scholarly journals Fungal–Metal Interactions: A Review of Toxicity and Homeostasis

2021 ◽  
Vol 7 (3) ◽  
pp. 225
Author(s):  
Janelle R. Robinson ◽  
Omoanghe S. Isikhuemhen ◽  
Felicia N. Anike
Keyword(s):  
Filamentous Fungi ◽  
Metal Ion ◽  
Current Knowledge ◽  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Metal Exposure ◽  
Metal Interactions ◽  
Nanoparticle Biosynthesis ◽  
Iron Manganese ◽  
Microarray Analyses

Metal nanoparticles used as antifungals have increased the occurrence of fungal–metal interactions. However, there is a lack of knowledge about how these interactions cause genomic and physiological changes, which can produce fungal superbugs. Despite interest in these interactions, there is limited understanding of resistance mechanisms in most fungi studied until now. We highlight the current knowledge of fungal homeostasis of zinc, copper, iron, manganese, and silver to comprehensively examine associated mechanisms of resistance. Such mechanisms have been widely studied in Saccharomyces cerevisiae, but limited reports exist in filamentous fungi, though they are frequently the subject of nanoparticle biosynthesis and targets of antifungal metals. In most cases, microarray analyses uncovered resistance mechanisms as a response to metal exposure. In yeast, metal resistance is mainly due to the down-regulation of metal ion importers, utilization of metallothionein and metallothionein-like structures, and ion sequestration to the vacuole. In contrast, metal resistance in filamentous fungi heavily relies upon cellular ion export. However, there are instances of resistance that utilized vacuole sequestration, ion metallothionein, and chelator binding, deleting a metal ion importer, and ion storage in hyphal cell walls. In general, resistance to zinc, copper, iron, and manganese is extensively reported in yeast and partially known in filamentous fungi; and silver resistance lacks comprehensive understanding in both.

scholarly journals Taking nature into lab: biomineralization by heavy metal resistant streptomycetes in soil

2013 ◽  
Vol 10 (2) ◽  
pp. 2345-2375 ◽  
Author(s):  
E. Schütze ◽  
A. Weist ◽  
M. Klose ◽  
T. Wach ◽  
M. Schumann ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Control Soil ◽  
Natural Conditions ◽  
Laboratory Methods ◽  
Dominant Property ◽  
Resistant Strains ◽  
Heavy Metal Resistant ◽  
And Control

Abstract. Biomineralization by heavy metal resistant streptomycetes was tested to evaluate the potential influence on metal mobilities in soil. Thus, we designed an experiment adopting conditions from classical laboratory methods to natural conditions prevailing in metal-rich soils with media spiked with heavy metals, soil agar, and nutrient enriched or unamended soil incubated with the bacteria. As a result, all strains were able to form struvite minerals on tryptic soy broth (TSB) media supplemented with AlCl2, MnCl2 and CuSO4, as well as on soil agar. Some strains additionally formed struvite on nutrient enriched contaminated and control soil, as well as on metal contaminated soil without addition of media components. In contrast, switzerite was exclusively formed on minimal media spiked with MnCl2 by four heavy metal resistant strains, and on nutrient enriched control soil by one strain. Hydrated nickel hydrogen phosphate was only crystallized on complex media supplemented with NiSO4 by most strains. Thus, mineralization is a~dominant property of streptomycetes, with different processes likely to occur under laboratory conditions and sub-natural to natural conditions. This new understanding may be transferred to formation of minerals in rock and sediment evolution, to ore deposit formation, and also might have implications for our understanding of biological metal resistance mechanisms. We assume that biogeochemical cycles, nutrient storage and metal resistance might be affected by formation and re-solubilization of minerals like struvite in soil at microscale.

Resolving Sample Traces in Complex Mixtures with Microarray Analyses

2011 ◽  
pp. 108-155
Author(s):  
George I. Lambrou ◽  
Eleftheria Koultouki ◽  
Maria Adamaki ◽  
Maria Moschovi
Keyword(s):  
Nucleic Acids ◽  
Statistical Methods ◽  
Current Knowledge ◽  
Complex Mixture ◽  
Theoretical Framework ◽  
Complex Mixtures ◽  
Complex Signal ◽  
Microarray Technology ◽  
Detailed Review ◽  
Microarray Analyses

This chapter reviews the microarray technology and deal with the majority of aspects regarding microarrays. It focuses on today’s knowledge of separation techniques and methodologies of complex signal, i.e. samples. Overall, the chapter reviews the current knowledge on the topic of microarrays and presents the analyses and techniques used, which facilitate such approaches. It starts with the theoretical framework on microarray technology; second, the chapter gives a brief review on statistical methods used for microarray analyses, and finally, it contains a detailed review of the methods used for discriminating traces of nucleic acids within a complex mixture of samples.

Contact Patch to Rim Distance: The Quintessential Tool for Metal-On-Metal Bearing in Vivo Performance Analysis – a Review

2017 ◽  
Vol 27 (3) ◽  
pp. 220-225 ◽  
Author(s):  
Michel J. Le Duff ◽  
Edward Ebramzadeh ◽  
Harlan C. Amstutz
Keyword(s):  
Metal Ion ◽  
Current Knowledge ◽  
Inverse Correlation ◽  
Contact Patch ◽  
Essential Variable ◽  
Metal On Metal ◽  
The Us ◽  
The Subject ◽  
Film Lubrication

With metal-on-metal (MoM) bearings, fluid film lubrication is disrupted when the contact patch area between the femoral head and the cup is close to the edge of the acetabular component, making the calculation of the contact patch to rim (CPR) distance a key variable in the study of the performance of MoM bearings. A few research centers have used models of varying complexity to calculate the CPR distance and determine its relationship with assessments of component wear. In this review, we aimed to summarise the current knowledge related to the application of CPR distance calculations in the study of in vivo performance of MoM bearings. Our systematic search of the US National Library of Medicine yielded 9 relevant publications in which 3 different models were used for the computation of the CPR distance. The 3 models show different levels of complexity and their use is mainly dependent upon the size of the subject sample and the nature of the data collected as a dependent variable. The studies reviewed consistently showed a strong inverse correlation between CPR distance and wear or metal ion levels suggesting that any study aiming to determine the risk factors for MoM hip devices needs to include an assessment of CPR distance. Cup anteversion can be measured reliably with various tools and should not be an obstacle to the use of this essential variable that is CPR distance.

scholarly journals CzcD Is a Heavy Metal Ion Transporter Involved in Regulation of Heavy Metal Resistance in Ralstonia sp. Strain CH34

1999 ◽  
Vol 181 (22) ◽  
pp. 6876-6881 ◽  
Author(s):  
Andreas Anton ◽  
Cornelia Große ◽  
Jana Reißmann ◽  
Thomas Pribyl ◽  
Dietrich H. Nies
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heavy Metal ◽  
Metal Ion ◽  
Constitutive Expression ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Cation Diffusion ◽  
Ion Efflux ◽  
Domains Of Life ◽  
Membrane Bound

ABSTRACT The Czc system of Ralstonia sp. strain CH34 mediates resistance to cobalt, zinc, and cadmium through ion efflux catalyzed by the CzcCB2A cation-proton antiporter. The CzcD protein is involved in the regulation of the Czc system. It is a membrane-bound protein with at least four transmembrane α-helices and is a member of a subfamily of the cation diffusion facilitator (CDF) protein family, which occurs in all three domains of life. The deletion ofczcD in a Ralstonia sp. led to partially constitutive expression of the Czc system due to an increased transcription of the structural czcCBA genes, both in the absence and presence of inducers. The czcD deletion could be fully complemented in trans by CzcD and two other CDF proteins from Saccharomyces cerevisiae, ZRC1p and COT1p. All three proteins mediated a small but significant resistance to cobalt, zinc, and cadmium in Ralstonia, and this resistance was based on a reduced accumulation of the cations. Thus, CzcD appeared to repress the Czc system by an export of the inducing cations.

Heavy metal resistance mechanisms in actinobacteria for survival in AMD contaminated soils

Geochemistry ◽  
2005 ◽  
Vol 65 ◽  
pp. 131-144 ◽  
Author(s):  
Andre Schmidt ◽  
Götz Haferburg ◽  
Manuel Sineriz ◽  
Dirk Merten ◽  
Georg Büchel ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Contaminated Soils ◽  
Heavy Metal Resistance ◽  
Resistance Mechanisms ◽  
Metal Resistance

scholarly journals Co-selection of antibiotic and heavy metal resistance in freshwater bacteria

2016 ◽  
Vol 75 (s2) ◽  
Author(s):  
Andrea Di Cesare ◽  
Ester Eckert ◽  
Gianluca Corno
Keyword(s):  
Heavy Metal ◽  
Resistance Genes ◽  
Heavy Metal Resistance ◽  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Resistant Bacteria ◽  
Human Pathogens ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Selection Of

<p class="p1">Antibiotic resistant bacteria are found in most environments, especially in highly anthropized waters. A direct correlation between human activities (<em><span class="s1">e.g., </span></em>pollution) and spread and persistence of antibiotic resistant bacteria (ARB) and resistance genes (ARGs) within the resident bacterial communities appears more and more obvious. Furthermore, the threat posed for human health by the presence of ARB and ARGs in these environments is enhanced by the risk of horizontal gene transfer of resistance genes to human pathogens. Although the knowledge on the spread of antibiotic resistances in waters is increasing, the understanding of the driving factors determining the selection for antibiotic resistance in the environment is still scarce. Antibiotic pollution is generally coupled with contamination by heavy metals (HMs) and other chemicals, which can also promote the development of resistance mechanisms, often through co-selecting for multiple resistances. The co-selection of heavy metal resistance genes and ARGs in waters, sediments, and soils, increases the complexity of the ecological role of ARGs, and reduces the effectiveness of control actions. In this mini-review we present the state-of-the-art of the research on antibiotic- and HM-resistance and their connection in the environment, with a focus on HM pollution and aquatic environments. We review the spread and the persistence of HMs and/or ARB, and how it influences their respective gene co-selection. In the last chapter, we propose Lake Orta, a system characterized by an intensive HM pollution followed by a successful restoration of the chemistry of the water column, as a study-site to evaluate the spread and selection of HMs and antibiotic resistances in heavily disturbed environments.</p>

scholarly journals CandidaInfections, Causes, Targets, and Resistance Mechanisms: Traditional and Alternative Antifungal Agents

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Claudia Spampinato ◽  
Darío Leonardi
Keyword(s):  
Antifungal Agents ◽  
Fungal Infections ◽  
Current Knowledge ◽  
Resistance Mechanisms ◽  
Antifungal Drugs ◽  
Diagnostic Methods ◽  
Opportunistic Pathogens ◽  
Yeast Infection ◽  
Life Threatening ◽  
Therapeutic Alternatives

The genusCandidaincludes about 200 different species, but only a few species are human opportunistic pathogens and cause infections when the host becomes debilitated or immunocompromised.Candidainfections can be superficial or invasive. Superficial infections often affect the skin or mucous membranes and can be treated successfully with topical antifungal drugs. However, invasive fungal infections are often life-threatening, probably due to inefficient diagnostic methods and inappropriate initial antifungal therapies. Here, we briefly review our current knowledge of pathogenic species of the genusCandidaand yeast infection causes and then focus on current antifungal drugs and resistance mechanisms. An overview of new therapeutic alternatives for the treatment ofCandidainfections is also provided.

Copper Resistance Mechanisms of Biomining Bacteria and Archaea Living under Extremely High Concentrations of Metals

2009 ◽  
Vol 71-73 ◽  
pp. 279-282 ◽  
Author(s):  
A. Orell ◽  
C.A. Navarro ◽  
Carlos A. Jerez
Keyword(s):  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Copper Resistance ◽  
Inorganic Polyphosphate ◽  
Resistance Determinants ◽  
High Metal ◽  
Pi Complex ◽  
Cu Resistance ◽  
High Concentrations ◽  
Cu Tolerance

Extremophiles such as the acidophilic Sulfolobus metallicus (Archaea) and Acidithiobacillus ferrooxidans (Bacteria) can resist Cu (CuSO4) concentrations of 200 mM and 800 mM respectively. These microorganisms are important in biomining processes to extract copper and other metals. A. ferrooxidans grown at low Cu concentrations (5 mM) expressed genes coding for ATPases most likely involved in pumping the metal from the cytoplasm to the periplasm of the bacterium. At 100 mM Cu the previous systems were repressed and there was a great induction in the expression of efflux systems known to use the proton motive force energy to export the metal outside the cell. These Cu-resistance determinants from A. ferrooxidans were found to be functional since when expressed in Escherichia coli they conferred higher Cu tolerance to it. Novel Cu-resistance determinants for A. ferrooxidans were found and characterized. S. metallicus possessed at least 2 CopM metallochaperones and 2 CopA ATPases whose expressions were induced by Cu (5 to 50 mM). Furthermore, we previously reported that both microorganisms accumulate high levels of inorganic polyphosphate (PolyP) and that intracellular Cu concentration stimulates polyP hydrolysis. The resulting Pi would then be transported out of the cell as a metal-Pi complex to detoxify the cells. In addition, our results suggest that at high Cu concentrations polyP could also provide energy for the metal efflux. All the data suggest that both biomining microorganisms use different systems to respond to Cu depending on the extracellular concentrations of the metal and suggest that the presence of different additional systems to respond to Cu may explain the extremely high metal resistance of these extremophiles.

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