School of Life Sciences and Engineering, Foshan University, Foshan, 528000, China.
Jilin Wildlife Rescue and Rehabilitation Center, Forestry Department of Jilin Province, Changchun, 130122, China.
BMC Vet Res. 2020 Mar 5;16(1):80. doi: 10.1186/s12917-020-02301-x.
Duck circovirus (DuCV) is a potential immunosuppressive virus that causes feather disorders in young ducks. In this study, DuCV obtained from various species of ducks was investigated by polymerase chain reaction (PCR) in southern and southwestern China (Guangdong, Guangxi and Yunnan provinces) from 2018 to 2019.
A total of 848 bursa samples were collected from dead Mulard, Cherry Valley Pekin, Muscovy and Mallard ducks from duck farms. The positivity rate of DuCV in the total sample was approximately 36.91%. We found that the prevalence of DuCV in Yunnan (43.09%) was higher than those in Guangxi (34.38%) and Guangdong (34.4%). However, the positivity rates of DuCV in the four duck species were not significantly different (P > 0.05). Nineteen randomly selected complete viral genomes were sequenced. The complete genomes of the DuCV were 1987 to 1995 nt in length, and were 81.7-99.3% homologous to the other 57 sequences in GenBank. Phylogenetic analyses based on the complete genomes of 76 DuCVs showed that the 19 novel DuCV sequences from Guangdong and Guangxi provinces mainly belonged to the DuCV-1 and DuCV-2 genetic groups, respectively. However, the two genotype groups coexisted in Yunnan Province. In addition, recombination analysis showed putative recombination sites in 3 strains in Yunnan that originated from strains Guangdong and Guangxi. Interestingly, the epidemiological investigation showed that Mulard ducks, Cherry Valley Pekin ducks and Muscovy ducks more than 4 weeks old were more susceptible to infection with the novel DuCV than ducks less than 4 weeks old.
These data provide insight into the molecular epidemiology and genetic diversity of DuCVs circulating in southern and southwestern China for the first time.
鸭圆环病毒（DuCV）是一种潜在的免疫抑制性病毒，可导致雏鸭出现羽毛紊乱。本研究采用聚合酶链反应（PCR）方法，于 2018 年至 2019 年在华南和西南地区（广东、广西和云南）对来自不同鸭种的 DuCV 进行了检测。
从鸭场死亡的杂交瘤鸭、樱桃谷鸭、麝香鸭和绿头鸭中采集了 848 份法氏囊样本。总样本中 DuCV 的阳性率约为 36.91%。我们发现云南（43.09%）的 DuCV 流行率高于广西（34.38%）和广东（34.4%）。然而，四种鸭种的 DuCV 阳性率无显著差异（P＞0.05）。随机选择了 19 个完整的病毒基因组进行测序。DuCV 的完整基因组长度为 1987 至 1995 个核苷酸，与 GenBank 中其他 57 个序列的同源性为 81.7-99.3%。基于 76 株 DuCV 完整基因组的系统进化分析表明，广东和广西的 19 株新的 DuCV 序列主要属于 DuCV-1 和 DuCV-2 遗传群，而云南的两个基因型群同时存在。此外，重组分析显示云南的 3 株分离株存在潜在的重组位点，这些分离株来源于广东和广西的分离株。有趣的是，流行病学调查显示，4 周龄以上的杂交瘤鸭、樱桃谷鸭和麝香鸭比 4 周龄以下的鸭更容易感染新型 DuCV。
这些数据首次提供了中国南方和西南部流行的 DuCV 分子流行病学和遗传多样性的信息。
