Veterinary Population Medicine, University of Minnesota, Saint Paul, MN 55108, USA.
Vet Microbiol. 2012 Nov 9;160(1-2):23-8. doi: 10.1016/j.vetmic.2012.05.009. Epub 2012 May 15.
PRRSv is an economically important swine pathogen which can be disseminated from infected pig herds via movement of contaminated manure. The process of manure handling and inadequate cleaning of transport vehicles are commonly implicated as sources of PRRSv transmission. Stability of PRRSv in pig manure at different temperatures is unknown. The objective of this study was to determine PRRSv-infectivity half-life in manure and in a cell culture medium at 4, 20, 60 and 80°C. To assure sample consistency across the study, all samples were prepared from common homogenized solutions (MEM and manure) and frozen at -20°C. Samples were thawed, transferred to a water bath set at a specific temperature, inoculated with 100 μl of PRRSv at designated time points and then tested for virus infectivity. Regression models were created to estimate PRRSv half-life based on incubation temperature. There was an exponential decrease in PRRSv infectivity with increasing temperature. At every temperature tested, PRRSv had shorter half-life when incubated in manure compared to MEM. PRRSv half-life in MEM and manure was estimated at 112.6 and 120.5 h at 4°C, 14.6 and 24.5 h at 20°C, 1.6 and 1.7 h at 40°C, 2.9 and 8.5 min at 60°C, and 0.36-0.59 min at 80°C, respectively. Results of this study can be used as basis for developing strategies to inactivate PRRSv present in manure-contaminated environments using heating treatments. For example, these data suggest that submitting transport trailers to temperature of 50°C for 8h would decrease PRRSv from 10(6) TCID(50)/ml to less than 10(1) TCID(50)/ml.
PRRSv 是一种具有重要经济意义的猪病原体，可通过污染粪便的猪群传播。粪便处理过程和运输车辆清洗不充分通常被认为是 PRRSv 传播的来源。PRRSv 在不同温度下的猪粪中的稳定性尚不清楚。本研究的目的是确定 PRRSv 在粪便中和在细胞培养液中在 4、20、60 和 80°C 下的感染性半衰期。为了确保整个研究中样品的一致性，所有样品均由普通的均化溶液（MEM 和粪便）制备，并在-20°C 下冷冻。将样品解冻，转移到设定在特定温度的水浴中，在指定时间点接种 100 μl 的 PRRSv，然后测试病毒感染性。创建回归模型以根据孵育温度估计 PRRSv 的半衰期。随着温度的升高，PRRSv 的感染性呈指数下降。在测试的每个温度下，PRRSv 在粪便中的半衰期比在 MEM 中短。在 4°C 下，MEM 和粪便中的 PRRSv 半衰期估计为 112.6 和 120.5 h，在 20°C 下为 14.6 和 24.5 h，在 40°C 下为 1.6 和 1.7 h，在 60°C 下为 2.9 和 8.5 min，在 80°C 下为 0.36-0.59 min。本研究的结果可用于为使用加热处理来灭活受粪便污染环境中的 PRRSv 制定策略提供依据。例如，这些数据表明，将运输拖车暴露于 50°C 温度下 8 小时，可将 PRRSv 从 10(6)TCID(50)/ml 降低到低于 10(1)TCID(50)/ml。
