Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China.
Shanghai Key laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai JiaoTong University, Shanghai 200240, PR China.
Infect Genet Evol. 2018 Nov;65:425-429. doi: 10.1016/j.meegid.2018.08.029. Epub 2018 Aug 31.
In this study, a virulent systemic (VS) feline calicivirus (FCV) strain, SH, was isolated from a household cat with severe systemic clinical signs, and its full-length genome was determined and analyzed. Through immunofluorescence assays (IFA) and western blotting assays, we found that FCV SH strain, like other isolates, can stably proliferate in Crandell feline kidney (CRFK) cells. Moreover, the typical morphology of FCV particles, with a diameter of about 35 nm, was observed using electron microscopy. The full-length genome of FCV strain SH was sequenced and determined to be 7704 nucleotides (nt) in length with a 5'-terminal untranslated region (UTR) of 19 nt and a 3'-terminal UTR of 67 nt. Three open reading frames (ORF1, ORF2, and ORF 3) were found within the genome, coding for a polypeptide, a capsid precursor (VP1) and a minor structural protein (VP2), respectively. Amino acid sequence comparison revealed diversity (from 82.2% to 88.5% homology) between the VP1 protein sequences of the SH/14 isolate and those of 33 reference isolates from different regions. Phylogenetic analyses using alignments of VP1 protein sequences showed that the SH/14 isolate shares the highest sequence homology with the reported VS-FCV George strain (88.5%), and is located in the same clade as other reported VS-FCV isolates, indicating that the FCV SH/14 strain is a VS-FCV isolate. However, the SH/14 strain does not belong to the same lineage as most other Chinese FCV isolates, suggesting that, in China, a very large geographical entity, the virulent systemic FCV might has emerged.
在这项研究中，从一只患有严重全身性临床症状的家猫中分离到一株强毒系统性（VS）猫杯状病毒（FCV）SH 株，并测定和分析了其全长基因组。通过免疫荧光试验（IFA）和 Western blot 试验，我们发现 FCV SH 株与其他分离株一样，能够在猫肾细胞（CRFK）中稳定增殖。此外，使用电子显微镜观察到 FCV 粒子的典型形态，直径约为 35nm。FCV 株 SH 的全长基因组测序并确定为 7704 个核苷酸（nt），5'-端非翻译区（UTR）为 19nt，3'-UTR 为 67nt。在基因组内发现三个开放阅读框（ORF1、ORF2 和 ORF3），分别编码一个多肽、衣壳前体（VP1）和一个次要结构蛋白（VP2）。VP1 蛋白序列的氨基酸序列比较显示，SH/14 分离株与来自不同地区的 33 个参考分离株的 VP1 蛋白序列具有多样性（同源性为 82.2%至 88.5%）。使用 VP1 蛋白序列比对进行的系统发育分析表明，SH/14 分离株与报道的 VS-FCV George 株（88.5%）具有最高的序列同源性，并且与其他报道的 VS-FCV 分离株位于同一分支，表明 FCV SH/14 株是一株 VS-FCV 分离株。然而，SH/14 株与大多数其他中国 FCV 分离株不属于同一谱系，这表明在中国这个非常大的地理实体中，强毒系统性 FCV 可能已经出现。
