Detection and Genomic Characterization of Bovine Rhinitis Virus in China

SIMPLE SUMMARY: Bovine rhinitis virus (BRV) is an important pathogen causing bovine respiratory disease complex (BRDC) and it can be divided into two genotypes—bovine rhinitis A virus (BRAV) and bovine rhinitis B virus (BRBV). However, knowledge about the prevalence and molecular information of BRV in China is still limited. The purpose of this study was to investigate the prevalence and molecular characteristics of BRV in beef cattle with BRDC syndrome in China, and the results confirmed the circulation of BRAV and BRBV. The genomic sequences of BRAVs in this study showed an independent evolutionary trend while BRBVs exhibited significant genetic heterogeneity, and the recombination patterns of both types of BRVs were distinct from what was observed in a previous study. The present study reported the presence and prevalence of BRAV in China, providing recommendations for prevention and control of BRDC, and contributed to a better understanding of the evolution of BRV. ABSTRACT: Bovine rhinitis virus (BRV) is an etiological agent of bovine respiratory disease complex (BRDC) and can be divided into two genotypes—bovine rhinitis A virus (BRAV) and bovine rhinitis B virus (BRBV). However, knowledge about the prevalence and molecular information of BRV in China is still limited. In this study, 163 deep nasal swabs collected from bovines with BRDC syndrome on 16 farms across nine provinces of China were tested for BRAV and BRBV by a duplex real-time RT-PCR assay. The results showed that 28.22% (46/163) of the samples were BRV-positive, and the positive rates were 22.09% (36/163) for BRAV and 9.2% (15/163) for BRBV. The co-circulation of both BRV genotypes was observed on two farms. Furthermore, five near-complete BRV genomes, including three BRAVs and two BRBVs, were obtained. The phylogenetic analysis showed that the three obtained BRAVs were phylogenetically independent, while the two BRBVs exhibited significant genetic heterogeneity. Recombination analysis revealed that three BRAVs and one BRBV strain obtained in this study were recombinants. The present study confirmed the presence and prevalence of BRAV in China, and it found that both types of BRV are circulating in beef cattle, which contributes to a better understanding of the prevalence and molecular characteristics of BRV.