Department of Microbiological Sciences, North Dakota State University, Fargo, ND, United States.
Animal Disease Research and Diagnostic Laboratory, S. Dakota State University, Brookings, SD, United States.
J Virol Methods. 2018 Dec;262:32-37. doi: 10.1016/j.jviromet.2018.09.003. Epub 2018 Sep 12.
Neonatal enteritis caused by the porcine epidemic diarrhea virus (PEDV) is an important cause of high mortality and economic losses to the swine industry. Virus neutralization (V/N) assays are commonly requested in diagnostic laboratories for the assessment of protective antibodies. However, the visual assessment of viral cytopathic effects by operators to determine antibody titers or for viral quantification is a tedious, subjective and time-consuming process, especially when high volume testing is involved. To improve the ease of testing, a colorimetric virus neutralization and TCID assays were developed and validated in this study using (3-(4,5-dimethylthiazol-2-yl) Tr-2,5-diphenyltetrazolium- bromide) (MTT), a colorimetric agent which measures cell viability. The respective conventional assays were used as the gold standards. An OD cut off value of ≤0.53, selected by receiver operating characteristics analysis, could distinguish between wells with and without CPE accurately. Performance and reproducibility parameters of the colorimetric assays were comparable to the conventional assays. The described methods can reduce testing time in diagnostic laboratories, while significantly improving current protocols.
由猪流行性腹泻病毒（PEDV）引起的新生儿肠炎是导致养猪业高死亡率和经济损失的重要原因。病毒中和（V/N）检测常用于诊断实验室，以评估保护性抗体。然而，操作人员通过观察病毒细胞病变效应来确定抗体效价或进行病毒定量是一项繁琐、主观且耗时的过程，尤其是在涉及大量检测时。为了提高检测的便利性，本研究开发并验证了一种比色病毒中和和 TCID 检测方法，使用（3-(4,5-二甲基噻唑-2-基)三-2,5-二苯基四氮唑溴盐）（MTT）作为比色剂，可测量细胞活力。各自的常规检测被用作金标准。通过接受者操作特征分析选择的 OD 截止值≤0.53 可以准确区分有无 CPE 的孔。比色检测的性能和重现性参数与常规检测相当。所述方法可以减少诊断实验室的检测时间，同时显著改进现有方案。
