Molecular Identification and Phylogenetic Analysis of Bovine Coronavirus Isolated from Diarrheal Yak (Bos grunniens) in Qinghai Tibetan Plateau Area, China.

Bovine coronavirus (BCV) is viral pathogen causing severe diarrhea, respiratory system infections, and winter dysentery in calves. In the present study, we detected BCV in diarrhea newborn yaks in Qinghai Tibetan Plateau Area (QTPA), China. The molecular identification and phylogenetic analysis of BCV were performed by using the hemagglutinin (HE) gene and nucleocapsid protein (N) gene. The two genes sequencing homology were 99.0% to the reference strains (China isolates). The phylogenetic trees were all composed of four major clusters, the QTPA strains always were located in the same cluster along with the China strains. The evolutionary rate of BCV HE gene and N gene was estimated to be 4.1805×10-4 and 1.3338×10-4 substitutions/site/year. This study is a timely investigation for BCV and provides the epidemiological information of this virus in QTPA. Therefore, further studies are needed to carry out to determine the prevalence of BCV infection in yaks and other calves of diarrheic disease, and the study highlights the urgency to develop effective measures to control BCV in QTPA of China. [ABSTRACT FROM AUTHOR]