College of Animal & Veterinary Sciences, Southwest Minzu University, Chengdu, China.
Transbound Emerg Dis. 2022 Sep;69(5):e2913-e2925. doi: 10.1111/tbed.14641. Epub 2022 Jul 9.
Cats are susceptible to panleukopenia virus (FPV) and canine parvovirus type 2 (CPV-2) infection. FPV has been recognized as relatively conservative in genetic evolution compared to CPV-2, but information regarding FPV variations in cats is still limited. The aim of this study was to investigate the molecular prevalence of FPV and CPV-2 variants among cats in China. From April 2019 to December 2021, 193 diarrheal faecal samples of cats were collected from Southwest China and 127 (65.80%) samples tested positive to Carnivore protoparvovirus 1. FPV, CPV-2 and some their genomic variants were identified from positive samples, indicating a heterogeneous Carnivore protoparvovirus 1 circulation in the cat population in China. Among FPV strains, an A91S FPV mutant reached the detection rate of 39.37%, which showed that this FPV genomic variant has been prevalent in the tested cats. Moreover, 7 strains of A91S FPV variants were isolated and purified successfully using F81 cells, and the genomes were sequenced. Phylogenetic trees based on the nearly complete genomic sequences, VP2 and NS1 nucleotide sequences showed that the A91S FPV variants were located in the FPV clade, but all clustered into a separate branch. Structural prediction showed that A91S mutation in VP2 protein extended the random coil of aa residues from 92-95 to 91-95. Moreover, the analysis of all complete VP2 sequences of FPV and CPV-2 available in the GenBank database revealed that the A91S FPV variant has been prevalent in China since 2017 and has reported in four other countries in cats. Thus, our study revealed that heterogeneous Carnivore protoparvovirus 1 are circulating in the cat population in China, and first reported the prevalence and genomic characteristics of the A91S FPV variant, which contributed to a better understanding of the molecular prevalence and genetic evolution of FPV in cats.
猫易感染细小病毒（FPV）和犬细小病毒 2 型（CPV-2）。与 CPV-2 相比，FPV 在遗传进化方面被认为相对保守，但关于猫中 FPV 变异的信息仍然有限。本研究旨在调查中国猫中 FPV 和 CPV-2 变异株的分子流行情况。2019 年 4 月至 2021 年 12 月，从中国西南地区采集了 193 份腹泻粪便猫样本，其中 127 份（65.80%）样本对 Carnivore protoparvovirus 1 呈阳性。从阳性样本中鉴定出 FPV、CPV-2 和它们的一些基因组变异株，表明在中国猫群中存在异质性 Carnivore protoparvovirus 1 循环。在 FPV 株中，A91S FPV 突变株的检出率达到 39.37%，表明该 FPV 基因组变异株已在检测猫中流行。此外，使用 F81 细胞成功分离和纯化了 7 株 A91S FPV 变异株，并对其基因组进行了测序。基于近完整基因组序列、VP2 和 NS1 核苷酸序列构建的系统进化树显示，A91S FPV 变异株位于 FPV 分支，但均聚为一个单独的分支。结构预测表明，VP2 蛋白中的 A91S 突变使 aa 残基的无规卷曲从 92-95 延伸至 91-95。此外，对 GenBank 数据库中所有可用的 FPV 和 CPV-2 的完整 VP2 序列进行分析表明，A91S FPV 变异株自 2017 年以来在中国流行，并在其他四个国家的猫中报告。因此，本研究表明，异质性 Carnivore protoparvovirus 1 在我国猫群中流行，首次报道了 A91S FPV 变异株的流行情况和基因组特征，有助于更好地了解猫中 FPV 的分子流行情况和遗传进化。
