Abstract：
Bufavirus (BuV) was first identified in feces from children with acute diarrhea, and a genetically related Canine bufavirus (CBuV) was first reported in Italy in 2018. In this study, through the investigation of CBuV in 622 anal swabs from dogs with diarrhea symptoms collected from various provinces in northern, central and eastern China during 2018-2022, 14 samples were detected to be positive. And 5 samples were from dogs co-infected with other canine diarrhea related viruses, which consist of CPV-2, CDV and CCoV. The complete genome sequences (4219 nt) of the fourteen strains were amplified and sequenced. Through comparative analysis with 51 reference BuV strains, six strains might recombinate from the CBuV strains (HUN/2012/22, CaBuV/9AS/2005/ITA and CaBuV/35/2016/ITA) in Hungary and Italy as the parents, and two genetic recombination events from various parents were predicted to occur on the BUV-422 strain. Combined analyzing the phylogenetic tree and sequence alignment, it was found that these CBuVs are highly conserved in the nonstructural protein NS1, but indeed various amino acid mutation sites in the capsid protein VP2, and even some amino acid sites coincide with putative protein plastic regions and potential epitopes. The BUV-422 and BUV-512 strains show sequential mutation sites identical to the divergent strains of CaBuV/9AS/2005/ITA and CaBuV/35/2016/ITA. This study would enrich the molecular data of CBuV in China and provide essential reference for the epidemiological research and vaccine development of CBuV in the future.
摘要：
Bufavirus（BuV）首次在急性腹泻儿童的粪便中发现，与基因相关的犬科病毒（CBuV）于2018年在意大利首次报道。在这项研究中,通过对从北方各省收集的622只腹泻症状犬的肛门拭子中的CBuV进行调查，2018-2022年，中国中部和东部地区检测到14个样本为阳性。5个样本来自与其他犬腹泻相关病毒共感染的狗，由CPV-2、CDV和CCoV组成。对14个菌株的全基因组序列(4219nt)进行扩增和测序。通过与51株参考BuV菌株的比较分析，六个菌株可能从匈牙利和意大利的CBuV菌株（HUN/2012/22，CaBuV/9AS/2005/ITA和CaBuV/35/2016/ITA）中重组为亲本，并且预测在BUV-422菌株上发生来自不同亲本的两个遗传重组事件。结合系统发育树和序列比对分析，发现这些CBuV在非结构蛋白NS1中是高度保守的,但确实在衣壳蛋白VP2中的各种氨基酸突变位点,甚至一些氨基酸位点与推定的蛋白塑性区和潜在表位一致。BUV-422和BUV-512菌株显示与CaBuV/9AS/2005/ITA和CaBuV/35/2016/ITA的不同菌株相同的连续突变位点。本研究将丰富我国CBuV的分子资料,为今后CBuV的流行病学研究和疫苗开发提供必要的参考。
