Division of Virology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden; Centro Nacional de Investigación Disciplinaria en Microbiología Animal, INIFAP, Mexico DF, Mexico.
Facultad de Estudios Superiores Cuautitlán (FES-C), Universidad Nacional Autónoma de México (UNAM), Mexico.
Virus Res. 2014 Aug 8;188:155-61. doi: 10.1016/j.virusres.2014.04.012. Epub 2014 Apr 24.
The persistence of porcine rubulavirus (PorPV-LPMV) in five pigs that had survived an outbreak of a natural infection was determined. After the resolution of the outbreak, each animal was housed in an isolation pen together with one sentinel pig. Approximately every 2 months thereafter one group of animals was euthanized and tissue samples taken for virological and serological analysis. Infectious virus was not isolated from any samples; antibodies to PorPV-LPMV were detected in convalescent pigs by virus neutralisation test and blocking ELISA but not in sentinel pigs. PorPV-LPMV mRNA of the nucleoprotein (NP) and phosphoprotein (P) genes was detected by a nested polymerase chain reaction (nPCR) in samples of trigeminal and optic nerves, cervical spinal cord, tonsils, salivary gland, lung and pancreas from convalescent pigs. mRNA was also detected in the midbrain, corpus callosum, or olfactory bulb in four out of five pigs by nRT-PCR, this result was confirmed by the sequencing of a 260bp PCR product of P gene region. The highest average viral copies/μg of total RNA occurred in the olfactory bulb and pancreas tissues of convalescent pigs and midbrain, tonsil and pancreas of sentinel pigs housed with the convalescent pigs. Satellitosis and gliosis of the midbrain, olfactory bulb, corpus callosum, medulla oblongata or choroid plexus were microscopically observed in four convalescent pigs. The control pig remained negative in all tests. The results indicate that PorPV-LPMV mRNA persists and induces a durable humoral immune response in pigs that have recovered from a natural infection. After a possible reactivation of the virus, it was transmitted to sentinel pigs in contact with the convalescent pigs.
研究人员确定了在自然感染爆发中幸存下来的五头猪中持续存在猪 rubulavirus（PorPV-LPMV）。疫情解决后，每头动物都与一头哨兵猪一起被安置在隔离围栏中。此后，大约每两个月，一组动物被安乐死，并采集组织样本进行病毒学和血清学分析。从任何样本中都没有分离出传染性病毒；通过病毒中和试验和阻断 ELISA 检测到恢复期猪体内存在针对 PorPV-LPMV 的抗体，但在哨兵猪中未检测到。通过巢式聚合酶链反应（nPCR）在恢复期猪的三叉神经和视神经、颈脊髓、扁桃体、唾液腺、肺和胰腺样本中检测到核蛋白（NP）和磷蛋白（P）基因的 PorPV-LPMV mRNA。在五头猪中的四头中，通过 nRT-PCR 还在中脑、胼胝体或嗅球中检测到了 mRNA，这一结果通过对 P 基因区域 260bp PCR 产物的测序得到了证实。在恢复期猪的嗅球和胰腺组织以及与恢复期猪一起饲养的哨兵猪的中脑、扁桃体和胰腺中，病毒拷贝数/总 RNA 的平均值最高。中脑、嗅球、胼胝体、延髓或脉络丛的卫星病和神经胶质增生在四头恢复期猪中观察到。对照猪在所有检测中均呈阴性。结果表明，PorPV-LPMV mRNA 在自然感染后康复的猪中持续存在，并诱导持久的体液免疫反应。在病毒可能重新激活后，它传播给与恢复期猪接触的哨兵猪。
