title: Genetic diversity of ruminant Pestivirus strains collected in Northern Ireland between 1999 and 2011 and the role of live ruminant imports.
abstract: BACKGROUND
  The genus pestivirus within the family Flaviviridae includes bovine viral diarrhoea virus (BVDV) types 1 and 2, border disease virus (BDV) and classical swine fever virus. The two recognised genotypes of BVDV are divided into subtypes based on phylogenetic analysis, namely a-p for BVDV-1 and a-c for BVDV-2.
  
  
  METHODS
  Three studies were conducted to investigate the phylogenetic diversity of pestiviruses present in Northern Ireland. Firstly, pestiviruses in 152 serum samples that had previously tested positive for BVDV between 1999 and 2008 were genotyped with a RT-PCR assay. Secondly, the genetic heterogeneity of pestiviruses from 91 serum samples collected between 2008 and 2011 was investigated by phylogenetic analysis of a 288 base pair portion of the 5' untranslated region (UTR). Finally, blood samples from 839 bovine and 4,437 ovine animals imported in 2010 and 2011 were tested for pestiviral RNA. Analysis of animal movement data alongside the phylogenetic analysis of the strains was carried out to identify any links between isolates and animal movement.
  
  
  RESULTS
  No BVDV-2 strains were detected. All of the 152 samples in the first study were genotyped as BVDV-1. Phylogenetic analysis indicated that the predominant subtype circulating was BVDV-1a (86 samples out of 91). The remaining five samples clustered close to reference strains in subtype BVDV-1b. Out of the imported animals, 18 bovine samples tested positive and 8 inconclusive (Ct ≥36), while all ovine samples were negative. Eight sequences were obtained and were defined as BVDV-1b. Analysis of movement data between herds failed to find links between herds where BVDV-1b was detected.
  
  
  CONCLUSIONS
  Given that only BVDV-1a was detected in samples collected between 1968 and 1999, this study suggests that at least one new subtype has been introduced to Northern Ireland between 1999 and 2011 and highlights the potential for importation of cattle to introduce new strains.
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Belfast, UK.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Guelbenzu-Gonzalo
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Belfast, UK.
authors.forename: Lynsey
authors.initials: L
authors.lastname: Cooper
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Belfast, UK.
authors.forename: Craig
authors.initials: C
authors.lastname: Brown
authors.affiliation: Agri-Food and Biosciences Institute, Veterinary Sciences Division, Belfast, UK.
authors.forename: Sam
authors.initials: S
authors.lastname: Leinster
authors.affiliation: Department of Agriculture, Food and the Marine, Central Veterinary Research Laboratory, Backweston, Ireland.
authors.forename: Ronan
authors.initials: R
authors.lastname: O'Neill
authors.affiliation: Department of Agriculture, Environment and Rural Affairs of Northern Ireland, Belfast, UK.
authors.forename: Liam
authors.initials: L
authors.lastname: Doyle
authors.affiliation: Animal Health Ireland, Carrick-on-Shannon, Ireland.
authors.forename: David A
authors.initials: DA
authors.lastname: Graham
keywords: 5’untranslated region; Bovine viral diarrhoea virus; Importation; Phylogenetic analysis