Identification of a second encephalitis-associated astrovirus in cattle
Identification of a second encephalitis-associated astrovirus in cattle
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DOI：
10.1038/emi.2016.5
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发表时间：
2016-01-20
影响因子：
13.2
通讯作者：
Bouzalas I
中科院分区：
文献类型：
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作者：
Seuberlich T;Wüthrich D;Selimovic-Hamza S;Drögemüller C;Oevermann A;Bruggmann R;Bouzalas I
亲爱的编辑，人类星状病毒作为引起青少年胃肠炎的最常见病原体之一特别重要。近年来，一些星状病毒分离株被确定为免疫功能低下的人类患者脑炎的潜在原因。1-5这些发现被描述为在美国（BoAstV NeuroS 1）和我们在瑞士的实验室（BoAstV-CH 13）从患有不明病因脑炎的牛的神经组织中分离出的遗传学上密切相关的牛星状病毒分离株（BoAstV）所证实。6，7在瑞士约四分之一（5/22）的病原学未解决的非化脓性脑炎牛中回顾性发现了BoAstV-CH 13;然而，这些病例中的大多数（17/22）与BoAstV-CH 13无关。在这里，我们报告的另一种神经侵入性星状病毒的鉴定，在这组牛与非化脓性脑炎，这有不到65%的遗传相似性，目前已知的星状病毒isolates.In 2006年，一个4岁的Braunvieh牛（案件ID 42535）被通知为临床牛海绵状脑病（BSE）怀疑瑞士当局。关于临床表现的准确信息不可用，但BSE可疑动物的体征谱通常涉及行为和气质的变化、高反应性和不协调。尸检BSE检测为阴性，组织病理学检查诊断为重度非化脓性脑膜脑脊髓炎（图1A）。这种炎症模式强烈提示动物存在病毒感染，但未进行进一步的病原学研究。该动物被纳入我们关于BoAstV感染和脑炎的研究中，并通过无偏的下一代RNA测序（NGS）和生物信息学病原体发现管道进行了进一步研究。来自动物42 535的冷冻脑组织RNA提取物（延髓）的Illumina测序产生了21 443 420个读取对。在计算机模拟减去与牛参考基因组比对的读段并重新组装剩余读段后，我们鉴定了792、1010、1103和3170个核苷酸的四个连续序列（重叠群），其与绵羊星状病毒分离株条目（登录号NC_002469）的不同蛋白质具有最高氨基酸序列相似性（64%-83%）。1)国家生物技术信息中心数据库的。重叠群之间的缺口通过RT-PCR桥接，然后进行桑格测序。5号！和3！端
Dear Editor, Human astroviruses are of particular importance as one of the most common pathogens that cause juvenile gastroenteritis. In recent years, several astrovirus isolates were identified as potential causes of encephalitis in immunocompromised human patients. 1–5 These discoveries were paralleled by the description of phylogenetically closely related bovine astrovirus isolates (BoAstV) from the nervous tissue of cattle with encephalitis of unknown etiology in the USA (BoAstV NeuroS1) and by our laboratory in Switzerland (BoAstV-CH13). 6, 7 BoAstV-CH13 was retrospectively found in approximately one-quarter (5/22) of the cattle with etiologically unresolved non-suppurative encephalitis in Switzerland; however, most of these cases (17/22) were unrelated to BoAstV-CH13. Here, we report the identification of yet another neuroinvasive astrovirus in this set of cattle with non-suppurative encephalitis, which has less than 65% genetic similarity to currently known astrovirus isolates.In 2006, a 4-year-old Braunvieh cow (case ID 42535) was notified as a clinical bovine spongiform encephalopathy (BSE) suspect to the Swiss authorities. Precise information about the clinical presentation was not available, but the spectrum of signs in BSE-suspect animals usually involves changes in behavior and temperament, hyper-reactivity, and incoordination. Post mortem BSE testing was negative, and histopathological examination led to the diagnosis of severe non-suppurative meningo-encephalomyelitis (Figure 1A). This inflammatory pattern strongly suggested that the animal had a viral infection, but further etiologic investigations were not undertaken. The animal was included in our research on BoAstV infection and encephalitis and was further investigated by unbiased next-generation RNA sequencing (NGS) and a bioinformatics pathogen discovery pipeline. Illumina sequencing of frozen brain tissue RNA extracts (medulla oblongata) from animal 42 535 resulted in 21 443 420 read pairs. After in-silico subtraction of reads that aligned to the bovine reference genome and de novo assembly of the remaining reads, we identified four contiguous sequences (contigs) of 792, 1010, 1103, and 3170 nucleotides that matched with the highest amino acid sequence similarity (64%–83%) to different proteins of a sheep astrovirus isolate entry (accession number NC_002469. 1) of the National Center for Biotechnology Information database. Gaps between the contigs were bridged by RT-PCR followed by Sanger sequencing. The 5! and 3! ends