Communication Dans Un Congrès Année : 2024

Development of real-time RT-PCR assays for the rapid characterization of Foot-and-mouth disease virus

Aurore Romey
Anthony Relmy
  • Fonction : Auteur
  • PersonId : 1075108
Sandra Blaise-Boisseau
Labib Bakkali Kassimi
Guillaume Girault

Résumé

Background/Introduction Foot-and-mouth disease (FMD) is a highly contagious disease caused by the Foot-and-mouth disease virus (FMDV). Seven antigenically distinct serotypes (O, A, C, Asia 1, SAT 1, SAT 2 and SAT 3) and multiple subtypes exist. The laboratory diagnosis of FMD is based on virological, molecular and serological tests. The sequencing of the VP1 gene is the most accurate way to identify the circulating strain during an outbreak, but it takes 24-48 hours to get a final result using all the tests. In case of an FMD outbreak, it is of high importance to follow in real-time the circulating strains. To do this, the rtRT-PCR is a rapid tool of choice. Some assays already exist, targeting serotypes or higher levels of discrimination such as topotypes. In this study, we propose three new rtRT-PCR assays, targeting serotypes O and SAT 2. Material and methods The first rtRT-PCR assay designed in this study was a direct answer to an emergency related to SAT2/V in North Africa at the beginning of 2024. The following are an answer to topotypes/lineages considered at high risk for Europe (O/EA-3 and O/ME-SA/SA-2018). VP1 sequences were retrieved from public databases and aligned, to identify conserved regions. Primers and probes were designed, and analysed in silico against a large panel of VP1 from all serotypes. Once validated, the assays were tested in vitro against a panel of FMDV strains from the EURL collection. Results The SAT2/V assay was tested with 65 strains and 100 % of SAT2/V samples were detected (36/36). The O/EA-3 assay was tested with 34 strains, and 94% of O/EA-3 samples were detected (17/18). Finally, the O/ME-SA/SA-2018 assay was challenged with 32 strains, and 92% of samples were detected (11/12). Discussion and conclusions The three rtRT-PCR assays developed in this study present a good potential of detection, with 100%, 94% and 92% of samples detected, for SAT2/V, O/EA-3 and O/ME-SA/SA-2018 respectively. All three assays did not detect the other strains tested (except for one old O/WA strain for the O/EA-3 system), selected according to specific rules: the selected strains should belong to serotypes/topotypes/lineages/sublineages circulating in the same geographic area than the target from the assay, and/or with a spatio-temporal rule, i.e., strains that have caused recent epizooties. The SAT2/V assay has been shared with laboratories in North Africa to test field samples and will be helpful to follow the SAT2/V progression. The two other assays are ready and can be used in case of an incursion of the related serotype/topotype. More samples should also be tested to precisely define the accuracy of the assays. Finally, the strategy used during this study can be used in case of a new outbreak of FMD to rapidly develop rtRT-PCR assay, and this will be an additional tool to combat FMD.
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Dates et versions

anses-04805349 , version 1 (26-11-2024)

Identifiants

  • HAL Id : anses-04805349 , version 1

Citer

Thomas Deshayes, Aurore Romey, Anne-Laure Salomez, Cindy Bernelin-Cottet, Anthony Relmy, et al.. Development of real-time RT-PCR assays for the rapid characterization of Foot-and-mouth disease virus. EUFMD Open Session 2024, EuFMD, Oct 2024, Alcala de Henares (Madrid), Spain. ⟨anses-04805349⟩
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