scholarly journals Comprehensive analysis of the dermatophyte Trichophyton rubrum transcriptional profile reveals dynamic metabolic modulation

2020 ◽  
Vol 477 (5) ◽  
pp. 873-885 ◽  
Author(s):  
Maíra Pompeu Martins ◽  
Antonio Rossi ◽  
Pablo Rodrigo Sanches ◽  
Julio Cesar Bortolossi ◽  
Nilce Maria Martinez-Rossi

The environmental challenges imposed onto fungal pathogens require a dynamic metabolic modulation, which relies on activation or repression of critical factors and is essential for the establishment and perpetuation of host infection. Wherefore, to overcome the different host microenvironments, pathogens not only depend on virulence factors but also on metabolic flexibility, which ensures their dynamic response to stress conditions in the host. Here, we evaluate Trichophyton rubrum interaction with keratin from a metabolic perspective. We present information about gene modulation of the dermatophyte during early infection stage after shifting from glucose- to keratin-containing culture media, in relation to its use of glucose as the carbon source. Analyzing T. rubrum transcriptome using high-throughput RNA-sequencing technology, we identified the modulation of essential genes related to nitrogen, fatty acid, ergosterol, and carbohydrate metabolisms, among a myriad of other genes necessary for the growth of T. rubrum in keratinized tissues. Our results provide reliable and critical strategies for adaptation to keratin and confirm that the urea-degrading activity associated with the reduction in disulfide bonds and proteolytic activity facilitated keratin degradation. The global modulation orchestrates the responses that support virulence and the proper adaptation to keratin compared with glucose as the carbon source. The gene expression profiling of the host-pathogen interaction highlights candidate genes involved in fungal adaptation and survival and elucidates the machinery required for the establishment of the initial stages of infection.

2016 ◽  
Vol 18 (6) ◽  
pp. 953
Author(s):  
Gloria Ines Estrada Salazar ◽  
José A. Chacón-Cardona

Resumen:Objetivo: Determinar la frecuencia de las dermatomicosis en personas de diferentes instituciones de atención social en la ciudad de Manizales durante el año 2011. Método: Mediante la toma de muestras de los sitios que presentaban algún tipo de lesión sospechosa de ser una micosis cutánea, se hizo un análisis directo con KOH y cultivo en medios de Saboureaud y Mycosel. Se aplicó un instrumento de recolección de información para establecer  factores asociados con la presencia de estos microorganismos.Resultados: Los hongos levaduriformes encontrados con mayor frecuencia fueron: Candida albicans, Trichosporon sp, y los mohos saprofitos Penicillium sp, fusarium sp; seguido de hongos dermatofitos como: Trichophyton mentagrophites, Trichophyton rubrum, Epidermophyton floccosum y Microsporum gypseum. Las lesiones secas y descamativas se encontraron con mayor frecuencia. El compartir baños y vivir en hacinamiento y el uso de elementos comunes fueron los factores asociados más importantes en este estudio.Conclusiones. Las dermatomicosis son frecuentes en poblaciones vulnerables y se asocian a diferentes factores muy similares a los encontrados en otros estudios de igual naturaleza.    Palabras clave: dermatomicosis, onicomicosis, jóvenes, ancianos, factores asociados. Summary:Objective: To determine the frequency of ringworm in people of different social care institutions in the city of Manizales in 2011.Method: Using the sampling sites that had some kind of suspicious lesion from a cutaneous mycosis, direct analysis with KOH and culture media was Saboureaud and Mycosel. An instrument of data collection was used to establish factors associated with the presence of these microorganisms.Results: The yeast found most frequently were: Candida albicans, Trichosporon sp and Penicillium molds saprophytes sp, Fusarium sp, followed by dermatophyte fungi such as Trichophyton mentagrophytes, Trichophyton rubrum, Epidermophyton floccosum and Microsporum gypseum. Dry scaly lesions were found more frequently. The shared bathrooms and living in overcrowded and the use of common elements were the most important in this study associated factors.Conclusions: Dermatomycoses are common in vulnerable populations and are associated with different very similar to those found in other studies of the same nature factors. Keywords: ringworm, onychomycosis, young, old, associated factors.


2020 ◽  
Author(s):  
Hannah E. Brown ◽  
Calla L. Telzrow ◽  
Joseph W. Saelens ◽  
Larissa Fernandes ◽  
J. Andrew Alspaugh

AbstractThe ability for cells to maintain homeostasis in the presence of extracellular stress is essential for their survival. Stress adaptations are especially important for microbial pathogens to respond to rapidly changing conditions, such as those encountered during the transition from the environment to the infected host. Many fungal pathogens have acquired the ability to quickly adapt to changes in extracellular pH to promote their survival in the various micro-environments encountered during a host infection. For example, the fungal-specific Rim/Pal alkaline response pathway has been well characterized in many fungal pathogens, including Cryptococcus neoformans. However, alternative mechanisms for sensing and responding to host pH have yet to be extensively studied. Recent observations from a genetic screen suggest that the C. neoformans sterol homeostasis pathway is required for growth at elevated pH. This work explores interactions among mechanisms of membrane homeostasis, alkaline pH tolerance, and Rim pathway activation. We find that the sterol homeostasis pathway is necessary for growth in an alkaline environment, and that an elevated pH is sufficient to induce Sre1 activation. This pH-mediated activation of the Sre1 transcription factor is linked to the biosynthesis of ergosterol, but is not dependent on Rim pathway signaling, suggesting that these two pathways are responding to alkaline pH independently. Furthermore, we discover that C. neoformans is more susceptible to membrane-targeting antifungals in alkaline conditions highlighting the impact of micro-environmental pH on the treatment of invasive fungal infections. Together, these findings further connect membrane integrity and composition with the fungal pH response and pathogenesis.


Author(s):  
Daniel Yu ◽  
Megan A Outram ◽  
Emma Creen ◽  
Ashley Smith ◽  
Yi-Chang Sung ◽  
...  

Effectors are a key part of the arsenal of plant pathogenic fungi and promote pathogen virulence and disease. Effectors typically lack sequence similarity to proteins with known functional domains and motifs, limiting our ability to predict their functions and understand how they are recognised by plant hosts. As a result, cross-disciplinary approaches involving structural biology and protein biochemistry are often required to decipher and better characterise effector function. These approaches are reliant on high yields of relatively pure protein, which often requires protein production using a heterologous expression system. For some effectors, establishing an efficient production system can be difficult, particularly those that require multiple disulfide bonds to achieve their naturally folded structure. Here, we describe the use of a co-expression system within the heterologous host E. coli termed CyDisCo (cytoplasmic disulfide bond formation in E. coli) to produce disulfide bonded fungal effectors. We demonstrate that CyDisCo and a naturalised co-expression approach termed FunCyDisCo (Fungi-CyDisCo) can significantly improve the production yields of numerous disulfide bonded effectors from diverse fungal pathogens. The ability to produce large quantities of functional recombinant protein has facilitated functional studies and crystallisation of several of these reported fungal effectors. We suggest this approach could be broadly useful in the investigation of the function and recognition of a broad range of disulfide-bond containing effectors.


2011 ◽  
Vol 57 (4) ◽  
pp. 333-338 ◽  
Author(s):  
Fernanda C.A. Maranhão ◽  
Henrique C.S. Silveira ◽  
Antonio Rossi ◽  
Nilce M. Martinez-Rossi

Trichophyton rubrum is the most common etiological agent of human dermatophytosis. Despite the incidence and medical importance of this dermatophyte, little is known about the mechanisms of host invasion and pathogenicity. Host invasion depends on the adaptive cellular responses of the pathogen that allow it to penetrate the skin layers, which are mainly composed of proteins and lipids. In this study, we used suppression subtractive hybridization to identify transcripts overexpressed in T. rubrum cultured in lipid as carbon source. Among the subtractive cDNA clones isolated, 85 clones were positively screened by cDNA array dot blotting and were sequenced. The putative proteins encoded by the isolated transcripts showed similarities to fungal proteins involved in metabolism, signaling, defense, and virulence, such as the MDR/ABC transporter, glucan 1,3-β-glucosidase, chitin synthase B, copper-sulfate-regulated protein, and serine/threonine phosphatase (calcineurin A). These results provide the first molecular insight into the genes differentially expressed during the adaptation of T. rubrum to a lipidic carbon source.


2020 ◽  
Vol 6 (4) ◽  
pp. 348
Author(s):  
Isabella Zangl ◽  
Reinhard Beyer ◽  
Ildiko-Julia Pap ◽  
Joseph Strauss ◽  
Christoph Aspöck ◽  
...  

Several Candida species are opportunistic human fungal pathogens and thrive in various environmental niches in and on the human body. In this study we focus on the conditions of the vaginal tract, which is acidic, hypoxic, glucose-deprived, and contains lactic acid. We quantitatively analyze the lactic acid tolerance in glucose-rich and glucose-deprived environment of five Candida species: Candidaalbicans, Candida glabrata, Candida parapsilosis, Candida krusei and Candida tropicalis. To characterize the phenotypic space, we analyzed 40–100 clinical isolates of each species. Each Candida species had a very distinct response pattern to lactic acid stress and characteristic phenotypic variability. C. glabrata and C. parapsilosis were best to withstand high concentrations of lactic acid with glucose as carbon source. A glucose-deprived environment induced lactic acid stress tolerance in all species. With lactate as carbon source the growth rate of C. krusei is even higher compared to glucose, whereas the other species grow slower. C. krusei may use lactic acid as carbon source in the vaginal tract. Stress resistance variability was highest among C. parapsilosis strains. In conclusion, each Candida spp. is adapted differently to cope with lactic acid stress and resistant to physiological concentrations.


2012 ◽  
Vol 11 (8) ◽  
pp. 1042-1054 ◽  
Author(s):  
Matthias Kretschmer ◽  
Joyce Wang ◽  
James W. Kronstad

ABSTRACTAn understanding of the connections between metabolism and elaboration of virulence factors during host colonization by the human-pathogenic fungusCryptococcus neoformansis important for developing antifungal therapies. Lipids are abundant in host tissues, and fungal pathogens in the phylum basidiomycota possess both peroxisomal and mitochondrial β-oxidation pathways to utilize this potential carbon source. In addition, lipids are important signaling molecules in both fungi and mammals. In this report, we demonstrate that defects in the peroxisomal and mitochondrial β-oxidation pathways influence the growth ofC. neoformanson fatty acids as well as the virulence of the fungus in a mouse inhalation model of cryptococcosis. Disease attenuation may be due to the cumulative influence of altered carbon source acquisition or processing, interference with secretion, changes in cell wall integrity, and an observed defect in capsule production for the peroxisomal mutant. Altered capsule elaboration in the context of a β-oxidation defect was unexpected but is particularly important because this trait is a major virulence factor forC. neoformans. Additionally, analysis of mutants in the peroxisomal pathway revealed a growth-promoting activity forC. neoformans, and subsequent work identified oleic acid and biotin as candidates for such factors. Overall, this study reveals that β-oxidation influences virulence inC. neoformansby multiple mechanisms that likely include contributions to carbon source acquisition and virulence factor elaboration.


Author(s):  
José Tonatiuh Gutiérrez Zavala ◽  
Irebe Ávila Díaz ◽  
Rosa Elia Magaña Lemus

Background and Aims: Orchids in Mexico are mainly threatened by deforestation, changes in land use, illegal trade, deficiencies in environmental policy and legislation, and a lack of community participation in the conservation of their forests. Erycina hyalinobulbon is an endemic twig epiphyte orchid with a short life cycle and with large flowers in relation to its size, for which it has been harvested from its wild populations. The objectives of this work were to evaluate the in vitro development of E. hyalinobulbon in culture media with organic supplements, to compare sucrose vs. N’Joy Stevia® as a carbon source for its initial stages of development, and to evaluate the development of its seedlings in media enriched with plant growth regulators (PGR).Methods: For the sowing of seeds, PhytamaxTM and MS medium at 30% of its basal salts were used in combination with organic supplement (coconut milk, pineapple puree and banana puree), along with the Phy medium used as control. In order to measure the effect of sucrose vs. N´Joy Stevia® as a carbon source, these two treatments were used, with the PhytamaxTM medium. To evaluate the development of seedlings with PGR, three treatments were tested: the 100% PhytamaxTM control, 30% PhytamaxTM with 1.166 ml/l of Maxi-grow and the medium Chiu.Key results: PhytamaxTM medium added with banana promoted germination by 9.3%, being a low cost and easy production option. Ninety days after sowing, N´Joy Stevia® as a carbon source promoted germination by 8%. The best development of the seedlings was registered in the medium PhytamaxTM without PGR.Conclusions: With this study, it was possible to develop an accessible in vitro propagation system for E. hyalinobulbon, in order to sustainably manage it and favor its conservation.


2021 ◽  
Vol 2 (10) ◽  
pp. 01-02
Author(s):  
Nida Tabassum Khan

Bioemulsifier is a poly-anionic and amphiphilic compound which can balance out the hydrocarbon emulsion in water by making an extremely thin layer between the hydrocarbon beads and water. Most extreme focus is acquired when culture media containing 12 carbon-based unsaturated fats are utilized as the carbon source. Bioemulsifier with proficient emulsifying action and low-production cost, meets various prerequisites of emulsification in the most practical manner in numerous industrial sectors such as in food and dairy.


2020 ◽  
Author(s):  
Sylvie Reverchon ◽  
Sam Meyer ◽  
Raphaël Forquet ◽  
Florence Hommais ◽  
Georgi Muskhelishvili ◽  
...  

AbstractBacterial pathogenic growth requires a swift coordination of pathogenicity functions with various kinds of environmental stresses encountered in the course of host infection. Among the factors critical for bacterial adaptation are changes of DNA topology and binding effects of nucleoid-associated proteins transducing the environmental signals to the chromosome and coordinating the global transcriptional response to stress. In this study we use the model phytopathogen Dickeya dadantii to analyse the organisation of transcription by the nucleoid-associated protein IHF. We determine both phenotypic effects of ihfA mutation on D. dadantii virulence and the transcriptional response under various conditions of growth. For the first time in enterobacteria, we examine the transcriptome of an IHF-depleted mutant under conditions of DNA relaxation, revealing a subtle interplay between IHF and DNA topology. We show that this mutation reorganises the genomic expression by altering the distribution of DNA supercoils along the chromosome at different length scales, thus affecting many virulence genes involved in both symptomatic and asymptomatic phases of infection, including those required for pectin catabolism. Altogether, we propose that IHF is a “domainin” protein, the inactivation of which impairs the coordination of chromosomal stress-response domains harbouring various virulence traits, thus abrogating the pathogenicity of D. dadantii.


Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 198
Author(s):  
Dragana Stojičić ◽  
Svetlana Tošić ◽  
Gordana Stojanović ◽  
Bojan Zlatković ◽  
Snežana Jovanović ◽  
...  

Clinopodium pulegium (Rochel) Bräuchler (Lamiaceae) is an endangered species endemic to the Southern Carpathians. It is characterized by the production of high amounts of essential oils, which emit volatile organic compounds (VOCs) that have an essential role in biotic and abiotic stress responses and in plant–plant and plant–insect interactions. The present study was initiated to phytochemically examine the influence of different carbon sources in the nutrition medium on VOC emissions of micropropagated C. pulegium plants, using gas chromatography–mass spectrometry analysis of headspace VOCs. The volatile profiles were subjected to multivariate analysis with respect to the presence, concentration and type of carbon source in the nutrient medium. In addition, the effect of different carbohydrates on the density and size of the leaf glandular trichomes, the main structures involved in the emission of VOCs, was determined. A total of 19 VOCs, primarily belonging to mono- and sesquiterpenes previously described in plants, were tentatively identified. Six VOCs were produced at levels higher than 2% of the total VOC emission, dominated by pulegone, ß-pinene and menthone. Inclusion of the carbohydrates in the culture media affected the production of the main leaf trichome-associated volatile allelochemicals although the qualitative composition of the volatiles changed only slightly. Multivariate analysis showed that the concentration, rather than the carbohydrate type, influenced the VOC profile.


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