Hu Xifeng, Ding Zhen, Li Yu, Chen Zheng, Wu Huansheng
Department of Preventive Veterinary Medicine, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, China.
Department of Veterinary Microbiology, Jiangxi Provincial Key Laboratory for Animal Science and Technology, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang, China.
Front Microbiol. 2022 Oct 21;13:944679. doi: 10.3389/fmicb.2022.944679. eCollection 2022.
In 2019, a novel porcine circovirus 4 (PCV4) was first identified in Hunan Province, China. The circular PCV4 DNA was detected in both diseased and healthy pigs. Recently, PCV4 prevalence surveys have been analyzed in many provinces in both China and South Korea with low positive rates. However, no serological data has been conducted to investigate the prevalence of PCV4 in pigs from Jiangxi Province. To address this issue, an indirect anti-PCV4 antibody enzyme-linked immunosorbent assay (ELISA) based on Cap and Rep protein as a coating antigen was established and applied to study the serum epidemiology of PCV4 in Jiangxi Province. Purified PCV4-His-tagged Cap and Rep were used as the coating antigen to develop an ELISA detection kit. There was no cross-reaction of the Cap/Rep-based ELISA with antisera against PCV2, TGEV and PRRSV, indicating a high specificity of this ELISA assay. The intra-assay coefficient variations (CVs) of Cap-based were 1.239%-9.796%, Rep-based 1.288%-5.011%, and inter-assay CVs of 1.167%-4.694% and 1.621%-8.979%, respectively, indicating a good repeatability. Finally, a total number of 507 serum samples were collected from Jiangxi Province to test for antibody prevalence of PCV4, and 17 (3.35%) and 36 (7.10%) of the samples were Cap and Rep antibody positive, respectively. In summary, our established ELISA kit could be used to detect PCV4 antibodies in serum with good repeatability and high specificity. In addition, field samples detection results showed that the antibody of PCV4 was poorly distributed in intensive pig farms in Jiangxi Province, China.
2019年，一种新型猪圆环病毒4型（PCV4）首次在中国湖南省被发现。在患病猪和健康猪中均检测到环状PCV4 DNA。最近，中国和韩国许多省份都对PCV4的流行情况进行了调查分析，阳性率较低。然而，尚未开展血清学数据调查来研究江西省猪群中PCV4的流行情况。为解决这一问题，建立了一种基于Cap和Rep蛋白作为包被抗原的间接抗PCV4抗体酶联免疫吸附测定（ELISA）方法，并应用于研究江西省PCV4的血清流行病学。纯化的带有His标签的PCV4 Cap和Rep被用作包被抗原，开发了一种ELISA检测试剂盒。基于Cap/Rep的ELISA与抗PCV2、猪传染性胃肠炎病毒（TGEV）和猪繁殖与呼吸综合征病毒（PRRSV）的抗血清无交叉反应，表明该ELISA检测方法具有高度特异性。基于Cap的批内变异系数（CV）为1.239% - 9.796%，基于Rep的批内变异系数为1.288% - 5.011%，批间变异系数分别为1.167% - 4.694%和1.621% - 8.979%，表明重复性良好。最后，从江西省共采集了507份血清样本检测PCV4抗体流行情况，其中17份（3.35%）和36份（7.10%）样本分别为Cap和Rep抗体阳性。综上所述，我们建立的ELISA试剂盒可用于检测血清中的PCV4抗体，具有良好的重复性和高特异性。此外，现场样本检测结果表明，PCV4抗体在中国江西省集约化猪场中的分布情况较差。
