Phylogenetic analysis of Brazilian bovine viral diarrhea virus type 2 (BVDV-2) isolates: evidence for a subgenotype within BVDV-2

Abstract

Flores, Eduardo F.; Ridpath, Julia F.; Weiblen, Rudi; Vogel, Fernanda S. F.; and Gil, Laura H.V.G., "Phylogenetic analysis of Brazilian bovine viral diarrhea virus type 2 (BVDV-2) isolates: evidence for a subgenotype within BVDV-2" (2002 AbstractPhylogenetic analysis divides bovine viral diarrhea viruses (BVDV) into two different genotypes (BVDV1 and BVDV2). BVDV1 strains have been further subdivided into two to 11 subgenotypes. Phylogenetic analysis of BVDV2 isolates, however, has not been able to identify discrete subgenotypes. In this study, we identified six South American BVDV2 strains and one North American BVDV2 strain that cluster to a separate genetic group within BVDV2, thus representing a distinct subgenotype. The 5% untranslated region (UTR) sequence homology between these six strains and other BVDV2 from North America, Europe and Asia (81.7%) is lower than the homology used to segregate BVDV1 into BVDV1a and BVDV1b (83.6%). Most nucleotide differences observed between the two subgroups of BVDV2 were concentrated in two regions, which also harbor most of the differences seen between BVDV1a and BVDV1b. To determine if this segregation was real, an additional analysis was performed comparing NS2/3 sequences. Analysis of a conserved sequence located between nucleotides 6670 and 7186 of the NS2/3 coding region also segregated these isolates to a separate group. The sequence homology between the two subgroups (86.3%) was higher than the homology in the 5%UTR (81.7%), with mean sequence homologies of 91 and 87.2% within the proposed subgroups. In contrast to the 5%UTR, alignment of the NS2/3 sequences revealed nucleotide differences distributed across the region. These results demonstrate that BVDV2 isolates cluster to two genetically distinct subgroups within BVDV2. The differences in both the 5%UTR and NS2/3 are consistent and justify this segregation. We suggest that BVDV2 may thereafter be subgenotyped into BVDV2a and BVDV2b. The existence of subgroups within the BVDV2 genotype with genetic heterogeneity similar to that seen among BVDV1 subgroups argues against BVDV2 isolates arising from BVDV1 in a recent evolutionary event. Unless the evolutionary clocks for BVDV1 and BVDV2 isolates tick along at different rates, these results indicate that BVDV2 have existed as long as BVDV1.

Genetic characterization of Brazilian bovine viral diarrhea virus isolates by partial nucleotide sequencing of the 5'-UTR region

“…The genotypes and subgenotypes obtained in this study by partial nucleotide sequencing of 5'-UTR region (Fig.1, Table 2) confirm the results reported by other authors (Canal et al 1998, Flores et al 2002) that demonstrated the presence of BVDV-1 and BVDV-2 in various Brazilian states. The finding of subgenotypes BVDV-1a and BVDV-1b corroborates the data by Gil (1998) and Gil et al (1998).…”

“…These were further split into subgenotypes. To date,11 Genetic characterization of Brazilian bovine viral diarrhea virus Genetic characterization of Brazilian bovine viral diarrhea virus Genetic characterization of Brazilian bovine viral diarrhea virus Genetic characterization of Brazilian bovine viral diarrhea virus Genetic characterization of Brazilian bovine viral diarrhea virus isolates by partial nucleotide sequencing of the 5'-UTR region isolates by partial nucleotide sequencing of the 5'-UTR region isolates by partial nucleotide sequencing of the 5'-UTR region isolates by partial nucleotide sequencing of the 5'-UTR region isolates by partial nucleotide sequencing of the 5'-UTR region 1 subgenotypes of BVDV-1 (Vilcek et al 2001) and 2 subgenotypes of BVDV-2 (Flores et al 2002, Vilcek et al 2004) have been described.…”

“…Genotyping and subgenotyping of BVDV isolates have been accomplished mainly by the analysis of 5'-UTR region, since it is highly conserved among pestiviruses (Ridpath et al 1994, Sandvick et al 1997, Ridpath & Bolin 1998, Letellier et al 1999, Baule 2000, Flores et al 2002. The aim of the present study was to characterize bovine viral diarrhea virus isolates from cattle affected by different clinical syndromes in Brazil by partial nucleotide sequencing of the 5'-UTR region.…”

Genetic typing of bovine viral diarrhoea virus in cattle on Irish farms

“…In 2013 a BVDV-1q subgroup was isolated from a Bactrian camel in China (Gao et al 2013). There is less diversity between BVDV-2 isolates, with two subtypes, 2a and 2b, identified (Fulton et al 2005;Flores et al 2002), although, a third subtype, 2c has been proposed (Tajima et al 2001). This subtype was found to be the cause of a severely virulent BVD outbreak in Germany during 2012 and 2013 (Doll and Holsteg 2013).…”

“…The sub-division of both species of BVDV has been documented with the more genetically diverse, BVDV-1, containing 17 subgenotypes (Gao et al 2013). Two subgenotypes of BVDV-2 (BVDV type 2a and BVDV type 2b) have also been demonstrated in a number of studies (Fulton et al 2005;Flores et al 2002). A third subtype was tentatively suggested in 2001 (Tajima et al 2001) prior to a German outbreak of BVDV in 2012…”