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1.
J Mycol Med ; 29(3): 245-252, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400864

RESUMO

In recent decades, the epidemiology of invasive candidiasis (IC) has progressively changed worldwide. This notably includes emergence of several Candida species. Although some surveillance programs provided global trends in IC epidemiology, data from countries from the Middle East and North Africa (MENA) remain scarce. In this manuscript, we reviewed the existing available data on the epidemiology of Candida species associated with IC, particularly candidemia, in MENA region regarding species distribution. As witnessed worldwide, an evident shift of Candidaalbicans towards non-albicansCandida (NAC) has been observed in the MENA region. The worrying emergence of multi-drug resistant Candida species in MENA calls for a better understanding of their epidemiology. This represents an essential prerequisite for the implementation of effective infection control strategies and surveillance systems to prevent IC among high-risk patients.


Assuntos
Candidemia/epidemiologia , Candidíase Invasiva/epidemiologia , Farmacorresistência Fúngica Múltipla , África do Norte/epidemiologia , Antifúngicos/uso terapêutico , Candida/classificação , Candida/fisiologia , Candidemia/tratamento farmacológico , Candidemia/prevenção & controle , Candidíase Invasiva/tratamento farmacológico , Candidíase Invasiva/prevenção & controle , Humanos , Oriente Médio/epidemiologia
2.
J Mycol Med ; 28(2): 257-268, 2018 Jun.
Artigo em Francês | MEDLINE | ID: mdl-29545121

RESUMO

Among the subdivision of Saccharomycotina (ascomycetes budding yeasts), the CTG clade (formerly the Candida clade) includes species that display a particular genetic code. In these yeasts, the CTG codon is predominantly translated as a serine instead of a leucine residue. It is now well-known that some CTG clade species have a major impact on human and its activities. Some of them are recognized as opportunistic agents of fungal infections termed candidiasis. In addition, another series of species belonging to the CTG clade draws the attention of some research groups because they exhibit a strong potential in various areas of biotechnology such as biological control, bioremediation, but also in the production of valuable biocompounds (biofuel, vitamins, sweeteners, industrial enzymes). Here we provide an overview of recent advances concerning the biology, clinical relevance, and currently tested biotechnological applications of species of the CTG clade. Future directions for scientific research on these particular yeasts are also discussed.


Assuntos
Candida , Candidíase/microbiologia , Microbiologia Industrial , Códon , Humanos
3.
Mycopathologia ; 183(1): 227-239, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28639066

RESUMO

The airways of patients with cystic fibrosis (CF) are frequently colonized by various filamentous fungi, mainly Aspergillus fumigatus and Scedosporium species. To establish within the respiratory tract and cause an infection, these opportunistic fungi express pathogenic factors allowing adherence to the host tissues, uptake of extracellular iron, or evasion to the host immune response. During the colonization process, inhaled conidia and the subsequent hyphae are exposed to reactive oxygen species (ROS) and reactive nitrogen species (RNS) released by phagocytic cells, which cause in the fungal cells an oxidative stress and a nitrosative stress, respectively. To cope with these constraints, fungal pathogens have developed various mechanisms that protect the fungus against ROS and RNS, including enzymatic antioxidant systems. In this review, we summarize the different works performed on ROS- and RNS-detoxifying enzymes in fungi commonly encountered in the airways of CF patients and highlight their role in pathogenesis of the airway colonization or respiratory infections. The potential of these enzymes as serodiagnostic tools is also emphasized. In addition, taking advantage of the recent availability of the whole genome sequence of S. apiospermum, we identified the various genes encoding ROS- and RNS-detoxifying enzymes, which pave the way for future investigations on the role of these enzymes in pathogenesis of these emerging species since they may constitute new therapeutics targets.


Assuntos
Enzimas/metabolismo , Interações Hospedeiro-Patógeno , Evasão da Resposta Imune , Pneumopatias Fúngicas/microbiologia , Estresse Oxidativo , Scedosporium/enzimologia , Scedosporium/patogenicidade , Fibrose Cística/complicações , Humanos , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Scedosporium/imunologia , Scedosporium/metabolismo
4.
Methods Enzymol ; 576: 167-206, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27480687

RESUMO

Natural compounds extracted from microorganisms or plants constitute an inexhaustible source of valuable molecules whose supply can be potentially challenged by limitations in biological sourcing. The recent progress in synthetic biology combined to the increasing access to extensive transcriptomics and genomics data now provide new alternatives to produce these molecules by transferring their whole biosynthetic pathway in heterologous production platforms such as yeasts or bacteria. While the generation of high titer producing strains remains per se an arduous field of investigation, elucidation of the biosynthetic pathways as well as characterization of their complex subcellular organization are essential prequels to the efficient development of such bioengineering approaches. Using examples from plants and yeasts as a framework, we describe potent methods to rationalize the study of partially characterized pathways, including the basics of computational applications to identify candidate genes in transcriptomics data and the validation of their function by an improved procedure of virus-induced gene silencing mediated by direct DNA transfer to get around possible resistance to Agrobacterium-delivery of viral vectors. To identify potential alterations of biosynthetic fluxes resulting from enzyme mislocalizations in reconstituted pathways, we also detail protocols aiming at characterizing subcellular localizations of protein in plant cells by expression of fluorescent protein fusions through biolistic-mediated transient transformation, and localization of transferred enzymes in yeast using similar fluorescence procedures. Albeit initially developed for the Madagascar periwinkle, these methods may be applied to other plant species or organisms in order to establish synthetic biology platform.


Assuntos
Catharanthus/enzimologia , Catharanthus/genética , Genes de Plantas , Genômica/métodos , Biologia Sintética/métodos , Transcriptoma , Leveduras/genética , Vias Biossintéticas , Catharanthus/citologia , Catharanthus/metabolismo , Engenharia Metabólica/métodos , Microscopia de Fluorescência/métodos , Transformação Genética , Leveduras/citologia , Leveduras/enzimologia , Leveduras/metabolismo
5.
Plant Biol (Stuttg) ; 17(6): 1242-6, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26284695

RESUMO

Catharanthus roseus constitutes the unique source of several valuable monoterpenoid indole alkaloids, including the antineoplastics vinblastine and vincristine. These alkaloids result from a complex biosynthetic pathway encompassing between 30 and 50 enzymatic steps whose characterisation is still underway. The most recent identifications of genes from this pathway relied on a tobacco rattle virus-based virus-induced gene silencing (VIGS) approach, involving an Agrobacterium-mediated inoculation of plasmids encoding the two genomic components of the virus. As an alternative, we developed a biolistic-mediated approach of inoculation of virus-encoding plasmids that can be easily performed by a simple bombardment of young C. roseus plants. After optimisation of the transformation conditions, we showed that this approach efficiently silenced the phytoene desaturase gene, leading to strong and reproducible photobleaching of leaves. This biolistic transformation was also used to silence a previously characterised gene from the alkaloid biosynthetic pathway, encoding iridoid oxidase. Plant bombardment caused down-regulation of the targeted gene (70%), accompanied by a correlated decreased in MIA biosynthesis (45-90%), similar to results obtained via agro-transformation. Thus, the biolistic-based VIGS approach developed for C. roseus appears suitable for gene function elucidation and can readily be used instead of the Agrobacterium-based approach, e.g. when difficulties arise with agro-inoculations or when Agrobacterium-free procedures are required to avoid plant defence responses.


Assuntos
Alcaloides/biossíntese , Catharanthus/genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Genes de Plantas , Vetores Genéticos , Vírus de Plantas , Agrobacterium , Antineoplásicos Fitogênicos/biossíntese , Vias Biossintéticas/genética , Catharanthus/metabolismo , Genoma Viral , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plasmídeos , Nicotiana/virologia , Transformação Genética
6.
Plant Biol (Stuttg) ; 8(5): 731-6, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16773556

RESUMO

Signalling pathways involving histidine kinase receptors (HKRs) are widely used by prokaryotes and fungi to regulate a large palette of biological processes. In plants, HKRs are known to be implicated in cytokinin, ethylene, and osmosensing transduction pathways. In this work, a full length cDNA named CRCIK was isolated from the tropical species CATHARANTHUS ROSEUS (L.) G. Don. It encodes a 1205 amino acid protein that belongs to the hybrid HKR family. The deduced amino acid sequence shows the highest homology with AtHK1, an osmosensing HKR in ARABIDOPSIS THALIANA. In return, CrCIK protein shares very low identity with the other 10 ARABIDOPSIS HKRs. Southern blot analysis indicates that the CRCIK corresponding gene is either present in multiple copies or has very close homologues in the genome of the tropical periwinkle. The gene is widely expressed in the plant. In C. ROSEUS C20D cell suspension, it is slightly induced after exposure to low temperature, pointing to a putative role in cold-shock signal transduction.


Assuntos
Catharanthus/enzimologia , Catharanthus/genética , DNA Complementar/genética , Proteínas Quinases/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Clonagem Molecular , DNA de Plantas/genética , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Histidina Quinase , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
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