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5 février 2021: 1 événement

  • Département Biologie des Génomes

    Vendredi 5 février 11:00-12:00 - Jay HINTON - Institute of Integrative Biology, University of Liverpool, UK

    How has Salmonella become so dangerous in Africa ?

    Résumé : With 3.4 million infections each year, invasive non-Typhoidal Salmonella (iNTS) is a major cause of illness worldwide. In Sub-Saharan Africa bloodstream infections with iNTS Salmonella Typhimurium are causing 49,000 deaths annually. Co-infection with HIV or malaria in adults, and a young age (<5 years) are known risk factors. The main causative agent of iNTS is a pathovariant of Salmonella Typhimurium called ST313, which is multi-drug resistant and closely-related to the ST19 variant of Salmonella responsible for gastroenteritis globally.
    Using a combination of comparative genomics and comparative transcriptomics, we discovered phenotypic differences that distinguish African from global Salmonella pathovariants (Canals et al., 2019), and identified a single core genome SNP responsible for the up-regulation of a single promoter that controlled expression of a Salmonella virulence factor (Hammarlöf et al., 2018), and offers part of the explanation of the pan-African epidemic of bloodstream infection.
    All of our Salmonella transcriptomic data are now available online in a user-friendly website that allows comparison of gene expression between African and global pathovariants of
    S. Typhimurium : https://tinyurl.com/SalComD23580
    Most recently, we used thousands of historical and contemporary Salmonella isolates, to understand the precise evolutionary trajectory of the S. Typhimurium ST313 pathogen in Africa. A series of novel genome degradation events impacted upon the function of Salmonella genes required for colonisation of the mammalian gut, providing evidence of niche adaptation and the continuing evolution of ST313 (Pulford et al., 2020).
    I will summarise the evolutionary pathway of invasive S. Typhimurium across Africa, and explain the value of an integrated functional genomic analysis for understanding how bacterial pathogens cause disease.
    References : Canals et al. (2019) PLoS Biology 10.1371/journal.pbio.3000059
    Hammarlöf et al. (2018). PNAS DOI : 10.1073/pnas.1714718115
    Pulford et al. (2020) Nature Microbiology DOI:10.1038/s41564-020-00836-1
    Contact : Nara Figueroa Bossi <nara.figueroa i2bc.paris-saclay.fr>
    and
    Lionello Bossi <lionello.bossi i2bc.paris-saclay.fr>

    Lieu : Visio

    En savoir plus : Département Biologie des Génomes