Laboratory of Veterinary Pathology and Microbiology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan; Department of Animal Medicine, Faculty of Veterinary Medicine, Damanhur University, El-Beheira.
Department of Veterinary Pathology, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh, Egypt.
J Comp Pathol. 2020 Oct;180:35-45. doi: 10.1016/j.jcpa.2020.08.002. Epub 2020 Sep 13.
Equine herpesvirus-9 (EHV-9), equine herpesvirus-1 (EHV-1) and zebra-borne EHV-1 are members of the family Herpesviridae and cause encephalitis and rhinopneumonitis in a range of animal species. The aim of this study was to characterize and compare the rhinopneumonitis induced by experimental intranasal inoculation of groups of hamsters with EHV-9, EHV-1 strain Ab4p or zebra-borne EHV-1 viruses. Animals inoculated with EHV-9 had earlier and more severe neurological and respiratory signs than those inoculated with EHV-1 strain Ab4p or zebra-borne EHV-1. At 4-5 days post inoculation (dpi), hamsters inoculated with EHV-9 had significantly increased expression of open reading fame (ORF) 30, the viral gene encoding the DNA polymerase, in lung tissue. ORF 30 expression at these time points was higher in the hamsters infected with EHV-9 than in those inoculated with the other two viruses. Severe, mild or very mild rhinitis was seen in animals inoculated with EHV-1 strain Ab4p, EHV-9 and zebra-borne EHV-1, respectively. Viral antigen was detected in olfactory receptor neurons, inflammatory cells and desquamated epithelial cells in animals in all groups until 5 dpi. Tracheitis was also seen in all three virus-infected groups with viral antigen detected in tracheal epithelium. Inoculated hamsters developed interstitial pneumonia of increasing severity over the course of the experiment. Bronchopneumonia and vasculitis were also seen in all three infected groups. These results confirm that, in addition to their neurotropism, EHV-9 and zebra-borne EHV-1 are pneumotropic viruses. EHV-1 strain Ab4p caused more severe upper respiratory tract disease, but no significant differences were detected in the severity of pneumonia induced by each virus.
马疱疹病毒 9 型（EHV-9）、马疱疹病毒 1 型（EHV-1）和斑马源性 EHV-1 均属于疱疹病毒科，可引起多种动物的脑炎和鼻肺炎。本研究旨在对感染 EHV-9、EHV-1 Ab4p 株和斑马源性 EHV-1 病毒的仓鼠进行鼻腔接种，以分析和比较鼻肺炎的特征。与感染 EHV-1 Ab4p 株或斑马源性 EHV-1 的仓鼠相比，感染 EHV-9 的仓鼠出现神经和呼吸道症状更早、更严重。感染后 4-5 天，EHV-9 感染的仓鼠肺部组织中开放阅读框（ORF）30 的表达显著增加，ORF30 是编码病毒 DNA 聚合酶的基因。在这些时间点，感染 EHV-9 的仓鼠的 ORF30 表达高于感染其他两种病毒的仓鼠。感染 EHV-1 Ab4p、EHV-9 和斑马源性 EHV-1 的仓鼠分别表现出严重、轻度或非常轻度的鼻炎。在所有病毒感染组的嗅神经元、炎症细胞和脱落的上皮细胞中均检测到病毒抗原，直至感染后 5 天。在所有三组病毒感染的仓鼠中均观察到气管炎，气管上皮细胞中检测到病毒抗原。接种的仓鼠在实验过程中逐渐发展为间质性肺炎，且程度逐渐加重。在所有三组感染组中还观察到支气管肺炎和血管炎。这些结果证实，除了神经亲和性外，EHV-9 和斑马源性 EHV-1 还是肺嗜性病毒。EHV-1 Ab4p 株引起更严重的上呼吸道疾病，但每种病毒引起的肺炎严重程度没有明显差异。
