Canadian Food Inspection Agency, Animal Health Microbacteriology Laboratory (Germplasm), Ottawa, Ontario, Canada.
Theriogenology. 2013 Jul 15;80(2):77-83. doi: 10.1016/j.theriogenology.2013.03.022. Epub 2013 Apr 23.
Two experiments were conducted to determine the association of porcine circovirus type 2 (PCV2) with embryos and the risk of viral transmission by embryo transfer. In the first experiment, 240 embryos from uninfected donors were exposed to PCV2a 10(4)TCID50/mL in vitro before transfer to seronegative recipients; in the second experiment, 384 embryos recovered from infected donors, 10 days after donor inoculation with PCV2, were transferred to seronegative recipients. In total, 1120 embryos and/or ova were collected from 37 viral-free donors (experiment 1) and 1019 from 59 PCV2-infected donors (experiment 2) (P < 0.01). The washing and/or disinfection procedure recommended by the International Embryo Transfer Society was applied to embryos in both experiments. Transfer of embryos experimentally exposed in vitro to high titers of virus caused seroconversion of recipients (58%; N = 7/12) and their piglets (81%; N = 13/16). Postmortem, PCV2 DNA was detected in various organs of embryo transfer recipients and their embryo transfer-derived piglets. In contrast, the transfer of embryos recovered from infectious PCV2 donors did not result in the seroconversion of embryo recipients (N = 24) or their embryo transfer-derived piglets (N = 76). Neither PCV2 DNA nor infectious virus was detected in the tissues of either recipients or embryo transfer-derived piglets collected postmortem in the second experiment. The results obtained in this study indicate that the transmission of PCV2 from infected donors by embryo transfer is unlikely if the sanitary recommendations of the International Embryo Transfer Society are followed. In practical terms, this means that embryo transfer can be successfully used for the intentional elimination of PCV2 and to create virus-free offspring for the safe exchange of swine genetic materials.
进行了两项实验，以确定猪圆环病毒 2 型（PCV2）与胚胎的关联，以及通过胚胎转移传播病毒的风险。在第一项实验中，将 240 个来自未感染供体的胚胎暴露于体外的 PCV2a 10(4)TCID50/mL 中，然后转移到血清阴性的受体；在第二项实验中，将从感染供体中回收的 384 个胚胎（在供体接种 PCV2 后 10 天）转移到血清阴性的受体。总共从 37 个无病毒供体（实验 1）和 1019 个 PCV2 感染供体（实验 2）中收集了 1120 个胚胎和/或卵（P<0.01）。在两项实验中，都应用了国际胚胎转移协会推荐的洗涤和/或消毒程序。将胚胎体外暴露于高病毒滴度下的转移导致受体（58%；N=12/12）及其仔猪（81%；N=13/16）的血清转化。尸检时，在胚胎转移受体及其胚胎转移衍生仔猪的各种器官中检测到 PCV2 DNA。相比之下，从传染性 PCV2 供体中回收的胚胎的转移不会导致胚胎受体（N=24）或其胚胎转移衍生仔猪（N=76）的血清转化。在第二项实验中，死后从受体或胚胎转移衍生仔猪收集的组织中均未检测到 PCV2 DNA 或传染性病毒。本研究的结果表明，如果遵循国际胚胎转移协会的卫生建议，通过胚胎转移从感染供体传播 PCV2 的可能性不大。实际上，这意味着胚胎转移可成功用于有意消除 PCV2，并为安全交换猪遗传材料而创建无病毒后代。
