High frame-rate resolution of cell division during Candida albicans filamentation

Acknowledgements: Strain YMG7139 was supplied by Peter Sudbery, University of Sheffield. DDT was funded by a BBSRC-DTG, BB/F016964/1, at Aberdeen. ACB is funded by a Royal Society URFUF080611 and a MRC NIRG90671. JB was funded by the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) REA grant agreement number 303635; by an European Research Council Advanced Award, number 340087, RAPLODAPT, and an award from the Israel Science foundation (340/13).Peer reviewedPublisher PD

Contact-induced apical asymmetry drives the thigmotropic responses of Candida albicans hyphae

Acknowledgements We thank Marco Thiel for assistance with data interpretation, Peter Sudbery for the provision of strains and Jeremy Craven for useful discussions. This work was supported by a BBSRC-DTG to D. D. T., NIH award DK083592 to F. J. B. and P. A. J., and a Royal Society URF UF080611 and MRC NIRG 90671 to A. C. B.Non peer reviewedPublisher PD

Host carbon sources modulate cell wall architecture, drug resistance and virulence in a fungal pathogen

The survival of all microbes depends upon their ability to respond to environmental challenges. To establish infection, pathogens such as Candida albicans must mount effective stress responses to counter host defences while adapting to dynamic changes in nutrient status within host niches. Studies of C. albicans stress adaptation have generally been performed on glucose-grown cells, leaving the effects of alternative carbon sources upon stress resistance largely unexplored. We have shown that growth on alternative carbon sources, such as lactate, strongly influence the resistance of C. albicans to antifungal drugs, osmotic and cell wall stresses. Similar trends were observed in clinical isolates and other pathogenic Candida species. The increased stress resistance of C. albicans was not dependent on key stress (Hog1) and cell integrity (Mkc1) signalling pathways. Instead, increased stress resistance was promoted by major changes in the architecture and biophysical properties of the cell wall. Glucose- and lactate-grown cells displayed significant differences in cell wall mass, ultrastructure, elasticity and adhesion. Changes in carbon source also altered the virulence of C. albicans in models of systemic candidiasis and vaginitis, confirming the importance of alternative carbon sources within host niches during C. albicans infection

Multi trace element profiling in pathogenic and non-pathogenic fungi

Acknowledgements SW and EM were funded by an MRC NIRG to AB (G0900211/90671). AP was funded by a British Mycological Society Summer Studentship. AB was funded by a Royal Society URF (UF080611) and a Senior Wellcome Research Fellowship (206412/A/17/Z), which also funded TB. DW was funded by a Senior Wellcome Research Fellowship (214317/A/18/Z). The work was carried out in the MRC Centre for Medical Mycology (MR/N006364/2). This article is part of the Fungal Adaptation to Hostile Challenges special issue for the third International Symposium on Fungal Stress (ISFUS), which is supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo grant 2018/20571-6 and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior grant 88881.289327/2018-01.Peer reviewedproofPublisher PD

Cell wall glycans and soluble factors determine the interactions between the hyphae of Candida albicans and Pseudomonas aeruginosa

The fungus, Candida albicans, and the bacterium, Pseudomonas aeruginosa, are opportunistic human pathogens that have been coisolated from diverse body sites. Pseudomonas aeruginosa suppresses C. albicans proliferation in vitro and potentially in vivo but it is the C. albicans hyphae that are killed while yeast cells are not. We show that hyphal killing involves both contact-mediated and soluble factors. Bacterial culture filtrates contained heat-labile soluble factors that killed C. albicans hyphae. In cocultures, localized points of hyphal lysis were observed, suggesting that adhesion and subsequent bacteria-mediated cell wall lysis is involved in the killing of C. albicans hyphae. The glycosylation status of the C. albicans cell wall affected the rate of contact-dependent killing because mutants with severely truncated O-linked, but not N-linked, glycans were hypersensitive to Pseudomonas-mediated killing. Deletion of HWP1, ALS3 or HYR1, which encode major hypha-associated cell wall proteins, had no effect on fungal susceptibility

Crosstalk between the calcineurin and cell wall integrity pathways prevents chitin overexpression in Candida albicans

Funding Information: We thank Carol Munro for helpful discussions during the research, Raif Yuecel, Elizabeth Adams, Linda Duncan, Barry Lewis and Kimberley Sim for assistance with FACS at Aberdeen Cytometry Core Facility, and Yang Meng and Dominique Sanglard with help in construction of mutants. We also thank Linghuo Jiang, David Soll, Jes?s Pla, Jan Quinn, Terry Roemer and Joseph Heitman for mutant strains. N.A.R.G. acknowledges support from the Wellcome Trust [Senior Investigator (101873/Z/13/Z), Collaborative (200208/A/15/Z and 215599/Z/19/Z) and Strategic (097377/Z11/Z) Awards] and from the Medical Research Council Centre for Medical Mycology (MR/N006364/2). This work was also supported by a Marie Curie FP7-PEOPLE-ITN-2008 grant (MB004 RGE0655 ARIADNE) and by a Wellcome Trust project grant (086827). Open access funding provided by University of Exeter. Deposited in PMC for immediate release.Peer reviewedPublisher PD

Variant of TYR and Autoimmunity Susceptibility Loci in Generalized Vitiligo.

BACKGROUND Generalized vitiligo is an autoimmune disease characterized by melanocyte loss, which results in patchy depigmentation of skin and hair, and is associated with an elevated risk of other autoimmune diseases. METHODS To identify generalized vitiligo susceptibility loci, we conducted a genomewide association study. We genotyped 579,146 single-nucleotide polymorphisms (SNPs) in 1514 patients with generalized vitiligo who were of European-derived white (CEU) ancestry and compared the genotypes with publicly available control genotypes from 2813 CEU persons. We then tested 50 SNPs in two replication sets, one comprising 677 independent CEU patients and 1106 CEU controls and the other comprising 183 CEU simplex trios with generalized vitiligo and 332 CEU multiplex families. RESULTS We detected significant associations between generalized vitiligo and SNPs at several loci previously associated with other autoimmune diseases. These included genes encoding major-histocompatibility-complex class I molecules (P=9.05×10−23) and class II molecules (P=4.50×10−34), PTPN22 (P=1.31×10−7), LPP (P=1.01×10−11), IL2RA (P=2.78×10−9), UBASH3A (P=1.26×10−9), and C1QTNF6 (P=2.21×10−16). We also detected associations between generalized vitiligo and SNPs in two additional immune-related loci, RERE (P=7.07×10−15) and GZMB (P=3.44×10−8), and in a locus containing TYR (P=1.60×10−18), encoding tyrosinase. CONCLUSIONS We observed associations between generalized vitiligo and markers implicating multiple genes, some associated with other autoimmune diseases and one (TYR) that may mediate target-cell specificity and indicate a mutually exclusive relationship between susceptibility to vitiligo and susceptibility to melanoma

Embedded Weapons-Grade Tungsten Alloy Shrapnel Rapidly Induces Metastatic High-Grade Rhabdomyosarcomas in F344 Rats

Continuing concern regarding the potential health and environmental effects of depleted uranium and lead has resulted in many countries adding tungsten alloy (WA)-based munitions to their battlefield arsenals as replacements for these metals. Because the alloys used in many munitions are relatively recent additions to the list of militarily relevant metals, very little is known about the health effects of these metals after internalization as embedded shrapnel. Previous work in this laboratory developed a rodent model system that mimicked shrapnel loads seen in wounded personnel from the 1991 Persian Gulf War. In the present study, we used that system and male F344 rats, implanted intramuscularly with pellets (1 mm × 2 mm cylinders) of weapons-grade WA, to simulate shrapnel wounds. Rats were implanted with 4 (low dose) or 20 pellets (high dose) of WA. Tantalum (20 pellets) and nickel (20 pellets) served as negative and positive controls, respectively. The high-dose WA-implanted rats (n = 46) developed extremely aggressive tumors surrounding the pellets within 4–5 months after implantation. The low-dose WA-implanted rats (n = 46) and nickel-implanted rats (n = 36) also developed tumors surrounding the pellets but at a slower rate. Rats implanted with tantalum (n = 46), an inert control metal, did not develop tumors. Tumor yield was 100% in both the low- and high-dose WA groups. The tumors, characterized as high-grade pleomorphic rhabdomyosarcomas by histopathology and immunohistochemical examination, rapidly metastasized to the lung and necessitated euthanasia of the animal. Significant hematologic changes, indicative of polycythemia, were also observed in the high-dose WA-implanted rats. These changes were apparent as early as 1 month postimplantation in the high-dose WA rats, well before any overt signs of tumor development. These results point out the need for further studies investigating the health effects of tungsten and tungsten-based alloys

Success Factors of European Syndromic Surveillance Systems: A Worked Example of Applying Qualitative Comparative Analysis

Introduction: Syndromic surveillance aims at augmenting traditional public health surveillance with timely information. To gain a head start, it mainly analyses existing data such as from web searches or patient records. Despite the setup of many syndromic surveillance systems, there is still much doubt about the benefit of the approach. There are diverse interactions between performance indicators such as timeliness and various system characteristics. This makes the performance assessment of syndromic surveillance systems a complex endeavour. We assessed if the comparison of several syndromic surveillance systems through Qualitative Comparative Analysis helps to evaluate performance and identify key success factors. Materials and Methods: We compiled case-based, mixed data on performance and characteristics of 19 syndromic surveillance systems in Europe from scientific and grey literature and from site visits. We identified success factors by applying crisp-set Qualitative Comparative Analysis. We focused on two main areas of syndromic surveillance application: seasonal influenza surveillance and situational awareness during different types of potentially health threatening events. Results: We found that syndromic surveillance systems might detect the onset or peak of seasonal influenza earlier if they analyse non-clinical data sources. Timely situational awareness during different types of events is supported by an automated syndromic surveillance system capable of analysing multiple syndromes. To our surprise, the analysis of multiple data sources was no key success factor for situational awareness. Conclusions: We suggest to consider these key success factors when designing or further developing syndromic surveillance systems. Qualitative Comparative Analysis helped interpreting complex, mixed data on small-N cases and resulted in concrete and practically relevant findings

Healthy Cotwins Share Gut Microbiome Signatures With Their Inflammatory Bowel Disease Twins and Unrelated Patients

BACKGROUND & AIMS: It is currently unclear whether reported changes in the gut microbiome are cause or consequence of inflammatory bowel disease (IBD). Therefore, we studied the gut microbiome of IBD-discordant and -concordant twin pairs, which offers the unique opportunity to assess individuals at increased risk of developing IBD, namely healthy cotwins from IBD-discordant twin pairs. METHODS: Fecal samples were obtained from 99 twins (belonging to 51 twin pairs), 495 healthy age-, sex- and BMI-matched controls, and 99 unrelated IBD patients. Whole-genome metagenomic shotgun sequencing was performed. Taxonomic and functional (pathways) composition was compared between healthy-cotwins, IBD-twins, unrelated IBD patients, and healthy controls with multivariable, i.e. adjusted for potential confounding, generalized linear models. RESULTS: No significant differences were observed in the relative abundance of species and pathways between healthy cotwins and their IBD-twins (false discovery rate (FDR)<0.10). Compared to healthy controls, 13, 19, and 18 species, and 78, 105, and 153 pathways were found to be differentially abundant in healthy-cotwins, IBD-twins and unrelated IBD patients, respectively (FDR<0.10). Of these, 8/19 (42.1%) and 1/18 (5.6%) species, and 37/105 (35.2%) and 30/153 (19.6%) pathways overlapped between healthy cotwins and IBD-twins, and healthy cotwins and unrelated IBD patients respectively. Many of the shared species and pathways have previously been associated with IBD. The shared pathways include potentially inflammation-related pathways, for example: an increase in propionate degradation and L-arginine degradation pathways. CONCLUSIONS: The gut microbiome of healthy cotwins from IBD-discordant twin pairs displays IBD-like signatures. These IBD-like microbiome signatures might precede the onset of IBD. However, longitudinal follow up studies are needed to infer a causal relationship