Ha Zhuo, Xie Chang-Zhan, Li Jin-Feng, Wen Shu-Bo, Zhang Ke-Long, Nan Fu-Long, Zhang He, Guo Ying-Cheng, Wang Wei, Lu Hui-Jun, Jin Ning-Yi
College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, China.
Institute of Military Veterinary medicine, Academy of Military Medical Sciences, Changchun, 130122, China.
BMC Vet Res. 2018 Oct 26;14(1):321. doi: 10.1186/s12917-018-1634-6.
First identified in the United States in 2016, porcine circovirus type 3 (PCV3) is a newly emerging porcine circovirus exhibiting a wide range of clinical syndromes, which may be associated with the pathogenicity observed in pigs.
The aim of this study was to identify and characterize the full genome sequence of PCV3 strains circulating in Northeast China. Herein, 105 lung samples isolated from sick pigs in Northeast China during 2018 were analyzed for PCV3. Using PCR, the total PCV3-positive rate was 33.3% (35/105), with rates of 17.8% (8/45), 66.7% (10/15), and 37.8% (17/45) in Heilongjiang, Jilin, and Liaoning province, respectively. Additionally, our findings showed that PCV3-positive samples had a high rate of co-infection with PCV2, PPV6, and PPV7. To study the evolution of the PCV3 in Northeast China, we sequenced the entire genome of 13 strains of PCV3. The results of phylogenetic analyses revealed that PCV3 could be divided into two clades, PCV3a and PCV3b. Interestingly, a G deletion at position 1072 was found in the 1999 nt genome of PCV3-CN2018LN-4 (MH277118). The G deletion terminated replicase protein translation and induced a truncated replicase protein.
These results contribute to the understanding of PCV3 molecular epidemiology and evolution in Northeast China. A new strain of PCV3 with truncated replicase protein was identified.
猪圆环病毒3型（PCV3）于2016年在美国首次被发现，是一种新出现的猪圆环病毒，表现出广泛的临床综合征，这可能与在猪身上观察到的致病性有关。
本研究的目的是鉴定和表征在中国东北地区流行的PCV3毒株的全基因组序列。在此，对2018年从中国东北地区患病猪分离的105份肺样本进行了PCV3分析。使用聚合酶链反应（PCR），PCV3总阳性率为33.3%（35/105），其中黑龙江省、吉林省和辽宁省的阳性率分别为17.8%（8/45）、66.7%（10/15）和37.8%（17/45）。此外，我们的研究结果表明，PCV3阳性样本与PCV2、PPV6和PPV7的共感染率很高。为了研究中国东北地区PCV3的进化，我们对13株PCV3的全基因组进行了测序。系统发育分析结果显示，PCV3可分为两个进化枝，即PCV3a和PCV3b。有趣的是，在PCV3-CN2018LN-4（MH277118）的1999 nt基因组中，在第1072位发现了一个G缺失。该G缺失终止了复制酶蛋白的翻译，并诱导产生了一个截短的复制酶蛋白。
这些结果有助于了解中国东北地区PCV3的分子流行病学和进化。鉴定出了一种具有截短复制酶蛋白的新型PCV3毒株。
