Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species

Microbial Biotechnology, Journal Year: 2016, Volume and Issue: 10(2), P. 296 - 322

Published: June 7, 2016

Fungi of the genus Aspergillus are widespread in environment. Some species, most commonly fumigatus, may lead to a variety allergic reactions and life-threatening systemic infections humans. Invasive aspergillosis occurs primarily patients with severe immunodeficiency, has dramatically increased recent years. There several factors at play that contribute aspergillosis, including both fungus host-related such as strain virulence host pulmonary structure/immune status, respectively. The environmental tenacity Aspergilllus, its dominance diverse microbial communities/habitats, ability navigate ecophysiological biophysical challenges infection attributable, large part, robust stress-tolerance biology exceptional capacity generate cell-available energy. Aspects stress metabolism, ecology, interactions animal hosts, clinical presentations treatment regimens have been well-studied over past Here, we synthesize these findings relation way which some species become successful opportunistic pathogens human- other hosts. We focus on capabilities pathogens, key aspects their ecophysiology flexibility undergo sexual cycle or form cryptic species. Additionally, advances diagnosis disease discussed well implications questions yet be resolved.

Language: Английский

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Aspergillus penicillioides differentiation and cell division at 0.585 water activity

Environmental Microbiology, Journal Year: 2016, Volume and Issue: 19(2), P. 687 - 697

Published: Nov. 21, 2016

Water availability acts as the most stringent constraint for life on Earth. Thus, understanding water relations of microbial extremophiles is imperative to our ability increase agricultural productivity (e.g., by enhancing processing and turnover dead organic matter in soils arid regions), reduce human exposure mycotoxins buildings food-supply chain, prevent spoilage foods/animal feeds, books, museum specimens artworks better control microbiology industrial fermentations. Only a small number systems can retain activity at <0.710 (ISME J 2015 9: 1333-1351). It has long-been considered that resilient these Xeromyces bisporus, which inhabits sugar-rich substrates (Appl Environ Microbiol 1968 16: 1853-1858). The current study focused germination Aspergillus penicillioides, xerophile also able grow under low humidity saline conditions. Investigations differed from those reported earlier: firstly, aerially borne conidia were harvested, then used inoculations, their dry condition; secondly, cultures incubated 24°C, i.e. below optimum temperature, minimize possibility loss substrate; thirdly, remained sealed throughout 73-day period (microscopic examination was carried out directly 48 through Petri plate lid); fourthly, parameters determined were: rates extent conidial swelling, production differentiated germination-structures septate germlings, subsequent development mycelium and/or sporulation; fifthly, assessments over range water-activity values time points obtain complete profile process. Conidia swelled, formed produced germlings just 0.585 (≡58.5% relative humidity), outside currently understood thermodynamic window life. Furthermore, analyses data suggest theoretical minimum 0.565 A. penicilliodes. In relation astrobiology, findings have an application limits extraterrestrial environments. light plans exploration missions Mars other places, need safeguard martian scientific sites potential resources (including water) future habitation, knowledge-based effective policy planetary protection essential. As it is, Mars-bound spacecraft may frequently be contaminated with aspergilli penicillioides) organisms which, when transported bodies, pose contamination risk. crafting countermeasures offset this, important know precisely possible capabilities interplanetary visitors.

Language: Английский

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Antimicrobial activity of prodigiosin is attributable to plasma-membrane damage

Natural Product Research, Journal Year: 2016, Volume and Issue: 31(5), P. 572 - 577

Published: June 29, 2016

The bacterial pigment prodigiosin has various biological activities; it is, for instance, an effective antimicrobial. Here, we investigate the primary site targeted by prodigiosin, using cells of microbial pathogens humans as model systems: Candida albicans, Escherichia coli, Staphylococcus aureus. Inhibitory concentrations prodigiosin; leakage intracellular K+ ions, amino acids, proteins and sugars; impacts on activities proteases, catalases oxidases; changes in surface appearance pathogen were determined. Prodigiosin was highly inhibitory (30% growth rate reduction C. E. S. aureus at 0.3, 100 0.18 μg ml−1, respectively); caused substances (most severe aureus); to each enzyme; indicative cell-surface damage. Collectively, these findings suggest that log Poctanol–water 5.16, is not a toxin but hydrophobic stressor able disrupt plasma membrane via chaotropicity-mediated mode-of-action.

Language: Английский

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Investigating Europa’s Habitability with the Europa Clipper

Space Science Reviews, Journal Year: 2023, Volume and Issue: 219(8)

Published: Nov. 29, 2023

Abstract The habitability of Europa is a property within system, which driven by multitude physical and chemical processes defined many interdependent parameters, so that its full characterization requires collaborative investigation. To explore as an integrated system to yield complete picture habitability, the Clipper mission has three primary science objectives: (1) characterize ice shell ocean including their heterogeneity, properties, nature surface–ice–ocean exchange; (2) Europa’s composition any non-ice materials on surface in atmosphere, carbon-containing compounds; (3) geology features localities high interest. will also address several cross-cutting topics search for current or recent activity form thermal anomalies plumes, performing geodetic radiation measurements, assessing high-resolution, co-located observations at select sites provide reconnaissance potential future landed mission. Synthesizing mission’s well incorporating remote Earth-based observatories, James Webb Space Telescope, other space-based resources, constrain complex task guided Habitability Assessment Board (HAB).

Language: Английский

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Microbial Diversity in a Hypersaline Sulfate Lake: A Terrestrial Analog of Ancient Mars

Frontiers in Microbiology, Journal Year: 2017, Volume and Issue: 8

Published: Sept. 26, 2017

Life can persist under severe osmotic stress and low water activity in hypersaline environments. On Mars, evidence for the past presence of saline bodies is prevalent resulted widespread deposition sulfate chloride salts. Here we investigate Spotted Lake (British Columbia, Canada), a lake with extreme (>3 M) levels salts as an exemplar conditions thought to be associated ancient Mars. We provide first characterization microbial structure sediments through metagenomic sequencing, report bacteria-dominated community abundant Proteobacteria, Firmicutes, Bacteroidetes, well diverse extremophiles. Microbial abundance functional comparisons reveal similarities Ace Lake, meromictic Antarctic anoxic sulfidic bottom waters. Our analysis suggests that hypersaline-associated species occupy niches characterized foremost by differential Archaea, uncharacterized Bacteria, Cyanobacteria. Potential biosignatures this environment are discussed, specifically likelihood strong sulfur isotopic fractionation record within due reducing bacteria. With its high seasonal freeze-thaw cycles, analog paleolakes on Mars which salt deposits may have offered periodically habitable environments, could concentrated preserved organic materials or their biomarkers over geologic time.

Language: Английский

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Hyperdiverse archaea near life limits at the polyextreme geothermal Dallol area

Nature Ecology & Evolution, Journal Year: 2019, Volume and Issue: 3(11), P. 1552 - 1561

Published: Oct. 28, 2019

Language: Английский

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NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats

FEMS Microbiology Reviews, Journal Year: 2018, Volume and Issue: 42(5), P. 672 - 693

Published: June 8, 2018

NaCl-saturated brines such as saltern crystalliser ponds, inland salt lakes, deep-sea and liquids-of-deliquescence on halite are commonly regarded a paradigm for the limit of life Earth. There are, however, other habitats that thermodynamically more extreme. Typically, environments contain all domains perform complete biogeochemical cycling. Despite their reduced water activity, ∼0.755 at 5 M NaCl, some halophiles belonging to Archaea Bacteria exhibit optimum growth/metabolism in these brines. Furthermore, recognised water-activity microbial function, ∼0.585 strains fungi, lies far below 0.755. Other biophysical constraints biosphere (temperatures >121°C; pH > 12; high chaotropicity; e.g. ethanol >18.9% w/v (24% v/v) MgCl2 >3.03 M) can prevent any cellular metabolism or ecosystem function. By contrast, biomass-dense, metabolically diverse, highly active complex ecosystems; this underscores moderate character. Here, we survey evidence biologically permissive, fertile mid-range rather than Indeed, were NaCl sufficiently soluble, might grow concentrations up 8 M. It may be finite solubility has stabilised genetic composition halophile populations limited action natural selection driving evolution towards greater xerophilicity. Further implications considered origin(s) aspects astrobiology.

Language: Английский

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Glycerol enhances fungal germination at the water‐activity limit for life

Environmental Microbiology, Journal Year: 2016, Volume and Issue: 19(3), P. 947 - 967

Published: Sept. 15, 2016

Summary For the most‐extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 0.640 water (approximately 70.0–64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water‐activity regimes, using an experimental system which represents biophysical limit of Earth's biosphere. Spores from a variety species, including Aspergillus penicillioides , Eurotium halophilicum Xerochrysium xerophilum (formerly Chrysosporium ) Xeromyces bisporus were produced by cultures growing on media supplemented with (and contained up to 189 mg g dry spores −1 ). The ability these germinate, kinetics germination, then determined range designed recreate stresses experienced in microbial habitats or anthropogenic systems (with water‐activities 0.765 0.575). A. amstelodami E. X. occurred at lower than previously recorded (0.640, 0.685, 0.651, 0.664 0.637 respectively). In addition, low substantially faster those reported previously. Extrapolations indicated theoretical minima below values; as 0.570 for . Glycerol is present high concentrations (up molar levels) many types habitat. We discuss likely role expanding function relation temporal constraints location findings here have also critical implications understanding extremes biosphere; potency disease‐causing microorganisms; biotechnologies that operate limits function.

Language: Английский

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Bacillus subtilis Spore Resistance to Simulated Mars Surface Conditions

Frontiers in Microbiology, Journal Year: 2019, Volume and Issue: 10

Published: Feb. 26, 2019

In a Mars exploration scenario, knowing if and how highly resistant Bacillus subtilis spores would survive on the Martian surface is crucial to design planetary protection measures avoid false positives in life-detection experiments. Therefore, this study systematic screening was performed determine whether B. could an average day Mars. For that, from two comprehensive sets of isogenic mutant strains, defective DNA or repair genes, were exposed 24 h simulated atmospheric environment with without 8 UV radiation [M(+)UV M(-)UV, respectively]. When M(+)UV, spore survival dependent (1) core dehydration maintenance, (2) by α/β-type small acid soluble proteins (SASP), (3) removal major photoproduct (SP) DNA. turn, when mainly multilayered coat, double-strand breaks. able for at least limited time environment, both solar radiation. Moreover, M(-)UV-treated exhibited rates significantly higher than M(+)UV-treated spores. This suggests that real surface, shielding (e.g., dust, rocks, spacecraft irregularities) might extend rates. Thus, future efforts should focus determining damage wild-type M(+/-)UV assessing viability via regolith other relevant materials.

Language: Английский

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The PanCam Instrument for the ExoMars Rover

Astrobiology, Journal Year: 2017, Volume and Issue: 17(6-7), P. 511 - 541

Published: May 22, 2017

The scientific objectives of the ExoMars rover are designed to answer several key questions in search for life on Mars. In particular, unique subsurface drill will address some these, such as possible existence and stability organics. PanCam establish surface geological morphological context mission, working collaboration with other instruments. Here, we describe geology, atmospheric science, 3-D vision. We discuss design PanCam, which includes a stereo pair Wide Angle Cameras (WACs), each has an 11-position filter wheel High Resolution Camera (HRC) high-resolution investigations rock texture at distance. cameras electronics housed optical bench that provides mechanical interface mast planetary protection barrier. electronic is via Interface Unit (PIU), power conditioning DC-DC converter. also calibration target mounted deck radiometric calibration, fiducial markers geometric inspection mirror. Key Words: Mars—ExoMars—Instrumentation—Geology—Atmosphere—Exobiology—Context. Astrobiology 17, 511–541.

Language: Английский

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