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Journal of Fungi (Basel, Switzerland) Sep 2022Patients with chromoblastomycosis (CBM) suffer chronic tissue lesions that are hard to treat. Considering that biofilm is the main growth lifestyle of several pathogens...
Patients with chromoblastomycosis (CBM) suffer chronic tissue lesions that are hard to treat. Considering that biofilm is the main growth lifestyle of several pathogens and it is involved with both virulence and resistance to antimicrobial drugs, we have investigated the ability of CBM fungi to produce this complex, organized and multicellular structure. and conidial cells were able to adhere on a polystyrene abiotic substrate, differentiate into hyphae and produce a robust viable biomass containing extracellular matrix. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) showed the tridimensional architecture of the mature biofilms, revealing a dense network of interconnected hyphae, inner channels and amorphous extracellular polymeric material. Interestingly, the co-culture of each fungus with THP-1 macrophage cells, used as a biotic substrate, induced the formation of a mycelial trap covering and damaging the macrophages. In addition, the biofilm-forming cells of and were more resistant to the conventional antifungal drugs than the planktonic-growing conidial cells. The efflux pump activities of and biofilms were significantly higher than those measured in conidia. Taken together, the data pointed out the biofilm formation by CBM fungi and brought up a discussion of the relevance of studies about their antifungal resistance mechanisms.
PubMed: 36135688
DOI: 10.3390/jof8090963 -
Plant Disease Oct 2020Maize (Zea mays L.) is one of the most important commodities, and Brazil is the second-largest maize exporter country in the world. In April 2019, the period of the...
Maize (Zea mays L.) is one of the most important commodities, and Brazil is the second-largest maize exporter country in the world. In April 2019, the period of the second crop maize (safrinha), it was observed black decayed lesions on roots and wilting of some maize plants, causing a "sudden death" in a commercial area in the west of Paraná state, Brazil (Figure 1A-C). Symptomatic root and stalk were collected, and tissues surface disinfected with 70% ethanol for 30 s, 1.5% NaOCl for 1 min and rinsed three times in sterile distilled water, slices of necrotic tissues were transferred to potato dextrose agar (PDA) medium and grown for 7 days at 27 ± 1ºC with a photoperiod of 12 h. Pure cultures were obtained through monosporic isolation. The fungal morphology is alike Gaeumannomyces radicicola, which is a synonym of Phialophora radicicola var. radicicola, Harpophora radicicola, P. zeicola, H. zeicola and G. graminis var. maydis (Hernández-Restrepo et al. 2016). Colonies on PDA showed flat, white to light gray at first (Fig. 1D), turning gray to black with age (Fig. 1E). Colony diameter approximately 5.2 cm on PDA in the dark after 7 days at 27ºC. Conidiophores with slightly thickened wall, mostly branched, varying in dimensions, with a range of 57.5-166.5 (avg. 128.7 μm) × 2.9-5.9 (avg. 4.2 μm) n = 25 (Fig. 1H-J). The conidia showed lunate-shaped with rounded ends, produced successively at the apex of phialide, 3.3-9.7 (avg. 6.6 μm) × 1.5-3.6 μm (avg. 2.5 μm), n = 100 (Fig. 1G-J). Morphological characteristics were comparable to the description of this specie (Cain 1952; Gams 2000; McKeen 1952). The total genomic DNA of a representative isolate, LEMIDPRZm 19-01 was extracted and the partial large subunit (28S nrDNA; LSU), internal transcribed spacer nrDNA including the intervening 5.8S nrDNA (ITS), and part of the largest subunit of the RNA polymerase II gene (RPB1) were amplified and sequenced, as following by Hernández-Restrepo et al. (2016) and Klaubauf et al. (2014). The primers to LSU - NL1 (O'Donnel, 1993) and LR5 (Vilgalys; Hester, 1990); ITS - ITS5 and ITS4 (White et al., 1990); and RPB1 - RPB1F and RPB1R (Klaubauf et al., 2014) were used in this study. The gene sequences of LSU (MT123866), ITS (MT114427), and RPB1 (MT123867) were deposited in GenBank and showed 99.67%, 99.75%, and 100% identity with type material G. radicicola CBS 296.53 (KM484962, KM484845, and KM485061). A multi-locus phylogenetic analysis based on Bayesian Inference showed the isolate LEMIDPRZm 19-01 in the G. radicicola clade (Fig. 2). To confirm pathogenicity, ex vivo assays were performed with mycelial PDA discs of 5 mm from a 7-day-old culture using detached roots (adapted method by Degani et al., 2019), on wounded and unwounded stalk and leaves, each treatment consisted of five replications. PDA discs without fungal were used in negative tissue controls. Pathogenicity tests were also conducted in vivo, two experiments performed: i) the stalk tissue was inoculated by sterilized toothpick grown on PDA with fungal mycelium and the leaves inoculated as ex vivo assay, and toothpick without fungal mycelium was used to stalk negative control, whereas PDA discs without fungal were used in the tested leaves; ii) 6 mycelial PDA discs/500 mL were placed on potato dextrose broth (PDB) media and it remained in agitation for 10 days to obtain a mycelial suspension. Subsequently, the mycelial was crushed to soil infestation, and 50 mL from this suspension were dropped in each 2 L maize pot with soil sterilization 10 days after emergence. Maize pots with soil sterilization without mycelium fungal were used as negative controls. Four replications (maize pots), for each treatment, were used in both tests. Experiments were repeated twice. In the ex vivo assay, all inoculated tissues with and without wounds showed necrotic lesions (Fig. 1K-N). In the first in vivo assay, stalk rot symptoms, including wilting of the inoculated plants causing premature plant death, were observed within 6 days (Fig. 1O-Q). In the second in vivo assay, inoculated plants had inferior growth than compared with plant control. Sixty days after inoculation, the plants were removed from the pots and it was observed a roots degeneration with symptoms of necrosis (Fig. 1R-U). No symptoms were detected in the control treatments and the pathogen was re-isolated from symptomatic tissues confirming Koch's postulate for all assays. So far, to our knowledge, the pathogen distribution was reported solely in the west area of Paraná state, but it may become a potential threat to Brazilian maize production. Further monitoring is necessary to better understand the epidemiology of this pathogen to address a strategy for disease control. The pathogen has already been detected in Canada, South Africa, and China. To our knowledge, this is the first report of G. radicicola in Brazil, as well as in South America.
PubMed: 33026305
DOI: 10.1094/PDIS-03-20-0556-PDN -
Frontiers in Cellular and Infection... 2023Chromoblastomycosis (CBM) is a form of chronic mycosis that affects the skin and mucous membranes and is caused by species of dematiaceous fungi including Exophiala...
INTRODUCTION
Chromoblastomycosis (CBM) is a form of chronic mycosis that affects the skin and mucous membranes and is caused by species of dematiaceous fungi including Exophiala spp., Phialophora spp., and Fonsecaea spp. The persistence of this disease and limitations associated with single-drug treatment have complicated efforts to adequately manage this condition.
METHODS
In this study, a microdilution assay was used to explore the synergistic antifungal activity of everolimus (EVL) in combination with itraconazole (ITC), voriconazole (VRC), posaconazole (POS), and amphotericin B (AMB) against a range of clinical dematiaceous fungal isolates.
RESULTS
These analyses revealed that the EVL+POS and EVL+ITC exhibited superior in vitro synergistic efficacy, respectively inhibiting the growth of 64% (14/22) and 59% (13/22) of tested strains. In contrast, the growth of just 9% (2/22) of tested strains was inhibited by a combination of EVL+AMB, and no synergistic efficacy was observed for the combination of EVL+VRC.
DISCUSSION
Overall, these findings indicate that EVL holds promise as a novel drug that can be synergistically combined with extant antifungal drugs to improve their efficacy, thereby aiding in the treatment of CBM.
Topics: Humans; Antifungal Agents; Everolimus; Amphotericin B; Mycoses; Voriconazole; Microbial Sensitivity Tests; Fungi
PubMed: 36909734
DOI: 10.3389/fcimb.2023.1131416 -
PeerJ 2019Morels ( spp.) are iconic edible mushrooms with a long history of human consumption. Some microbial taxa are hypothesized to be important in triggering the formation of...
Morels ( spp.) are iconic edible mushrooms with a long history of human consumption. Some microbial taxa are hypothesized to be important in triggering the formation of morel primordia and development of fruiting bodies, thus, there is interest in the microbial ecology of these fungi. To identify and compare fungal and prokaryotic communities in soils where is cultivated in outdoor greenhouses, ITS and 16S rDNA high throughput amplicon sequencing and microbiome analyses were performed. , , , and were found to comprise the core microbiome of ascocarps. These bacterial taxa were also abundant in the soil beneath growing fruiting bodies. A total of 29 bacterial taxa were found to be statistically associated to fruiting bodies. Bacterial community network analysis revealed high modularity with some 16S rDNA operational taxonomic unit clusters living in specialized fungal niches (e.g., pileus, stipe). Other fungi dominating the soil mycobiome beneath morels included , , and . This research informs understanding of microbial indicators and potential facilitators of ecology and fruiting body production.
PubMed: 31579614
DOI: 10.7717/peerj.7744 -
Cureus Aug 2022Cutaneous chromoblastomycosis is a chronic subcutaneous fungal disease of the skin caused by , especially by , ,and species affecting the skin, lungs, intestines,...
Cutaneous chromoblastomycosis is a chronic subcutaneous fungal disease of the skin caused by , especially by , ,and species affecting the skin, lungs, intestines, stomach, and central nervous system. It is treated using itraconazole in mild cases and amphotericin B in severe cases. A six-year-old female child presented to the Dermatology Outpatient Department with pigmented brown to blackish tanned plaques and verrucous lesions on the face and extremities. These lesions were present for the past two and a half years and were slowly enlarging and involving other areas like the trunk. The lesions were proven on biopsy to be cutaneous blastomycosis. The patient was put on infusions of amphotericin B in a calculated pediatric dose. Her blood pressure and renal function tests were checked daily to avoid any electrolyte derangements, nephrotoxicity, and systemic infusion reactions caused by amphotericin B. Amphotericin B reduced the size of the cutaneous lesions, and treatment response was assessed on regular follow-ups. Chromoblastomycosis should be considered in the differential diagnosis to enable timely treatment and to prevent its lethal complications such as epidermoid carcinoma. Treatment should continue for two to three months until histopathology is negative to ensure complete eradication.
PubMed: 36158439
DOI: 10.7759/cureus.28286 -
Frontiers in Microbiology 2021is a dematiaceous fungus that causes mainly chromoblastomycosis, but also disseminated infections such as phaeohyphomycosis and mycetoma. These diseases are extremely...
is a dematiaceous fungus that causes mainly chromoblastomycosis, but also disseminated infections such as phaeohyphomycosis and mycetoma. These diseases are extremely hard to treat and often refractory to current antifungal therapies. In this work, we have evaluated the effect of 1,10-phenanthroline-5,6-dione (phendione) and its metal-based complexes, [Ag (phendione)]ClO and [Cu(phendione)](ClO).4HO, against , focusing on (i) conidial viability when combined with amphotericin B (AmB); (ii) biofilm formation and disarticulation events; (iii) interaction with human macrophages; and (iv) infection of larvae. The combination of AmB with each of the test compounds promoted the additive inhibition of growth, as judged by the checkerboard assay. During the biofilm formation process over polystyrene surface, sub-minimum inhibitory concentrations (MIC) of phendione and its silver(I) and copper(II) complexes were able to reduce biomass and extracellular matrix production. Moreover, a mature biofilm treated with high concentrations of the test compounds diminished biofilm viability in a concentration-dependent manner. Pre-treatment of conidial cells with the test compounds did not alter the percentage of infected THP-1 macrophages; however, [Ag(phendione)]ClO caused a significant reduction in the number of intracellular fungal cells compared to the untreated system. In addition, the killing process was significantly enhanced by post-treatment of infected macrophages with the test compounds. induced a typically cell density-dependent effect on larvae death after 7 days of infection. Interestingly, exposure to the silver(I) complex protected the larvae from infection. Collectively, the results corroborate the promising therapeutic potential of phendione-based drugs against fungal infections, including those caused by .
PubMed: 34025603
DOI: 10.3389/fmicb.2021.641258 -
PeerJ 2024Conventional biofilters, which rely on bacterial activity, face challenges in eliminating hydrophobic compounds, such as aromatic compounds. This is due to the low... (Comparative Study)
Comparative Study
BACKGROUND
Conventional biofilters, which rely on bacterial activity, face challenges in eliminating hydrophobic compounds, such as aromatic compounds. This is due to the low solubility of these compounds in water, which makes them difficult to absorb by bacterial biofilms. Furthermore, biofilter operational stability is often hampered by acidification and drying out of the filter bed.
METHODS
Two bioreactors, a bacterial biofilter (B-BF) and a fungal-bacterial coupled biofilter (F&B-BF) were inoculated with activated sludge from the secondary sedimentation tank of the Sinopec Yangzi Petrochemical Company wastewater treatment plant located in Nanjing, China. For approximately 6 months of operation, a F&B-BF was more effective than a B-BF in eliminating a gas-phase mixture containing benzene, toluene, ethylbenzene, and -xylene (BTE-X).
RESULTS
After operating for four months, the F&B-BF showed higher removal efficiencies for toluene (T), ethylbenzene (E), benzene (B), and -X (-Xylene), at 96.9%, 92.6%, 83.9%, and 83.8%, respectively, compared to those of the B-BF (90.1%, 78.7%, 64.8%, and 59.3%). The degradation activity order for B-BF and F&B-BF was T > E > B > -X. Similarly, the rates of mineralization for BTE-X in the F&B-BF were 74.9%, 66.5%, 55.3%, and 45.1%, respectively, which were higher than those in the B-BF (56.5%, 50.8%, 43.8%, and 30.5%). Additionally, the F&B-BF (2 days) exhibited faster recovery rates than the B-BF (5 days).
CONCLUSIONS
It was found that a starvation protocol was beneficial for the stable operation of both the B-BF and F&B-BF. Community structure analysis showed that the bacterial genus and the fungal genus were both important in the degradation of BTE-X. The fungal-bacterial consortia can enhance the biofiltration removal of BTE-X vapors.
Topics: Xylenes; Filtration; Fungi; Benzene Derivatives; Bioreactors; Bacteria; Biodegradation, Environmental; Toluene; Benzene; China; Biofilms
PubMed: 38903883
DOI: 10.7717/peerj.17452 -
Environmental Science and Pollution... Apr 2021Dark septate endophytes (DSEs) can improve plant stress tolerance by promoting growth and affecting element accumulation. Due to its ability to accumulate high Cd, Zn,...
Dark septate endophytes (DSEs) can improve plant stress tolerance by promoting growth and affecting element accumulation. Due to its ability to accumulate high Cd, Zn, and Ni concentrations in its shoots, Noccaea caerulescens is considered a promising candidate for phytoextraction in the field. However, the ability of DSEs to improve trace element (TE) phytoextraction with N. caerulescens has not yet been studied. The aim of this study was therefore to determine the ability of five DSE strains, previously isolated from poplar roots collected at different TE-contaminated sites, to improve plant development, mineral nutrient status, and metal accumulation by N. caerulescens during a pot experiment using two soils differing in their level of TE contamination. Microscopic observations revealed that the tested DSE strains effectively colonised the roots of N. caerulescens. In the highly contaminated (HC) soil, a threefold increase in root biomass was found in plants inoculated with the Leptodontidium sp. Pr30 strain compared to that in the non-inoculated condition; however, the plant nutrient status was not affected. In contrast, the two strains Phialophora mustea Pr27 and Leptodontidium sp. Me07 had positive effects on the mineral nutrient status of plants without significantly modifying their biomass. Compared to non-inoculated plants cultivated on HC soil, Pr27- and Pr30-inoculated plants extracted more Zn (+ 30%) and Cd (+ 90%), respectively. In conclusion, we demonstrated that the responses of N. caerulescens to DSE inoculation ranged from neutral to beneficial and we identified two strains (i.e. Leptodontidium sp. (Pr30) and Phialophora mustea (Pr27)) isolated from poplar that appeared promising as they increased the amounts of Zn and Cd extracted by improving plant growth and/or TE accumulation by N. caerulescens. These results generate interest in further characterising the DSEs that naturally colonise N. caerulescens and testing their ability to improve phytoextraction.
Topics: Biodegradation, Environmental; Cadmium; Endophytes; Phialophora; Plant Roots; Soil Pollutants; Zinc
PubMed: 33387325
DOI: 10.1007/s11356-020-11793-x -
The Plant Genome Nov 2020Brown stem rot (BSR) reduces soybean [Glycine max (L.) Merr.] yield by up to 38%. The BSR causal agent is Phialophora gregata f. sp. sojae, a slow-growing, necrotrophic...
Brown stem rot (BSR) reduces soybean [Glycine max (L.) Merr.] yield by up to 38%. The BSR causal agent is Phialophora gregata f. sp. sojae, a slow-growing, necrotrophic fungus whose life cycle includes latent and pathogenic phases, each lasting several weeks. Brown stem rot foliar symptoms are often misdiagnosed as other soybean diseases or nutrient stress, making BSR resistance especially difficult to phenotype. To shed light on the genes and networks contributing to P. gregata resistance, we conducted RNA sequencing (RNA-seq) of a resistant genotype (PI 437970, Rbs3). Leaf, stem, and root tissues were collected 12, 24, and 36 h after stab inoculation with P. gregata, or mock infection, in the plant stem. By using multiple tissues and time points, we could see that leaves, stems, and roots use the same defense pathways. Our analyses suggest that P. gregata induces a biphasic defense response, with pathogen-associated molecular pattern (PAMP) triggered immunity observed in leaves at 12 and 24 h after infection (HAI) and effector triggered immunity detected at 36 h after infection in the stems. Gene networks associated with defense, photosynthesis, nutrient homeostasis, DNA replication, and growth are the hallmarks of resistance to P. gregata. While P. gregata is a slow-growing pathogen, our results demonstrate that pathogen recognition occurs hours after infection. By exploiting the genes and networks described here, we will be able to develop novel diagnostic tools to facilitate breeding and screening for BSR resistance.
Topics: Ascomycota; Disease Resistance; Humans; Plant Diseases; Plant Stems; Glycine max
PubMed: 33217212
DOI: 10.1002/tpg2.20037 -
Journal of Enzyme Inhibition and... Dec 2020causes several fungal human diseases, mainly chromoblastomycosis, which is extremely difficult to treat. Several studies have shown that human immunodeficiency virus...
causes several fungal human diseases, mainly chromoblastomycosis, which is extremely difficult to treat. Several studies have shown that human immunodeficiency virus peptidase inhibitors (HIV-PIs) are attractive candidates for antifungal therapies. This work focused on studying the action of HIV-PIs on peptidase activity secreted by and their effects on fungal proliferation and macrophage interaction. We detected a peptidase activity from able to cleave albumin, sensitive to pepstatin A and HIV-PIs, especially lopinavir, ritonavir and amprenavir, showing for the first time that this fungus secretes aspartic-type peptidase. Furthermore, lopinavir, ritonavir and nelfinavir reduced the fungal growth, causing remarkable ultrastructural alterations. Lopinavir and ritonavir also affected the conidia-macrophage adhesion and macrophage killing. Interestingly, had its growth inhibited by ritonavir combined with either itraconazole or ketoconazole. Collectively, our results support the antifungal action of HIV-PIs and their relevance as a possible alternative therapy for fungal infections.
Topics: Antifungal Agents; Aspartic Acid Proteases; Carbamates; Dose-Response Relationship, Drug; Furans; HIV Protease Inhibitors; Humans; Lopinavir; Macrophages; Microbial Sensitivity Tests; Molecular Structure; Phialophora; Ritonavir; Structure-Activity Relationship; Sulfonamides
PubMed: 32037904
DOI: 10.1080/14756366.2020.1724994