Setting up a SPF Chicken Model for the Pathotyping of West Nile Virus (WNV) Strains
Résumé
Birds play a central role in WNV epidemiology by spreading and amplifying the
virus. Increasing numbers of WNV isolates are detected in Europe, and the virulence
of these genetically variable isolates is not well characterized for birds.
Therefore, we investigated whether SPF chickens could be a valuable avian model
for the pathotyping of WNV strains. One-day-old SPF chickens were inoculated
subcutaneously (SC) or intracerebrally (IC) with four lineage 1 WNV strains
(Is98, It2008, Fr2000 or Kunjin) and were daily clinically monitored for 2 weeks
after infection. Additionally, one-day-old SPF chickens were SC inoculated,
and one-week-old SPF chickens were SC or IC inoculated with two
Euro-Mediterranean isolates, Is98 and Fr2000, to sample blood and feathers at
regular time points. These samples were analysed by WN NS2a-specific rRT-PCR
and WN NS1 antigen-capture ELISA that were developed for the purpose of this
study. Differences in strain virulence were evidenced after IC inoculation of oneday-
old SPF chickens, with Is98 eliciting the highest mortality rates and Kunjin
the lowest ones, while lethality of Fr2000 and It2008 was intermediate. Neither
viral load in sera and feathers nor NS1 antigen in the serum correlated with the
differential pathogenicity of Is98 and Fr2000. However, irrespective of the inoculated
strain, younger chickens showed higher and longer-lasting viremias than
older chickens. In all experimental groups, the detection window for viral RNA in
feathers lasted up to 14 dpi. Altogether, the data presented in this study show that
WNV strain virulence can be discriminated in a one-day-old SPF chicken model
on the basis of mortality rates, while viremia and viral load in feathers appear to
be age dependent rather than strain dependent.
Domaines
Sciences du Vivant [q-bio]
Fichier principal
DRIDIArticlePublié_{57279340-480C-4B75-8906-FC950211CBF0}.pdf (589.03 Ko)
Télécharger le fichier
Origine : Accord explicite pour ce dépôt
Loading...