Leaderless FMDV O is fully attenuated in cattle and does not establish persistent infections - Anses - Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail Accéder directement au contenu
Communication Dans Un Congrès Année : 2023

Leaderless FMDV O is fully attenuated in cattle and does not establish persistent infections

Résumé

The leader protease Lpro of FMDV is an important virulence factor. Leaderless FMD viruses of serotype A, wherein a large part of the Lpro open reading frame has been deleted, have been shown to be strongly attenuated in cattle and pigs during the acute phase of infection. It has not been investigated, however, if leaderless viruses can cause persistent infection of epithelia in the upper respiratory tract of cattle. Neither has there been any in vivo evaluation of leaderless viruses of other serotypes. In this experiment, two groups of eight cattle each were inoculated with either wildtype FMDV O/FRA/1/2001 or its leaderless derivative O FRA delta Lpro by intranasopharyngeal deposition. Throughout the experiment, serum, saliva, nasal and oropharyngeal fluid were collected for virological analysis. Two cattle from each group were euthanized 24 hours after inoculation and tissue samples were collected to evaluate early-stage virus distribution. The remaining six cattle in the wildtype group developed pronounced generalized disease and shed large amounts of virus during the first 10 to 14 days of the experiment. The O FRA delta Lpro group did not show any clinical signs of FMD nor was there any detectable virus in serum or secretions. Two of six animals in the wildtype group remained persistently infected until the end of the experiment on day 35. There was no evidence of persistent infection in the delta Lpro group. Our experiment confirms the strong attenuation of leaderless FMDV in cattle. No clinical disease, virus shedding or persistent infection was observed after inoculation with a leaderless derivative of virulent O/FRA/1/2001 virus. In a companion study presented at the conference by Michaud et al., O FRA delta Lpro was also found to be strongly attenuated in air-liquid interface cultures of bovine soft palate cells and was unable to establish persistent infection.
Fichier non déposé

Dates et versions

anses-04426800 , version 1 (30-01-2024)

Licence

Paternité - Pas d'utilisation commerciale - Pas de modification

Identifiants

  • HAL Id : anses-04426800 , version 1

Citer

Benedikt Litz, Anja Landmesser, Florian Pfaff, Sandra Blaise-Boisseau, Michael Eschbaumer. Leaderless FMDV O is fully attenuated in cattle and does not establish persistent infections. Global Foot-and-Mouth (F M D) Research Alliance (G F R A), GFRA, Nov 2023, Kampala, Uganda. ⟨anses-04426800⟩
6 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More