manhong Sun

J. Fungi 2023, 9(7), 764; https://doi.org/10.3390/jof9070764 - 20 Jul 2023

Viewed by 1844

Abstract

Clonostachys chloroleuca (formerly classified as C. rosea) is an important mycoparasite active against various plant fungal pathogens. Mitogen-activated protein kinase (MAPK) signaling pathways are vital in mycoparasitic interactions; they participate in responses to diverse stresses and mediate fungal development. In previous studies, [...] Read more.

Clonostachys chloroleuca (formerly classified as C. rosea) is an important mycoparasite active against various plant fungal pathogens. Mitogen-activated protein kinase (MAPK) signaling pathways are vital in mycoparasitic interactions; they participate in responses to diverse stresses and mediate fungal development. In previous studies, the MAPK-encoding gene Crmapk has been proven to be involved in mycoparasitism and the biocontrol processes of C. chloroleuca, but its regulatory mechanisms remain unclear. Aldose 1-epimerases are key enzymes in filamentous fungi that generate energy for fungal growth and development. By protein–protein interaction assays, the glucose-6-phosphate 1-epimerase CrGlu6 was found to interact with Crmapk, and expression of the CrGlu6 gene was significantly upregulated when C. chloroleuca colonized Sclerotinia sclerotiorum sclerotia. Gene deletion and complementation analyses showed that CrGlu6 deficiency caused abnormal morphology of hyphae and cells, and greatly reduced conidiation. Moreover, deletion mutants presented much lower antifungal activities and mycoparasitic ability, and control efficiency against sclerotinia stem rot was markedly decreased. When the CrGlu6 gene was reinserted, all biological characteristics and biocontrol activities were recovered. These findings provide new insight into the mechanisms of glucose-6-phosphate 1-epimerase in mycoparasitism and help to further reveal the regulation of MAPK and its interacting proteins in the biocontrol of C. chloroleuca. Full article

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

► Show Figures

Figure 1

23 pages, 2369 KiB

Open AccessArticle

Nutritional Assessment of Lactarius drassinus and L. controversus from the Cold Desert Region of the Northwest Himalayas for Their Potential as Food Supplements

by Hom-Singli Mayirnao, Samta Gupta, Sarda Devi Thokchom, Karuna Sharma, Tahir Mehmood, Surinder Kaur, Yash Pal Sharma and Rupam Kapoor

J. Fungi 2023, 9(7), 763; https://doi.org/10.3390/jof9070763 - 20 Jul 2023

Cited by 2 | Viewed by 2130

Abstract

Kargil is a cold desert with hostile ecological conditions such as low temperature and precipitation, as well as difficult terrains. However, several wild mushrooms thrive well under such an extreme environment. Despite their abundance, the chemical composition of indigenous mushrooms has not been [...] Read more.

Kargil is a cold desert with hostile ecological conditions such as low temperature and precipitation, as well as difficult terrains. However, several wild mushrooms thrive well under such an extreme environment. Despite their abundance, the chemical composition of indigenous mushrooms has not been explored. This study aimed to assess the potential of two wild edible mushrooms from Kargil, Lactarius drassinus and Lactarius controversus, as food supplements by evaluating their nutritional and nutraceutical properties. Nutritional attributes such as total protein, available carbohydrates, soluble sugars, and vitamins were found to be high in the mushroom species. Furthermore, high mineral accumulation and relatively lower antinutrient concentrations resulted in higher bioavailabilities of Zn, Fe, Ca, and Mg. Gas-chromatography–mass-spectrometry-based metabolite profiling revealed that although the two mushroom species showed similar metabolite compositions, their relative concentrations differed. Sugars were the predominant compounds identified in both the species, with sugar alcohols being the major contributor. The second most abundant class of compound in L. drassinus was amino acids, with 5-oxoproline as the major contributor. On the other hand, fatty acids were the second most abundant compounds in L. controversus, with high oleic and linoleic acid concentrations. In the ultra-performance-liquid-chromatography-based quantification of phenolic compounds, chlorogenic acid was found to be highest in in terms of its concentration in both the mushrooms studied, followed by quercetin dihydrate and gallic acid in L. drassinus and L. controversus, respectively. Moreover, high antioxidant activities attributable to their high phenol, flavonoid, and carotenoid concentrations were observed. Overall, the two mushrooms offer well-balanced sources of nutritional and nutraceutical compounds, making them healthy foods. Full article

(This article belongs to the Special Issue Edible Mushroom 3.0)

► Show Figures

Figure 1

25 pages, 1998 KiB

Open AccessArticle

Evaluating Food Additives Based on Organic and Inorganic Salts as Antifungal Agents against Monilinia fructigena and Maintaining Postharvest Quality of Apple Fruit

by Nadia Lyousfi, Ikram Legrifi, Nabil Ennahli, Abdelali Blenzar, Said Amiri, Salah-Eddine Laasli, Nadia Handaq, Zineb Belabess, Essaid Ait Barka and Rachid Lahlali

J. Fungi 2023, 9(7), 762; https://doi.org/10.3390/jof9070762 - 19 Jul 2023

Cited by 3 | Viewed by 1882

Abstract

A set of commonly used food additives was evaluated for their antifungal activity against the brown rot disease of fruits caused by the fungal pathogen Monilinia fructigena, which is one of the most economically important agents, causing important damage to pome fruits, [...] Read more.

A set of commonly used food additives was evaluated for their antifungal activity against the brown rot disease of fruits caused by the fungal pathogen Monilinia fructigena, which is one of the most economically important agents, causing important damage to pome fruits, such as pears and apples. The radial mycelial growth of the fungal pathogen was assessed in PDA amended with different concentrations (0.5, 2, 2.5, and 5%) of each additive. The results underlined that most of the additives displayed a significant inhibition of mycelial growth, with the extent of inhibition varying depending on the specific additive and concentration used. Five food additives showed high inhibition rates (above 88%), of which sodium bicarbonate, sodium carbonate, copper sulphate, and sodium hydroxide were the most effective, whereas ammonium carbonate, magnesium chlorite, and citric acid were the least effective. Interestingly, the coatings containing sodium bicarbonate, copper sulphate, and ammonium bicarbonate significantly reduced the incidence of brown rot disease in apples, but other additives were not effective, such as ammonium carbonate and magnesium sulphate. The anhydrous sodium sulphate used at a concentration of 2%, was found to be one of the least effective additives, with a reduction rate of 20%. Subsequently, food additives showing good growth inhibition rates and reduction in disease severity were then tested in semi-commercial trials at temperatures of 4 °C and 22 °C. The results indicated that these additives demonstrate effectiveness in controlling M. fructigena at specific concentrations, and lower temperatures (4 °C) can improve the efficiency of the control measures. In addition, the selected food additives exhibited significant antimicrobial activity against M. fructigena, suggesting their application as a promising alternative for managing brown rot disease in apple fruits. Full article

(This article belongs to the Special Issue Plant Fungal Pathogens: Isolation, Characterization and Control Strategies, 2nd Edition)

► Show Figures

Figure 1

34 pages, 14662 KiB

Open AccessArticle

New Species of Didymellaceae within Aquatic Plants from Southwestern China

by Tong Chen, Siyuan Wang, Xinwei Jiang, Ying Huang, Minghe Mo and Zefen Yu

J. Fungi 2023, 9(7), 761; https://doi.org/10.3390/jof9070761 - 19 Jul 2023

Cited by 4 | Viewed by 2493

Abstract

Members of Didymellaceae have a wide geographical distribution throughout different ecosystems, and most species are associated with fruit, leaf, stem and root diseases of land plants. However, species that occur in aquatic plants are not clearly known. During a survey of the diversity [...] Read more.

Members of Didymellaceae have a wide geographical distribution throughout different ecosystems, and most species are associated with fruit, leaf, stem and root diseases of land plants. However, species that occur in aquatic plants are not clearly known. During a survey of the diversity of endophytes in aquatic plants in Yunnan, Sichuan, and Guizhou provinces, we obtained 51 isolates belonging to Didymellaceae based on internal transcribed spacer region (ITS) sequences. Further, the phylogenetic positions of these isolates were determined by combined sequences composed of ITS, partial large subunit nrRNA gene (28S nrDNA; LSU), RNA polymerase II second largest subunit (rpb2) and partial beta-tubulin gene (tub2). Combining morphological characteristics and multi-locus phylogenetic analyses, two new varieties belong to Boeremia and 12 new species distributed into seven genera were recognized from 51 isolates, i.e., Cumuliphoma, Didymella, Dimorphoma, Ectophoma, Leptosphaerulina, Remotididymella, and Stagonosporopsis. Among these species, only one species of Stagonosporopsis and two species of Leptosphaerulina show teleomorphic stages on OA, but have no anamorphic state. Each new species is described in detail, and the differences between new species and their phylogenetically related species are discussed here. The high frequency of new species indicates that aquatic plants may be a special ecological niche which highly promotes species differentiation. At the same time, the frequent occurrence of new species may indicate the need for extensive investigation of fungal resources in those aquatic environments where fungal diversity may be underestimated. Full article

(This article belongs to the Special Issue Freshwater Fungal Diversity)

► Show Figures

Figure 1

13 pages, 3178 KiB

Open AccessReview

Fungal Biodegradation of Polyurethanes

by Clotilde Maestri, Lionel Plancher, Alexis Duthoit, Ronan L. Hébert and Patrick Di Martino

J. Fungi 2023, 9(7), 760; https://doi.org/10.3390/jof9070760 - 19 Jul 2023

Cited by 6 | Viewed by 3761

Abstract

Polyurethanes (PURs) are versatile polymers used in a wide variety of fields, such as the medical, automotive, textile, thermal insulation, and coating industries as well as many everyday objects. Many PURs have applications that require a long service life, sometimes with exposure to [...] Read more.

Polyurethanes (PURs) are versatile polymers used in a wide variety of fields, such as the medical, automotive, textile, thermal insulation, and coating industries as well as many everyday objects. Many PURs have applications that require a long service life, sometimes with exposure to aggressive conditions. They can undergo different types of physicochemical and biological degradation, but they are not compostable, and many of them constitute persistent waste in the environment. Although both bacteria and fungi can be involved in the degradation of PURs, fungi are often the main biodegradation agents. The chemical structure of PURs determines their degree of biodegradation. Fungal biodegradation of PURs is linked to the production of enzymes, mainly esterases and proteases, alongside laccases, peroxidases, and tyrosinases, which can modify the structure of polyurethane compounds by forming carbonyl groups. The experimental analysis of the biodegradation of PUR can be carried out by bringing the polymer into contact with a mold in pure culture or with a microbial consortium. Then, global measurements can be taken, such as weight loss, tensile tests, or the ability of microorganisms to grow in the presence of PUR as the sole carbon source. The analysis of the chemical structure of the polymer and its degradation products after fungal growth can confirm biodegradation and specify the mechanism. The main avenues of future research are directed towards the development of fully biodegradable PURs and, on the contrary, towards the development of PURs that are more resistant to degradation phenomena, in particular biodegradation, for applications where the material is in contact with living organisms. Full article

(This article belongs to the Special Issue Fungal Biodeterioration)

► Show Figures

Figure 1

11 pages, 1020 KiB

Open AccessArticle

The Potential of Metarhizium anisopliae Blastospores to Control Aedes aegypti Larvae in the Field

by Simone Azevedo Gomes, Aline Teixeira Carolino, Thais Berçot Pontes Teodoro, Gerson Adriano Silva, Ricardo de Oliveira Barbosa Bitencourt, Carlos Peres Silva, Abeer M. Alkhaibari, Tariq M. Butt and Richard Ian Samuels

J. Fungi 2023, 9(7), 759; https://doi.org/10.3390/jof9070759 - 18 Jul 2023

Cited by 9 | Viewed by 2363

Abstract

Entomopathogenic fungi are promising as an environmentally benign alternative to chemical pesticides for mosquito control. The current study investigated the virulence of Metarhizium anisopliae blastospores against Aedes aegypti under both laboratory and field conditions. Virulence bioassays of conidia and blastospores were conducted in [...] Read more.

Entomopathogenic fungi are promising as an environmentally benign alternative to chemical pesticides for mosquito control. The current study investigated the virulence of Metarhizium anisopliae blastospores against Aedes aegypti under both laboratory and field conditions. Virulence bioassays of conidia and blastospores were conducted in the laboratory, while field simulation bioassays were conducted under two conditions: totally shaded (TS) or partially shaded (PS). In the first bioassay (zero h), the larvae were added to the cups shortly after the preparation of the blastospores, and in the subsequent assays, larvae were added to the cups 3, 6, 9, and 12 days later. The survival of the larvae exposed to blastospores in the laboratory was zero on day two, as was the case for the larvae exposed to conidia on the sixth day. Under TS conditions, zero survival was seen on the third day of the bioassay. Under PS conditions, low survival rates were recorded on day 7. For the persistence bioassay under PS conditions, low survival rates were also observed. Metarhizium anisopliae blastospores were more virulent to Ae. aegypti larvae than conidia in the laboratory. Blastospores remained virulent under field simulation conditions. However, virulence rapidly declined from the third day of field bioassays. Formulating blastospores in vegetable oil could protect these propagules when applied under adverse conditions. This is the first time that blastospores have been tested against mosquito larvae under simulated field conditions, and the current study could be the basis for the development of a new biological control agent. Full article

(This article belongs to the Special Issue Multifaceted Beauveria bassiana and Other Insect-Related Fungi 2.0)

► Show Figures

Figure 1

17 pages, 1904 KiB

Open AccessArticle

Synthesis of Altissimacoumarin D and Other Prenylated Coumarins and Their Ability to Reverse the Multidrug Resistance Phenotype in Candida albicans

by Anna Claudia Silva, Daniel Clemente de Moraes, Denilson Costa do Carmo, Giselle Cristina Casaes Gomes, A. Ganesan, Rosangela Sabbatini Capella Lopes, Antonio Ferreira-Pereira and Cláudio Cerqueira Lopes

J. Fungi 2023, 9(7), 758; https://doi.org/10.3390/jof9070758 - 18 Jul 2023

Cited by 2 | Viewed by 1526

Abstract

Azoles are the main antifungal agents employed in clinical practice to treat invasive candidiasis. Nonetheless, their efficacy is limited by fungal resistance mechanisms, mainly the overexpression of efflux pumps. Consequently, candidiasis has a worrisome death rate of 75%. One potential strategy to overcome [...] Read more.

Azoles are the main antifungal agents employed in clinical practice to treat invasive candidiasis. Nonetheless, their efficacy is limited by fungal resistance mechanisms, mainly the overexpression of efflux pumps. Consequently, candidiasis has a worrisome death rate of 75%. One potential strategy to overcome efflux-mediated resistance is to inhibit this process. Ailanthus altissima is a Chinese tree that produces several active substances, including altissimacoumarin D. Due to the low yield of its extraction and the need to search for new drugs to treat candidiasis, this study aimed to synthesize altissimacoumarin D and its analogues, as well as evaluating their ability to reverse the resistance phenotype of Candida albicans. Coumarin isofraxidin was prepared via total synthesis through a solvent-free Knoevenagel condensation as the key step. Isofraxidin and other commercially available coumarins were alkylated with prenyl or geranyl groups to yield the natural product altissimacoumarin D and seven analogues. The antifungal activity of the coumarins and their ability to reverse the fungal resistance phenotype were assessed using microbroth methodologies. Toxicity was evaluated using erythrocytes and an in silico prediction. All compounds improved the antifungal activity of fluconazole by inhibiting efflux pumps, and ACS47 and ACS50 were the most active. None of the coumarins were toxic to erythrocytes. In silico predictions indicate that ACS47 and ACS50 may be safe for human use. ACS47 and ACS50 are promising candidates when used as adjuvants in the antifungal therapy against C. albicans-resistant strains. Full article

(This article belongs to the Special Issue Multidrug-Resistant Fungi)

► Show Figures

Figure 1

8 pages, 265 KiB

Open AccessCommunication

Prevalence of Histoplasma Antigenuria among Outpatient Cohort with Advanced HIV in Kampala, Uganda

by Preethiya Sekar, Elizabeth Nalintya, Richard Kwizera, Claudine Mukashyaka, Godfrey Niyonzima, Loryndah Olive Namakula, Patricia Nerima, Ann Fieberg, Biyue Dai, Jayne Ellis, David R. Boulware, David B. Meya, Nathan C. Bahr and Radha Rajasingham

J. Fungi 2023, 9(7), 757; https://doi.org/10.3390/jof9070757 - 18 Jul 2023

Cited by 4 | Viewed by 1867

Abstract

In sub-Saharan Africa, an estimated 25% of people with HIV present with advanced HIV and are at high risk of opportunistic infections. Whereas histoplasmosis has occasionally been seen in Uganda, the understanding of the local risk of acute infection is limited. We sought [...] Read more.

In sub-Saharan Africa, an estimated 25% of people with HIV present with advanced HIV and are at high risk of opportunistic infections. Whereas histoplasmosis has occasionally been seen in Uganda, the understanding of the local risk of acute infection is limited. We sought to determine the prevalence of Histoplasma antigenuria using an enzyme immunoassay (EIA, clarus Histoplasma GM EIA, IMMY; Norman, OK, USA) in a cohort of outpatients with advanced HIV disease in Kampala, Uganda. Among the persons with positive urine Histoplasma antigen tests, we assessed their clinical presentation and outcomes. The EIA was run on stored urine samples as per the manufacturer’s instructions. Specimens ≥1 EIA units were considered positive. Among the 388 tested urine samples, 4 (1.2%) were positive for Histoplasma antigen. The histoplasmosis prevalence among participants with a CD4 < 100 cells/mcL was 2.5% (4/158). Three of the four participants with a positive Histoplasma antigen test reported systemic symptoms consistent with histoplasmosis. All four participants had a positive urine lipoarabinomannan test and were treated for tuberculosis. By the four-week follow-up visit, all participants were clinically improved, alive, and in care without antifungal therapy. In advanced HIV, the clinical presentations of tuberculosis and histoplasmosis overlap. The value of histoplasmosis screening and pre-emptive treatment is an area of future research. Full article

(This article belongs to the Special Issue Histoplasma and Histoplasmosis 2023)

15 pages, 4026 KiB

Open AccessArticle

Antimicrobial Activity the Essential Oil from Croton pluriglandulosus Carn. Leaves against Microorganisms of Clinical Interest

by Rayara J. P. Carvalho, Pedro F. N. Souza, Ellen A. Malveira, Nilton A. S. Neto, Romério R. S. Silva, Gabriel L. C. Melo, Ayrles F. B. Silva, Leandro B. Lima, Cynthia C. de Albuquerque, Rafael W. Bastos, Gustavo H. Goldman and Cleverson D. T. de Freitas

J. Fungi 2023, 9(7), 756; https://doi.org/10.3390/jof9070756 - 17 Jul 2023

Cited by 2 | Viewed by 1809

Abstract

Multiresistant pathogens pose a serious threat to human health. The genus Candida is one class of human pathogenic yeasts responsible for infections affecting healthy and immunocompromised patients. In this context, plant essential oils emerged as a future natural alternative to control the diseases [...] Read more.

Multiresistant pathogens pose a serious threat to human health. The genus Candida is one class of human pathogenic yeasts responsible for infections affecting healthy and immunocompromised patients. In this context, plant essential oils emerged as a future natural alternative to control the diseases caused by these pathogens. Based on that, the present study aimed to evaluate the antimicrobial potential of essential oil from C. pluriglandulosus and understand the mechanism of action. Here, it highlighted antimicrobial activity and the mechanisms of action of the essential oil extracted from C. pluriglandulosus Carn.-Torres & Riina (CpEO) leaves on human pathogenic microorganisms in planktonic and biofilm lifestyles. In addition, for the first time, the oil composition was revealed by GC-MS analysis and the toxicity to human red blood cells (HRBC). Twenty-six chemical compounds were identified in CpEO, elemicin, bicyclogermacrene, caryophyllene, brevifolin, and 2,4,6-trimethoxy-styrene. Through hemolytic assay, it was shown that CpEO has no toxicity to human RBCs. At the concentration of 50 μg mL⁻¹, CpEO did not show great antibacterial potential. However, promising data were found for C. krusei and C. parapsilosis inhibiting by 89.3% and 80.7% of planktonic cell growth and 83.5% and 77.9% the biofilm formation, respectively. Furthermore, the mechanisms of action CpEO were elucidated by fluorescence. Scanning electron microscopy revealed damage to the cell membrane and pore formation, ROS overproduction, and induction of apoptosis in candida cells. Our results reinforce the potential of CpEO as an effective alternative molecule of pharmaceutical interest. Full article

► Show Figures

Figure 1

11 pages, 3917 KiB

Open AccessArticle

Conidia Fusion: A Mechanism for Fungal Adaptation to Nutrient-Poor Habitats

by Xinju Yang, Fa Zhang, Yaoquan Yang, Faping Zhou, Saranyaphat Boonmee, Wen Xiao and Xiaoyan Yang

J. Fungi 2023, 9(7), 755; https://doi.org/10.3390/jof9070755 - 17 Jul 2023

Cited by 1 | Viewed by 1445

Abstract

Conidia fusion (CF) is a commonly observed structure in fungi. However, it has not been systematically studied. This study examined 2457 strains of nematode-trapping fungi (NTF) to explore the species specificity, physiological period, and physiological significance of CF. The results demonstrated that only [...] Read more.

Conidia fusion (CF) is a commonly observed structure in fungi. However, it has not been systematically studied. This study examined 2457 strains of nematode-trapping fungi (NTF) to explore the species specificity, physiological period, and physiological significance of CF. The results demonstrated that only six species of Arthrobotrys can form CF among the sixty-five tested NTF species. The studies on the model species Arthrobotrys oligospora (DL228) showed that CF occurred in both shed and unshed plus mature and immature conidia. Additionally, the conidia fusion rate (CFR) increased significantly with the decrease of nutrient concentration in habitats. The studies on the conidia fusion body (CFB) produced by A. oligospora (DL228) revealed that the more conidia contained in the CFB, the faster and denser the mycelia of the CFB germinated in weak nutrient medium and soil plates. On the one hand, rapid mycelial extension is beneficial for the CFB to quickly find new nutrient sources in habitats with uneven nutrient distribution. On the other hand, dense mycelium increases the contact area with the environment, improving the nutrient absorption efficiency, which is conducive to improving the survival rate of conidia in the weak nutrient environment. In addition, all species that form CF produce smaller conidia. Based on this observation, CF may be a strategy to balance the defects (nutrient deficiency) caused by conidia miniaturization. Full article

(This article belongs to the Special Issue New Perspectives on Entomopathogenic and Nematode-Trapping Fungi, 2nd Edition)

► Show Figures

Figure 1

32 pages, 16662 KiB

Open AccessArticle

Four Novel Species and Two New Records of Boletes from India

by Kanad Das, Aniket Ghosh, Dyutiparna Chakraborty, Sudeshna Datta, Ishika Bera, Ranjith Layola MR, Farheen Banu, Alfredo Vizzini and Komsit Wisitrassameewong

J. Fungi 2023, 9(7), 754; https://doi.org/10.3390/jof9070754 - 17 Jul 2023

Cited by 5 | Viewed by 2086

Abstract

Repeated macrofungal explorations, followed by thorough examination of species through morphology and molecular phylogeny, have made it clear that European and American names of wild mushrooms were inadvertently misapplied quite often to Asian lookalikes by mycologists/taxonomists in the past. Therefore, in order to [...] Read more.

Repeated macrofungal explorations, followed by thorough examination of species through morphology and molecular phylogeny, have made it clear that European and American names of wild mushrooms were inadvertently misapplied quite often to Asian lookalikes by mycologists/taxonomists in the past. Therefore, in order to reveal this mushroom treasure, in recent years, taxonomical research on wild mushrooms has been intensified in Asian countries, including India, by undertaking a combined approach of morpho-taxonomy and multigene molecular phylogeny. Boletoid mushrooms (Boletaceae) are no exception. While working on boletoid mushrooms of the Indian Himalayas, authors recently came across six interesting species of boletoid mushrooms. In the present communication, four novel species, namely Leccinellum binderi, Cyanoboletus paurianus, Xerocomus uttarakhandae, and Xerocomellus himalayanus, are established based on morphology and molecular phylogenetic estimations. Moreover, Cyanoboletus macroporus and Xerocomus fraternus are also reported here for the first time in India. Full article

(This article belongs to the Special Issue Fungal Diversity and Systematics in the Digital Era)

► Show Figures

Figure 1

15 pages, 1239 KiB

Open AccessArticle

Repurposing Benzimidazoles against Causative Agents of Chromoblastomycosis: Albendazole Has Superior In Vitro Activity Than Mebendazole and Thiabendazole

by Rowena Alves Coelho, Maria Helena Galdino Figueiredo-Carvalho, Fernando Almeida-Silva, Vanessa Brito de Souza Rabello, Gabriela Rodrigues de Souza, Leandro Stefano Sangenito, Luna Sobrino Joffe, André Luis Souza dos Santos, Maria Cristina da Silva Lourenço, Marcio L. Rodrigues and Rodrigo Almeida-Paes

J. Fungi 2023, 9(7), 753; https://doi.org/10.3390/jof9070753 - 16 Jul 2023

Cited by 2 | Viewed by 1877

Abstract

Chromoblastomycosis (CBM) is a neglected human implantation mycosis caused by several dematiaceous fungal species. Currently available therapy is usually associated with physical methods, especially surgery, and with high refractoriness. Therefore, drug discovery for CBM is essential. Drug repositioning is a strategy used to [...] Read more.

Chromoblastomycosis (CBM) is a neglected human implantation mycosis caused by several dematiaceous fungal species. Currently available therapy is usually associated with physical methods, especially surgery, and with high refractoriness. Therefore, drug discovery for CBM is essential. Drug repositioning is a strategy used to facilitate the discovery of new treatments for several diseases. The aim of this study was to discover substances with antifungal activity against CBM agents from a collection of drugs previously approved for use in human diseases. A screening was performed with the NIH Clinical Collection against Fonsecaea pedrosoi. Ten substances, with clinical applicability in CBM, inhibited fungal growth by at least 60%. The minimum inhibitory concentration (MIC) of these substances was determined against other CBM agents, and the benzimidazoles albendazole, mebendazole and thiabendazole presented the lowest MIC values. The selectivity index, based on MIC and cytotoxicity of these substances, revealed albendazole to be more selective. To investigate a possible synergism of this benzimidazole with itraconazole and terbinafine, the chequerboard method was used. All interactions were classified as indifferent. Our current results suggest that benzimidazoles have repositioning potential against CBM agents. Albendazole seems to be the most promising, since it presented the highest selectivity against all dematiaceous fungi tested. Full article

(This article belongs to the Special Issue Medical Mycology in Developing Countries: The Neglected and Forgotten Mycoses)

► Show Figures

Figure 1

14 pages, 3201 KiB

Open AccessArticle

Host Range and Loop-Mediated Isothermal Amplification Detection of Globisporangium sylvaticum from Guizhou, China

by Jing Zhang, Xiaonan Sun, Ningjing Ao, Huayan Zou, Huijuan Shao, Koji Kageyama and Wenzhuo Feng

J. Fungi 2023, 9(7), 752; https://doi.org/10.3390/jof9070752 - 15 Jul 2023

Cited by 3 | Viewed by 1540

Abstract

Globisporangium, especially G. sylvaticum, causes devastating root rot, blight, and other diseases in various species of cash crops. To investigate the distribution and host range of G. sylvaticum in Guizhou, a suitable habitat for this pathogen, we collected 156 root-diseased samples, [...] Read more.

Globisporangium, especially G. sylvaticum, causes devastating root rot, blight, and other diseases in various species of cash crops. To investigate the distribution and host range of G. sylvaticum in Guizhou, a suitable habitat for this pathogen, we collected 156 root-diseased samples, isolated the pathogens, and found that G. sylvaticum is widespread and has eleven host plants, including four novel hosts. Furthermore, to effectively identify G. sylvaticum, we developed a simple and dependable method based on loop-mediated isothermal amplification (LAMP), which used a primer set designed from the internal transcribed spacer sequences with high specificity and sensitivity of 1 pg/μL. Additionally, to perform field identification, we used the “Plant-LAMP” method with crude DNA extraction to detect the pathogen in 45 root samples from nine species of plants. Our results showed that this method could effectively detect G. sylvaticum in diseased roots. Therefore, our findings not only enrich existing research on the diversity of pathogenic Globisporangium in Guizhou but also present an efficient LAMP field detection method that could significantly contribute to plant disease management and prevention. Full article

(This article belongs to the Special Issue Monitoring, Detection and Surveillance of Fungal Plant Pathogens)

► Show Figures

Figure 1

Journal Menu

Journal Browser

J. Fungi, Volume 9, Issue 7 (July 2023) – 89 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI