Gan Junji, Tang Ye, Lv Haifeng, Xiong Wenbin, Tian Xiaoyan
Animal Infectious Disease Laboratory, School of Veterinary Medicine, Yangzhou University, Yangzhou, China.
Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China.
Anim Dis. 2021;1(1):10. doi: 10.1186/s44149-021-00013-9. Epub 2021 Jul 19.
Canine coronavirus (CCoV), a member of the genus , is an enveloped, single-stranded positive-sense RNA virus that responsible for gastroenteritis in dogs. In this study, two CCoV isolates were successfully propagated from 53 CCoV-positive clinical specimens by serial passaging in A-72 cells. These two strains, CCoV JS1706 and CCoV JS1712, caused cytopathic effects in A-72 cells. The sizes of virus plaque formed by them differed in early passages. Electron microscopy revealed a large quantity of typical coronavirus particles with 80-120 nm in diameter in cell culture media and cytoplasm of infected cells, in which they appeared as inclusion bodies. RT-PCR analysis of gene indicated that these two isolates were belonged to CCoV IIa subtype. Homology of RdRp, S, M and N proteins between the two strains were 100, 99.6, 99.2 and 100.0%, respectively, whereas they were 99.4-100%, 83.1-95.2%, 88.5-99.2% and 91.9-99.7% identity compared to CCoV II reference strains. Phylogenetic analysis of RdRp, S, M and N protein showed that they were closely related to CCoV II strains. These two subtype IIa isolates will be useful for evaluating the pathogenesis and evolution of CCoV and for developing diagnostic reagents and vaccines.
犬冠状病毒(CCoV)是 属的成员,是一种有包膜的单链正链RNA病毒,可引起犬的肠胃炎。在本研究中,通过在A - 72细胞中连续传代,成功从53份CCoV阳性临床标本中培养出两株CCoV分离株。这两株毒株CCoV JS1706和CCoV JS1712在A - 72细胞中引起细胞病变效应。它们在早期传代时形成的病毒蚀斑大小不同。电子显微镜检查显示,在细胞培养基和感染细胞的细胞质中存在大量直径为80 - 120 nm的典型冠状病毒颗粒,它们以包涵体的形式出现。对 基因的RT - PCR分析表明,这两株分离株属于CCoV IIa亚型。两株毒株之间的RdRp、S、M和N蛋白的同源性分别为100%、99.6%、99.2%和100.0%,而与CCoV II参考毒株相比,它们的同一性分别为99.4 - 100%、83.1 - 95.2%、88.5 - 99.2%和91.9 - 99.7%。对RdRp、S、M和N蛋白的系统发育分析表明,它们与CCoV II毒株密切相关。这两株IIa亚型分离株将有助于评估CCoV的发病机制和进化,以及开发诊断试剂和疫苗。