猪血凝性脑脊髓炎病毒抗体的调查

应用血凝和血凝抑制试验检测了从吉林省部分地区采集的猪血清中血凝性脑脊髓炎病毒（HEV）抗体。结果，212份样品中有94份呈现HEV抗体阳性反应，阳性率高达44．3％。被采集血清的猪未表现临床症状，说明该地区的猪群中存在HEV隐性感染。     

猪血凝性脑脊髓炎病毒实时荧光RT-PCR检测方法的建立与应用

为建立一种快速、准确、常规的猪血凝性脑脊髓炎病毒(porcine hemagglutinating encephalomyelitis virus,PHEV)检测方法,根据PHEV N蛋白基因序列,设计1对引物和1条探针,建立了PHEV实时荧光RT-PCR检测方法。该方法特异性好,与猪繁殖与呼吸综合征病毒(PRRSV)、猪伪狂犬病病毒(PRV)、猪流行性腹泻病毒(PEDV)、猪传染性胃肠炎病毒(TGEV)、猪瘟病毒(CSFV)和猪圆环病毒2型(PCV2)均无交叉反应;用阳性质粒Puc57-PHEVn评估其敏感性,发现检测下限达10~(-6) ng/μL(224拷贝/μL)。采集233份发病猪组织样品进行临床检测,发现该方法与巢式RT-PCR的符合率达98.3%,准确筛查出巢式RT-PCR并测序阳性的样品14份,且检出率高于巢式RT-PCR。结果表明,本方法敏感、特异,可用于PHEV临床样品的检测。     

猪血凝性脑脊髓炎病毒的血清学调查

应用血凝和血凝抑制试验检测了从辽宁省部分地区采集的猪血清中血凝性脑脊髓炎病毒（HEV）的抗体滴度。结果表明,368份血清样品中,有162份呈抗体阳性反应,阳性率高达44.0%。被采集血清的猪未表现出临床症状,说明该地区存在血凝性脑脊髓炎病毒的隐性感染。     

猪血凝性脑脊髓炎研究进展

流行病学及病理变化 猪血凝性脑脊髓炎病毒属于冠状病毒科(Coronaviridae)冠状病毒属(Coronavirus)的成员，引起幼猪的一种急性、高度接触性传染病。通常只侵鲁1～3周龄的乳猪，不感染其他动物。流行病学研究发现猪的HEV感染甚为普遍，很可能是全球性的。     

猪血凝性脑脊髓病毒在J774A.1细胞中的增殖特性及炎性因子表达

为了探讨宿主巨噬细胞(J774A.1细胞)在猪血凝性脑脊髓炎病毒(Procine hemagglutinatin encephalomyelitis virus,PHEV)感染过程中的作用及其参与炎性反应的应答特征,本研究通过CPE观察、TCID50、免疫荧光(IFA)、ELISA和PT-PCR等方法,对PHEV感染J774A.1细胞的增殖特性及炎性因子IL-6、TNF-a、IL-1β等mRNA转录水平和蛋白水平的表达情况进行检测分析。IFA的检测结果显示,感染后8h后仅有少量的被荧光抗体标记细胞出现绿色荧光,随着感染时间的延长,荧光标记的细胞逐渐增加,直至感染后32~40h出现大量细胞出现荧光。TCID50结果显示,PHEV感染滴度的增值趋势与mRNA含量的变化基本一致,在感染后24~32h增殖速度最快,至32h病毒感染滴度达到最高。荧光定量RT-PCR结果显示,PHEV感染可诱导J774A.1细胞分泌的TNF-a、IL-6、IL-1βmRNA转录水平均显著升高,尤其IL-6mRNA的表达量显著增加,在48h达到对照组的25倍;TNF-αmRNA的表达量在感染后8h内增加为对照组的4倍,随后一直维持较高水平。ELISA结果显示,TNF-a、IL-6、IL-1β蛋白水平表达也显著增加。上述研究结果表明,PHEV不仅可以感染J774A.1细胞,而且能诱导其分泌多种细胞因子参与免疫应答,为进一步阐明机体重要免疫细胞在PHEV过程中的作用奠定了基础。     

PGRN缺失对猪血凝性脑脊髓炎病毒脑内感染小鼠的影响

已有研究表明溶酶体与β冠状病毒复制密切相关,为研究调控溶酶体功能的关键蛋白颗粒蛋白前体(progranulin, PGRN)对β冠状病毒猪血凝性脑脊髓炎病毒(porcine hemagglutinating encephalomyelitis virus, PHEV)复制的影响,本研究以PGRN缺失及其对照小鼠为研究对象,探究PGRN在PHEV脑内感染小鼠过程中的作用。研究发现,与PHEV脑内感染野生型小鼠相比,PGRN缺失小鼠脑内感染病毒后其存活时间延长,同时脑内病毒含量显著降低,细胞因子IFN和TNF-a的含量升高;此外,神经退行性病变相关蛋白TDP-43表达显著升高,表明PGRN缺失能减缓病毒的复制,增强免疫反应,并影响病毒的致病性。研究结果为进一步揭示溶酶体蛋白PGRN在PHEV复制过程中的作用机制提供研究基础,并为β冠状病毒致病机制研究提供参考。     

哺乳仔猪血凝性脑脊髓炎

1症状 该病可分为脑脊髓炎型和呕吐消瘦型。这两种类型可以同时存在于一个猪群中,也可发生于不同的猪群或不同的地区。     

猪血凝性脑脊髓炎研究进展

猪血凝性脑脊髓炎(PHE)是由血凝性脑脊髓炎病毒(HEV)感染引起猪的一种急性传染病,主要侵害1周龄~3周龄的哺乳仔猪。感染仔猪以呕吐、衰竭和神经症状为特征,病死率很高。血凝性脑脊髓炎病毒具有嗜神经性,主要从感染部位经外周神经向中枢神经系统传播,引起中枢神经系统损伤,从而造成非化脓性脑炎的病变。论文主要对猪血凝性脑脊髓炎的病原、临床症状和病理变化、致病机制、潜在危害及防治等方面进行综述。     

血凝性脑脊髓炎病毒血凝抑制试验方法的研究

为检测某猪场的猪感染血凝性脑脊髓炎病毒的情况,用250 mL/L 的鸡红细胞和200 g/L的高岭土去除非特异性物质,使用4单位抗原及5 mL/L鸡红细胞做HI 试验,发现这些条件较适宜。用此法对其他5 种猪传染病抗血清进行检查,发现均不产生非特异性血清学反应。另外,本试验用滤纸吸附血清与分离血清做HI比较试验,其HI价差异不显著,从而为以后进行血清学调查提供了一种便利的方法。用分离的HEV与日本HEV 67N毒株抗原进行比较,两者的HI价一致。     

Persistence of passively acquired antibodies to hemagglutinating encephalomyelitis virus in swine

The persistence of passively acquired antibodies to hemagglutinating encephalomyelitis virus (HEV) was determined in 4 pigs in each of the litters of 10 sows. At time of delivery by the sows, the colostrum and serum samples (from the 10 sows) had hemagglutination-inhibiting antibodies to HEV. All of the pigs also had hemagglutination-inhibiting antibodies to HEV at 2 days of age. The level of circulating antibodies to HEV decreased at a nonlinear rate and persisted for about 4 to 18 (mean 10.5) weeks in the circulation of pigs. All 40 pigs were seronegative at 20 weeks of age.     

Virus isolated and immunofluorescence in different organs of pigs infected with hemagglutinating encephalomyelitis virus

Hemagglutinating encephalomyelitis virus (HEV; also designated vomiting and wasting disease virus) was inoculated oronasally in 26 colostrum-deprived pigs. Anorexia and vomition were seen after an incubation period of 4 to 6 days. In pigs killed during the incubation period or within 2 days after the onset of the clinical signs, HEV could be isolated regularly from the tonsils and the respiratory tract, irregularly from the digestive tract, rarely from the blood, and never from lymph nodes and spleen. The brainstem almost always contained virus after clinical signs appeared, but was only one positive during the incubation period. Olfactory bulb, cerebrum, cerebellum, and vagal nerve were also frequently virus positive in pigs which were ill when killed. The results of the examination by immunofluorescent antibody technique indicated that HEV multiplies in the epithelium lining the respiratory tract and the tonsillar crypts, in neuroepithelium of the nasal mucosa, and in neurons of the digestive tract. The neuronotropism of HEV was also shown by the presence of fluorescence in the perikaryon of neurons in the brainstem and in the trigeminal ganglion without the involvement of other cell types. The presence of viral antigens in the perikaryon of trigeminal sensory ganglion cells in pigs killed during the incubation period was considered as positive evidence for viral spread via nerves.     

Phenotypic analysis of peripheral leukocytes in piglets infected with classical swine fever virus.

The phenotypic changes in circulating leukocytes in swine fever influenced by classical swine fever virus (CSFV) infection with different strain virulence was studied in piglets. The phenotypic differences were measured by monoclonal antibodies specific for porcine differentiation antigens. The pattern of phenotypic change varied with the virulence of CSFV. Infection with virulent, but not the attenuated strain of CSFV resulted in the dramatic early loss of CD8-bearing T lymphocytes from the circulation. A similar trend was also seen in the gammadelta T-cell compartment following infection with the highly virulent strain, Washington. The loss of circulating B-lymphocytes was consistent with the failure to generate neutralising antibody. These observations contrasted the finding that the number of leukocytes expressing the CD4 surface antigen increased in piglets infected with CSFV. These data provide preliminary information on the potential range of leukocyte changes produced in piglets following infection with CSFV.