31 research outputs found
Cluster of Symptomatic Graft-to-Host Transmission of Herpes Simplex Virus Type 1 in an Endothelial Keratoplasty Setting
PURPOSE: Descemet's membrane endothelial keratoplasty (DMEK) is becoming the gold standard to treat corneal endothelial dysfunctions worldwide. Compared with conventional penetrating keratoplasty, infectious complications after DMEK are ill defined. We describe the clinical picture of 2 DMEK recipients, operated on the same day and in the same clinic, who developed atypical herpes simplex virus type 1 (HSV-1) infection in the transplant recipient eye within days post-DMEK. Because recipients received cornea tissue from 2 different donors prepared by the same eye bank, the likelihood of a common HSV-1 source was determined. DESIGN: Case series. PARTICIPANTS: Two DMEK recipients who developed atypical intraocular HSV-1 disease shortly after surgery and surplus cornea specimens of 6 donors. METHODS: Surplus cornea donor (pre-DMEK cornea remnants and conditioned cornea storage and transport media) and recipient samples (post-DMEK aqueous humor) were assayed for HSV-1 DNA and infectious virus by real-time polymerase chain reaction (RT-PCR) and cell culture, respectively. Target-enriched whole viral genome sequencing was performed on HSV-1 DNAâpositive ocular specimens. MAIN OUTCOMES MEASURES: Clinical picture of atypical intraocular HSV-1 infection post-DMEK and presence and homology of HSV-1 genomes between ocular specimens of DMEK donors and recipients. RESULTS: Herpes simplex virus type 1 DNA was detected in aqueous humor and donor cornea specimens of both DMEK cases, but not in the cornea remnants of 6 randomly selected donors processed by the same eye bank. Infectious HSV-1 was isolated from the cornea remnant and corresponding culture medium of 1 cornea donor. Notably, whole-genome sequencing of virus DNA-positive specimens demonstrated exceptionally high genetic similarity between HSV-1 strains in recipient and donor specimens of both DMEK cases. CONCLUSIONS: Data indicate cross-contamination of cornea grafts during DMEK preparation with subsequent graft-to-host HSV-1 transmission that caused atypical sight-threatening herpetic eye disease shortly after DMEK. Ophthalmologists should be aware that HSV-1 transmission by DMEK is possible and can lead to atypical ocular disease, a condition that can easily be prevented by taking appropriate technical and clinical measures at both eye bank and surgical levels
Foundations of the DEFT Project: tertiary educators Developing Expertise Fostering Thinking
We describe the rationale, creation, and activity of a long-term co-constructed voluntary professional development initiative for tertiary educators. This is a Community of Practice (CoP) formed to investigate âthinkingâ as a topic which may be explicitly taught. The aim of this paper is to share the value of this CoP in one context and insights into how similar approaches may be useful to other tertiary educators. The project has run for a year to date, involving a small but growing collective of tertiary educators, with members from one Canadian and several Australian Universities. Our methodology is participatory: we regularly meet, reflect, and record our reflections. Our records contain data relating to our motivation, our insights, and the impact of these upon our choices in our teaching practices. In particular, our rationale includes the mutual desire to invest in developing understanding of our teaching challenges, to enable us to create thoughtful teaching approaches fit for our purposes and contexts. Hence, the central focus of our CoP is the Development of our Expertise in Fostering Thinking (DEFT). This focus has illuminated gaps in existing scholarly literature pertaining to communal development of theory, personal development of schemata, capacity for reflexivity, and instantiation in our disciplines. Opportunities and risks associated with our other sources of professional learning are identified and discussed. We elaborate on a double-layered approach, in which we explore the construction of our own schemata as a precursor to helping students build their schemata as a foundation for their own understanding, and the role of flexible, critical, and creative thinking on our part. We utilise the scholarship of expertise, frequently returning to such questions as âHow do we know what our students are thinking?â Insights gleaned from our reflections are shared, and recommendations are presented on the formation of similar projects
Untargeted metagenomics protocol for the diagnosis of infection from CSF and tissue from sterile sites
Metagenomic next-generation sequencing (mNGS) is an untargeted technique capable of detecting all microbial nucleic acid within a sample. This protocol outlines our wet laboratory method for mNGS of cerebrospinal fluid (CSF) specimens and tissues from sterile sites. We use this method routinely in our clinical service, processing 178 specimens over the past 2.5 years in a laboratory that adheres to ISO:15189 standards. We have successfully used this protocol to diagnose multiple cases of encephalitis and hepatitis
Absence of detectable monkeypox virus DNA in 11,000 English blood donations during the 2022 outbreak
BACKGROUND: A large, worldwide outbreak of mpox (formerly referred to as monkeypox) involving mainly men who have sex with men commenced in May 2022. We evaluated the frequency of positivity for the causative agent, monkeypox virus (MPXV), in blood donations collected in August 2022, during the outbreak period in Southern England. METHODS/MATERIALS: The sensitivity and specificity of an MPXV-specific PCR and a generic non-variola orthopoxvirus (NVO) PCR were evaluated using samples from mpox cases and synthetic DNA standards. Residual minipools from nucleic acid testing were obtained from 10,896 blood donors in Southern England, with 21% from London. RESULTS: MPXV and NVO PCRs were both capable of detection of single copies of target sequence with calculated limits of detection (LOD)90 âs of 2.3 and 2.1 DNA copies and analytical sample sensitivities of 46 and 42 MPXV DNA copies/ml, respectively. 454 minipools produced from 10,896 unique donors were assayed for MPXV DNA by both methods. No positive minipools were detected by either PCR. CONCLUSIONS: Although blood donors are unrepresentative of the UK population in terms of MPXV infection risk, the uniformly negative MPXV DNA testing results provide reassurance that MPXV viraemia and potential transmission risk were rare or absent in donors during the outbreak period. Minipools from blood donors allow rapid implementation of large-scale population-based screening for emerging pathogens and represent an important resource for pandemic preparedness
The âDEFTâ Project
The student experience of university is shaped in part by what lecturers â who are significant figures and role models â expect of students. In particular, what is the type and quality of thinking that we expect students to be engaging in? The DEFT (Developing Expertise Fostering Thinking) Project is a Professional Development Project being co-created and undertaken by a group of university lecturers across diverse institutions and contexts. We are interested in how our students think, what they think about, and how we can be more effective and precise in fostering thinking amongst our cohorts.
This work builds on scholarly literature on the nature of expertise â the quality we want to develop. In particular we draw upon the PhD of one of our number, Peter Ellerton, who leads the University of Queensland Critical Thinking Project. We also draw upon inspiration from considerations as to the nature of mathematical thinking. Our work is strongly but not exclusively contextualized within the Mathematical Sciences. The approach is a praxis approach, drawing upon the growing practical expertise of each of us as educators working within Universities in Australia and Canada.
In working together across diverse institutions and time zones, we are utilising videoconferencing for regular meetings in which we discuss our work and approaches. We discuss our current practices, and reflect upon these in the light of our theoretical framing. A keystone of the work is the assumption that (both for ourselves as educators and our students as developing professionals in diverse field) the development of expertise relies upon building understanding and conceptual schema through (deliberate) practice
In Vivo Emergence of a Novel Protease Inhibitor Resistance Signature in HIV-1 Matrix.
Protease inhibitors (PIs) are the second- and last-line therapy for the majority of HIV-infected patients worldwide. Only around 20% of individuals who fail PI regimens develop major resistance mutations in protease. We sought to explore the role of mutations in gag-pro genotypic and phenotypic changes in viruses from six Nigerian patients who failed PI-based regimens without known drug resistance-associated protease mutations in order to identify novel determinants of PI resistance. Target enrichment and next-generation sequencing (NGS) with the Illumina MiSeq system were followed by haplotype reconstruction. Full-length Gag-protease gene regions were amplified from baseline (pre-PI) and virologic failure (VF) samples, sequenced, and used to construct gag-pro-pseudotyped viruses. Phylogenetic analysis was performed using maximum-likelihood methods. Susceptibility to lopinavir (LPV) and darunavir (DRV) was measured using a single-cycle replication assay. Western blotting was used to analyze Gag cleavage. In one of six participants (subtype CRF02_AG), we found 4-fold-lower LPV susceptibility in viral clones during failure of second-line treatment. A combination of four mutations (S126del, H127del, T122A, and G123E) in the p17 matrix of baseline virus generated a similar 4-fold decrease in susceptibility to LPV but not darunavir. These four amino acid changes were also able to confer LPV resistance to a subtype B Gag-protease backbone. Western blotting demonstrated significant Gag cleavage differences between sensitive and resistant isolates in the presence of drug. Resistant viruses had around 2-fold-lower infectivity than sensitive clones in the absence of drug. NGS combined with haplotype reconstruction revealed that resistant, less fit clones emerged from a minority population at baseline and thereafter persisted alongside sensitive fitter viruses. We used a multipronged genotypic and phenotypic approach to document emergence and temporal dynamics of a novel protease inhibitor resistance signature in HIV-1 matrix, revealing the interplay between Gag-associated resistance and fitness
Recommendations for the introduction of metagenomic high-throughput sequencing in clinical virology, part I:Wet lab procedure
Metagenomic high-throughput sequencing (mHTS) is a hypothesis-free, universal pathogen detection technique for determination of the DNA/RNA sequences in a variety of sample types and infectious syndromes. mHTS is still in its early stages of translating into clinical application. To support the development, implementation and standardization of mHTS procedures for virus diagnostics, the European Society for Clinical Virology (ESCV) Network on Next-Generation Sequencing (ENNGS) has been established. The aim of ENNGS is to bring together professionals involved in mHTS for viral diagnostics to share methodologies and experiences, and to develop application recommendations. This manuscript aims to provide practical recommendations for the wet lab procedures necessary for implementation of mHTS for virus diagnostics and to give recommendations for development and validation of laboratory methods, including mHTS quality assurance, control and quality assessment protocols
Recommendations for the introduction of metagenomic high-throughput sequencing in clinical virology, part I: Wet lab procedure
Metagenomic high-throughput sequencing (mHTS) is a hypothesis-free, universal pathogen detection technique for determination of the DNA/RNA sequences in a variety of sample types and infectious syndromes. mHTS is still in its early stages of translating into clinical application. To support the development, implementation and standardization of mHTS procedures for virus diagnostics, the European Society for Clinical Virology (ESCV) Network on Next-Generation Sequencing (ENNGS) has been established. The aim of ENNGS is to bring together professionals involved in mHTS for viral diagnostics to share methodologies and experiences, and to develop application recommendations. This manuscript aims to provide practical recommendations for the wet lab procedures necessary for implementation of mHTS for virus diagnostics and to give recommendations for development and validation of laboratory methods, including mHTS quality assurance, control and quality assessment protocols
Recommendations for the introduction of metagenomic high-throughput sequencing in clinical virology, part I: Wet lab procedure
Metagenomic high-throughput sequencing (mHTS) is a hypothesis-free, universal pathogen detection technique for determination of the DNA/RNA sequences in a variety of sample types and infectious syndromes. mHTS is still in its early stages of translating into clinical application. To support the development, implementation and standardization of mHTS procedures for virus diagnostics, the European Society for Clinical Virology (ESCV) Network on Next-Generation Sequencing (ENNGS) has been established. The aim of ENNGS is to bring together professionals involved in mHTS for viral diagnostics to share methodologies and experiences, and to develop application recommendations. This manuscript aims to provide practical recommendations for the wet lab procedures necessary for i