Pan-genomic analysis of clonal bacterial samples using nanopore reads and genome graphs

Bacterial genetic variation originates through multiple mechanisms, including mutations during replication, movement of mobile elements, and various forms of recombination. As a result, genomes can be highly divergent with only a small fraction of genes core to all and a large pangenome of genes which have been identified in one or more sequenced samples. In this context, the ability to accurately detect genetic variation throughout the pangenome and compare many genomes remains a difficult problem. Here we present a novel pangenome reference graph structure, which represents the known genetic variation within a species as a collection of `floating' graphs. Each of these represents some homologous region such as a cluster of genes. By approximating a sequenced genome as a mosaic of genomes from the reference panel, this design forms the basis for a systematic framework in which to analyse diverse sets of samples where a single reference would be inappropriate. Applying this method to E. coli, we demonstrate how it enables us to describe genetic variation at both a coarse (gene presence) and a fine (SNP/indel) level. We demonstrate how this enables us to successfully compare divergent genomes within a species, gaining dramatically higher sensitivity to SNP variation than single reference-genome approaches. We go on to demonstrate how this method enables us to investigate global genetic variation in K. pneumoniae, and to describe the spectrum of allele frequencies in accessory genes. The method works for either long Nanopore or short Illumina reads, and we hope will provide the basis for addressing many questions in diverse datasets

Changing behaviour 'more or less'-do theories of behaviour inform strategies for implementation and de-implementation? A critical interpretive synthesis

BACKGROUND: Implementing evidence-based care requires healthcare practitioners to do less of some things (de-implementation) and more of others (implementation). Variations in effectiveness of behaviour change interventions may result from failure to consider a distinction between approaches by which behaviour increases and decreases in frequency. The distinction is not well represented in methods for designing interventions. This review aimed to identify whether there is a theoretical rationale to support this distinction. METHODS: Using Critical Interpretative Synthesis, this conceptual review included papers from a broad range of fields (biology, psychology, education, business) likely to report approaches for increasing or decreasing behaviour. Articles were identified from databases using search terms related to theory and behaviour change. Articles reporting changes in frequency of behaviour and explicit use of theory were included. Data extracted were direction of behaviour change, how theory was operationalised, and theory-based recommendations for behaviour change. Analyses of extracted data were conducted iteratively and involved inductive coding and critical exploration of ideas and purposive sampling of additional papers to explore theoretical concepts in greater detail. RESULTS: Critical analysis of 66 papers and their theoretical sources identified three key findings: (1) 9 of the 15 behavioural theories identified do not distinguish between implementation and de-implementation (5 theories were applied to only implementation or de-implementation, not both); (2) a common strategy for decreasing frequency was substituting one behaviour with another. No theoretical basis for this strategy was articulated, nor were methods proposed for selecting appropriate substitute behaviours; (3) Operant Learning Theory makes an explicit distinction between techniques for increasing and decreasing frequency. DISCUSSION: Behavioural theories provide little insight into the distinction between implementation and de-implementation. Operant Learning Theory identified different strategies for implementation and de-implementation, but these strategies may not be acceptable in health systems. Additionally, if behaviour substitution is an approach for de-implementation, further investigation may inform methods or rationale for selecting the substitute behaviour

A phylogenetics and variant calling pipeline to support SARS-CoV-2 genomic epidemiology in the UK

In response to the escalating SARS-CoV-2 pandemic, in March 2020 the COVID-19 Genomics UK (COG-UK) consortium was established to enable national-scale genomic surveillance in the UK. By the end of 2020, 49% of all SARS-CoV-2 genome sequences globally had been generated as part of the COG-UK programme, and to date, this system has generated >3 million SARS-CoV-2 genomes. Rapidly and reliably analysing this unprecedented number of genomes was an enormous challenge. To fulfil this need and to inform public health decision-making, we developed a centralized pipeline that performs quality control, alignment, and variant calling and provides the global phylogenetic context of sequences. We present this pipeline and describe how we tailored it as the pandemic progressed to scale with the increasing amounts of data and to provide the most relevant analyses on a daily basis

16S sequencing and functional analysis of the fecal microbiome during treatment of newly diagnosed pediatric inflammatory bowel disease

JJA is funded by a National Institute of Health Research Academic Clinical Fellowship and has received an Action Medical Research training fellowship. TC is funded by a Crohn’s in Childhood research association fellowship. CMC received a PhD studentship from SULSA Spirit industrial studentship. The NGS analysis was made possible by the award of a grant from the Source Bioscience 110th year anniversary promotion to CMC. The Rowett Institute receives funding from the Scottish Government (RESAS).Peer reviewedPublisher PD

Clinical Management of H. pylori Infection for Indigenous and Northern Communities in Canada: Guidelines Developed from CANHelp Research

Community H. pylori (Hp) projects conducted by the CANHelp Working Group during 2007- 2018 generated local evidence of relevance to clinical decision-making about Hp infection in Arctic Indigenous communities. We used this information to adapt current Canadian guidelines for northern and Indigenous populations in Canada. Following the guidelines, we present the context and rationale for their development. Because evidence is limited for many of the recommendations we present, due weight should be given to the individual patient’s motivation, values, preferences, and circumstances

Assignment of epidemiological lineages in an emerging pandemic using the pangolin tool.

Funder: Oxford Martin School, University of OxfordThe response of the global virus genomics community to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been unprecedented, with significant advances made towards the 'real-time' generation and sharing of SARS-CoV-2 genomic data. The rapid growth in virus genome data production has necessitated the development of new analytical methods that can deal with orders of magnitude of more genomes than previously available. Here, we present and describe Phylogenetic Assignment of Named Global Outbreak Lineages (pangolin), a computational tool that has been developed to assign the most likely lineage to a given SARS-CoV-2 genome sequence according to the Pango dynamic lineage nomenclature scheme. To date, nearly two million virus genomes have been submitted to the web-application implementation of pangolin, which has facilitated the SARS-CoV-2 genomic epidemiology and provided researchers with access to actionable information about the pandemic's transmission lineages

Community-driven Epidemiologic Research: Guiding Principles

Increasingly, public health research standards call for engaging communities who live with health issues under investigation to help ensure that results translate into effective public health measures. Here, we share guiding principles for community-driven epidemiologic research developed over a decade conducting research sought and controlled by participating communities. These principles provide a roadmap for epidemiologic research that effectively addresses community priorities while meeting academic standards: research questions are developed collaboratively in community-university partnerships; knowledge takes shape from information donated by participants through methods that turn information into scientifically useful data and analysis that reveals data patterns that address research questions; thus, knowledge is generated collaboratively by academic researchers and community partners; academic researchers are bound by ethical, professional, scientific, contractual, and other legal standards to be responsible stewards of information donated by participants; community review protocols ensure that interpretation and presentation of research results reflects the voices of all partners; meaningful community review creates the trust needed for open access to research results as required of academic researchers; all partners share credit for achievements. Lacking models for operationalizing these principles, we developed specific guidelines for research project initiation, data use, authorship, acknowledgment, and data dissemination. Conventions in academia present formidable challenges to effective community engagement and are often at odds with calls from community organizations and funding agencies to conduct research driven by community priorities and values. We hope others can benefit from time and effort we have spent crafting solutions that bridge this divide