Nagai Makoto, Omatsu Tsutomu, Aoki Hiroshi, Otomaru Konosuke, Uto Takehiko, Koizumi Motoya, Minami-Fukuda Fujiko, Takai Hikaru, Murakami Toshiaki, Masuda Tsuneyuki, Yamasato Hiroshi, Shiokawa Mai, Tsuchiaka Shinobu, Naoi Yuki, Sano Kaori, Okazaki Sachiko, Katayama Yukie, Oba Mami, Furuya Tetsuya, Shirai Junsuke, Mizutani Tetsuya
Research and Education Center for Prevention of Global Infectious Disease of Animal, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan.
Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Tokyo, 180-8602, Japan.
Arch Virol. 2015 Oct;160(10):2491-501. doi: 10.1007/s00705-015-2543-7. Epub 2015 Jul 28.
A viral metagenomics approach was used to investigate fecal samples of Japanese calves with and without diarrhea. Of the different viral pathogens detected, read counts gave nearly complete astrovirus-related RNA sequences in 15 of the 146 fecal samples collected in three distinct areas (Hokkaido, Ishikawa, and Kagoshima Prefectures) between 2009 and 2015. Due to the lack of genetic information about bovine astroviruses (BoAstVs) in Japan, these sequences were analyzed in this study. Nine of the 15 Japanese BoAstVs were closely related to Chinese BoAstVs and clustered into a lineage (tentatively named lineage 1) in all phylogenetic trees. Three of 15 strains were phylogenetically separate from lineage 1, showing low sequence identities, and clustered instead with an American strain isolated from cattle with respiratory disease (tentatively named lineage 2). Interestingly, two of 15 strains clustered with lineage 1 in the open reading frame (ORF)1a and ORF1b regions, while they clustered with lineage 2 in the ORF2 region. Remarkably, one of 15 strains exhibited low amino acid sequence similarity to other BoAstVs and was clustered separately with porcine astrovirus type 5 in all trees, and ovine astrovirus in the ORF2 region, suggesting past interspecies transmission.
采用病毒宏基因组学方法对日本腹泻和未腹泻犊牛的粪便样本进行研究。在2009年至2015年期间于三个不同地区（北海道、石川县和鹿儿岛县）采集的146份粪便样本中，在所检测到的不同病毒病原体中，读取计数在其中15份样本中获得了几乎完整的与星状病毒相关的RNA序列。由于日本缺乏关于牛星状病毒（BoAstVs）的遗传信息，本研究对这些序列进行了分析。15株日本BoAstVs中的9株与中国BoAstVs密切相关，并在所有系统发育树中聚为一个谱系（暂命名为谱系1）。15株菌株中有3株在系统发育上与谱系1分离，序列同一性较低，而是与从患有呼吸道疾病的牛中分离出的一株美国菌株聚在一起（暂命名为谱系2）。有趣的是，15株菌株中有2株在开放阅读框（ORF）1a和ORF1b区域与谱系1聚在一起，而在ORF2区域与谱系2聚在一起。值得注意的是，15株菌株中有1株与其他BoAstVs的氨基酸序列相似性较低，在所有树中均与5型猪星状病毒单独聚在一起，在ORF2区域与绵羊星状病毒聚在一起，表明过去发生过种间传播。
