58 research outputs found

    Supervision of Maori doctoral students: A descriptive report

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    This report follows up a previous paper that outlined the goals and plans of a research project that focused on both theoretical and cultural questions regarding the supervisory process for Māori doctoral students (McKinley, Grant, Middleton, Irwin, & Williams, 2007). The major goal of the project is to enhance understanding of the teaching and learning process of supervision for students and supervisors, particularly around issues of culture that arise in research methodologies and practices. This paper reports on the completed project by providing further operational background, design features, the nature of the student and supervisor samples and a summary of interview findings. The results show that there are indeed distinctive issues arising within the supervision of Māori doctoral students. Some of these are to do with both pleasures and challenges found in the supervision relationship, while others relate to the kinds of projects the students undertake. Many projects for example, push at the disciplinary boundaries of Western knowledge and are often rooted in a political desire to enhance the everyday lives of Māori. Yet others are connected to identity formation processes that concern many Māori during their years as doctoral students. A central message for supervisors from this work is that the supervision of Māori doctoral students may require unfamiliar forms of engagement but that these are likely to be deeply rewarding in many different ways

    Comparative analysis of core genome MLST and SNP typing within a European Salmonella serovar Enteritidis outbreak

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    Multi-country outbreaks of foodborne bacterial disease present challenges in their detection, tracking, and notification. As food is increasingly distributed across borders, such outbreaks are becoming more common. This increases the need for high-resolution, accessible, and replicable isolate typing schemes. Here we evaluate a core genome multilocus typing (cgMLST) scheme for the high-resolution reproducible typing of Salmonella enterica (S. enterica) isolates, by its application to a large European outbreak of S. enterica serovar Enteritidis. This outbreak had been extensively characterised using single nucleotide polymorphism (SNP)-based approaches. The cgMLST analysis was congruent with the original SNP-based analysis, the epidemiological data, and whole genome MLST (wgMLST) analysis. Combination of the cgMLST and epidemiological data confirmed that the genetic diversity among the isolates predated the outbreak, and was likely present at the infection source. There was consequently no link between country of isolation and genetic diversity, but the cgMLST clusters were congruent with date of isolation. Furthermore, comparison with publicly available Enteritidis isolate data demonstrated that the cgMLST scheme presented is highly scalable, enabling outbreaks to be contextualised within the Salmonella genus. The cgMLST scheme is therefore shown to be a standardised and scalable typing method, which allows Salmonella outbreaks to be analysed and compared across laboratories and jurisdictions. [Abstract copyright: Copyright © 2018. Published by Elsevier B.V.

    Changing Pattern of Human Listeriosis, England and Wales, 2001–2004

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    Disease has reemerged, mainly in patients ≄60 years of age with bacteremia

    Whole-genome sequencing for national surveillance of Shiga toxin–producing Escherichia coli O157

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    Background. National surveillance of gastrointestinal pathogens, such as Shiga toxin–producing Escherichia coli O157 (STEC O157), is key to rapidly identifying linked cases in the distributed food network to facilitate public health interventions. In this study, we used whole-genome sequencing (WGS) as a tool to inform national surveillance of STEC O157 in terms of identifying linked cases and clusters and guiding epidemiological investigation. Methods. We retrospectively analyzed 334 isolates randomly sampled from 1002 strains of STEC O157 received by the Gastrointestinal Bacteria Reference Unit at Public Health England, Colindale, in 2012. The genetic distance between each isolate, as estimated by WGS, was calculated and phylogenetic methods were used to place strains in an evolutionary context. Results. Estimates of linked clusters representing STEC O157 outbreaks in England and Wales increased by 2-fold when WGS was used instead of traditional typing techniques. The previously unidentified clusters were often widely geographically distributed and small in size. Phylogenetic analysis facilitated identification of temporally distinct cases sharing common exposures and delineating those that shared epidemiological and temporal links. Comparison with multi locus variable number tandem repeat analysis (MLVA) showed that although MLVA is as sensitive as WGS, WGS provides a more timely resolution to outbreak clustering. Conclusions. WGS has come of age as a molecular typing tool to inform national surveillance of STEC O157; it can be used in real time to provide the highest strain-level resolution for outbreak investigation. WGS allows linked cases to be identified with unprecedented specificity and sensitivity that will facilitate targeted and appropriate public health investigations

    Diversity of the Genomes and Neurotoxins of Strains of Clostridium botulinum Group I and Clostridium sporogenes Associated with Foodborne, Infant and Wound Botulism.

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    Clostridium botulinum Group I and Clostridium sporogenes are closely related bacteria responsible for foodborne, infant and wound botulism. A comparative genomic study with 556 highly diverse strains of C. botulinum Group I and C. sporogenes (including 417 newly sequenced strains) has been carried out to characterise the genetic diversity and spread of these bacteria and their neurotoxin genes. Core genome single-nucleotide polymorphism (SNP) analysis revealed two major lineages; C. botulinum Group I (most strains possessed botulinum neurotoxin gene(s) of types A, B and/or F) and C. sporogenes (some strains possessed a type B botulinum neurotoxin gene). Both lineages contained strains responsible for foodborne, infant and wound botulism. A new C. sporogenes cluster was identified that included five strains with a gene encoding botulinum neurotoxin sub-type B1. There was significant evidence of horizontal transfer of botulinum neurotoxin genes between distantly related bacteria. Population structure/diversity have been characterised, and novel associations discovered between whole genome lineage, botulinum neurotoxin sub-type variant, epidemiological links to foodborne, infant and wound botulism, and geographic origin. The impact of genomic and physiological variability on the botulism risk has been assessed. The genome sequences are a valuable resource for future research (e.g., pathogen biology, evolution of C. botulinum and its neurotoxin genes, improved pathogen detection and discrimination), and support enhanced risk assessments and the prevention of botulism

    Applying phylogenomics to understand the emergence of Shiga Toxin producing Escherichia coli O157:H7 strains causing severe human disease in the United Kingdom

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    Shiga Toxin producing Escherichia coli (STEC) O157:H7 is a recently emerged zoonotic pathogen with considerable morbidity. Since the serotype emerged in the 1980s, research has focussed on unravelling the evolutionary events from the E. coli O55:H7 ancestor to the contemporaneous globally dispersed strains. In this study the genomes of over 1000 isolates from human clinical cases and cattle, spanning the history of STEC O157:H7 in the United Kingdom were sequenced. Phylogenetic analysis reveals the ancestry, key acquisition events and global context of the strains. Dated phylogenies estimate the time to the most recent common ancestor of the current circulating global clone to 175 years ago, followed by rapid diversification. We show the acquisition of specific virulence determinates occurred relatively recently and coincides with its recent detection in the human population. Using clinical outcome data from 493 cases of STEC O157:H7 we assess the relative risk of severe disease including HUS from each of the defined clades in the population and show the dramatic effect Shiga toxin complement has on virulence. We describe two strain replacement events that have occurred in the cattle population in the UK over the last 30 years; one resulting in a highly virulent strain that has accounted for the majority of clinical cases in the UK over the last decade. This work highlights the need to understand the selection pressures maintaining Shiga-toxin encoding bacteriophages in the ruminant reservoir and the study affirms the requirement for close surveillance of this pathogen in both ruminant and human populations

    Closing gaps for performing a risk assessment on Listeria monocytogenes in ready-to-eat (RTE) foods : activity 3, the comparison of isolates from different compartments along the food chain, and from humans using whole genome sequencing (WGS) analysis

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    We would like to thank all the persons and institutes that have provided the project with isolates and accompanying information. Without them, this project would not have been possible. Lin Cathrine T. Brandal, Norwegian Institute of Public Health, Norway Julio VĂĄzquez Moreno and Raquel Abad Torreblanca, Instituto de Salud Carlos III, Spain Marc Lecuit, Institut Pasteur, France Alexandre Leclercq, Institut Pasteur, France Iva Hristova, National Center of Infectious and Parasitic Diseases, Bulgaria Marija Trkov, National Laboratory of Health, Environment and Food, Slovenia Cecilia Jernberg, Public Health Agency of Sweden, Sweden Ariane Pietzka, Austrian Agency for Health and Food Safety, Austria Eelco Franz and Ingrid Friesema, RIVM, The Netherlands Carlo Spanu, University of Sassari Sardinia Ifip, French Institute for Pig and Pork Industry, Maisons-Alfort, France All the NRLs for providing the isolates from the EU baseline study Special thanks to Sylvain Brisse and Alexandra Moura, Institut Pasteur, France, for providing cgMLST data. The authors would also like to thank the EFSA staff members: Maria Teresa da Silva Felicio, Beatriz Guerra, Ernesto LĂŹebana and Valentina Rizzi as well as the members of the Working Group on Listeria monocytogenes contamination of ready-to-eat foods: Kostas Koutsoumanis, Roland Lindqvist, Moez Sanaa, Panagiotis Skandamis, Niko Speybroek, Johanna Takkinen and Martin Wagner for the support, revisions and suggestions during the development of the present procurement activity and report.Publisher PD

    LiSEQ – whole-genome sequencing of a cross-sectional survey of Listeria monocytogenes in ready-to-eat foods and human clinical cases in Europe

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    Funding information This work was funded by EFSA, contract number C/EFSA/BIOCONTAM/2014/01-CT 1 on “Closing gaps for performing a risk assessment on Listeria monocytogenes in ready-to-eat (RTE) foods: activity 3, the comparison of isolates from different compartments along the food chain, and from humans using whole genome sequencing (WGS) analysis’, EFSA-Q-2014-00 026. Acknowledgements A. P., T. D. and K. G. are affiliated to the National Institute for Health Research – Health Protection Research Unit (NIHR HPRU) in Gastrointestinal Infections at University of Liverpool in partnership with Public Health England, in collaboration with the University of East Anglia, the University of Oxford and the Quadram Institute. A. P., T. D. and K. G. are based at Public Health England. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, the Department of Health or Public Health England.Peer reviewedPublisher PD

    A pragmatic harm reduction approach to manage a large outbreak of wound botulism in people who inject drugs, Scotland 2015

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    Abstract Background People who inject drugs (PWID) are at an increased risk of wound botulism, a potentially fatal acute paralytic illness. During the first 6 months of 2015, a large outbreak of wound botulism was confirmed among PWID in Scotland, which resulted in the largest outbreak in Europe to date. Methods A multidisciplinary Incident Management Team (IMT) was convened to conduct an outbreak investigation, which consisted of enhanced surveillance of cases in order to characterise risk factors and identify potential sources of infection. Results Between the 24th of December 2014 and the 30th of May 2015, a total of 40 cases were reported across six regions in Scotland. The majority of the cases were male, over 30 and residents in Glasgow. All epidemiological evidence suggested a contaminated batch of heroin or cutting agent as the source of the outbreak. There are significant challenges associated with managing an outbreak among PWID, given their vulnerability and complex addiction needs. Thus, a pragmatic harm reduction approach was adopted which focused on reducing the risk of infection for those who continued to inject and limited consequences for those who got infected. Conclusions The management of this outbreak highlighted the importance and need for pragmatic harm reduction interventions which support the addiction needs of PWID during an outbreak of spore-forming bacteria. Given the scale of this outbreak, the experimental learning gained during this and similar outbreaks involving spore-forming bacteria in the UK was collated into national guidance to improve the management and investigation of future outbreaks among PWID
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