Molecular characterization of Brazilian wild-type strains of bovine respiratory syncytial virus reveals genetic diversity and a putative new subgroup of the virus

Abstract

2020) Molecular characterization of Brazilian wild-type strains of bovine respiratory syncytial virus reveals genetic diversity and a putative new subgroup of the virus, Veterinary Quarterly, 40:1, 83-96, ABSTRACT Background: Bovine orthopneumovirus, formerly known as bovine respiratory syncytial virus (BRSV), is frequently associated with bovine respiratory disease (BRD). Aim: To perform the molecular characterization of the G and F proteins of Brazilian wildtype BRSV strains derived from bovine respiratory infections in both beef and dairy cattle. Materials and Methods: Ten BRSV strains derived from a dairy heifer rearing unit (n ¼ 3) in 2011 and steers of three other feedlots (n ¼ 7) in 2014 and 2015 were analyzed. For the BRSV G and F partial gene amplifications, RT-nested-PCR assays were performed with sequencing in both directions with forward and reverse primers used. Results: The G gene-based analysis revealed that two strains were highly similar to the BRSV sequences representative of subgroup III, including the Bayovac vaccine strain. However, the remaining seven Brazilian BRSV strains were diverse when compared with strains representative of the BRSV I to VIII subgroups. The central hydrophobic region of the Brazilian BRSV G gene showed the replacement of conserved cysteines and other residues of importance to antibody reactivity. The deduced F gene amino acid sequences from the Brazilian BRSV strains showed changes that were absent in the representative sequences of the known subgroups. Viral isolation on the nasopharyngeal swab suspensions failed to isolate BRSV. Conclusion: Results suggest that these strains represent a putative new subgroup of BRSV with mutations observed in the immunodominant region of the G protein. However, further studies on these Brazilian BRSV strains should be performed to establish their pathogenic potential. ARTICLE HISTORY

Circulation of Indigenous Bovine Respiratory Syncytial Virus Strains in Turkish Cattle: The First Isolation and Molecular Characterization

“…It is a protein that is central to virus entry into cells, as well as being responsible for the fusion of infected cells with adjacent cells, resulting in the formation of large multinucleated syncytia [ 28 ]. Furthermore, the F gene is also a highly conserved region of the BRSV genome compared with the G gene [ 11 ]. The results of partial sequencing of the F gene of the current three isolates revealed that they were 100% identical to each other and were closely related to the sequence submitted (KY499619) from Turkey by Timurkan et al [ 3 ].…”

“…Phylogenetic analysis based on both F and G proteins has led to a subdivision of BRSV into eight subgroups, denoted I–VIII [ 7 , 9 , 10 , 11 ]. These subgroups tend to separate geographically; subgroup I BRSV strains are typically isolated in the UK and Switzerland, whereas subgroup II normally includes strains from the Netherlands, Denmark, Belgium, France, and Japan [ 9 , 12 ].…”

“…Subgroups VII and VIII are a recent addition and are predominantly seen in Europe, particularly in Italy and Croatia [ 7 , 10 ]. In addition, a putative new BRSV subgroup, tentatively named subgroup IX, has been proposed, in order to classify recent strains isolated from Brazil, which have mutations in the immunodominant region of the G protein [ 11 ].…”

Isolation, identification, and phylogenetic analysis of subgroup III strain of bovine respiratory syncytial virus contributed to outbreak of acute respiratory disease among cattle in Northeast China

“…Similar to the human respiratory syncytial virus, BRSV belongs to the genus Orthopneumovirus of the Pneumoviridae family and harbors an approximately 15 k bp-long single-stranded negative-sense RNA genome [ 7 , 8 ], which encodes 11 proteins including three surface glycoproteins (glycoprotein G, small hydrophobic protein SH, and fusion protein F), nucleoprotein (N), viral RNA-dependent polymerase protein (L), phosphoprotein (P), matrix protein (M), transcriptional anti-termination factor M2-1, RNA regulatory protein M2-2, and two nonstructural proteins, namely, NS1 and NS2 [ 9 , 10 ]. Since the 1990s, molecular-genetic characterization studies have revealed that the emergence of new variants manifests a geographic correlation [ 6 ].…”

Sequence and unique phylogeny of G genes of bovine respiratory syncytial viruses circulating in Japan

“…13 Several studies have used G sequences, and one study has used both G and F sequences to analyze genetic evolution of BRSV; these studies have shown that BRSV strains can be classified into 9 genetic subgroups, I–IX. 1,4,9,12 We used the G gene, in combination with information on the F gene, to analyze Japanese BRSV strains to obtain molecular epidemiologic characterization of the virus to provide genetic information for vaccine-based disease control.…”