Genoepidemiological Evaluation of Bovine viral diarrhea virus 2 Species Based on Secondary Structures in the 5' Untranslated Region

Abstract

ABSTRACT. Bovine viral diarrhea virus 2 (BVDV-2) strains demonstrated in cattle, sheep, and adventitious contaminants of biological products have been evaluated by the palindromic nucleotide substitutions (PNS) method at the three variable loci (V1, V2 and V3) in the 5' untranslated region (UTR), to determine their taxonomical status. Variation in conserved genomic sequences was used as parameter for epidemiological evaluation of the species in relation with geographical distribution, animal host and virulence. Four genotypes, BVDV-2a, BVDV-2b, BVDV-2c, and BVDV-2d have been identified within the species. Taxonomical segregation corresponded to geographical distribution of genotype variants. Genotype 2a was present worldwide, and was the only circulating also in sheep, in addition to cattle. Genotypes 2b, 2c and 2d were restricted to South America. Contamination of biological products was related to genotypes 2a and 2d. Genetic variation could be related with chronological diffusion of the BVDV-2 species variants in different geographic areas. Chronologically, the species emerged in North America in 1978, spreading in UK and Japan, continental Europe, South America and New Zealand. Correlation between clinical features related with isolation of BVDV-2 strains and genetic variation indicated that subgenotype 1, variant 4 of genotype 2a was related with hemorrhagic syndrome. These observations suggest that evaluation of genomic secondary structure, by identifying markers for expression of virus biological activities and species evolutionary history, may be applied as useful tool for epidemiological evaluation of the BVDV-2 species, and possibly for other species of the genus Pestivirus. KEY WORDS: BVDV-2, genoepidemiology, palindromic nucleotide substitutions, pestivirus.

Priming Cross-Protective Bovine Viral Diarrhea Virus-Specific Immunity Using Live-Vectored Mosaic Antigens

“…Two BVDV genotypes (type 1 and 2) are recognized according to serological and genetic relatedness [7]. The BVDV isolates circulating in the world are heterogeneous: BVDV genotype 1 (BVDV-1) is subdivided into a minimum of 12 sub-genotypes (BVDV1a, b, c.…l), whereas BVDV genotype 2 (BVDV-2) is classified into 4 subtypes, 2a-2d [8, 9]. The BVDV can also be divided into cytopathic and non-cytopathic biotypes (cpBVDV and ncpBVDV, respectively), based on their lytic effects on infected cells.…”

Species characterization in the genus Pestivirus according to palindromic nucleotide substitutions in the 5′-untranslated region

“…The determination of divergence between single strain sequences or genetic groups was obtained easily by comparing base pairing from aligned secondary structure sequences. This provided clear information such as the level of heterogeneity within a species, the genetic distance between species in terms of variation of base pairs in the secondary structure, or helping for the characterization and clustering of specific strains (Table 4) group BVDV-2A, constituting a separate genotype in addition to the four genotypes, BVDV-2a, BVDV2b, BVDV-2c, and BVDV-2d previously described (Giangaspero et al, 2008a). In the present study, the…”

Pestivirus Species Potential Adventitious Contaminants of Biological Products

“…Hyper-virulent strains 890 and CD-87 have been previously included in BVDV species in a separate cluster [55,57]. Correlation between clinical features related with isolation of BVDV-2 strains with genetic variation indicated that genotype 2a; subgenotype 1, variants 4 and 5 were related with hemorrhagic syndrome [53]. The hemorrhagic syndrome has been reported also in European cattle [24,36,[58][59][60].…”

“…Chronologically, the species emerged in North America in 1978, spreading in UK and Japan, continental Europe, South America and New Zealand. Correlation between clinical features related with isolation of BVDV-2 strains and genetic variation indicated specific genomic variants related with hemorrhagic syndrome [53]. The PNS procedure was useful also for the evaluation of the probable common origin of the BVDV-3 species spreading via commercialization of FBS batches from South America [35].…”

“…The PNS procedure [52] demonstrated the potential for its application to epidemiological investigations on pestiviruses, including traceability purposes, through the identification of genomic characters linked to the geographical origin, animal host and virulence of strains. Genetic variation could be related with diffusion of the BVDV-2 species variants in different geographic areas [53]. Chronologically, the species emerged in North America in 1978, spreading in UK and Japan, continental Europe, South America and New Zealand.…”