Relationship between molecular pathogen detection and clinical disease in febrile children across Europe: a multicentre, prospective observational study

BackgroundThe PERFORM study aimed to understand causes of febrile childhood illness by comparing molecular pathogen detection with current clinical practice.MethodsFebrile children and controls were recruited on presentation to hospital in 9 European countries 2016-2020. Each child was assigned a standardized diagnostic category based on retrospective review of local clinical and microbiological data. Subsequently, centralised molecular tests (CMTs) for 19 respiratory and 27 blood pathogens were performed.FindingsOf 4611 febrile children, 643 (14%) were classified as definite bacterial infection (DB), 491 (11%) as definite viral infection (DV), and 3477 (75%) had uncertain aetiology. 1061 controls without infection were recruited. CMTs detected blood bacteria more frequently in DB than DV cases for N. meningitidis (OR: 3.37, 95% CI: 1.92-5.99), S. pneumoniae (OR: 3.89, 95% CI: 2.07-7.59), Group A streptococcus (OR 2.73, 95% CI 1.13-6.09) and E. coli (OR 2.7, 95% CI 1.02-6.71). Respiratory viruses were more common in febrile children than controls, but only influenza A (OR 0.24, 95% CI 0.11-0.46), influenza B (OR 0.12, 95% CI 0.02-0.37) and RSV (OR 0.16, 95% CI: 0.06-0.36) were less common in DB than DV cases. Of 16 blood viruses, enterovirus (OR 0.43, 95% CI 0.23-0.72) and EBV (OR 0.71, 95% CI 0.56-0.90) were detected less often in DB than DV cases. Combined local diagnostics and CMTs respectively detected blood viruses and respiratory viruses in 360 (56%) and 161 (25%) of DB cases, and virus detection ruled-out bacterial infection poorly, with predictive values of 0.64 and 0.68 respectively.InterpretationMost febrile children cannot be conclusively defined as having bacterial or viral infection when molecular tests supplement conventional approaches. Viruses are detected in most patients with bacterial infections, and the clinical value of individual pathogen detection in determining treatment is low. New approaches are needed to help determine which febrile children require antibiotics.FundingEU Horizon 2020 grant 668303

Impact of infection on proteome-wide glycosylation revealed by distinct signatures for bacterial and viral pathogens

Mechanisms of infection and pathogenesis have predominantly been studied based on differential gene or protein expression. Less is known about posttranslational modifications, which are essential for protein functional diversity. We applied an innovative glycoproteomics method to study the systemic proteome-wide glycosylation in response to infection. The protein site-specific glycosylation was characterized in plasma derived from well-defined controls and patients. We found 3862 unique features, of which we identified 463 distinct intact glycopeptides, that could be mapped to more than 30 different proteins. Statistical analyses were used to derive a glycopeptide signature that enabled significant differentiation between patients with a bacterial or viral infection. Furthermore, supported by a machine learning algorithm, we demonstrated the ability to identify the causative pathogens based on the distinctive host blood plasma glycopeptide signatures. These results illustrate that glycoproteomics holds enormous potential as an innovative approach to improve the interpretation of relevant biological changes in response to infection

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Apport de l'enregistrement des potentiels évoqués myogéniques otolitiques en pathologie vestibulaire (A propos de 278 cas.)

STRASBOURG-Medecine (674822101) / SudocSudocFranceF

Last results concerning gene flow from transgenic oilseed rape to wild radish

CDRomInternational audienc

Effet de la structure génomique des hybrides interspécifiques colza-ravenelle sur la composition chromosomique des générations ultérieures

National audienceBecause of the development of transgenic herbicide resistant oilseed rape (Brassica napus, AACC, 2n=38) varieties, studies for assessing gene flow from this crop to its weeds have been performed. Our previous work showed that wild radish (Raphanus raphanistrum, RrRr, 2n=18) is one of the main weed which has to be considered under French cultivation conditions. At the first generation of interspecific hybridisation, viable reduced and unreduced gametes allow the production of F1 hybrids with different genomic structures. Theoretically, 10 different structures can be obtained from reciprocal crosses and 5 have already been observed. The identified hybrids were grown in presence of wild radish as pollinator and the chromosome numbers of the plants in the following generations ranged from 18 to 56. So a large variability can be observed, taking into account that we are looking for a rare event, the pollen donor remaining unknown at the harvest under natural conditions. Combination of different tools for characterisation i.e. morphology, transgene expression, cytogenetic analyses, molecular makers is needed for monitoring interspecific gene flow.Le développement des variétés transgéniques de colza résistantes à certains herbicides (Brassica napus, AACC, 2n=38) a conduit à s'interroger sur les possibilités de flux de gènes du colza vers ses adventices. Nos travaux antérieurs ont montré que la ravenelle (Raphanus raphanistrum, RrRr, 2n=18) était l'une des principales espèces à prendre en compte dans les conditions françaises de culture. L'ensemble des résultats acquis a montré que la production de gamètes réduits et non réduits pouvaient conduire aux différentes générations à une grande diversité de structures. Cette importante variabilité, combinée aux contraintes d'un suivi en conditions naturelles (recherche d'un événement rare, diversité des milieux et impossibilité d'identifier le pollinisateur), rend difficile la caractérisation du matériel produit. Lors de la production des hybrides F1, 10 combinaisons génomiques (dont 5 déjà observées) sont possibles, en considérant les deux sens possibles de croisements. Aux générations ultérieures, sous l'hypothèse d'hybrides mis en présence de ravenelles, le nombre de chromosomes peut varier de 18 à 56. L'analyse des différents outils de caractérisation (observations morphologiques, présence du transgène, caractérisation cytogénétique, marquage moléculaire) révèle que seule la combinaison de différentes méthodes peut permettre d'identifier les différents hybrides. La diversité des structures génomiques et la lourdeur des méthodes de caractérisation à mettre en œuvre conduit à s'interroger sur les possibilités d'un suivi au champ dès les premières générations

Last results concerning gene flow from transgenic oilseed rape to wild radish

International audienc

Gene flow from oilseed rape to weeds

International audienc

Spontaneous hybridisation between vegetable crops and weeds. 1: Garden radish (Raphanus sativus L.) and wild mustard (Sinapis arvensis L.)

In order to assess the risk of commercial F1 hybrid seed contamination due to outcrossing on male sterile radish line pollinated by wild mustard, two isolated field experiments were performed in the presence or absence of garden radish pollen. Additionally, spontaneous wild radish plants were observed under 200 m away from both fields. Seeds were harvested on the female radish line and sieved. Isozyme analyses combined with cytogenetical characterisation revealed that morphological observations were not efficient enough to distinguish the interspecific hybrids among the seedlings obtained. The radish-wild mustard interspecific hybrid production was higher without than with radish pollen competition: 42 and 3 interspecific hybrid seeds per 1 000 seeds were observed, respectively. Numerous cultivated-wild radish hybrids were observed from the two experiments without and with radish pollinator: 551 and 144 per 1 000 seeds, respectively. Sieving seems to be efficient in preventing the commercialisation of cultivated radish-wild mustard hybrids. (© Inra/Elsevier, Paris.)Hybridation spontanée entre plantes maraîchères et adventices : 1. Radis (Raphanus sativus L.) et moutarde des champs (Sinapis arvensis L.). Pour évaluer les risques de contamination des lots de semences dus à une pollinisation des lignées mâles stériles de radis par la moutarde des champs, deux expérimentations ont été réalisées en présence ou en l'absence de pollinisateurs radis. De plus des ravenelles ont été observées à environ 200 m des deux champs. Les graines ont été récoltées sur la lignée de radis femelle et tamisées. Les analyses isoenzymatiques combinées à des observations cytogénétiques ont révélé que la seule observation morphologique des plantules était insuffisante pour identifier les hybrides interspécifiques. La production d'hybrides interspécifiques radis-moutarde des champs est plus élevée en absence (42hybrides/l 000 graines) qu'en présence (3 hybrides/1 000 graines) de pollen de radis. En ce qui concerne les hybrides radis-ravenelle, 551 ont été obtenus pour 1 000 graines récoltées dans l'essai sans compétition pollinique et 144 dans l'essai avec compétition pollinique. Le tamisage est efficace pour limiter la commercialisation d'hybrides radis-moutarde des champs. (© Inra/Elsevier, Paris.