Increased genetic diversity of BVDV-1: recent findings and implications thereof

Abstract

Sequence-based genotyping was recently used to distinguish between the BVDV-1 and BVDV-2 species of the bovine viral diarrhoea virus (BVDV). Quite recently, a new putative species, BVDV-3, was also detected. The phylogenetic analysis of the 5'-untranslated region (UTR) and Npro region has revealed at least 17 distinct subtypes for BVDV-1 to date. The aim of this study was to further investigate the genetic heterogeneity of BVDV-1 in Italy, by analysing 173 virus sequences from isolates collected over an 18-year period (1997-2014). Viral RNA was extracted from the original biological samples identified as BVDV-1-positive. Reverse transcription (RT) and polymerase chain reaction (PCR) assays targeting a 288-base pair (bp) region of the 5'-UTR and a 428-bp region encoding the autoprotease Npro were performed, and the RT-PCR products were sequenced. The phylogenetic analysis of the 5'-UTR and Npro sequences re-confirmed the circulation of ten out of eleven subtypes previously discovered in Italy. Interestingly, four isolates differed significantly from all of the bovine pestiviruses identified so far, thereby providing evidence for the circulation of three novel subtypes that have not been documented so far. The growing number of reports on BVDV-1 heterogeneity, including the recent findings reported herein, raises concern related to the emergence and spread of new BVDV variants, with possible implications for animal health and disease control. This global issue needs to be addressed with the highest priority.

Phylogeography, phylodynamics and transmission chains of bovine viral diarrhea virus subtype 1f in Northern Italy

“…Recent studies on the phylogenetics of BVDV in Italy showed a high heterogeneity of subtypes, reporting at least 17 distinct subtypes (Giammarioli et al, 2015). Previous studies (Luzzago et al, 2014) showed that BVDV-1b and 1e had the highest prevalence and a wide spatio-temporal dispersion, conversely to BVDV-1f, characterized by a low prevalence in a restricted area, that is Northern Italy.…”

“…To date, BVDV is classified into two species, BVDV-1 and BVDV-2, further divided into 20 subtypes of BVDV-1 (1a-1t) (Giammarioli et al, 2015) and three subtypes for BVDV-2 (Beer et al, 2002;Tajima et al, 2001;Vilček et al, 2004). The genome codes for a single polyprotein that is cleaved by both cellular and viral proteases into structural (C, E rns , E1, E2) and non-structural (Npro, p7, NS2-3, NS4A, NS4B, NS5A, NS5B) proteins.…”

Bovine viral diarrhea virus (BVDV) genetic diversity in Spain: A review

“…Both are capable of causing acute and persistent infections. Moreover, to the date at least 21 genetic groups of BVDV-1 (named BVDV-1a to BVDV-1r) and four groups in BVDV-2 (BVDV-2a to BVDV-2d) have been described (Alpay & Weşilag, 2015;Deng et al, 2015;Giammarioli et al, 2015).…”

Circulation of bovine viral diarrhea virus – 1 (BVDV-1) in dairy cattle and buffalo farms in Ismailia Province, Egypt

“…Recently, a third BVDV species, called HoBi-like virus or BVDV3, was reported [4]. BVDV-1 is classified by genetic analysis into about 20 subtypes (1a-1t) [5][6][7][8][9][10] and BVDV-2 into three subtypes (2a-2c) [11][12][13]. BVDV subtyping is useful in molecular epidemiological studies, vaccine development and tracing the origin of emerging viruses [14].…”