Bluetongue virus serotype 27: detection and characterization of two novel variants in Corsica, France

J Gen Virol. 2016 Sep;97(9):2073-2083. doi: 10.1099/jgv.0.000557. Epub 2016 Jul 19.

Abstract

During the compulsory vaccination programme against bluetongue virus serotype 1 (BTV-1) in Corsica (France) in 2014, a BTV strain belonging to a previously uncharacterized serotype (BTV-27) was isolated from asymptomatic goats. The present study describes the detection and molecular characterization of two additional distinct BTV-27 variants found in goats in Corsica in 2014 and 2015. The full coding genome of these two novel BTV-27 variants show high homology (90-93 % nucleotide/93-95 % amino acid) with the originally described BTV-27 isolate from Corsican goats in 2014. These three variants constitute the novel serotype BTV-27 ('BTV-27/FRA2014/v01 to v03'). Phylogenetic analyses with the 26 other established BTV serotypes revealed the closest relationship to BTV-25 (SWI2008/01) (80 % nucleotide/86 % amino acid) and to BTV-26 (KUW2010/02) (73-74 % nucleotide/80-81 % amino acid). However, highest sequence homologies between individual segments of BTV-27/FRA2014/v01-v03 with BTV-25 and BTV-26 vary. All three variants share the same segment 2 nucleotype with BTV-25. Neutralization assays of anti-BTV27/FRA2014/v01-v03 sera with a reassortant virus containing the outer capsid proteins of BTV-25 (BTV1VP2/VP5 BTV25) further confirmed that BTV-27 represents a distinct BTV serotype. Relationships between the variants and with BTV-25 and BTV-26, hypotheses about their origin, reassortment events and evolution are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Asymptomatic Diseases
  • Bluetongue / virology*
  • Bluetongue virus / classification*
  • Bluetongue virus / isolation & purification*
  • Cluster Analysis
  • France
  • Genome, Viral
  • Goats
  • Phylogeny
  • RNA, Viral / genetics
  • Sequence Analysis, DNA
  • Sequence Homology
  • Serogroup*

Substances

  • RNA, Viral