重庆肉牛腹泻相关病毒的检测及遗传进化分析

为了解重庆市肉牛病毒性腹泻的病原流行情况，本研究对重庆市8个肉牛养殖场的81份腹泻粪便样本中牛病毒性腹泻-黏膜病病毒（bovine viral diarrhea virus，BVDV）、牛冠状病毒（bovine coronavirus，BCV）、牛轮状病毒（bovine rotavirus，BRV）和牛星状病毒（bovine astrovirus，BAstV）4种致腹泻病毒进行了RT-PCR检测，对PCR产物进行测序，用Mega 6.0软件进行系统发育分析。结果显示，BRV、BAstV和BVDV检出率分别为66.7%、8.6%和7.4%，BCV未检出。遗传进化分析结果表明，测序的5个BRV单独聚为一小支，与GenBank中其他VP6序列有明显的遗传距离；BVDV与中国株和丹麦株聚为一支，遗传关系最近；5个BAstV单独聚为一支，与中国香港株遗传关系最近，但仍有明显的遗传距离。本试验结果表明，重庆地区肉牛腹泻主要发生在6月龄以下犊牛，BRV是该地区肉牛腹泻的重要原因，BRV、BAstV和BVDV 3种病毒的遗传多样性值得进一步关注。

Detection and Genetic Evolution of Diarrhea-related Viruses in Chongqing Beef Cattle

In order to investigate the pathogen prevalence of bovine viral diarrhea in Chongqing, this study carried out an investigation of bovine viral diarrhea virus (BVDV), bovine coronavirus (BCV), bovine rotavirus (BRV) and bovine astrovirus (BAstV) on a total of 81 diarrhea samples of beef cattle which were collected from Chongqing by RT-PCR. After the PCR products were sequenced, phylogenetic analysis was performed with Mega 6.0 software. From 81 samples, the positive rate of BRV,BAstV and BVDV were 66.7%,8.6% and 7.4%, respectively,BCV was not detected.Phylogenetic analysis showed that 5 strains of BRV sequences were clustered into a small branch, which had significant genetic distance with other VP6 sequences in GenBank; 5 strains of BVDV, Chinese and Denmark strains were clustered into one branch,genetic relationship were close; 5 strains of BAstV clustered into a branch with Hongkong strain, but there was still an obvious genetic distance. The result showed that calves under the age of half year were the main group of beef cattle with diarrhea in Chongqing. BRV was an important cause of diarrhea in Chongqing, the genetic diversity of BRV,BAstV and BVDV could be reference to further concern.