猪血凝性脑脊髓炎病毒临床感染病理变化特征及其变异分析

Pathological characteristics and variation analysis of clinical infection of porcine hemagglutination encephalomyelitis virus

研究旨在确认辽宁地区猪血凝性脑脊髓炎的存在,并验证其发病和病原遗传变异特征。试验选择某猪场发病仔猪疑似病例进行了病原核酸检测诊断,对确诊病例进行病理变化特征观察,对其S1基因序列进行了扩增、测序及病原变异分析。结果显示,确认辽宁省某猪场发病仔猪为猪血凝性脑脊髓炎;眼观病理变化特征为脑软膜和脑实质有出血斑点,心冠脂肪有出血斑点,全身淋巴结肿胀出血,小肠和大肠黏膜出血;组织学病理变化特征为非化脓性脑炎、出血性淋巴结炎、出血性肠炎、间质性肾炎。对猪血凝性脑脊髓炎病毒(PHEV)辽宁流行株(暂命名为PHEV-LN202001)S基因进行的同源性及进化树分析结果证明,该毒株与美国15TOSU24992毒株亲缘关系较近,形成了一个小分支,与传统毒株、长春毒株距离较远,整体同源性73.52%。研究表明,该毒株可能为外源输入性毒株,而且发生较大变异。

The purpose of the study was to confirm the existence of porcine hemagglutination encephalomyelitis in Liaoning Province,and to verify its pathogenesis and pathogenic genetic variation characteristics.The test selected suspected cases of piglets from a pig farm for pathogen nucleic acid detection and diagnosis,observed the pathological changes of confirmed cases,and carried out amplification,sequencing and pathogen variation analysis of the S1 gene sequence.The results showed that the piglets from a pig farm in Liaoning Province were confirmed to be porcine hemagglutinating encephalomyelitis.The pathological changes of the eye are characterized by hemorrhagic spots in the pia mater and brain parenchyma,blood spots in the coronary fat,swelling and hemorrhage of lymph nodes in the whole body,and hemorrhage in the small intestine and large intestine mucosa.Histological and pathological changes were characterized by non-suppurative encephalitis,hemorrhagic lymphadenitis,hemorrhagic enteritis,and interstitial nephritis.The homology and phylogenetic tree analysis of S gene of the Liaoning epidemic strain of PHEV(temporarily named PHEV-LN202001)showed that the strain was closely related to the American strain 15TOSU24992,and formed a small branch,which was far from the traditional strain and the Changchun strain,and the overall homology was 73.52%.The study indicates that the strain may be an exogenous imported strain with greater variation.