Giannitti F, Diab S, Mete A, Stanton J B, Fielding L, Crossley B, Sverlow K, Fish S, Mapes S, Scott L, Pusterla N
California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California, Davis, CA, USA Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, USA
California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California, Davis, CA, USA.
Vet Pathol. 2015 Nov;52(6):1148-56. doi: 10.1177/0300985814568683. Epub 2015 Feb 3.
Equine coronavirus (ECoV) is a Betacoronavirus recently associated clinically and epidemiologically with emerging outbreaks of pyrogenic, enteric, and/or neurologic disease in horses in the United States, Japan, and Europe. We describe the pathologic, immunohistochemical, ultrastructural, and molecular findings in 2 horses and 1 donkey that succumbed to natural infection with ECoV. One horse and the donkey (case Nos. 1, 3) had severe diffuse necrotizing enteritis with marked villous attenuation, epithelial cell necrosis at the tips of the villi, neutrophilic and fibrinous extravasation into the small intestinal lumen (pseudomembrane formation), as well as crypt necrosis, microthrombosis, and hemorrhage. The other horse (case No. 2) had hyperammonemic encephalopathy with Alzheimer type II astrocytosis throughout the cerebral cortex. ECoV was detected by quantitative polymerase chain reaction in small intestinal tissue, contents, and/or feces, and coronavirus antigen was detected by immunohistochemistry in the small intestine in all cases. Coronavirus-like particles characterized by spherical, moderately electron lucent, enveloped virions with distinct peplomer-like structures projecting from the surface were detected by negatively stained transmission electron microscopy in small intestine in case No. 1, and transmission electron microscopy of fixed small intestinal tissue from the same case revealed similar 85- to 100-nm intracytoplasmic particles located in vacuoles and free in the cytoplasm of unidentified (presumably epithelial) cells. Sequence comparison showed 97.9% to 99.0% sequence identity with the ECoV-NC99 and Tokachi09 strains. All together, these results indicate that ECoV is associated with necrotizing enteritis and hyperammonemic encephalopathy in equids.
马冠状病毒（ECoV）是一种β冠状病毒，最近在临床和流行病学上与美国、日本和欧洲马匹中出现的发热性、肠道性和/或神经性疾病暴发有关。我们描述了2匹马和1头驴自然感染ECoV后死亡的病理、免疫组织化学、超微结构和分子学发现。一匹马和那头驴（病例编号1、3）患有严重的弥漫性坏死性肠炎，伴有明显的绒毛萎缩、绒毛尖端上皮细胞坏死、嗜中性粒细胞和纤维蛋白渗出到小肠腔（假膜形成），以及隐窝坏死、微血栓形成和出血。另一匹马（病例编号2）患有高氨血症性脑病，整个大脑皮层出现阿尔茨海默II型星形细胞增多症。通过定量聚合酶链反应在小肠组织、内容物和/或粪便中检测到ECoV，所有病例均通过免疫组织化学在小肠中检测到冠状病毒抗原。在病例1的小肠中，通过负染透射电子显微镜检测到具有球形、中等电子透明、包膜病毒粒子且表面有明显的纤突样结构的冠状病毒样颗粒，对同一病例固定的小肠组织进行透射电子显微镜检查发现，在空泡中以及未识别（可能是上皮）细胞的细胞质中存在类似的85至100纳米的胞质内颗粒。序列比较显示与ECoV-NC99和十胜09株的序列同一性为97.9%至99.0%。总之，这些结果表明ECoV与马科动物的坏死性肠炎和高氨血症性脑病有关。
