98 research outputs found
Decolonising and diversifying the Library through student partnerships
This case study looks at the work to develop initiatives to diversify Warwick University Libraryās collections, spaces and services, carried out in conjunction with our key student partners, Warwickās Library Associates. It explores the origins of the voluntary Library Associates scheme, with an emphasis on working in true partnership with students, to deliver library improvements in line with their priorities and those of their peers. It examines the process of co-creating interventions to aid diversifying and demonstrates the role of the students as drivers for the initiatives. It discusses the ongoing work to be done to meaningfully diversify the Library and involves the student voice in the reporting of the project
Assessing differences between clinical isolates of Aspergillus fumigatus from cases of proven invasive aspergillosis and colonizing isolates with respect to phenotype (virulence in Tenebrio molitor larvae) and genotype
The fungus Aspergillus fumigatus, the cause of invasive aspergillosis (IA), is a serious risk
to transplant patients and those with respiratory diseases. Host immune suppression is considered
the most important factor for the development of IA. Less is known about the importance of fungal
virulence in the development of IA including the significance of variation between isolates. In
this study, isolates of A. fumigatus from cases diagnosed as having proven IA or colonisation (no
evidence of IA) were compared in assays to measure isolate virulence. These assays included the
measurement of radial growth and protease production on agar, sensitivity to UV light and oxidative
stressors, and virulence in Tenebrio molitor (mealworm) larvae. These assays did not reveal obvious
differences in virulence between the two groups of isolates; this provided the impetus to conduct
genomic analysis. Whole genome sequencing and analysis did not allow grouping into coloniser or IA
isolates. However, focused analysis of single nucleotide polymorphisms revealed variation in three
putative genes: AFUA_5G09420 (ccg-8), AFUA_4G00330, and AFUA_4G00350. These are known to
be responsive to azole exposure, and ccg-8 deletion leads to azole hypersensitivity in other fungi. A.
fumigatus virulence is challenging, but the findings of this study indicate that further research into the
response to oxidative stress and azole exposure are required to understand the development of IA
Assignment of Reference 5ā-end 16S rDNA Sequences and Species-Specific Sequence Polymorphisms Improves Species Identification of Nocardia
16S rDNA sequence analysis is the most accurate method for definitive species identification of nocardiae. However, conflicting results can be found due to sequence errors in gene databases. This study tested the feasibility of species identification of Nocardia by partial (5ā-end 606-bp) 16S rDNA sequencing, based on sequence comparison with āreferenceā sequences of well-annotated strains. This new approach was evaluated using 96 American Type Culture Collection (n=6), and clinical (n=90) Nocardia isolates. Nucleotide sequence-based polymorphisms within species were indicative of āsequence typesā for that species. Sequences were compared with those in the GenBank, Bioinformatics Bacteria Identification and Ribosomal Database Project databases. Compared with the reference sequence set, all 96 isolates were correctly identified using the criterion of ā„99% sequence similarity. Seventy-eight (81.3%) were speciated by database comparison; alignment with reference sequences resolved the identity of 14 (15%) isolates whose sequences yielded 100% similarity to sequences in GenBank under >1 species designation. Of 90 clinical isolates, the commonest species was Nocardia nova (33.3%) followed by Nocardia cyriacigeorgica (26.7%). Recently-described or uncommon species included Nocardia veterana (4.4%), Nocarida bejingensis (2.2%) and, Nocardia abscessus and Nocardia arthriditis (each n=1). Nocardia asteroides sensu stricto was rare (n=1). There were nine sequence types of N. nova, three of Nocardia brasiliensis with two each of N. cyriacigeorgica and Nocardia farcinica. Thirteen novel sequences were identified. Alignment of sequences with reference sequences facilitated species identification of Nocardia and allowed delineation of sequence types within species, suggesting that such a barcoding approach can be clinically useful for identification of bacteria
Clinical Utility of the Cryptococcal Antigen Lateral Flow Assay in a Diagnostic Mycology Laboratory
Abstract Background: Cryptococcus neoformans causes life-threatening meningitis. A recently introduced lateral flow immunoassay (LFA) to detect cryptococcal antigen (CRAG) is reportedly more rapid and convenient than standard latex agglutination (LA), but has not yet been evaluated in a diagnostic laboratory setting
Influence of single nucleotide polymorphisms in COMT, MAO-A and BDNF genes on dyskinesias and levodopa use in Parkinsonās disease
Background: Clinical heterogeneity in the development of levodopa-induced dyskinesias suggests endogenous factors play a significant role in determining their overall prevalence. We hypothesised that single nucleotide polymorphisms (SNPs) in specific genes may result in a clinical phenotype conducive to an increased risk of dyskinesia.
Methods: We examined the influence of SNPs in the catechol O-methyltransferase (COMT), monoamine oxidase A (MAO-A) and brain-derived neurotrophic factor (BDNF) genes on time to onset and prevalence of dyskinesias in a cohort of 285 pathologically confirmed Parkinsonās disease patients.
Results: Dyskinetic patients demonstrated younger age at disease onset (60.3 years vs. 66.4 years, p<0.0001), a longer disease duration (17.0 years vs. 12.0 years, p<0.0001) and a higher maximum daily levodopa equivalent dose (LED; 926.7 mg/day vs. 617.1 mg/day, p<0.0001) than patients without dyskinesias. No individual SNP was found to influence prevalence or time to onset of dyskinesias, including after adjustment for age at disease onset, disease duration, and maximum daily LED. We observed that patients carrying alleles conferring both high COMT activity and increased MAO-A mRNA expression received significantly higher maximum and mean daily LEDs than those with low enzyme activity/mRNA expression (max LED: 835mg Ā± 445mg vs. 508mg Ā± 316mg; p=0.0056, mean LED: 601mg Ā± 335mg vs. 398mg Ā± 260mg; p=0.025).
Conclusions: Individual SNPs in BDNF, COMT and MAO-A genes did not influence prevalence or time to onset of dyskinesias in this cohort. The possibility that combined COMT and MAO-A genotype is a significant factor in determining an individualās lifetime levodopa exposure warrants further investigation
Neuropathologic assessment of participants in two multi-center longitudinal observational studies: the Alzheimer Disease Neuroimaging Initiative (ADNI) and the Dominantly Inherited Alzheimer Network (DIAN)
It has been hypothesized that the relatively rare autosomal dominant Alzheimer disease (ADAD) may be a useful model of the more frequent, sporadic, late-onset AD (LOAD). Individuals with ADAD have a predictable age at onset and the biomarker profile of ADAD participants in the preclinical stage may be used to predict disease progression and clinical onset. However, the extent to which the pathogenesis and neuropathology of ADAD overlaps with that of LOAD is equivocal. To address this uncertainty, two multicenter longitudinal observational studies, the Alzheimer Disease Neuroimaging Initiative (ADNI) and the Dominantly Inherited Alzheimer Network (DIAN), leveraged the expertise and resources of the existing Knight Alzheimer Disease Research Center (ADRC) at Washington University School of Medicine, St. Louis, Missouri, USA, to establish a Neuropathology Core (NPC). The ADNI/DIAN-NPC is systematically examining the brains of all participants who come to autopsy at the 59 ADNI sites in the USA and Canada and the 14 DIAN sites in the USA (8), Australia (3), UK (1), and Germany (2). By 2014, 41 ADNI and 24 DIAN autopsies (involving 9 participants and 15 family members) had been performed. The autopsy rate in the ADNI cohort in the most recent year was 93% (total since NPC inception: 70%). In summary, the ADNI/DIAN NPC has implemented a standard protocol for all sites to solicit permission for brain autopsy and to send brain tissue to the NPC for a standardized, uniform, and state-of-the-art neuropathologic assessment. The benefit to ADNI and DIAN of the implementation of the NPC is very clear. The NPC provides final āgold standardā neuropathological diagnoses and data against which the antecedent observations and measurements of ADNI and DIAN can be compared
Molecular Typing of Australian Scedosporium Isolates Showing Genetic Variability and Numerous S. aurantiacum
Molecular typing showed genetic diversity, dismissed 2 suspected outbreaks of scedosporiosis, and identified multiple strains of the newly described species S. aurantiacum
Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Identification of Yeasts Is Contingent on Robust Reference Spectra
BACKGROUND: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for yeast identification is limited by the requirement for protein extraction and for robust reference spectra across yeast species in databases. We evaluated its ability to identify a range of yeasts in comparison with phenotypic methods. METHODS: MALDI-TOF MS was performed on 30 reference and 167 clinical isolates followed by prospective examination of 67 clinical strains in parallel with biochemical testing (total nā=ā264). Discordant/unreliable identifications were resolved by sequencing of the internal transcribed spacer region of the rRNA gene cluster. PRINCIPAL FINDINGS: Twenty (67%; 16 species), and 24 (80%) of 30 reference strains were identified to species, (spectral score ā„2.0) and genus (score ā„1.70)-level, respectively. Of clinical isolates, 140/167 (84%) strains were correctly identified with scores of ā„2.0 and 160/167 (96%) with scores of ā„1.70; amongst Candida spp. (nā=ā148), correct species assignment at scores of ā„2.0, and ā„1.70 was obtained for 86% and 96% isolates, respectively (vs. 76.4% by biochemical methods). Prospectively, species-level identification was achieved for 79% of isolates, whilst 91% and 94% of strains yielded scores of ā„1.90 and ā„1.70, respectively (100% isolates identified by biochemical methods). All test scores of 1.70-1.90 provided correct species assignment despite being identified to "genus-level". MALDI-TOF MS identified uncommon Candida spp., differentiated Candida parapsilosis from C. orthopsilosis and C. metapsilosis and distinguished between C. glabrata, C. nivariensis and C. bracarensis. Yeasts with scores of <1.70 were rare species such as C. nivariensis (3/10 strains) and C. bracarensis (nā=ā1) but included 4/12 Cryptococcus neoformans. There were no misidentifications. Four novel species-specific spectra were obtained. Protein extraction was essential for reliable results. CONCLUSIONS: MALDI-TOF MS enabled rapid, reliable identification of clinically-important yeasts. The addition of spectra to databases and reduction in identification scores required for species-level identification may improve its utility
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