Characterization of the mouse neuroinvasiveness of selected European strains of West Nile virus

PLoS One. 2013 Sep 18;8(9):e74575. doi: 10.1371/journal.pone.0074575. eCollection 2013.

Abstract

West Nile virus (WNV) has caused outbreaks and sporadic infections in Central, Eastern and Mediterranean Europe for over 45 years. Most strains responsible for the European and Mediterranean basin outbreaks are classified as lineage 1. In recent years, WNV strains belonging to lineage 1 and 2 have been causing outbreaks of neuroinvasive disease in humans in countries such as Italy, Hungary and Greece, while mass mortality among birds was not reported. This study characterizes three European strains of WNV isolated in Italy (FIN and Ita09) and Hungary (578/10) in terms of in vitro replication kinetics on neuroblastoma cells, LD50 values in C57BL/6 mice, median day mortality, cumulative mortality, concentration of virus in the brain and spinal cord, and the response to infection in the brain. Overall, the results indicate that strains circulating in Europe belonging to both lineage 1 and 2 are highly virulent and that Ita09 and 578/10 are more neurovirulent compared to the FIN strain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Biomarkers / metabolism
  • Brain / pathology
  • Brain / virology
  • Chlorocebus aethiops
  • Europe
  • Immunohistochemistry
  • Kinetics
  • Lethal Dose 50
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Nervous System / pathology*
  • Nervous System / virology*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Viral / metabolism
  • Survival Analysis
  • Vero Cells
  • Viral Load
  • Viral Proteins / chemistry
  • Viral Proteins / metabolism
  • Virus Replication
  • West Nile Fever / virology*
  • West Nile virus / physiology*

Substances

  • Biomarkers
  • RNA, Messenger
  • RNA, Viral
  • Viral Proteins

Grants and funding

The research leading to these results has received complete funding from the European Community's Seventh Framework Programme (FP7/2007 - 2013) under the project "VECTORIE", EC grant agreement number 261466. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.