Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
Laboratory of Animal Pathology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil.
Transbound Emerg Dis. 2018 Apr;65(2):331-337. doi: 10.1111/tbed.12807. Epub 2018 Jan 10.
The recently described atypical porcine pestivirus (APPV) has been associated with congenital tremor (CT) type A-II in piglets in different countries. Another important neurological pathogen of pigs is porcine teschovirus (PTV), which has been associated with non-suppurative encephalomyelitis in pigs with severe or mild neurological disorders. There have been no reports of APPV and/or PTV coinfection associated with CT or encephalomyelitis in Brazilian pig herds. The aim of this study was to describe the pathological and molecular findings associated with simultaneous infection of APPV and PTV in piglets with clinical manifestations of CT that were derived from a herd with high rates of CT-associated lethality. In 2017, three piglets from the same litter with CT died spontaneously. The principal pathological alterations in all piglets were secondary demyelination and hypomyelination at the cerebellum, brainstem and spinal cord confirmed by histopathology and luxol fast blue-cresyl violet stain. Additional significant pathological findings included multifocal neuronal necrosis, neuronophagia and gliosis found in the cerebral cortex and spinal cord of all piglets, while atrophic enteritis and mesocolonic oedema were observed in some of them. APPV and PTV RNA were detected in the central nervous system of affected piglets, and PTV was also detected in the intestine and faeces. The pathological alterations and molecular findings together suggest a dual infection due to APPV and PTV at this farm. Moreover, the combined effects of these pathogens can be attributed to the elevated piglet mortality, as coinfections involving PTV have a synergistic effect on the affected animals.
最近描述的非典型猪瘟病毒（APPV）与不同国家仔猪的先天性震颤（CT）A型-II 有关。另一种重要的猪神经病原体是猪肠道病毒（PTV），它与有严重或轻度神经障碍的猪的非化脓性脑脊髓炎有关。在巴西的猪群中，尚未有报道称 APPV 和/或 PTV 合并感染与 CT 或脑脊髓炎有关。本研究的目的是描述与临床表现为 CT 的仔猪同时感染 APPV 和 PTV 的病理和分子发现，这些仔猪来自一个 CT 相关死亡率较高的猪群。2017 年，同窝的三只仔猪自发性出现 CT 而死亡。所有仔猪的主要病理改变都是小脑、脑干和脊髓的继发性脱髓鞘和少突胶质细胞发育不良，通过组织病理学和卢索快速蓝-克雷斯尔紫染色得到证实。其他重要的病理发现包括所有仔猪大脑皮层和脊髓中的局灶性神经元坏死、神经元吞噬和神经胶质增生，而其中一些仔猪还观察到萎缩性肠炎和结肠系膜水肿。受影响仔猪的中枢神经系统中检测到 APPV 和 PTV RNA，PTV 也在肠道和粪便中检测到。病理改变和分子发现共同提示该农场存在 APPV 和 PTV 的双重感染。此外，这些病原体的共同作用可归因于仔猪死亡率的升高，因为涉及 PTV 的合并感染对受影响的动物具有协同作用。
