NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam.
Animal and Plant Quarantine Agency, Gimcheon, Gyeongsangbukdo, Republic of Korea.
Vet Med Sci. 2020 Aug;6(3):535-542. doi: 10.1002/vms3.256. Epub 2020 Mar 11.
Porcine epidemic diarrhea (PED) is a highly contagious swine disease caused by the PED virus (PEDV), which is a member of the family Coronaviridae. Since the first outbreaks in Belgium and the United Kingdom were reported in 1971, PED has spread throughout many countries around the world and causing significant economic loss. This study was conducted to investigate the recent distribution of PEDV strains in Vietnam during the 2015-2016 seasons.
A total of 30 PED-specific PCR-positive intestinal and faecal samples were collected from unvaccinated piglets in Vietnam during the 2015-2016 seasons. The full length of the spike (S) gene of these PEDV strains were analysed to determine their phylogeny and genetic relationship with other available PEDV strains globally.
Phylogenetic analysis of the complete S gene sequences revealed that the 28 Vietnamese PEDV strains collected in the northern and central regions clustered in the G2 group (both G2a and G2b sub-groups), while the other 2 PEDV strains (HUA-PED176 and HUA-PED254) collected in the southern region were clustered in the G1/G1b group/sub-group. The nucleotide (nt) and deduced amino acid (aa) analyses based on the complete S gene sequences showed that the Vietnamese PEDV strains were closely related to each other, sharing nt and aa homology of 93.2%-99.9% and 92.6%-99.9%, respectively. The N-glycosylation patterns and mutations in the antigenic region were observed in Vietnamese PEDV strains.
This study provides, for the first time, up-to-date information on viral circulation and genetic distribution, as well as evidence to assist in the development of effective PEDV vaccines in Vietnam.
猪流行性腹泻（PED）是一种由猪流行性腹泻病毒（PEDV）引起的高度传染性猪病，该病毒属于冠状病毒科。自 1971 年首次在比利时和英国报告疫情以来，PED 已在世界许多国家传播，并造成重大经济损失。本研究旨在调查 2015-2016 年越南 PEDV 株的近期分布情况。
本研究共收集了 30 份来自越南未接种疫苗仔猪的 PED 特异性 PCR 阳性肠和粪便样本。对这些 PEDV 株的全长刺突（S）基因进行分析，以确定其与全球其他可用 PEDV 株的系统发育和遗传关系。
对完整 S 基因序列的系统发育分析显示，在北部和中部地区采集的 28 株越南 PEDV 株聚集在 G2 组（G2a 和 G2b 亚组），而在南部地区采集的另外 2 株 PEDV 株（HUA-PED176 和 HUA-PED254）聚集在 G1/G1b 组/亚组。基于完整 S 基因序列的核苷酸（nt）和推导的氨基酸（aa）分析表明，越南 PEDV 株彼此密切相关，nt 和 aa 同源性分别为 93.2%-99.9%和 92.6%-99.9%。在越南 PEDV 株中观察到 N-糖基化模式和抗原区的突变。
本研究首次提供了关于病毒循环和遗传分布的最新信息，并为越南开发有效的 PEDV 疫苗提供了证据。
