Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture and Rural Affairs, Nanjing, China.
College of Animal Science, Tibet Agricultural and Animal Husbandry University, Provincial Key Laboratory of Tibet Plateau Animal Epidemic Disease Research, LinZhi, China.
Vet Med Sci. 2022 Nov;8(6):2553-2561. doi: 10.1002/vms3.911. Epub 2022 Sep 1.
Porcine circovirus-like virus P1, like porcine circovirus type 2 (PCV2), is a potential pathogen of post-weaning multisystemic wasting syndrome in swine. Yaks are a valuable species and an iconic symbol of the Tibet Plateau which is the highest and largest plateau in the world. In this study, a total of 105 yak diarrheal samples, collected from 13 farms in Linzhi in the Tibet Plateau from January 2019 to December 2021, that were screened for P1 and PCV2 by polymerase chain reaction, 10.48% (n = 11) were positive for P1, 4.76% (n = 5) for PCV2, and 5.71% (n = 6) were positive for coinfection of P1 and PCV2. In addition, the whole genomes of eight P1 strains and eight PCV2 strains were sequenced. Alignment of deduced amino acid sequences of P1 ORF1 and PCV2 ORF2 gene revealed that ON012566 had one unique amino acid mutation at residues 137 (T to P). This mutation has important implication for the study of virus virulence, tissue tropism, and immune response. Phylogenetic analysis shows that the yak-origin P1 strains in this study with cattle-origin P1 reference strains were grouped into one cluster. The yak-origin PCV2 (ON012566) and a buffalo-origin PCV2 (KM116514) reference strain clustered in the same branch in the PCV2b regions. Meanwhile, the remaining PCV2 strains and buffalo-origin PCV2 reference strain (ON012565) clustered in the PCV2d regions. To summarize, to our knowledge, this is the first report on the molecular prevalence and genome characteristics of P1 and PCV2 in yaks in the world and will contribute to further study of the molecular epidemiology, source, and evolution of P1 and PCV2 strains.
猪圆环病毒样病毒 P1 与猪圆环病毒 2 型（PCV2）一样，是导致猪断奶后多系统消耗综合征的潜在病原体。牦牛是一种有价值的物种，是世界上海拔最高、面积最大的青藏高原的标志性象征。在这项研究中，从 2019 年 1 月至 2021 年 12 月，在青藏高原林芝的 13 个农场共采集了 105 份牦牛腹泻样本，通过聚合酶链反应（PCR）对 P1 和 PCV2 进行了筛选，10.48%（n=11）的样本 P1 阳性，4.76%（n=5）的样本 PCV2 阳性，5.71%（n=6）的样本为 P1 和 PCV2 混合感染。此外，还对 8 株 P1 株和 8 株 PCV2 株的全基因组进行了测序。P1 ORF1 和 PCV2 ORF2 基因推导氨基酸序列的比对显示，ON012566 在残基 137（T 到 P）处有一个独特的氨基酸突变。该突变对病毒毒力、组织嗜性和免疫反应的研究具有重要意义。系统进化分析表明，本研究中的牦牛源 P1 株与牛源 P1 参考株聚为一簇。牦牛源 PCV2（ON012566）和水牛源 PCV2（KM116514）参考株在 PCV2b 区聚在同一分支。同时，其余的 PCV2 株和水牛源 PCV2 参考株（ON012565）聚在 PCV2d 区。总之，据我们所知，这是首次在世界范围内报道牦牛中 P1 和 PCV2 的分子流行情况和基因组特征，这将有助于进一步研究 P1 和 PCV2 株的分子流行病学、来源和进化。
