Insights into the epidemic characteristics and evolutionary history of the novel porcine circovirus type 3 in southern China
Insights into the epidemic characteristics and evolutionary history of the novel porcine circovirus type 3 in southern China
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DOI：
10.1111/tbed.12752
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发表时间：
2018-04-01
影响因子：
4.3
通讯作者：
Zhang, G.
中科院分区：
文献类型：
--
作者：
Fu, X.;Fang, B.;Zhang, G.
猪圆环病毒3型（Porcine circovirus type 3，PCV 3）是在美国、中国和波兰等地从猪源分离到的一种新的圆环病毒。这种新型圆环病毒与猪皮炎和肾病综合征（PDNS）、繁殖障碍和多系统炎症有关;此外，PCV 3对养猪业构成潜在威胁。在这项回顾性研究中，进行了系统发育分析，以解决这种新型圆环病毒的流行病学和进化动力学。PCV_3总阳性率为26.7%（76/285），近3年呈逐年上升趋势。在这些PCV 3阳性样本中，22.3%（17/76）合并感染了PCV 2。PCV 3可在多种标本类型中检出，且阳性率不同，死胎检出率最高。本研究还根据猪圆环病毒3型（PCV 3）cap蛋白上的两个氨基酸突变（A24 V和R27 K）将其分为3个进化枝（PCV 3a、PCV 3b和PCV 3c）。此外，PCV 3的起源大约是1966年，可能起源于蝙蝠相关的圆环病毒。结果表明，PCV 3在我国南方地区广泛分布，并已在猪群中流行近世纪。PCV 3已经进化成不同的进化枝引起的cap蛋白的突变，因此，进一步研究PCV 3的流行病学应该进行。
Porcine circovirus type 3 (PCV3) is a newly identified circovirus from swine in the USA, China and Poland. This novel circovirus has been associated with porcine dermatitis and nephropathy syndrome (PDNS), reproductive failure and multisystemic inflammation; moreover, PCV3 poses a potential threat to the swine industry. In this retrospective study, a phylogenetic analysis was conducted to address the epidemiology and evolutionary dynamics of this novel circovirus. The total positive sample rate of PCV3 was 26.7% (76/285) and has increased gradually over the past 3years. Of these PCV3-positive samples, 22.3% (17/76) were coinfected with PCV2. PCV3 can be detected in multiple sample types with different positive rates, and the positive rate is highest among stillborn. We also divide PCV3 into three clades (PCV3a, PCV3b and PCV3c) based on two amino acid mutations (A24V and R27K) on the cap protein in this study. In addition, the origin of PCV3 was approximately 1966 and may have originated from a bat-associated circovirus. Our results suggested that PCV3 is widely distributed in southern China and has been circulating in swine herds for nearly half a century. PCV3 has evolved into different clades caused by mutations in cap proteins; thus, further research on PCV3 epidemiology should be conducted.