Schlottau K, Schulze C, Bilk S, Hanke D, Höper D, Beer M, Hoffmann B
Friedrich-Loeffler-Institut, Institute of Diagnostic Virology, Greifswald-Insel Riems, Germany.
Berlin-Brandenburg State Laboratory, Frankfurt (Oder), Germany.
Transbound Emerg Dis. 2016 Jun;63(3):253-9. doi: 10.1111/tbed.12493. Epub 2016 Mar 7.
Encephalitis can be caused by several infectious agents, including bacteria, fungi, parasites and viruses. In many cases, the causative agent cannot be identified, because the pathogens are unknown or detection methods are not routinely available. In our case, a 15-month-old cow developed central nervous disorders and died within 6 days after the onset of clinical signs. The histopathology revealed an acute encephalitis, predominantly in the brain stem, and a ganglionitis of the trigeminal ganglion with massive neuronal necroses in both the brain and the ganglion. However, a relevant panel of bacterial and viral infections of cattle could be routinely excluded. Therefore, a brain sample from the cow was analysed using a metagenomics approach with next-generation sequencing. A novel bovine astrovirus (BoAstV-BH89/14) could be identified using the analysis pipeline RIEMS, and the finding could be confirmed with a specific BoAstV RT-qPCR. The genome of the bovine astrovirus (BoAstV), belonging to the family Astroviridae in the genus Mamastrovirus, has a length of 6478 bp. Sequence identities between 71% to a sheep astrovirus and 69% to two recently described bovine astroviruses from the USA and Switzerland were ascertained. The latter were also connected to encephalitis cases in cattle. Like these, the new virus described here was detected in different brain sections using the specific BoAstV RT-qPCR and fluorescent in situ hybridization. In conclusion, while astroviruses so far were mainly found in relation to gastroenteritis in animals and humans, recently detected astrovirus infections were also related to encephalitis.
脑炎可由多种感染因子引起，包括细菌、真菌、寄生虫和病毒。在许多情况下，病原体无法确定，因为致病病原体未知或检测方法并非常规可用。在我们的病例中，一头15个月大的奶牛出现中枢神经系统紊乱，并在临床症状出现后6天内死亡。组织病理学显示为急性脑炎，主要累及脑干，三叉神经节出现神经节炎，脑和神经节均有大量神经元坏死。然而，牛的一系列相关细菌和病毒感染可被常规排除。因此，使用宏基因组学方法和下一代测序技术对该奶牛的脑样本进行了分析。通过RIEMS分析流程可鉴定出一种新型牛星状病毒（BoAstV-BH89/14），并可用特异性BoAstV RT-qPCR进行确认。牛星状病毒（BoAstV）属于星状病毒科乳星状病毒属，基因组长度为6478 bp。确定其与一种绵羊星状病毒的序列同一性为71%，与最近描述的来自美国和瑞士的两种牛星状病毒的序列同一性为69%。后两者也与牛的脑炎病例有关。与此类似，此处描述的新病毒通过特异性BoAstV RT-qPCR和荧光原位杂交在不同脑区被检测到。总之，虽然迄今为止星状病毒主要与动物和人类肠胃炎相关，但最近检测到的星状病毒感染也与脑炎有关。
