Eicosanoid production by Candida parapsilosis and other pathogenic yeasts

Altered gut fungi in systemic lupus erythematosus - A pilot study

Objective

Gut fungi, as symbiosis with the human gastrointestinal tract, may regulate physiology via multiple interactions with host cells. The plausible role of fungi in systemic lupus erythematosus (SLE) is far from clear and need to be explored.

Methods

A total of 64 subjects were recruited, including SLE, rheumatoid arthritis (RA), undifferentiated connective tissue diseases (UCTDs) patients and healthy controls (HCs). Fecal samples of subjects were collected. Gut fungi and bacteria were detected by ITS sequencing and 16S rRNA gene sequencing, respectively. Alpha and beta diversities of microbiota were analyzed. Linear discriminant analysis effect size analysis was performed to identify abundance of microbiota in different groups. The correlation network between bacterial and fungal microbiota was analyzed based on Spearman correlation.

Results

Gut fungal diversity and community composition exhibited significant shifts in SLE compared with UCTDs, RA and HCs. Compared with HCs, the alpha and beta diversities of fungal microbiota decreased in SLE patients. According to principal coordinates analysis results, the constitution of fungal microbiota from SLE, RA, UCTDs patients and HCs exhibited distinct differences with a clear separation between fungal microbiota. There was dysbiosis in the compositions of fungal and bacterial microbiota in the SLE patients, compared to HCs. Pezizales, Cantharellales and Pseudaleuria were enriched in SLE compared with HCs, RA and UCTDs. There was a complex relationship network between bacterial and fungal microbiota, especially Candida which was related to a variety of bacteria.

Conclusion

This study presents a pilot analysis of fungal microbiota with diversity and composition in SLE, and identifies several gut fungi with different abundance patterns taxa among SLE, RA, UCTDs and HCs. Furthermore, the gut bacterial-fungal association network in SLE patients was altered compared with HCs.

Characterization and functional analysis of zinc trafficking in the human fungal pathogen Candida parapsilosis

The zinc restriction and zinc toxicity are part of host defence, called nutritional immunity. The crucial role of zinc homeostasis in microbial survival within a host is established, but little is known about these processes in the opportunistic human fungal pathogen Candida parapsilosis. Our in silico predictions suggested the presence of at least six potential zinc transporters (ZnTs) in C. parapsilosis-orthologues of ZRC1, ZRT3 and ZRT101-but an orthologue of PRA1 zincophore was not found. In addition, we detected a species-specific gene expansion of the novel ZnT ZRT2, as we identified three orthologue genes in the genome of C. parapsilosis. Based on predictions, we created homozygous mutant strains of the potential ZnTs and characterized them. Despite the apparent gene expansion of ZRT2 in C. parapsilosis, only CpZRT21 was essential for growth in a zinc-depleted acidic environment, in addition we found that CpZrc1 is essential for zinc detoxification and also protects the fungi against the elimination of murine macrophages. Significantly, we demonstrated that C. parapsilosis forms zincosomes in a Zrc1-independent manner and zinc detoxification is mediated by the vacuolar importer CpZrc1. Our study defines the functions of C. parapsilosis ZnTs, including a species-specific survival and zinc detoxification system.

Identification of a key protein set involved in Moniliophthora perniciosa necrotrophic mycelium and basidiocarp development

Moniliophthora perniciosa is a hemibiotrophic fungus that causes witches' broom disease in cacao (Theobroma cacao L.). The biotrophic fungal phase initiates the disease and is characterized by a monokaryotic mycelium, while the necrotrophic phase is characterized by a dikaryotic mycelium and leads to necrosis of infected tissues. A study of the necrotrophic phase was conducted on bran-based solid medium, which is the only medium that enables basidiocarp and basidiospore production. Six different fungal developmental phases were observed according to the mycelium colour or the organ produced: white, yellow, pink, dark pink, primordium and basidiocarp. In this study, we identified notable proteins in each phase, particularly those accumulated prior to basidiocarp formation. Proteins were analysed by proteomics; 2-D gels showed 300-550 spots. Statistically differentially accumulated spots were sequenced by mass spectrometry and 259 proteins were identified and categorized into nine functional classes. Proteins related to energy metabolism, protein folding and morphogenesis that were potentially involved in primordium and basidiocarp formation were identified; these proteins may represent useful candidates for further analysis related to the spread and pathogenesis of this fungus. To the best of our knowledge, this report describes the first proteomic analysis of the developmental phases of Moniliophthora perniciosa.

Synergistic Activity of New Diclofenac and Essential Oils Combinations against Different Candida spp

According to recent studies, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) have shown a good antimicrobial and antifungal activity. Their association with essential oils (EOs) could be useful for the treatment of infections caused by Candida spp. The aim of this studyis to evaluate the synergistic antifungal activity of new combinations between Diclofenac Sodium Salt (DSS), a widely used NSAID, with EOs of Mentha × piperita, Pelargonium graveolens and Melaleuca alternifolia. The in-vitro antifungal activity was determined on different Candida strains. The determination of the chemical composition of EOs was carried out by gaschromatography-massspectrometry (GC-MS). Susceptibility testing of planktonic cells was performed by using the broth microdilution assay and checkerboard methods. Minimum Inhibitory Concentrations (MIC) of DSS was in a range from 1.02 to 2.05 μg/mL reaching a MIC value of 0.05 μg/mL when combined with Pelargonium graveolens (FICI = 0.23–0.35) or Menthapiperita (FICI = 0.22–0.30) EOs. These preliminary results show thatthe combination of the EOs with DSS improves the antifungal activity on all the tested Candida strains.

Revealing hypoglycemic and hypolipidemic mechanism of Xiaokeyinshui extract combination on streptozotocin-induced diabetic mice in high sucrose/high fat diet by metabolomics and lipidomics

Type 2 diabetic mellitus (T2DM), often accompanied by disorders of glucose and lipid metabolism, has troubled hundreds of millions of people. Xiaokeyinshui extract combination (XEC), derived from traditional Chinese medicines formula, has exerted hypoglycemic effects against T2DM. However, its mechanism of metabolic level is still unclear. In this study, a T2DM mice model, induced by a high sucrose/high fat diet combined with low-dose streptozotocin (STZ) injections, was adopted. The biochemical index was determined and a combination of metabolomics and lipidomics analyses of plasma were performed. The results showed that XEC increased secretion of insulin and level of HDL-C, decreased levels of FBG, HbA1c, TC, TG, LDL-C and repaired islet structure in diabetic mice. In addition, the metabolic profiles of plasma were analyzed and 54 potential biomarkers were screened out, mainly including carbohydrates, lipids and amino acids. These potential biomarkers were found to be correlated with the following pathways: galactose metabolism, fructose and mannose metabolism, TCA cycle, arachidonic acid metabolism, glycerolipid metabolism, glycerophospholipid metabolism, sphingolipid metabolism and amino acid metabolism. In conclusion, we speculated that carbohydrate metabolism, lipid metabolism and amino acid metabolism played roles in the therapeutic mechanisms of XEC on T2DM.

Multicopper Oxidases in Saccharomyces cerevisiae and Human Pathogenic Fungi

Multicopper oxidases (MCOs) are produced by microscopic and macroscopic fungal species and are involved in various physiological processes such as morphogenesis, lignin degradation, and defense mechanisms to stress inducing environmental conditions as well as fungal virulence. This review will summarize our current understanding regarding the functions of MCOs present in Saccharomyces cerevisiae and in different human fungal pathogens. Of the two main MCO groups, the first group of MCOs is involved in iron homoeostasis and the second includes laccases. This review will also discuss their role in the pathogenesis of human fungal pathogens.