Key Laboratory of Preventive Veterinary Medicine, Department of Veterinary Medicine, Animal Science College, Hebei North University, Zhangjiakou 075131, PR China.
Artillery Training Base of General Staff, Zhangjiakou 075131, PR China.
Int Immunopharmacol. 2014 Apr;19(2):201-5. doi: 10.1016/j.intimp.2014.01.026. Epub 2014 Feb 6.
As pigs are susceptible to infection with both avian and human influenza A viruses, they have been proposed to be an intermediate host for the generation of pandemic virus through reassortment. The broad susceptibility of pigs to influenza viruses emphasizes the importance of surveillance of swine influenza virus. Thus, A latex agglutination test (LAT) was developed for rapid detection of antibodies to swine influenza virus. The nucleoprotein (NP) gene of the H9N2 swine influenza virus isolated from local farms was cloned, and expressed in Escherichia coli. Reactivity of the expressed protein was confirmed by Western blot. Subsequently, the NP gene was purified and used as the diagnostic antigen to develop a NP-based LAT for detecting antibodies to swine influenza virus. The LAT is shown to be specific for swine influenza virus and does not cross-react with swine sera that have antibodies to other swine viruses. The NP-LAT and HI test had a high agreement ratio in detecting 10 serum samples from naïve pigs, 28 serum samples from experimentally infected and vaccinated pigs. Compared with the hemagglutination inhibition (HI) test, the corresponding specificity, sensitivity, and correlation were 92.9%, 94.1%, and 94.1%, respectively, in detecting 321 serum samples from vaccinated pigs. The NP-LAT developed in our laboratory is a rapid and simple test suitable for field monitoring of antibodies to swine influenza virus. We conclude that it was specific and sensitive and it has great application potential in China's long-term prevention and control of swine influenza virus.
由于猪易感染禽流感和人流感 A 型病毒，因此它们被认为是通过重配产生大流行病毒的中间宿主。猪对流感病毒的广泛易感性强调了监测猪流感病毒的重要性。因此，开发了一种乳胶凝集试验（LAT）用于快速检测抗猪流感病毒的抗体。从当地农场分离的 H9N2 猪流感病毒的核蛋白（NP）基因被克隆，并在大肠杆菌中表达。通过 Western blot 确认了表达蛋白的反应性。随后，NP 基因被纯化并用作诊断抗原，以开发基于 NP 的 LAT 来检测抗猪流感病毒的抗体。该 LAT 特异性地针对猪流感病毒，与具有针对其他猪病毒抗体的猪血清不发生交叉反应。NP-LAT 和 HI 试验在检测 10 份来自未接种猪的血清样本、28 份来自实验感染和接种疫苗猪的血清样本时具有很高的一致性。与血凝抑制（HI）试验相比，在检测 321 份来自接种疫苗猪的血清样本时，其特异性、敏感性和相关性分别为 92.9%、94.1%和 94.1%。我们实验室开发的 NP-LAT 是一种快速简便的试验，适用于猪流感病毒抗体的现场监测。我们得出结论，它具有特异性和敏感性，在中国长期预防和控制猪流感病毒方面具有很大的应用潜力。
