Yu Zuhua, Wang Wenjie, Yu Chuan, He Lei, Ding Ke, Shang Ke, Chen Songbiao
Laboratory of Functional Microbiology and Animal Health, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, China.
Luoyang Key Laboratory of Live Carrier Biomaterial and Animal Disease Prevention and Control, Luoyang 471003, China.
Vet Sci. 2024 Jun 30;11(7):292. doi: 10.3390/vetsci11070292.
-1, (FPV), and (CPV) continue to spread in companion animals all over the world. As a result, FPV and CPV underwent host-to-host transfer in carnivorous wild-animal hosts. Here, a total of 82 fecal samples of suspected cat FPV infections were collected from Henan Province from 2020 to 2022. The previously published full-length sequence primers of VP2 and NS1 genes were used to amplify the targeted genes of these samples, and the complete gene sequences of 11 VP2 and 21 NS1 samples were obtained and analyzed. Analysis showed that the amino acid homology of the VP2 and NS1 genes of these isolates was 96.1-100% and 97.6-100%, respectively. The phylogenetic results showed that the VP2 and NS1 genes of the local isolates were mainly concentrated in the G1 subgroup, while the vaccine strains were distributed in the G3 subgroup. Finally, F81 cells were inoculated with the local endemic isolate Luoyang-01 (FPV-LY strain for short) for virus amplification, purification, and titer determination, and the pathogenesis of FPV-LY was detected. After five generations of blind transmission in F81 cells, cells infected with FPV-LY displayed characteristic morphological changes, including a round, threadlike, and wrinkled appearance, indicative of viral infection. The virus titer associated with this cytopathic effect (CPE) was measured at 1.5 × 10 TCID/mL. Subsequent animal regression tests confirmed that the virus titer of the PFV-LY isolate remained at 1.5 × 10 TCID/mL, indicating its highly pathogenic nature. Cats exposed to the virus exhibited typical clinical symptoms and pathological changes, ultimately succumbing to the infection. These results suggest that the gene mutation rate of FPV is increasing, resulting in a complex pattern of gene evolution in terms of host preference, geographical selection, and novel genetic variants. The data also indicate that continuous molecular epidemiological surveillance is required to understand the genetic diversity of FPV isolates.
-1，猫泛白细胞减少症病毒（FPV）和犬细小病毒（CPV）继续在世界各地的伴侣动物中传播。因此，FPV和CPV在食肉野生动物宿主中发生了宿主间转移。在此，2020年至2022年期间从河南省共收集了82份疑似猫FPV感染的粪便样本。使用先前发表的VP2和NS1基因全长序列引物扩增这些样本的靶向基因，获得并分析了11个VP2样本和21个NS1样本的完整基因序列。分析表明，这些分离株的VP2和NS1基因的氨基酸同源性分别为96.1% - 100%和97.6% - 100%。系统发育结果表明，本地分离株的VP2和NS1基因主要集中在G1亚组，而疫苗株分布在G3亚组。最后，用本地流行分离株洛阳 - 01（简称FPV - LY株）接种F81细胞进行病毒扩增、纯化和滴度测定，并检测FPV - LY的致病性。在F81细胞中连续盲传五代后，感染FPV - LY的细胞出现特征性形态变化，包括圆形、丝状和皱缩外观，表明病毒感染。与这种细胞病变效应（CPE）相关的病毒滴度测定为1.5×10⁷TCID₅₀/mL。随后的动物回归试验证实，PFV - LY分离株的病毒滴度保持在1.5×10⁷TCID₅₀/mL，表明其具有高致病性。接触该病毒的猫表现出典型的临床症状和病理变化，最终死于感染。这些结果表明，FPV的基因突变率正在增加，导致在宿主偏好、地理选择和新的遗传变异方面出现复杂的基因进化模式。数据还表明，需要持续进行分子流行病学监测以了解FPV分离株的遗传多样性。
