Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA; PIC North America, Hendersonville, TN, USA.
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine.
J Vet Diagn Invest. 2022 Sep;34(5):859-863. doi: 10.1177/10406387221114855. Epub 2022 Aug 10.
Surveillance is mandatory for tracking the progress of porcine reproductive and respiratory syndrome virus (PRRSV) control and elimination efforts in breeding herds. Processing fluids, the fluid recovered from tissues collected at castration and/or tail docking, are used for breeding herd surveillance by large segments of the industry, but the basic diagnostic characteristics of processing fluids are largely undescribed. We undertook 3 studies to address this information gap. In study 1, we found no differences among the PRRSV RT-rtPCR results obtained with 4 commercial RNA extraction kits. In study 2, we found that PRRSV RNA was highly stable in processing fluid samples at -20°C or 4°C, but detrimental effects were observed at ≥22°C within 24 h. In study 3, using a modified PRRSV ELISA at a sample:positive cutoff of ≥0.5, we found excellent discrimination in the detection of PRRSV antibody (IgM, IgA, IgG) in processing fluids from herds of known PRRSV status. Judicious handling of processing fluid samples from sow herds, and the use of methods available in veterinary diagnostic laboratories, can provide a foundation for reliable PRRSV surveillance.
对繁殖群进行监测是跟踪猪繁殖与呼吸综合征病毒（PRRSV）控制和清除工作进展的必要手段。加工液是从去势和/或断尾采集的组织中回收的液体，被行业的很大一部分用于繁殖群监测，但加工液的基本诊断特征在很大程度上尚未描述。我们进行了 3 项研究来解决这一信息差距。在研究 1 中，我们发现 4 种商业 RNA 提取试剂盒获得的 PRRSV RT-rtPCR 结果没有差异。在研究 2 中，我们发现 PRRSV RNA 在-20°C 或 4°C 的加工液样品中高度稳定，但在 24 小时内≥22°C 时观察到有害影响。在研究 3 中，使用改良的 PRRSV ELISA，在样本阳性截断值≥0.5 的情况下，我们发现从已知 PRRSV 状态的猪群中采集的加工液中 PRRSV 抗体（IgM、IgA、IgG）的检测具有极好的区分度。明智地处理母猪群的加工液样本，并使用兽医诊断实验室中可用的方法，可以为可靠的 PRRSV 监测提供基础。
