Latest Publications
Combining models to generate consensus medium-term projections of hospital admissions, occupancy and deaths relating to COVID-19 in England
Harrison Manley,Thomas Bayley,Gabriel Danelian, Lucy Burton, Thomas Finnie, Andre Charlett, Nicholas A. Watkins, Paul Birrell, Daniela De Angelis, Matt Keeling, Sebastian Funk, Graham Medley, Lorenzo Pellis, Marc Baguelin, Graeme J. Ackland, Johanna Hutchinson, Steven Riley and Jasmina Panovska-Griffiths
Mathematical modelling has played an important role in offering informed advice during the COVID-19 pandemic. In England, a cross government and academia collaboration generated medium-term projections (MTPs) of possible epidemic trajectories over the future 4–6 weeks from a collection of epidemiological models. In this article, we outline this collaborative modelling approach and evaluate the accuracy of the combined and individual model projections against the data over the period Learning from our experience of ensemble modelling during the COVID-19 epidemic, our findings highlight the importance of developing cross-institutional multi-model infectious disease hubs for future outbreak control.
Mitochondrial and microbial diversity of the invasive mosquito vector species Culex tritaeniorhynchus across its extensive inter-continental geographic range
Claire L. Jeffries, Luciano M Tantely, Perparim Kadriaj, Marcus S C Blagrove, Ioanna Lytra, James Orsborne, Hasan Mohammad Al-Amin, Abdul Rahim Mohammed, Mohammad Shafiul Alam, Romain Girod, Yaw A Afrane, Silvia Bino, Vincent Robert, Sebastien Boyer, Matthew Baylis, Enkelejda Velo, Grant L Hughes, Thomas Walker
In this study, we used laboratory vector competence experiments to determine if Cx. tritaeniorhynchus from a Southern European population were competent JEV vectors. We obtained samples from multiple geographically dispersed Cx. tritaeniorhynchus populations from countries within Europe, Africa, Eurasia and Asia to perform phylogenetic analysis to measure the level of mitochondrial divergence using the cytochrome oxidase subunit 1 (CO1) gene. We also undertook bacterial 16S rRNA gene amplicon sequencing to determine microbial diversity and used multi-locus sequence typing (MLST) to determine any evidence for the presence of strains of the naturally occurring endosymbiotic bacterium Wolbachia. Cx. tritaeniorhynchus from a Greek population were shown be be competent vectors of JEV with high levels of virus present in saliva. We found a signficant level of mitochondrial genetic diversity using the mosquito CO1 gene between geographically dispersed populations. Furthermore, we report diverse microbiomes identified by 16S rRNA gene amplicon sequencing within and between geographical populations. Evidence for the detection of the endosymbiotic bacteria Wolbachia was confirmed using Wolbachia-specific PCR and MLST.
Response patterns of the microbiome during hexavalent chromium remediation by Tagetes erecta L
Juanjuan Xiao, Deying Wang, Banerjee Sinchan, Ryan Mushinski, Decai Jin, Ye Deng
Chromium pollution, particularly hexavalent chromium [Cr(VI)], may threaten the environment and human health. This study investigated the potential of Tagetes erecta L. (Aztec marigold) for phytoremediation of soil contaminated with Cr(VI), and focused on the effects of varying concentrations of Cr(VI) on both the physicochemical properties of soil and microbiome of Tagetes erecta L. We observed that Tagetes erecta L. showed tolerance to Cr(VI) stress and maintained normal growth under these conditions, as indicated by bioconcentration factors of 0.33–0.53 in shoots and 0.39–0.70 in roots. Meanwhile, the structure and diversity of bacterial communities were significantly affected by Cr(VI) pollution. This study explored the interactions between heavy metals, microorganisms, and plants, providing valuable insights for developing in situ bioremediation of Cr(VI)-contaminated soils.
Membraneless channels sieve cations in ammonia-oxidizing marine archaea
Andriko von Kügelgen, C. Keith Cassidy, Sofie van Dorst, Lennart L. Pagani, Christopher Batters, Zephyr Ford, Jan Löwe, Vikram Alva, Phillip J. Stansfeld & Tanmay A. M. Bharat
Nitrosopumilus maritimus is an ammonia-oxidizing archaeon that is crucial to the global nitrogen cycle. A critical step for nitrogen oxidation is the entrapment of ammonium ions from a dilute marine environment at the cell surface and their subsequent channelling to the cell membrane of N. maritimus. Here we elucidate the structure of the molecular machinery responsible for this process, comprising the surface layer (S-layer), using electron cryotomography and subtomogram averaging from cells. We supplemented our in situ structure of the ammonium-binding S-layer array with a single-particle electron cryomicroscopy structure, revealing detailed features of this immunoglobulin-rich and glycan-decorated S-layer. This in situ structural study illuminates the biogeochemically essential process of ammonium binding and channelling, common to many marine microorganisms that are fundamental to the nitrogen cycle.
Xavier Didelot publications
Presence of phage-plasmids in multiple serovars of Salmonella enterica
Satheesh Nair, Clare R. Barker, Matthew Bird, David R. Greig, Caitlin Collins, Anaïs PainsetMarie Chattaway, Derek Pickard, Lesley Larkin, Saheer Gharbia, Xavier Didelot and Paolo Ribeca
Evidence is accumulating in the literature that the horizontal spread of antimicrobial resistance (AMR) genes mediated by bacteriophages and bacteriophage-like plasmid (phage-plasmid) elements is much more common than previously envisioned. For instance, we recently identified and characterized a circular P1-like phage-plasmid harbouring a blaCTX-M-15 gene conferring extended-spectrum beta-lactamase (ESBL) resistance in Salmonella enterica serovar Typhi. As the prevalence and epidemiological relevance of such mechanisms has never been systematically assessed in Enterobacterales, in this study we carried out a follow-up retrospective analysis of UK Salmonella isolates previously sequenced as part of routine surveillance protocols between 2016 and 2021. In addition to providing a first comprehensive view of the presence of phage-plasmids in Salmonella, our work highlights the need for a better surveillance and understanding of phage-plasmids as AMR carriers, especially through their characterization with long-read sequencing. Microbial Genomics. May 2024
Rapid expansion and international spread of M1UK in the post-pandemic UK upsurge of Streptococcus pyogenes
The UK observed a marked increase in scarlet fever and invasive group A streptococcal infection in 2022 with severe outcomes in children and similar trends worldwide. Here we report lineage M1UK to be the dominant source of invasive infections in this upsurge. Compared with ancestral M1global strains, invasive M1UK strains exhibit reduced genomic diversity and fewer mutations in two-component regulator genes covRS. The emergence of M1UK is dated to 2008. Following a bottleneck coinciding with the COVID-19 pandemic, three emergent M1UK clades underwent rapid nationwide expansion, despite lack of detection in previous years. All M1UK isolates thus-far sequenced globally have a phylogenetic origin in the UK, with dispersal of the new clades in Europe. While waning immunity may promote streptococcal epidemics, the genetic features of M1UK point to a fitness advantage in pathogenicity, and a striking ability to persist through population bottlenecks. Nature Communications. May 2024
Accelerating Progress Towards the 2030 Neglected Tropical Diseases Targets: How Can Quantitative Modeling Support Programmatic Decisions?
Vasconcelos, Andreia, King, Jonathan D., Nunes-Alves, Cláudio, Anderson, Roy, Argaw, Daniel, Basáñez, Maria-Gloria, Bilal, Shakir, Blok, David J., Blumberg, Seth, Borlase, Anna, Brady, Oliver J., Browning, Raiha, Chitnis, Nakul, Coffeng, Luc E., Crowley, Emily H, Cucunubá, Zulma M., Cummings, Derek A. T., Davis, Christopher N., Davis, Emma L., Dixon, Matthew, Dobson, Andrew, Dyson, Louise et al
Over the past decade, considerable progress has been made in the control, elimination, and eradication of neglected tropical diseases (NTDs). Mathematical modeling can help inform selection of interventions to meet the targets set out in the NTD road map 2021–2030, and such studies should prioritize questions that are relevant for decision-makers, especially those designing, implementing, and evaluating national and subnational programs. In September 2022, the World Health Organization hosted a stakeholder meeting to identify such priority modeling questions across a range of NTDs and to consider how modeling could inform local decision making. Here, we summarize the outputs of the meeting, highlight common themes in the questions being asked, and discuss how quantitative modeling can support programmatic decisions that may accelerate progress towards the 2030 targets.