Explaining caregiver burden in a large sample of UK dementia caregivers: The role of contextual factors, behavioural problems, psychological resilience, and anticipatory grief.

OBJECTIVES: Dementia caregiver burden is a significant public health concern, affecting both the wellbeing of caregivers and their care-recipients. This study investigated a range of variables associated with caregiver burden in a large sample of UK dementia caregivers. Clinical characteristics and novel psychological constructs were used - including anticipatory grief and psychological resilience. Anticipatory grief refers to the process of experiencing loss prior to the death of a significant person. METHOD: Caregivers of persons with dementia (N = 530) completed a survey obtaining the Zarit-Burden Interview (ZBI-SF) and other psychological and demographic/caregiving-related factors. RESULTS: Findings illustrate that 71% of the sample experienced high levels of caregiver burden and around 95% met the criteria for clinically significant levels of burden. A regression model explained 49% of the variance in subjective caregiver burden; contextual factors (care-recipients living situation, frequency of caregiving), behavioural challenges in the care-recipient (memory-related problem behaviours), caregiver psychological resilience and caregiver anticipatory grief (heartfelt long & sadness, worry & felt isolation) were all significant variables. Caregiver anticipatory grief, followed by psychological resilience, had the strongest association with burden. CONCLUSION: Caregiver anticipatory grief and psychological resilience, have a significant interaction with the clinical presentation of the dementia sufferer in explaining subjective caregiver burden. More grief and resilience-focused interventions targeting both the practical and emotional challenges are imperative to reduce burden and thus to ensure caregiver wellbeing.

Exploratory factor analysis of the caregiver grief inventory in a large UK sample of dementia carers.

OBJECTIVES: Anticipatory grief (AG) is the process of experiencing loss prior to the death of a significant person. Coping with this multifaceted experience in the context of dementia caregiving is a relatively novel, yet significant area in caregiving literature. The Marwit-Meuser Caregiver Grief Inventory (MM-CGI) and its abbreviated MM-CGI-Short-Form (MM-CGI-SF) is the most widely used scale measuring AG. However, limited research has employed robust analytical strategies to assess its dimensional structure. This study employed contemporary factor analytical techniques to assess the dimensional structure of the MM-CGI/SF. METHOD: Caregivers of persons with dementia (n = 508) completed a survey containing MM-CGI/SF and other associated psychological measures. Exploratory factor analysis was employed to compare eight alternative factor analytical models to determine the optimal model. Internal-consistency reliability was assessed by Cronbach's α and construct validity was assessed by Spearman's correlation-coefficient. RESULTS: The best fitting model was the MM-CGI-SF three factor model (Personal Sacrifice and Burden, Heartfelt Sadness and Longing and Worry and Felt Isolation). The MM-CGI-SF three factor model demonstrated internal consistency reliability and factor correlations with associated psychological measures indicated construct validity. CONCLUSION: The MM-CGI-SF three factor model demonstrated adequate fit and utility, however, the Worry and Felt Isolation subscale needs further replication and revision to assess its dimensionality. The MM-CGI-SF is the more useful tool due to its brevity and better model fit.

Evaluating a brief online compassion-focused intervention for intensive care nurses.

BACKGROUND: High levels of stress have been found within health care staff, particularly in the nursing population, which is somewhat attributed to the Covid-19 pandemic. The development of self-compassion, a protective psychological construct, may promote well-being in the health care staff population. As part of a service development project, the authors delivered and evaluated a brief online compassion-focused intervention with nurses working within Intensive Care Units (ICUs). AIMS: Aims were to explore feasibility within the ICU nursing population and consider potential benefits to psychological well-being. METHODS: ICU nurses registered for an online, 4 week, compassion-focused intervention as part of a service development project. Measures of compassion, burnout, trauma, and the emotional climate of their work environment were analysed in two groups; those who completed the intervention and those who did not. Baseline and post-intervention measures were analysed to infer the potential benefits of the intervention. RESULTS: Compared with their baseline scores, those who completed the intervention showed improvements on measures of compassion, soothing in emotional climate, and reductions in burnout, trauma and threat in emotional climate. At baseline, those who did not complete the intervention scored lower on measures of compassion and soothing within their emotional climate, as well as higher levels of trauma and threat within the emotional climate, compared with those who engaged with the intervention. CONCLUSIONS: Brief online compassion-focused interventions may be a useful platform to promote well-being in ICU nurses, but possibly only for those who have a pre-established level of self-compassion.

Inducible Cell Fusion Permits Use of Competitive Fitness Profiling in the Human Pathogenic Fungus Aspergillus fumigatus.

Antifungal agents directed against novel therapeutic targets are required for treating invasive, chronic, and allergic Aspergillus infections. Competitive fitness profiling technologies have been used in a number of bacterial and yeast systems to identify druggable targets; however, the development of similar systems in filamentous fungi is complicated by the fact that they undergo cell fusion and heterokaryosis. Here, we demonstrate that cell fusion in Aspergillus fumigatus under standard culture conditions is not predominately constitutive, as with most ascomycetes, but can be induced by a range of extracellular stressors. Using this knowledge, we have developed a barcode-free genetic profiling system that permits high-throughput parallel determination of strain fitness in a collection of diploid A. fumigatus mutants. We show that heterozygous cyp51A and arf2 null mutants have reduced fitness in the presence of itraconazole and brefeldin A, respectively, and a heterozygous atp17 null mutant is resistant to brefeldin A.

VSpipe, an Integrated Resource for Virtual Screening and Hit Selection: Applications to Protein Tyrosine Phospahatase Inhibition.

The use of computational tools for virtual screening provides a cost-efficient approach to select starting points for drug development. We have developed VSpipe, a user-friendly semi-automated pipeline for structure-based virtual screening. VSpipe uses the existing tools AutoDock and OpenBabel together with software developed in-house, to create an end-to-end virtual screening workflow ranging from the preparation of receptor and ligands to the visualisation of results. VSpipe is efficient and flexible, allowing the users to make choices at different steps, and it is amenable to use in both local and cluster mode. We have validated VSpipe using the human protein tyrosine phosphatase PTP1B as a case study. Using a combination of blind and targeted docking VSpipe identified both new and known functional ligand binding sites. Assessment of different binding clusters using the ligand efficiency plots created by VSpipe, defined a drug-like chemical space for development of PTP1B inhibitors with potential applications to other PTPs. In this study, we show that VSpipe can be deployed to identify and compare different modes of inhibition thus guiding the selection of initial hits for drug discovery.

CADRE: the Central Aspergillus Data REpository 2012.

The Central Aspergillus Data REpository (CADRE; http://www.cadre-genomes.org.uk) is a public resource for genomic data extracted from species of Aspergillus. It provides an array of online tools for searching and visualising features of this significant fungal genus. CADRE arose from a need within the medical community to understand the human pathogen Aspergillus fumigatus. Due to the paucity of Aspergillus genomic resources 10 years ago, the long-term goal of this project was to collate and maintain Aspergillus genomes as they became available. Since our first release in 2004, the resource has expanded to encompass annotated sequence for eight other Aspergilli and provides much needed support to the international Aspergillus research community. Recent developments, however, in sequencing technology are creating a vast amount of genomic data and, as a result, we shortly expect a tidal wave of Aspergillus data. In preparation for this, we have upgraded the database and software suite. This not only enables better management of more complex data sets, but also improves annotation by providing access to genome comparison data and the integration of high-throughput data.

Aspergillus genomes and the Aspergillus cloud.

Aspergillus Genomes is a public resource for viewing annotated genes predicted by various Aspergillus sequencing projects. It has arisen from the union of two significant resources: the Aspergillus/Aspergillosis website and the Central Aspergillus Data REpository (CADRE). The former has primarily served the medical community, providing information about Aspergillus and associated diseases to medics, patients and scientists; the latter has focused on the fungal genomic community, providing a central repository for sequences and annotation extracted from Aspergillus Genomes. By merging these databases, genomes benefit from extensive cross-linking with medical information to create a unique resource, spanning genomics and clinical aspects of the genus. Aspergillus Genomes is accessible from http://www.aspergillus-genomes.org.uk.

The negative cofactor 2 complex is a key regulator of drug resistance in Aspergillus fumigatus.

The frequency of antifungal resistance, particularly to the azole class of ergosterol biosynthetic inhibitors, is a growing global health problem. Survival rates for those infected with resistant isolates are exceptionally low. Beyond modification of the drug target, our understanding of the molecular basis of azole resistance in the fungal pathogen Aspergillus fumigatus is limited. We reasoned that clinically relevant antifungal resistance could derive from transcriptional rewiring, promoting drug resistance without concomitant reductions in pathogenicity. Here we report a genome-wide annotation of transcriptional regulators in A. fumigatus and construction of a library of 484 transcription factor null mutants. We identify 12 regulators that have a demonstrable role in itraconazole susceptibility and show that loss of the negative cofactor 2 complex leads to resistance, not only to the azoles but also the salvage therapeutics amphotericin B and terbinafine without significantly affecting pathogenicity.

The 2008 update of the Aspergillus nidulans genome annotation: a community effort.

The identification and annotation of protein-coding genes is one of the primary goals of whole-genome sequencing projects, and the accuracy of predicting the primary protein products of gene expression is vital to the interpretation of the available data and the design of downstream functional applications. Nevertheless, the comprehensive annotation of eukaryotic genomes remains a considerable challenge. Many genomes submitted to public databases, including those of major model organisms, contain significant numbers of wrong and incomplete gene predictions. We present a community-based reannotation of the Aspergillus nidulans genome with the primary goal of increasing the number and quality of protein functional assignments through the careful review of experts in the field of fungal biology.

Correction: Mitochondrial Complex I Is a Global Regulator of Secondary Metabolism, Virulence and Azole Sensitivity in Fungi.

[This corrects the article DOI: 10.1371/journal.pone.0158724.].

A Nonredundant Phosphopantetheinyl Transferase, PptA, Is a Novel Antifungal Target That Directs Secondary Metabolite, Siderophore, and Lysine Biosynthesis in Aspergillus fumigatus and Is Critical for Pathogenicity.

Secondary metabolites are key mediators of virulence for many pathogens. Aspergillus fumigatus produces a vast array of these bioactive molecules, the biosynthesis of which is catalyzed by nonribosomal peptide synthetases (NRPSs) or polyketide synthases (PKSs). Both NRPSs and PKSs harbor carrier domains that are primed for acceptance of secondary metabolic building blocks by a phosphopantetheinyl transferase (P-pant). The A. fumigatus P-pant PptA has been shown to prime the putative NRPS Pes1 in vitro and has an independent role in lysine biosynthesis; however, its role in global secondary metabolism and its impact on virulence has not been described. Here, we demonstrate that PptA has a nonredundant role in the generation of the vast majority of detectable secondary metabolites in A. fumigatus, including the immunomodulator gliotoxin, the siderophores triacetylfusarinine C (TAFC) and ferricrocin (FC), and dihydroxy naphthalene (DHN)-melanin. We show that both the lysine and iron requirements of a pptA null strain exceed those freely available in mammalian tissues and that loss of PptA renders A. fumigatus avirulent in both insect and murine infection models. Since PptA lacks similarity to its mammalian orthologue, we assert that the combined role of this enzyme in both primary and secondary metabolism, encompassing multiple virulence determinants makes it a very promising antifungal drug target candidate. We further exemplify this point with a high-throughput fluorescence polarization assay that we developed to identify chemical inhibitors of PptA function that have antifungal activity.IMPORTANCE Fungal diseases are estimated to kill between 1.5 and 2 million people each year, which exceeds the global mortality estimates for either tuberculosis or malaria. Only four classes of antifungal agents are available to treat invasive fungal infections, and all suffer pharmacological shortcomings, including toxicity, drug-drug interactions, and poor bioavailability. There is an urgent need to develop a new class of drugs that operate via a novel mechanism of action. We have identified a potential drug target, PptA, in the fungal pathogen Aspergillus fumigatus PptA is required to synthesize the immunotoxic compound gliotoxin, DHN-melanin, which A. fumigatus employs to evade detection by host cells, the amino acid lysine, and the siderophores TAFC and FC, which A. fumigatus uses to scavenge iron. We show that strains lacking the PptA enzyme are unable to establish an infection, and we present a method which we use to identify novel antifungal drugs that inactivate PptA.

Mitochondrial Complex I Is a Global Regulator of Secondary Metabolism, Virulence and Azole Sensitivity in Fungi.

Recent estimates of the global burden of fungal disease suggest that that their incidence has been drastically underestimated and that mortality may rival that of malaria or tuberculosis. Azoles are the principal class of antifungal drug and the only available oral treatment for fungal disease. Recent occurrence and increase in azole resistance is a major concern worldwide. Known azole resistance mechanisms include over-expression of efflux pumps and mutation of the gene encoding the target protein cyp51a, however, for one of the most important fungal pathogens of humans, Aspergillus fumigatus, much of the observed azole resistance does not appear to involve such mechanisms. Here we present evidence that azole resistance in A. fumigatus can arise through mutation of components of mitochondrial complex I. Gene deletions of the 29.9KD subunit of this complex are azole resistant, less virulent and exhibit dysregulation of secondary metabolite gene clusters in a manner analogous to deletion mutants of the secondary metabolism regulator, LaeA. Additionally we observe that a mutation leading to an E180D amino acid change in the 29.9 KD subunit is strongly associated with clinical azole resistant A. fumigatus isolates. Evidence presented in this paper suggests that complex I may play a role in the hypoxic response and that one possible mechanism for cell death during azole treatment is a dysfunctional hypoxic response that may be restored by dysregulation of complex I. Both deletion of the 29.9 KD subunit of complex I and azole treatment alone profoundly change expression of gene clusters involved in secondary metabolism and immunotoxin production raising potential concerns about long term azole therapy.