Oue Yasuhiro, Morita Yoshinori, Kondo Takashi, Nemoto Manabu
Hokkaido Tokachi Livestock Hygiene Service Center, 59-6 Kisen, Kawanishicho, Obihiro, Hokkaido 089-1182, Japan.
J Vet Med Sci. 2013;75(9):1261-5. doi: 10.1292/jvms.13-0056. Epub 2013 May 1.
Equine coronavirus (ECoV) outbreaks have occurred three times at Obihiro Racecourse in Hokkaido, Japan. The third ECoV outbreak occurred between late February and early April 2012. The main clinical signs of affected horses were anorexia, pyrexia and leucopenia; gastrointestinal disease was observed in about 10% of affected horses. Two ECoV strains were isolated from diarrheal samples. All paired sera (9/9) collected from febrile horses showed seroconversion by neutralization test. Sequence and phylogenetic analysis of the ECoV isolated showed that putative amino acid sequences in S and N genes were highly conserved among ECoV strains. In contrast, sequences of the region coding 4.7 kDa non-structural protein (p 4.7) differed among the strains. Because of the diversity of the p4.7 region, this region should be useful for epidemiological investigation of ECoV.
日本北海道带广赛马场曾三次爆发马冠状病毒（ECoV）疫情。第三次ECoV疫情发生在2012年2月下旬至4月初。受感染马匹的主要临床症状为厌食、发热和白细胞减少；约10%的受感染马匹出现胃肠道疾病。从腹泻样本中分离出两株ECoV毒株。通过中和试验，从发热马匹采集的所有配对血清（9/9）均显示血清转化。对分离出的ECoV进行的序列和系统发育分析表明，S基因和N基因中的推定氨基酸序列在ECoV毒株中高度保守。相比之下，编码4.7 kDa非结构蛋白（p4.7）区域的序列在不同毒株间存在差异。由于p4.7区域的多样性，该区域应有助于ECoV的流行病学调查。
