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Persoonia Jun 2023Black yeasts comprise a group of of the order with highly variable morphology, a great diversity of ecological niches and life cycles. Despite the ubiquity of these...
Black yeasts comprise a group of of the order with highly variable morphology, a great diversity of ecological niches and life cycles. Despite the ubiquity of these fungi, their diversity in freshwater sediments is still poorly understood. During a survey of culturable from river and stream sediments in various sampling sites in Spain, we obtained 47 isolates of black yeasts by using potato dextrose agar supplemented with cycloheximide. A preliminary morphological study and sequence analyses of the internal transcribed spacer region (ITS) and the large subunit (LSU) of the nuclear rDNA revealed that most of the isolates belonged to the family . We have confidently identified 30 isolates representing the following species: , , , , , and . However, we encountered difficulty in assigning 17 cultures to any known species within . Combining phenotypic and multi-locus phylogenetic analyses based on the ITS, LSU, β-tubulin (2) and translation elongation factor 1-α (1-α) gene markers, we propose the new genus in the to accommodate the novel species . Other novel species in this family include , , , , , , and . The new species , closely related to , is described, and the phylogeny of the genus in the family is discussed. By utilizing these four markers, we were able to strengthen the phylogenetic resolution and provide more robust taxonomic assessments within the studied group. Our findings indicate that freshwater sediments may serve as a reservoir for intriguing black yeasts, which warrant further investigation to address gaps in phylogenetic relationships, particularly within . : Torres-Garcia D, García D, Réblová M, et al. 2023. Diversity and novel lineages of black yeasts in Chaetothyriales from freshwater sediments in Spain. Persoonia 51: 194-228. doi: 10.3767/persoonia.2023.51.05.
PubMed: 38665982
DOI: 10.3767/persoonia.2023.51.05 -
The Journal of Investigative Dermatology Mar 2018Phaeohyphomycosis is a group of severe infections caused by dematiaceous fungi. We previously identified CARD9 deficiencies in four Chinese patients with...
Phaeohyphomycosis is a group of severe infections caused by dematiaceous fungi. We previously identified CARD9 deficiencies in four Chinese patients with phaeohyphomycosis caused by Phialophora verrucosa. In this study, we sought to identify the genetic and immunological mechanisms underlying rare dematiaceous fungal infections in three otherwise healthy patients with phaeohyphomycosis caused by Exophiala spinifera, Ochroconis musae, and Corynespora cassiicola. CARD9 sequencing in these patients showed one mutation (p.S23X) that, to our knowledge, has not been characterized and two previously characterized mutations (p.D274fsX60 and p.L64fsX59) that led to lack of CARD9 protein expression. Patient-derived CARD9-deficient cells showed a selective impairment of proinflammatory cytokine and chemokine production, NF-κB activation, and T helper type 22- and T helper type 17-associated responses upon fungus-specific stimulation, whereas phagocytosis and reactive oxygen species production were intact. Consistently, Card9-knockout mice were highly susceptible to phaeohyphomycosis and exhibited immune deficiencies similar to those of patients, including diminished NF-κB and p38 MAPK activation in local and in vitro functional studies. This work clarifies the association between inherited CARD9 deficiencies and phaeohyphomycosis, and furthers current knowledge on the spectrum and pathophysiology of diseases resulting from CARD9 deficiencies.
Topics: Adolescent; Adult; Animals; CARD Signaling Adaptor Proteins; Candidiasis, Chronic Mucocutaneous; Chemokines; Cytokines; Female; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; Mutation; NF-kappa B; Neutrophil Infiltration; Phaeohyphomycosis
PubMed: 29080677
DOI: 10.1016/j.jid.2017.10.009 -
Journal of Fungi (Basel, Switzerland) May 2023Soybean () acreage is increasing dramatically, together with the use of soybean as a source of vegetable protein and oil. However, soybean production is affected by... (Review)
Review
Soybean () acreage is increasing dramatically, together with the use of soybean as a source of vegetable protein and oil. However, soybean production is affected by several diseases, especially diseases caused by fungal seed-borne pathogens. As infected seeds often appear symptomless, diagnosis by applying accurate detection techniques is essential to prevent propagation of pathogens. Seed incubation on culture media is the traditional method to detect such pathogens. This method is simple, but fungi have to develop axenically and expert mycologists are required for species identification. Even experts may not be able to provide reliable type level identification because of close similarities between species. Other pathogens are soil-borne. Here, traditional methods for detection and identification pose even greater problems. Recently, molecular methods, based on analyzing DNA, have been developed for sensitive and specific identification. Here, we provide an overview of available molecular assays to identify species of the genera , , , , , , , , , , , and causing soybean diseases. We also describe the basic steps in establishing PCR-based detection methods, and we discuss potentials and challenges in using such assays.
PubMed: 37233298
DOI: 10.3390/jof9050587 -
Antimicrobial Agents and Chemotherapy Jul 2021Chromoblastomycosis (CBM) is a chronic subcutaneous infection caused by genera of melanized fungi: , , , , and . Melanin is a virulence factor known to influence...
Chromoblastomycosis (CBM) is a chronic subcutaneous infection caused by genera of melanized fungi: , , , , and . Melanin is a virulence factor known to influence antifungal susceptibility. A specific inhibitor of melanin biosynthesis is tricyclazole. The aim of this study was to evaluate the effect of melanin inhibition on antifungal susceptibility of chromoblastomycosis agents and describe the susceptibility profiles of some unusual CBM agents. Seventy-six clinical isolates, representing 13 species of the five main genera of CBM agents, were studied. The antifungal susceptibility testing was performed according to the M38-A2 protocol of CLSI (, 3rd ed., , 2017). In the melanin inhibition test, 16 mg/liter of tricyclazole was added to the medium used in the inoculum preparation and the susceptibility assay. CBM agents were less susceptible to amphotericin B than azoles and terbinafine. The unusual species showed similar susceptibility profiles to those of other species of the same genera. With tricyclazole exposure, MICs of terbinafine, posaconazole, and itraconazole for spp. significantly decreased ( < 0.05). For spp., this reduction was significant for posaconazole and itraconazole. For the other genera, there was a reduction in MICs of terbinafine and itraconazole; however, the statistical tests were not significant. Melanin inhibition can increase the antifungal susceptibility of most CBM agents to itraconazole and terbinafine, the main drugs used in the disease treatment. This increased susceptibility may open up new possibilities for therapy in refractory cases of CBM and/or cases caused by resistant fungal strains. Further studies are needed to confirm the same results .
Topics: Antifungal Agents; Ascomycota; Chromoblastomycosis; Humans; Itraconazole; Melanins; Microbial Sensitivity Tests; Terbinafine
PubMed: 33972246
DOI: 10.1128/AAC.00546-21 -
Journal of Fungi (Basel, Switzerland) Jan 2022Neutrophils are the first leukocytes recruited to the site of infection and are thought to be responsible for fungal elimination from the skin such as dermatophytes....
Neutrophils are the first leukocytes recruited to the site of infection and are thought to be responsible for fungal elimination from the skin such as dermatophytes. Neutrophils are able to secrete reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) that can kill different fungi, including , spp., , and . However, NET production in response to , the main etiologic agent of dermatophytosis, has yet to be studied. We demonstrated that human neutrophils produce NETs against different morphotypes of in a dose-dependent manner and NET formation is dependent on ROS production. In addition, ROS production by human neutrophils in response to is dependent on NADPH oxidase, but not on fungal viability. NETs mediated killing of Collectively, these results demonstrate that was able to trigger the production of NETs, suggesting that these extracellular structures may represent an important innate immune effector mechanism controlling physiological response to infection.
PubMed: 35205902
DOI: 10.3390/jof8020147 -
Clinical Microbiology and Infection :... Jan 2020Our objective was to characterize the fungal microbiota on normal ocular surface of humans with the culture-based method and high-throughput sequencing approach.
OBJECTIVES
Our objective was to characterize the fungal microbiota on normal ocular surface of humans with the culture-based method and high-throughput sequencing approach.
METHODS
A total of 45 adults were recruited from an urban community, and 90 conjunctival swabs were obtained, one from each eye of each participant. One of the two swabs from each participant was randomly chosen and allocated to internal transcribed spacer (ITS) sequencing, and the other was subjected to conventional fungal cultivation.
RESULTS
Four filamentous fungi were isolated from the 45 samples using the culture-based method, Penicillium citrinum, Aspergillus niger, Phialophora and Trichoderma. In the other 45 samples, 18 samples were positive for PCR amplification and sent for subsequent ITS sequencing. A total of 518 703 valid reads were generated and assigned into 467 operational taxonomic units. Overall, 4 phyla and 94 genera were identified. Two phyla, Basidiomycota (78.67%) and Ascomycota (19.54%), and five genera, Malassezia (74.65%), Rhodotorula (1.93%), Davidiella (1.89%), Aspergillus (1.25%) and Alternaria (0.61%), which accounted for >80% of the fungal microbiome and presented in >80% of the individuals tested, constituted the possible 'core fungal taxa' on normal ocular surface.
CONCLUSIONS
The fungal microbiome on normal ocular surface of humans was identified using the high-throughput sequencing method, providing a basis for further investigations on the potential role of the fungal microbiota in ocular health and disease.
Topics: Adult; Aged; DNA, Intergenic; Eye; Female; Fungi; Healthy Volunteers; High-Throughput Nucleotide Sequencing; Humans; Male; Middle Aged; Mycobiome; Sequence Analysis, DNA
PubMed: 31128284
DOI: 10.1016/j.cmi.2019.05.011 -
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 -
Frontiers in Microbiology 2017is a dematiaceous fungus able to cause chromoblastomycosis, phaeohyphomycosis and mycetoma. All these fungal diseases are extremely difficult to treat and often...
is a dematiaceous fungus able to cause chromoblastomycosis, phaeohyphomycosis and mycetoma. All these fungal diseases are extremely difficult to treat and often refractory to the current therapeutic approaches. Therefore, there is an urgent necessity to develop new antifungal agents to combat these mycoses. In this context, the aim of the present work was to investigate the effect of 1,10-phenanthroline-5,6-dione (phendione) and its metal-based derivatives [Ag(phendione)]ClO = ([Ag(phendione)]) and [Cu(phendione)](ClO).4HO = ([Cu(phendione)]) on crucial physiological events of conidial cells. Using the CLSI protocol, we have shown that phendione, [Ag(phendione)] and [Cu(phendione)] were able to inhibit fungal proliferation, presenting MIC/IC values of 12.0/7.0, 4.0/2.4, and 5.0/1.8 μM, respectively. [Cu(phendione)] had fungicidal action and when combined with amphotericin B, both at sub-MIC (½ × MIC) concentrations, significantly reduced (~40%) the fungal growth. Cell morphology changes inflicted by phendione and its metal-based derivatives was corroborated by scanning electron microscopy, which revealed irreversible ultrastructural changes like surface invaginations, cell disruption and shrinkages. Furthermore, [Cu(phendione)] and [Ag(phendione)] were able to inhibit metallopeptidase activity secreted by conidia by approximately 85 and 40%, respectively. Ergosterol content was reduced (~50%) after the treatment of conidial cells with both phendione and [Ag(phendione)]. To different degrees, all of the test compounds were able to disturb the conidia-into-mycelia transformation. Phendione and its Ag and Cu complexes may represent a promising new group of antimicrobial agents effective at inhibiting growth and morphogenesis.
PubMed: 28194139
DOI: 10.3389/fmicb.2017.00076 -
International Biodeterioration &... 2017Water-damaged buildings can lead to fungal growth and occupant health problems. Green building materials, derived from renewable sources, are increasingly utilized in...
Water-damaged buildings can lead to fungal growth and occupant health problems. Green building materials, derived from renewable sources, are increasingly utilized in construction and renovations. However, the question as to what fungi will grow on these green compared to non-green materials, after they get wet, has not been adequately studied. By determining what fungi grow on each type of material, the potential health risks can be more adequately assessed. In this study, we inoculated green and non-green pieces of ceiling tile, composite board, drywall, and flooring with indoor dust containing a complex mixture of naturally occurring fungi. The materials were saturated with water and incubated for two months in a controlled environment. The resulting fungal microbiomes were evaluated using ITS amplicon sequencing. Overall, the richness and diversity of the mycobiomes on each pair of green and non-green pieces were not significantly different. However, different genera dominated on each type of material. For example, spp. had the highest relative abundance on green and non-green ceiling tiles and green composite boards, but spp. dominated the non-green composite board. In contrast, spp. dominated green and non-green flooring samples. Green gypsum board was dominated by spp. and spp., but non-green gypsum board by spp. These data suggest that water-damaged green and non-green building materials can result in mycobiomes that are dominated by fungal genera whose member species pose different potentials for health risks.
PubMed: 29681691
DOI: 10.1016/j.ibiod.2017.07.018 -
Journal of Clinical Immunology Aug 2018Autosomal recessive CARD9 deficiency underlies life-threatening, invasive fungal infections in otherwise healthy individuals normally resistant to other infectious... (Review)
Review
UNLABELLED
Autosomal recessive CARD9 deficiency underlies life-threatening, invasive fungal infections in otherwise healthy individuals normally resistant to other infectious agents. In less than 10 years, 58 patients from 39 kindreds have been reported in 14 countries from four continents. The patients are homozygous (n = 49; 31 kindreds) or compound heterozygous (n = 9; 8 kindreds) for 22 different CARD9 mutations. Six mutations are recurrent, probably due to founder effects. Paradoxically, none of the mutant alleles has been experimentally demonstrated to be loss-of-function. CARD9 is expressed principally in myeloid cells, downstream from C-type lectin receptors that can recognize fungal components. Patients with CARD9 deficiency present impaired cytokine and chemokine production by macrophages, dendritic cells, and peripheral blood mononuclear cells and defective killing of some fungi by neutrophils in vitro. Neutrophil recruitment to sites of infection is impaired in vivo. The proportion of Th17 cells is low in most, but not all, patients tested. Up to 52 patients suffering from invasive fungal diseases (IFD) have been reported, with ages at onset of 3.5 to 52 years. Twenty of these patients also displayed superficial fungal infections. Six patients had only mucocutaneous candidiasis or superficial dermatophytosis at their last follow-up visit, at the age of 19 to 50 years. Remarkably, for 50 of the 52 patients with IFD, a single fungus was involved; only two patients had IFDs due to two different fungi. IFD recurred in 44 of 45 patients who responded to treatment, and a different fungal infection occurred in the remaining patient. Ten patients died from IFD, between the ages of 12 and 39 years, whereas another patient died at the age of 91 years, from an unrelated cause. At the most recent scheduled follow-up visit, 81% of the patients were still alive and aged from 6.5 to 75 years. Strikingly, all the causal fungi belonged to the phylum Ascomycota: commensal Candida and saprophytic Trychophyton, Aspergillus, Phialophora, Exophiala, Corynesprora, Aureobasidium, and Ochroconis. Human CARD9 is essential for protective systemic immunity to a subset of fungi from this phylum but seems to be otherwise redundant. Previously healthy patients with unexplained invasive fungal infection, at any age, should be tested for inherited CARD9 deficiency.
KEY POINTS
• Inherited CARD9 deficiency (OMIM #212050) is an AR PID due to mutations that may be present in a homozygous or compound heterozygous state. • CARD9 is expressed principally in myeloid cells and transduces signals downstream from CLR activation by fungal ligands. • Endogenous mutant CARD9 levels differ between alleles (from full-length normal protein to an absence of normal protein). • The functional impacts of CARD9 mutations involve impaired cytokine production in response to fungal ligands, impaired neutrophil killing and/or recruitment to infection sites, and defects of Th17 immunity. • The key clinical manifestations in patients are fungal infections, including CMC, invasive (in the CNS in particular) Candida infections, extensive/deep dermatophytosis, subcutaneous and invasive phaeohyphomycosis, and extrapulmonary aspergillosis. • The clinical penetrance of CARD9 deficiency is complete, but penetrance is incomplete for each of the fungi concerned. • Age at onset is highly heterogeneous, ranging from childhood to adulthood for the same fungal disease. • All patients with unexplained IFD should be tested for CARD9 mutations. Familial screening and genetic counseling should be proposed. • The treatment of patients with CARD9 mutations is empirical and based on antifungal therapies and the surgical removal of fungal masses. Patients with persistent/relapsing Candida infections of the CNS could be considered for adjuvant GM-CSF/G-CSF therapy. The potential value of HSCT for CARD9-deficient patients remains unclear.
Topics: Adult; Alleles; Animals; CARD Signaling Adaptor Proteins; Candidiasis, Chronic Mucocutaneous; Child; Computational Biology; Disease Models, Animal; Gene Expression; Gene Expression Regulation; Gene Frequency; Genetic Association Studies; Genetic Predisposition to Disease; Host-Pathogen Interactions; Humans; Immunity; Mice; Mononuclear Phagocyte System; Mutation; Phenotype
PubMed: 30136218
DOI: 10.1007/s10875-018-0539-2