Epidemic Clostridium difficile (027/BI/NAP1) rapidly emerged in the past decade as the leading cause of antibiotic-associated diarrhea worldwide. However, the key moments in the evolutionary history leading to its emergence and subsequent patterns of global spread remain unknown. Here we define the global population structure of C. difficile 027/BI/NAP1 based on whole-genome sequencing and phylogenetic analysis. We demonstrate that two distinct epidemic lineages, FQR1 and FQR2, not one as previously thought, emerged in North America within a relatively short period after acquiring the same fluoroquinolone resistance mutation and a highly-related conjugative transposon. The two epidemic lineages displayed distinct patterns of global spread, and the FQR2 lineage spread more widely leading to healthcare outbreaks in the UK, continental Europe and Australia. Our analysis identifies key genetic changes linked to the rapid trans-continental dissemination of epidemic C. difficile 027/BI/NAP1 and highlights the routes by which it spreads through the global healthcare system.

Chlamydia trachomatis is the world's most prevalent bacterial sexually transmitted infection and leading infectious cause of blindness, yet it is one of the least understood human pathogens, in part due to the difficulties of in vitro culturing and the lack of available tools for genetic manipulation. Genome sequencing has reinvigorated this field, shedding light on the contemporary history of this pathogen. Here, we analyze 563 full genomes, 455 of which are novel, to show that the history of the species comprises two phases, and conclude that the currently circulating lineages are the result of evolution in different genomic ecotypes. Temporal analysis indicates these lineages have recently expanded in the space of thousands of years, rather than the millions of years as previously thought, a finding that dramatically changes our understanding of this pathogen's history. Finally, at a time when almost every pathogen is becoming increasingly resistant to antimicrobials, we show that there is no evidence of circulating genomic resistance in C. trachomatis.

Proteins exhibiting hyper-variable sequences within a bacterial pathogen may be associated with host adaptation. Several lineages of the monophyletic pathogen Salmonella enterica serovar Typhi (S. Typhi) have accumulated non-synonymous mutations in the putative two-component regulatory system yehUT. Consequently we evaluated the function of yehUT in S. Typhi BRD948 and S. Typhimurium ST4/74. Transcriptome analysis identified the cstA gene, encoding a carbon starvation protein as the predominantly yehUT regulated gene in both these serovars. Deletion of yehUT had no detectable effect on the ability of these mutant Salmonella to invade cultured epithelial cells (S. Typhi and S. Typhimurium) or induce colitis in a murine model (S. Typhimurium only). Growth, metabolic and antimicrobial susceptibility tests identified no obvious influences of yehUT on these phenotypes.

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What progress has occurred in terms of developing the culture of sustainability in which UK property investors, occupiers, and developers are both informed and accepting of the sustainability principles? Although the rise in concern for 'triple bottom line' sustainability is now embedded in many government and corporate policies, it is still not integrated into UK property investment practice. Whilst the last decade has seen progress towards 'green buildings', there has not yet been a 'sea change' in market behaviour. In developing this premise, it draws on the third of three surveys undertaken by the authors spanning a decade and tracking investor attitudes towards 'green' and sustainable buildings. Stakeholders' attitudes towards a potential range of fiscal measures that might incentivize market movement towards the adaptation of more sustainable behaviour. The business case for investment in sustainable property currently rests on risk reduction, not proven return advantage. There is support among respondents for a range of fiscal incentives. Although challenges to implementation undoubtedly exist, they are, in the authors' view, worthy of further research and investigation. There is potential to stimulate, via the fiscal system, measures to reward sustainable practices in property investment and management which can be facilitated through a more open dialogue with government bodies.Quels ont été les progrès en termes de développement de la culture de la durabilité pour lesquels les investisseurs immobiliers, les occupants et les promoteurs au Royaume-Uni qui, à la fois, sont informés et acceptent les principes de durabilité? Bien que la préoccupation croissante vis-à -vis de la durabilité 'triple résultat' soit maintenant ancrée dans la politique de nombreux gouvernements et entreprises, elle n'est pas encore intégrée en pratique dans les investissements immobiliers au Royaume-Uni. Bien que la dernière décennie ait été le témoin d'un progrès vers les bâ timents écologiques, on n'a pas constaté de mouvements brusques dans le comportement du marché. En développant ces prémices, l'article s'appuie sur la troisième des trois études entreprises par les auteurs au cours d'une dizaine d'années afin d'analyser l'attitude des investisseurs en matière de bâ timents écologiques et durables. Les parties prenantes se tournent vers une palette de mesures fiscales possibles qui pourraient induire des mouvements du marché vers l'adaptation d'un comportement plus durable. Le dossier d'analyse portant sur les investissements dans des biens durables repose actuellement sur la réduction des risques et non sur les avantages de retour prouvés. On constate un certain soutien parmi les personnes interrogées en faveur d'une gamme d'incitations fiscales. Bien que leur mise en oeuvre présente indéniablement des difficultés, elles méritent, selon les auteurs, d'autres recherches et enquêtes. Il existe un potentiel pour stimuler, via le système fiscal, des mesures visant à récompenser les pratiques durables dans les investissements immob...