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Microorganisms Nov 2020Many free-living saprobic fungi are nature recruited organisms for the degradation of wastes, ranging from lignocellulose biomass to organic/inorganic chemicals, aided...
Many free-living saprobic fungi are nature recruited organisms for the degradation of wastes, ranging from lignocellulose biomass to organic/inorganic chemicals, aided by their production of enzymes. In this study, fungal strains were isolated from contaminated crude-oil fields in Nigeria. The dominant fungi were selected from each site and identified as and based on morphological and molecular characterization, with site percentage incidences of 56.67% and 66.70%, respectively. Selected strains response/tolerance to complex hydrocarbon (used engine oil) was studied by growing them on Bushnell Haas (BH) mineral agar supplemented with the hydrocarbon at different concentrations, i.e., 5%, 10%, 15%, and 20%, with a control having dextrose. Hydrocarbon degradation potentials of these fungi were confirmed in BH broth culture filtrates pre-supplemented with 1% engine oil after 15 days of incubation using GC/MS. In addition, the presence of putative enzymes, laccase (Lac), manganese peroxidase (MnP), and lignin peroxidase (LiP) was confirmed in culture filtrates using appropriate substrates. The analyzed fungi grew in hydrocarbon supplemented medium with no other carbon source and exhibited 39.40% and 45.85% dose inhibition response (DIR) respectively at 20% hydrocarbon concentration. An enzyme activity test revealed that these two fungi produced more Lac than MnP and LiP. It was also observed through the GC/MS analyses that while acted on all hydrocarbon components in the used engine oil, only degraded the long-chain hydrocarbons and BTEX. This study confirms that and have the potential to be exploited in the bio-treatment and removal of hydrocarbons from polluted soils.
PubMed: 33266344
DOI: 10.3390/microorganisms8121912 -
Antimicrobial Agents and Chemotherapy Aug 2019Recently, the species concept of opportunistic and its relatives has been revised, resulting in the recognition of its classical formae as independent species and the...
Recently, the species concept of opportunistic and its relatives has been revised, resulting in the recognition of its classical formae as independent species and the description of new species. In this study, we used isolates of all clinically relevant species and performed susceptibility testing using the EUCAST reference method to identify potential species-specific susceptibility patterns. susceptibility profiles of 101 mucoralean strains belonging to the genus (72), the closely related species (3), (12), (10), and (4) to six antifungals (amphotericin B, natamycin, terbinafine, isavuconazole, itraconazole, and posaconazole) were determined. The most active drug for all Mucorales was amphotericin B. Antifungal susceptibility profiles of pathogenic species were specific for isavuconazole, itraconazole, and posaconazole. The species formerly united in showed clear differences in their antifungal susceptibilities. , , ( f. ), and exhibited high MICs to all azoles tested. presented high MICs for isavuconazole and posaconazole, and and showed high MICs for isavuconazole. MIC values of spp. for posaconazole, isavuconazole, and itraconazole were high compared to those for and the Lichtheimiaceae ( and ). Molecular identification combined with susceptibility testing is recommended for species, especially if azoles are applied in treatment.
Topics: Amphotericin B; Antifungal Agents; Humans; Itraconazole; Microbial Sensitivity Tests; Mucor; Mucormycosis; Natamycin; Nitriles; Pyridines; Rhizopus; Species Specificity; Terbinafine; Triazoles
PubMed: 31182532
DOI: 10.1128/AAC.00653-19 -
Frontiers in Microbiology 2021Fungal spoilage of dairy products is a major concern due to food waste and economical losses, some fungal metabolites may furthermore have adverse effects on human...
Fungal spoilage of dairy products is a major concern due to food waste and economical losses, some fungal metabolites may furthermore have adverse effects on human health. The use of lactic acid bacteria (LAB) is emerging as a potential clean label alternative to chemical preservatives. Here, our aim was to characterize the growth potential at three storage temperatures (5, 16, and 25°C) of a panel of molds (four and nine strains) isolated from dairy products, then investigate the susceptibility of the molds toward 12 LAB cultures. Fungal cell growth and morphology in malt extract broth was monitored using oCelloScope at 25°C for 24 h. 01180036 was the fastest growing and ISI4 ( ISI4) the slowest of the tested molds. On yogurt-agar plates, all molds grew at 5, 16, and 25°C in a temperature-dependent manner with strains growing faster than strains regardless of temperature. The sensitivity toward 12 LAB cultures was tested using high-throughput overlay method and here all the molds except ISI4 were strongly inhibited. The antifungal action of these LAB was confirmed when spotting mold spores on agar plates containing live cells of the LAB strains. However, if cells were removed from the fermentates, the inhibitory effects decreased markedly. The antifungal effects of volatiles tested in a plate-on-plate system without direct contact between mold and LAB culture media were modest. Some LAB binary combinations improved the antifungal activity against the growth of several molds beyond that of single cultures in yogurt serum. The role of competitive exclusion due to manganese depletion was examined as a possible antifungal mechanism for six and two strains. It was shown that this mechanism was a major inhibition factor for the molds tested apart from the non-inhibited ISI4 since addition of manganese with increasing concentrations of up to 0.1 mM resulted in partly or fully restored mold growth in yogurt. These findings help to understand the parameters influencing the mold spoilage of dairy products and the interactions between the contaminating strains, substrate, and bioprotective LAB cultures.
PubMed: 33643260
DOI: 10.3389/fmicb.2021.631730 -
Mycobiology 2020During an investigation of fungi of the order Mucorales from freshwater and sediment samples in Korea, we isolated six strains, NNIBRFG6649, NNIBRFG6255, NNIBRFG1498,...
During an investigation of fungi of the order Mucorales from freshwater and sediment samples in Korea, we isolated six strains, NNIBRFG6649, NNIBRFG6255, NNIBRFG1498, CNUFC-YJ13, CNUFC-YR7, and NNIBRFG2739. The morphology and phylogeny of these strains were analyzed. Based on the morphological characteristics and molecular data from internal transcribed spacer (ITS) region, the isolates NNIBRFG6649 and NNIBRFG6255 were identified as , and . , respectively. The isolates NNIBRFG1498 and CNUFC-YJ13 were identified as . , whereas the isolates CNUFC-YR7 and NNIBRFG2739 were identified as . To the best of our knowledge, , . , . , and have not yet been reported in Korea.
PubMed: 32158603
DOI: 10.1080/12298093.2019.1703373 -
Microorganisms Aug 2017Disease caused by filamentous fungal human pathogens (FFHP) is increasing. These organisms cause severe mycoses in immunosuppressed individuals, such as those: (a) with... (Review)
Review
Disease caused by filamentous fungal human pathogens (FFHP) is increasing. These organisms cause severe mycoses in immunosuppressed individuals, such as those: (a) with AIDS; (b) having undergone transplantation; and/or (c) undergoing chemotherapy. Immunocompetent people can become infected. Some FFHP are isolated from foods which may be fomites. However, the information concerning particular species on specific food is large, dispersed and difficult to obtain. Reports of filamentous fungi from food/crops and causing human disease are frequently only available in the literature of food mycology/plant pathology and medical mycology, respectively: it is seldom cross-referenced. contains some species with strains that are the most dangerous FFHP, with causing the most serious diseases. and also contain species of high importance and approximately 15 other genera are involved. A checklist and database of FFHP species isolated from food is presented herein with emphasis on , and in summary tables to increase awareness of the connection between food and FFHP. Metadata on all FFHP is provided in a large supplementary table for updating and revision when necessary. Previous names of fungi have been revised to reflect current valid usage whenever appropriate. The information will form a foundation for future research and taxonomic revisions in the field. The paper will be highly useful for medical practitioners, food mycologists, fungal taxonomists, patients, regulators and food producers interested in reducing infectious diseases and producing high quality food.
PubMed: 28767050
DOI: 10.3390/microorganisms5030044 -
Scientific Reports Oct 2015The human intestine is home to a diverse range of bacterial and fungal species, forming an ecological community that contributes to normal physiology and disease...
The human intestine is home to a diverse range of bacterial and fungal species, forming an ecological community that contributes to normal physiology and disease susceptibility. Here, the fungal microbiota (mycobiome) in obese and non-obese subjects was characterized using Internal Transcribed Spacer (ITS)-based sequencing. The results demonstrate that obese patients could be discriminated by their specific fungal composition, which also distinguished metabolically "healthy" from "unhealthy" obesity. Clusters according to genus abundance co-segregated with body fatness, fasting triglycerides and HDL-cholesterol. A preliminary link to metabolites such as hexadecanedioic acid, caproic acid and N-acetyl-L-glutamic acid was also found. Mucor racemosus and M. fuscus were the species more represented in non-obese subjects compared to obese counterparts. Interestingly, the decreased relative abundance of the Mucor genus in obese subjects was reversible upon weight loss. Collectively, these findings suggest that manipulation of gut mycobiome communities might be a novel target in the treatment of obesity.
Topics: Adipose Tissue; Adult; Aspergillus; Blood Glucose; Candida; Caproates; Case-Control Studies; Cholesterol, HDL; DNA, Intergenic; Fasting; Female; Gastrointestinal Microbiome; Glutamates; Humans; Intestines; Male; Middle Aged; Mucor; Mycological Typing Techniques; Obesity; Palmitic Acids; Penicillium; Saccharomyces; Sequence Analysis, DNA; Triglycerides
PubMed: 26455903
DOI: 10.1038/srep14600 -
Diagnostic Cytopathology Mar 2022COVID 19 has been rapidly spreading across the globe. As a result of alteration of the immune milieu by COVID 19 and its treatment, there has been a rise in...
BACKGROUND
COVID 19 has been rapidly spreading across the globe. As a result of alteration of the immune milieu by COVID 19 and its treatment, there has been a rise in opportunistic fungal infections particularly Mucormycosis in these patients. Delay in diagnosis of these fungal infections can be fatal. The usual diagnostic modalities used to detect Mucor include potassium hydroxide (KOH) mount, fungal culture, and histopathology. Since histopathology and fungal culture have a long turnaround time we are dependent on KOH mount for rapid results. Here we investigate the role of stained cytology smears in the rapid diagnosis of Mucormycosis.
METHODS
A prospective observational study was conducted in a tertiary health care hospital on samples of patients clinically suspected to have Mucormycosis. We performed May Grunwald Giemsa (MGG) and Papanicolaou (PAP) stains on the remnant samples of nasal swabs/scrapings/biopsies after KOH test and fungal culture. We took 16 KOH positive and 16 KOH negative samples. We also examined 16 fresh samples from patients whose earlier samples were reported to be negative on KOH test.
RESULTS
The 6/16 KOH positive samples were found to be positive on stained cytology smears and 2 were mixed infections wherein both Mucor and Aspergillus were seen. The 4/16 KOH negative samples were positive for Mucor with one sample having both Mucor and Aspergillus. The 3/16 repeat samples which were earlier negative on KOH test were positive for Mucor.
CONCLUSION
Stained cytology smears if used in conjunction with KOH test can increase the overall sensitivity of detection of Mucormycosis and mixed infections.
Topics: Biopsy; COVID-19; Female; Humans; Mucormycosis; Mycoses; Prospective Studies; SARS-CoV-2; Specimen Handling; Vaginal Smears
PubMed: 34967146
DOI: 10.1002/dc.24924 -
Frontiers in Fungal Biology 2021The increased application of chemical control programs has led to the emergence and spread of insecticide resistance in mosquitoes. Novel environmentally safe control...
The increased application of chemical control programs has led to the emergence and spread of insecticide resistance in mosquitoes. Novel environmentally safe control strategies are currently needed for the control of disease vectors. The use of entomopathogenic fungi could be a suitable alternative to chemical insecticides. Currently, spp. and spp. are the most widely used entomopathogenic fungi for mosquito control, but increasing the arsenal with additional fungi is necessary to mitigate the emergence of resistance. Entomopathogenic fungi are distributed in a wide range of habitats. We have performed a comprehensive screen for candidate mosquitocidal fungi from diverse outdoor environments in Maryland and Puerto Rico. An initial screening of 22 fungi involving exposure of adult to 2-weeks-old fungal cultures identified five potent pathogenic fungi, one of which is unidentified and the remaining four belonging to the three genera sp., sp. and sp. These fungi were then screened against , revealing sp. as a potent mosquito killer. The entomopathogenic effects were confirmed through spore-dipping assays. We also probed further into the killing mechanisms of these fungi and investigated whether the mosquitocidal activities were the result of potential toxic fungus-produced metabolites. Preliminary assays involving the exposure of mosquitoes to sterile filtered fungal liquid cultures showed that sp., sp. and the unidentified isolate 1 were the strongest producers of factors showing lethality against . We have identified five fungi that was pathogenic for and one for , among these fungi, four of them (two strains of sp., , and the unidentified isolate 1) have never previously been described as lethal to insects. Further characterization of these entomopathogenic fungi and their metabolites needs to be done to confirm their potential use in biologic control against mosquitoes.
PubMed: 37744144
DOI: 10.3389/ffunb.2021.637234 -
Diagnostics (Basel, Switzerland) Dec 2022Rhino-orbital cerebral mucor mycosis is a rare disease entity, where retinal involvement is described in the literature mostly as CRAO. However, pathological studies...
Rhino-orbital cerebral mucor mycosis is a rare disease entity, where retinal involvement is described in the literature mostly as CRAO. However, pathological studies have shown mucor invading the choroid and retina with a neutrophilic reaction. So, it is pertinent that retinal inflammation secondary to invading mucor has some role in microstructural changes seen in the vitreous and retina of these patients. This novel study aims to describe the vitreal and retinal features of patients with vision-threatening rhino-orbital cerebral mucor mycosis and how they evolve on spectral domain optical coherence tomography (SD-OCT). This study shall also provide insight into the pathophysiology of these vitreoretinal manifestations by in vitro analysis of the exenterated orbital content. Fifteen eyes of fifteen patients with vision-threatening ROCM treated with standard care were enrolled in this study and underwent complete ophthalmic examination, serial colour fundus photography, and SD-OCT for both qualitative and quantitative analysis, at baseline and follow-up visits. SD-OCT on serial follow-up revealed thickening and increased inner-retinal reflectivity at presentation followed by thinning of both, other features such as the loss of the inner-retinal organized layer structure, external limiting membrane (ELM) disruption, necrotic spaces in the outer retina, and hyperreflective foci. Vitreous cells with vitreous haze were also seen. There was a significant reduction in CMT, inner and outer retinal thickness, total retinal thickness (all p < 0.05) with time, the quantum of reduction concentrated primarily to the inner retina. In summary, in vivo and in vitro analysis revealed that early microstructural changes were primarily a result of retinal infarctions secondary to thrombotic angioinvasion. With the late microstructural changes, there was possible sequelae of retinal infarction with some contribution from the inflammation, resulting from mucor invading the choroid and retina.
PubMed: 36553105
DOI: 10.3390/diagnostics12123098 -
MBio Dec 2021Calcineurin is a critical enzyme in fungal pathogenesis and antifungal drug tolerance and, therefore, an attractive antifungal target. Current clinically accessible...
Calcineurin is a critical enzyme in fungal pathogenesis and antifungal drug tolerance and, therefore, an attractive antifungal target. Current clinically accessible calcineurin inhibitors, such as FK506, are immunosuppressive to humans, so exploiting calcineurin inhibition as an antifungal strategy necessitates fungal specificity in order to avoid inhibiting the human pathway. Harnessing fungal calcineurin-inhibitor crystal structures, we recently developed a less immunosuppressive FK506 analog, APX879, with broad-spectrum antifungal activity and demonstrable efficacy in a murine model of invasive fungal infection. Our overarching goal is to better understand, at a molecular level, the interaction determinants of the human and fungal FK506-binding proteins (FKBP12) required for calcineurin inhibition in order to guide the design of fungus-selective, nonimmunosuppressive FK506 analogs. To this end, we characterized high-resolution structures of the Mucor circinelloides FKBP12 bound to FK506 and of the Aspergillus fumigatus, , and human FKBP12 proteins bound to the FK506 analog APX879, which exhibits enhanced selectivity for fungal pathogens. Combining structural, genetic, and biophysical methodologies with molecular dynamics simulations, we identify critical variations in these structurally similar FKBP12-ligand complexes. The work presented here, aimed at the rational design of more effective calcineurin inhibitors, indeed suggests that modifications to the APX879 scaffold centered around the C, C, C, C, and C positions provide the potential to significantly enhance fungal selectivity. Invasive fungal infections are a leading cause of death in the immunocompromised patient population. The rise in drug resistance to current antifungals highlights the urgent need to develop more efficacious and highly selective agents. Numerous investigations of major fungal pathogens have confirmed the critical role of the calcineurin pathway for fungal virulence, making it an attractive target for antifungal development. Although FK506 inhibits calcineurin, it is immunosuppressive in humans and cannot be used as an antifungal. By combining structural, genetic, biophysical, and methodologies, we pinpoint regions of the FK506 scaffold and a less immunosuppressive analog, APX879, centered around the C to C and C to C positions that could be altered with selective extensions and/or deletions to enhance fungal selectivity. This work represents a significant advancement toward realizing calcineurin as a viable target for antifungal drug discovery.
Topics: Amino Acid Sequence; Antifungal Agents; Calcineurin; Calcineurin Inhibitors; Drug Design; Fungal Proteins; Host-Pathogen Interactions; Humans; Mucor; Mucormycosis; Sequence Alignment; Tacrolimus; Tacrolimus Binding Protein 1A
PubMed: 34809463
DOI: 10.1128/mBio.03000-21