Optimized expression of Peptidyl-prolyl cis/transisomerase cyclophilinB with prokaryotic toxicity from Sporothrix globosa.

Cyclophilin B (CypB), a significant member of immunophilins family with peptidyl-prolyl cis-trans isomerase (PPIase) activity, is crucial for the growth and metabolism of prokaryotes and eukaryotes. Sporothrix globosa (S. globosa), a principal pathogen in the Sporothrix complex, causes sporotrichosis. Transcriptomic analysis identified the cypB gene as highly expressed in S. globosa. Our previous study demonstrated that the recombinant Escherichia coli strain containing SgcypB gene failed to produce sufficient product when it was induced to express the protein, implying the potential toxicity of recombinant protein to the bacterial host. Bioinformatics analysis revealed that SgCypB contains transmembrane peptides within the 52 amino acid residues at the N-terminus and 21 amino acids near the C-terminus, and 18 amino acid residues within the cytoplasm. AlphaFold2 predicted a SgCypB 3D structure in which there is an independent PPIase domain consisting of a spherical extracellular part. Hence, we chose to express the extracellular domain to yield high-level recombinant protein with PPIase activity. Finally, we successfully produced high-yield, truncated recombinant CypB protein from S. globosa (SgtrCypB) that retained characteristic PPIase activity without host bacterium toxicity. This study presents an alternative expression strategy for proteins toxic to prokaryotes, such as SgCypB. ONE-SENTENCE SUMMARY: The recombinant cyclophilin B protein of Sporothrix globosa was expressed successfully by retaining extracellular domain with peptidyl-prolyl cis-trans isomerase activity to avoid toxicity to the host bacterium.

Sporothrix schenckii regulates macrophage inflammatory responses via the c-JUN-induced Dab2 transcription.

Macrophages, which serve as a bridge between innate and adaptive immunity, play an important role in sporotrichosis. Sporothrix schenckii infections can produce immune responses such as macrophage polarization and inflammatory factor secretion. In the early stages of inflammation, the expression of DAB2 in macrophages is increased, which controls the secretion of inflammatory factors and affects the polarization of macrophages. However, the expressions and mechanisms of DAB2 in sporotrichosis are not clear. In this study, we examined the expression of DAB2 and its regulation of inflammatory factors under conditions of Sporothrix schenckii infection. Our results indicated that the Sporothrix schenckii infection increased the expression of DAB2 and revealed a mixed M1/M2-like type of gene expression in BMDMs with the inhibited Il-6, Il1-ß and Arg-1 and induced Tnf-α, Il-10 and Mgl-1. The deficiency of Dab2 gene suspended the changes of cytokines. In addition, JNK activity in BMDMs was inhibited by Sporothrix schenckii infection, leading to an increase in c-JUN. We also identified c-JUN as a transcription factor for Dab2 through chromatin immunoprecipitation and luciferase reporter assays. In an in vivo mouse model, sporotrichosis-induced skin lesions were accompanied with an upregulation of c-JUN and inhibition of JNK activity, which were in accord with findings from in vitro experiments. Taken together, these findings indicate that in the early stages of Sporothrix schenckii infection there is a promotion of DAB2 expression through the JNK/c-JUN pathway, effects that can then control the expression of inflammatory factors.

Influence of iron on growth and on susceptibility to itraconazole in Sporothrix spp.

We evaluated the growth and the susceptibility to oxidative stress of Sporothrix spp., exposed to different iron concentrations in culture medium, and the susceptibility of Sporothrix spp. to itraconazole, alone and in combination with to the iron chelator deferasirox. The results showed that the growth of S. brasiliensis isolates was more affected by iron availability in comparison to S. schenckii, but both fungal species conidia became more prone to oxidative stress when iron was added to culture medium. Conversely, the combination of itraconazole and deferasirox only resulted in synergism against a minority of S. schenckii isolates.

Proteomic analysis of Sporothrix schenckii cell wall reveals proteins involved in oxidative stress response induced by menadione.

Sporotrichosis is an emergent subcutaneous mycosis that is a threat to both humans and other animals. Sporotrichosis is acquired by the traumatic implantation of species of the Sporothrix genus. Added to the detoxification systems, pathogenic fungi possess different mechanisms that allow them to survive within the phagocytic cells of their human host during the oxidative burst. These mechanisms greatly depend from the cell wall (CW) since phagocytic cells recognize pathogens through specific receptors associated to the structure. To date, there are no studies addressing the modulation of the expression of S. schenckii CW proteins (CWP) in response to reactive oxygen species (ROS). Therefore, in this work, a proteomic analysis of the CW of S. schenckii in response to the oxidative agent menadione (O2•-) was performed. Proteins that modulate their expression were identified which can be related to the fungal survival mechanisms within the phagocyte. Among the up-regulated CWP in response to the oxidative agent, 13 proteins that could be involved in the mechanisms of oxidative stress response in S. schenckii were identified. The proteins identified were thioredoxin1 (Trx1), superoxide dismutase (Sod), GPI-anchored cell wall protein, ß-1,3-endoglucanase EglC, glycoside hydrolase (Gh), chitinase, CFEM domain protein, glycosidase crf1, covalently-linked cell wall protein (Ccw), 30 kDa heat shock protein (Hsp30), lipase, trehalase (Treh), fructose-bisphosphate aldolase (Fba1) and citrate synthase (Cs). The identification of CWP that modulates their expression in response to superoxide ion (O2•-) in S. schenckii is a useful approach to understand how the fungus defends itself against ROS, in order to evade the phagocytic cells from the host and cause the infection.

Congo Red affects the growth, morphology and activity of glucosamine-6-phosphate synthase in the human pathogenic fungus Sporothrix schenckii.

Sporothrix schenckii is the etiological agent of sporotrichosis, a mycosis of humans and other mammals. Little is known about the responses of this thermodimorphic pathogen to perturbations in the cell wall (CW) by different stress conditions. Here we describe the effect of Congo Red (CR) on the fungal growth, morphogenesis and activity of glucosamine-6-phosphate (GlcN-6-P) synthase. Under conditions of yeast development, 15 µM CR abolished conidia (CN) germination, but when yeast cells were first obtained in the absence of the dye and then post-incubated in its presence, yeasts rapidly differentiated into mycelial cells. On the other hand, under conditions of mycelium development, 150 µM CR did not affect CN germination, but filamentous cells underwent structural changes characterized by a distorted CW contour, the loss of polarity and the formation of red-pigmented, hyphal globose structures. Under these conditions, CR also induced a significant and transient increase in the activity of GlcN-6-P synthase, an essential enzyme in CW biogenesis.

Interaction with Pantoea agglomerans Modulates Growth and Melanization of Sporothrix brasiliensis and Sporothrix schenckii.

Sporothrix brasiliensis and Sporothrix schenckii stand as the most virulent agents of sporotrichosis, a worldwide-distributed subcutaneous mycosis. The origin of Sporothrix virulence seems to be associated with fungal interactions with organisms living in the same environment. To assess this hypothesis, the growth of these two species in association with Pantoea agglomerans, a bacterium with a habitat similar to Sporothrix spp., was evaluated. Growth, melanization, and gene expression of the fungus were compared in the presence or absence of the bacterium in the same culture medium. Both S. brasiliensis and S. schenckii grew in contact with P. agglomerans yielding heavily melanized conidia after 5 days of incubation at 30 °C in Sabouraud agar. This increased melanin production occurred around bacterial colonies, suggesting that fungal melanization is triggered by a diffusible bacterial product, which is also supported by a similar pattern of melanin production during Sporothrix spp. growth in contact with heat-killed P. agglomerans. Growth of P. agglomerans was similar in the presence or absence of the fungus. However, the growth of S. brasiliensis and S. schenckii was initially inhibited, but further enhanced when these species were co-cultured with P. agglomerans. Moreover, fungi were able to use killed bacteria as both carbon and nitrogen sources for growth. Representational difference analysis identified overexpressed genes related to membrane transport when S. brasiliensis was co-cultured with the bacteria. The down-regulation of metabolism-related genes appears to be related to nutrient availability during bacterial exploitation. These findings can lead to a better knowledge on Sporothrix ecology and virulence.

Evaluation of melanin production by Sporothrix luriei.

There is a paucity of studies on the cell biology of Sporothrix luriei, the less common of the pathogenic Sporothrix species worldwide. The production of DHN-melanin, eumelanin, and pyomelanin were evaluated on the mycelial and yeast forms of the S. luriei ATCC 18616 strain. The mycelial form of this species produced only pyomelanin, which protected the fungus against environmental stressors such as ultraviolet light, heat, and cold. The yeast form was unable to produce any of the tested melanin types. The lack of melanin in the parasitic form of S. luriei may be an explanation for its low frequency in human infections.

Functional diversity for biomass deconstruction in family 5 subfamily 5 (GH5_5) of fungal endo-ß1,4-glucanases.

Endo-ß1,4-glucanases in glycosyl hydrolase family 5 (GH5) are ubiquitous enzymes in the multicellular fungi and are common components of enzyme cocktails for biomass conversion. We recently showed that an endo-glucanase of subfamily 5 of GH5 (GH5_5) from Sporotrichum thermophile (StCel5A) was more effective at releasing glucose from pretreated corn stover, when part of an eight-component synthetic enzyme mixture, compared to its closely related counterpart from Trichoderma reesei, TrCel5A. StCel5A and TrCel5A belong to different clades of GH5_5 (GH5_5_1 and GH5_5_2, respectively). To test whether the superior activity of StCel5A was a general property of all enzymes in the GH5_5_2 clade, StCel5A, TrCel5A, and two additional members of each subfamily were expressed in a common host that had been engineered to suppress its native cellulases (T. reesei Δxyr1) and compared against each other alone on pure substrates, in synthetic mixtures on pure substrates, and against each other in synthetic mixtures on real biomass. The results indicated that superiority is a unique property of StCel5A and not of GH5_5_2 generally. The six Cel5A enzymes had significant differences in relative activities on different substrates, in specific activities, and in sensitivities to mannan inhibition. Importantly, the behavior of the six endo-glucanases on pure cellulose substrates did not predict their behavior in combination with other cellulolytic enzymes on a real lignocellulosic biomass substrate.

Identification of a type III polyketide synthase involved in the biosynthesis of spirolaxine.

Spirolaxine is a natural product isolated from Sporotrichum laxum ATCC 15155, which has shown a variety of biological activities including promising anti-Helicobacter pylori property. To understand how this compound is biosynthesized, the genome of S. laxum was sequenced. Analysis of the genome sequence revealed two putative type III polyketide synthase (PKS) genes in this strain, Sl-pks1 and Sl-pks2, which are located adjacent to each other (~2.0 kb apart) in a tail-to-tail arrangement. Disruption of these two genes revealed that Sl-PKS2 is the dedicated PKS involved in the biosynthesis of spirolaxine. The intron-free Sl-pks2 gene was amplified from the cDNA of S. laxum and ligated into the expression vector pET28a for expression in Escherichia coli BL21-CodonPlus (DE3)-RIL. The major products of Sl-PKS2 in E. coli were characterized as alkylresorcinols that contain a C13-C17 saturated or unsaturated hydrocarbon side chain based on the spectral data. This enzyme was purified and reacted with malonyl-CoA and a series of fatty acyl-SNACs (C6-C10). Corresponding alkylresorcinols were formed from the decarboxylation of the synthesized tetraketide resorcylic acids, together with fatty acyl-primed triketide and tetraketide pyrones as byproducts. This work provides important information about the PKS involved in the biosynthesis of spirolaxine, which will facilitate further understanding and engineering of the biosynthetic pathway of this medicinally important molecule.

Three new resorcylic acid derivatives from Sporotrichum laxum.

Sporotrichum laxum ATCC 15155 is the producing strain of the potent anti-Helicobacter pylori natural product spirolaxine (1). Investigation of the secondary metabolites in this fungus led to the isolation of five phthalides (1, 2, 3, 6 and 9) and five resorcylic acid derivatives (4, 5, 7, 8 and 10), among which 5, 7 and 8 are new compounds. The structures were elucidated by spectroscopic analyses, and the absolute configurations of 7 and 8 were determined by Mosher's method. Addition of soy flour into the potato dextrose agar has led to the increased production of 4-10. A biosynthetic pathway consisting of a highly reducing polyketide synthase (PKS), a nonreducing PKS and a series of tailoring enzymes was proposed to produce these fungal natural products. The resorcylic acid derivatives are proposed to result from early hydrolysis of the polyketide chain or incorporation of a longer fatty acyl starter unit.

Isolation of Sporothrix schenckii MNT1 and the biochemical and functional characterization of the encoded α1,2-mannosyltransferase activity.

Sporothrix (Sp.) schenckii is a pathogenic fungus that infects humans and animals, and is responsible for the disease named sporotrichosis. The cell wall of this fungus has glycoproteins with a high content of mannose and rhamnose units, which are synthesized by endoplasmic reticulum- and Golgi-localized glycosyltransferases. Little is known about the enzymic machinery involved in the synthesis of these oligosaccharides in Sp. schenckii, or the genes encoding these activities. This is in part because of the lack of an available genome sequence for this organism. Using a partial genomic DNA library we identified SsMNT1, whose predicted product has significant similarity to proteins encoded by members of the Saccharomyces (Sa.) cerevisiae KRE2/MNT1 gene family. In order to biochemically characterize the putative enzyme, SsMNT1 was heterologously expressed in the methylotrophic yeast Pichia pastoris. Recombinant SsMnt1 showed Mn(2+)-dependent mannosyltransferase activity and the ability to recognize as acceptors α-methyl mannoside, mannose, Man(5)GlcNAc(2) oligosaccharide and a variety of mannobiosides. The characterization of the enzymic products generated by SsMnt1 revealed that the enzyme is an α1,2-mannosyltransferase that adds up to two mannose residues to the acceptor molecule. Functional complementation studies were performed in Sa. cerevisiae and Candida albicans mutants lacking members of the KRE2/MNT1 gene family, demonstrating that SsMnt1 is involved in both the N- and O-linked glycosylation pathways, but not in phosphomannan elaboration.

Biosynthesis and functions of a melanoid pigment produced by species of the sporothrix complex in the presence of L-tyrosine.

Sporothrix schenckii is the etiological agent of sporotrichosis, the main subcutaneous mycosis in Latin America. Melanin is an important virulence factor of S. schenckii, which produces dihydroxynaphthalene melanin (DHN-melanin) in conidia and yeast cells. Additionally, l-dihydroxyphenylalanine (l-DOPA) can be used to enhance melanin production on these structures as well as on hyphae. Some fungi are able to synthesize another type of melanoid pigment, called pyomelanin, as a result of tyrosine catabolism. Since there is no information about tyrosine catabolism in Sporothrix spp., we cultured 73 strains, including representatives of newly described Sporothrix species of medical interest, such as S. brasiliensis, S. schenckii, and S. globosa, in minimal medium with tyrosine. All strains but one were able to produce a melanoid pigment with a negative charge in this culture medium after 9 days of incubation. An S. schenckii DHN-melanin mutant strain also produced pigment in the presence of tyrosine. Further analysis showed that pigment production occurs in both the filamentous and yeast phases, and pigment accumulates in supernatants during stationary-phase growth. Notably, sulcotrione inhibits pigment production. Melanin ghosts of wild-type and DHN mutant strains obtained when the fungus was cultured with tyrosine were similar to melanin ghosts yielded in the absence of the precursor, indicating that this melanin does not polymerize on the fungal cell wall. However, pyomelanin-producing fungal cells were more resistant to nitrogen-derived oxidants and to UV light. In conclusion, at least three species of the Sporothrix complex are able to produce pyomelanin in the presence of tyrosine, and this pigment might be involved in virulence.

Characterization and ligand identification of a membrane progesterone receptor in fungi: existence of a novel PAQR in Sporothrix schenckii.

BACKGROUND: Adaptive responses in fungi result from the interaction of membrane receptors and extracellular ligands. Many different classes of receptors have been described in eukaryotic cells. Recently a new family of receptors classified as belonging to the progesterone-adiponectin receptor (PAQR) family has been identified. These receptors have the seven transmembrane domains characteristic of G-protein coupled receptors, but their activity has not been associated directly to G proteins. They share sequence similarity to the eubacterial hemolysin III proteins. RESULTS: A new receptor, SsPAQR1 (Sporothrix schenckii progesterone-adiponectinQ receptor1), was identified as interacting with Sporothrix schenckii G protein alpha subunit SSG-2 in a yeast two-hybrid assay. The receptor was identified as a member of the PAQR family. The cDNA sequence revealed a predicted ORF of 1542 bp encoding a 514 amino acids protein with a calculated molecular weight of 57.8 kDa. Protein domain analysis of SsPAQR1 showed the 7 transmembrane domains (TM) characteristic of G protein coupled receptors and the presence of the distinctive motifs that characterize PAQRs. A yeast-based assay specific for PAQRs identified progesterone as the agonist. S. schenckii yeast cells exposed to progesterone (0.50 mM) showed an increase in intracellular levels of 3', 5' cyclic adenosine monophosphate (cAMP) within the first min of incubation with the hormone. Different progesterone concentrations were tested for their effect on the growth of the fungus. Cultures incubated at 35°C did not grow at concentrations of progesterone of 0.05 mM or higher. Cultures incubated at 25°C grew at all concentrations tested (0.01 mM-0.50 mM) with growth decreasing gradually with the increase in progesterone concentration. CONCLUSION: This work describes a receptor associated with a G protein alpha subunit in S. schenckii belonging to the PAQR family. Progesterone was identified as the ligand. Exposure to progesterone increased the levels of cAMP in fungal yeast cells within the first min of incubation suggesting the connection of this receptor to the cAMP signalling pathway. Progesterone inhibited the growth of both the yeast and mycelium forms of the fungus, with the yeast form being the most affected by the hormone.

Cell compensatory responses of fungi to damage of the cell wall induced by Calcofluor White and Congo Red with emphasis on Sporothrix schenckii and Sporothrix globosa. A review.

The cell wall (CW) of fungi exhibits a complex structure and a characteristic chemical composition consisting almost entirely of interacting crystalline and amorphous polysaccharides. These are synthesized by a number of sugar polymerases and depolymerases encoded by a high proportion of the fungal genome (for instance, 20% in Saccharomyces cerevisiae). These enzymes act in an exquisitely coordinated process to assemble the tridimensional and the functional structure of the wall. Apart from playing a critical role in morphogenesis, cell protection, viability and pathogenesis, the CW represents a potential target for antifungals as most of its constituents do not exist in humans. Chitin, ß-glucans and cellulose are the most frequent crystalline polymers found in the fungal CW. The hexosamine biosynthesis pathway (HBP) is critical for CW elaboration. Also known as the Leloir pathway, this pathway ends with the formation of UDP-N-GlcNAc after four enzymatic steps that start with fructose-6-phosphate and L-glutamine in a short deviation of glycolysis. This activated aminosugar is used for the synthesis of a large variety of biomacromolecules in a vast number of organisms including bacteria, fungi, insects, crustaceans and mammalian cells. The first reaction of the HBP is catalyzed by GlcN-6-P synthase (L-glutamine:D-fructose-6-phosphate amidotransferase; EC 2.6.1.16), a critical enzyme that has been considered as a potential target for antifungals. The enzyme regulates the amount of cell UDP-N-GlcNAc and in eukaryotes is feedback inhibited by the activated aminosugar and other factors. The native and recombinant forms of GlcN-6-P synthase has been purified and characterized from both prokaryotic and eukaryotic organisms and demonstrated its critical role in CW remodeling and morphogenesis after exposure of some fungi to agents that stress the cell surface by interacting with wall polymers. This review deals with some of the cell compensatory responses of fungi to wall damage induced by Congo Red and Calcofluor White.

Gamma radiation effects on Sporothrix schenckii yeast cells.

Sporotrichosis is a subcutaneous mycosis caused by Sporothrix schenckii. Zoonotic transmission to man can occur after scratches or bites of animals, mainly cats. In this study, the gamma radiation effects on yeast of S. schenckii were analyzed with a view of developing a radioattenuated vaccine for veterinary use. The cultures were irradiated at doses ranging from 1.0 to 9.0 kGy. The reproductive capacity was measured by the ability of cells to form colonies. No colonies could be recovered above 8.0 kGy, using inocula up to 10(7) cells. Nevertheless, yeast cells irradiated with 7.0 kGy already were unable to produce infection in immunosuppressed mice. Evaluation by the FungaLight™ Kit (Invitrogen) indicated that yeast cells remained viable up to 9.0 kGy. At 7.0 kGy, protein synthesis, estimated by the incorporation of [L-(35)S] methionine, continues at levels slightly lower than the controls, but a significant decrease was observed at 9.0 kGy. The DNA of 7.0 kGy irradiated cells, analyzed by electrophoresis in agarose gel, was degraded. Cytoplasmic vacuolation was the main change verified in these cells by transmission electron microscopy. The dose of 7.0 kGy was considered satisfactory for yeast attenuation since irradiated cells were unable to produce infection but retained viability, metabolic activity, and morphology.

Cell wall glycoproteins participate in the adhesion of Sporothrix schenckii to epithelial cells.

Sporothrix schenckii is the etiologic agent of sporotrichosis. This fungal infection is an emerging disease potentially fatal in immunocompromised patients. The adhesion to host cells is a crucial early event related with the dissemination of pathogens. In order to clarify the mechanisms of adhesion of S. schenckii yeast cell to epithelial cells, we studied the biochemical basis of this process. The electrophoretic analysis of cell wall protein from S. schenckii coupled at ConA and stained with HRP, revealed nine different proteins with MW ≥ 180, 115, 90, 80, 58, 40, 36, 22 and 18 kDa. Using ligand-like assay with biotinylated S. schenckii surface proteins, five proteins with MW ≥ 190, 180, 115, 90 and 80 kDa which have affinity to epithelial cells were identified. The adhesion of yeast to epithelial monolayer was significantly inhibited when S. schenckii was pretreated with concanavalinA (ConA) and wheat germ agglutinin (WGA) lectins, alkali, periodate, trypsin, endoglycosidase H (EndoH), salt solutions and detergents. The ability of adhesion of S. schenckii yeast was recovered by blocking the lectin with sugar complementary. These data suggest that surface glycoprotein with mannose and glucose residue could be participate in the process of fungal adhesion to epithelial cells.

Comparative analysis of extracellular matrix and cellular carbohydrate expression in the sporotrichosis and chromoblastomycosis.

This work was based on the analysis of digital images of histochemical profile from subcutaneous lesions in sporotrichosis (ST) and chromoblastomycosis (CM) patients. An additional aim was the detection of carbohydrate expression using lectin histochemical analysis of the different carbohydrates in the fungal cell wall from four different species (Sporothrix schenckii, Fonsecaea pedrosoi, Phialophora verrucosa, and Cladophialophora carrionii) associated with diseases mentioned earlier. Slides from tissue biopsies from ST and CM positive patients (n=10, each) were stained according to routine techniques. Slides were incubated with 25 µg/ml of Con A lectins and WGA conjugated to peroxidase. Digital image analysis was carried out in a workstation using OPTIMAS™ software system. Routine histochemistry results indicated that there is significantly higher collagen deposition and elastic fibers in ST characteristic lesions compared with that found in CM cases. The ST interstitial fibrosis area was larger than in CM lesions. Comparative lectin binding showed a positive and intense lectin staining pattern in the cell wall of S. schenckii, suggesting a higher expression of glucose/mannose and N-acetyl glucosamine in their cell surface as evidenced by Con A and WGA, respectively. However, these lectins were not effective to recognize some carbohydrates moieties in the F. pedrosoi, P. verrucosa, and C. carrionii. Such findings contribute to additional information about specific recognition processes between fungal parasites and their host cell targets may be mediated by the interaction of carbohydrate-binding proteins, such as lectins, on the surface of one type of cell that combine with complementary sugars on the surface of another cells into fibro-connective tissues associated with lesions.

Map of dimorphic switching­related signaling pathways in Sporothrix schenckii based on its transcriptome.

Sporothrix schenckii (S. schenckii) induces sporotrichosis, which has gained attention in recent years due to its worldwide prevalence. The dimorphic switching process is essential for the pathogenesis of S. schenckii. Previously, overexpression of several signal transduction genes, including SsDRK1 and SsSte20, was observed during the mycelium­to­yeast transition; these were necessary for asexual development, yeast­phase cell formation, cell wall integrity and melanin synthesis. However, the mechanisms of the signaling pathways during dimorphic switching of S. schenckii remain unclear. In the present study, transcriptome sequencing of the 48­h induced yeast forms and mycelium of S. schenckii was performed. In total, 24,904,510 high­quality clean reads were obtained from mycelium samples and 22,814,406 from 48­h induced yeast form samples. Following assembly, 31,779 unigene sequences were obtained with 52.98% GC content (The proportion of guanine G and cytosine C to all bases in nucleic acid). The results demonstrated that 12,217 genes, including genes involved in signal transduction and chitin synthesis, were expressed differentially between the two stages. According to these results, a map of the signaling pathways, including two­component and heterotrimeric G­protein signaling systems, Ras and MAPK cascades associated with the dimorphic switch, was drawn. Taken together, the transcriptome data and analysis performed in the present study lay the foundation for further research into the molecular mechanisms controlling the dimorphic switch of S. schenckii and support the development of anti­S. schenckii strategies targeting genes associated with signaling pathways.

Comparative proteomics in the three major human pathogenic species of the genus Sporothrix.

Sporotrichosis is a subcutaneous mycosis of humans and other mammals, caused by dimorphic species of the genus Sporothrix. In Brazil, human disease is broadly linked to transmission by infected cats and is mainly caused by Sporothrix brasiliensis, Sporothrix schenckii and Sporothrix globosa. In this study, we used a nanoscale liquid chromatography coupled with tandem mass spectrometry approach to provide the yeast proteomic profiles of S. brasiliensis, S. schenckii and S. globosa. From a total of 247 identified proteins, 137 were found as differentially expressed. Functional classification revealed that most are related to carbohydrate and amino acid metabolism as well as stress response. Our data indicate that S. brasiliensis metabolism is distinct of that of S. schenckii and S. globosa, mainly regarding amino acid metabolism and cell wall remodeling, which are induced in the former. Enzymes belonging to glycolytic pathway are, on the other hand, up-regulated in S. schenckii and S. globosa. These findings may explain the previously described more virulent character of S. brasiliensis. Besides complementing genomic comparisons already published, this first comparative proteomic study provided information that indicates new aspects of Sporothrix species metabolism as well as offers information that may be useful in the development of prospective functional studies.

Anti-Sporothrix activity of ibuprofen combined with antifungal.

The in vitro activity of ibuprofen, a nonsteroidal anti-inflammatory drug, was evaluated against Sporothrix brasiliensis and S. schenckii, either alone or in combination with amphotericin B, itraconazole, or terbinafine. The inhibitory activity of ibuprofen as a single agent was determined according to minimum inhibitory concentration (MIC) values, while the effect of ibuprofen combined with amphotericin B, itraconazole, or terbinafine was estimated by microdilution checkerboard methodology. The ultrastructural alterations of S. schenckii after exposure to the combination of ibuprofen and amphotericin B were evaluated by scanning electron microscopy (SEM) and flow cytometry analysis. As a single agent, ibuprofen inhibited Sporothrix growth with a MIC median of 256 µg/mL, while the MIC medians of ibuprofen in combination with antifungals were 16 µg/mL and 128 µg/mL. The MIC values of amphotericin B, itraconazole, and terbinafine were reduced when isolates were co-incubated with ibuprofen, mainly the polyene. The major alteration after treatment with the ibuprofen/amphotericin B combination was the increase in the presence of filamentous forms and high membrane damage with loss of plasma membrane integrity. In summary, we demonstrated that ibuprofen increases the in vitro activity of antifungals, mainly amphotericin B, against S. brasiliensis and S. schenckii. Future in vivo studies exploring combination therapy with ibuprofen and antifungals in animal models are needed to confirm its efficacy.