新疆某规模化奶牛场牛传染性鼻气管炎病毒抗体水平检测

为了调查新疆地区某规模化奶牛场牛传染性鼻气管炎（IBR）发病情况,通过采集不同生长阶段牛群血清共计362 份,使用牛传染性鼻气管炎病毒gB（IBR-gB）抗体检测试剂盒检测牛传染性鼻气管炎病毒（IBRV）抗体效价,评估该奶牛场IBRV疫苗免疫效果。结果显示,后备牛中犊牛和青年牛IBRV抗体阳性率分别为88.57%（31/35）、75.00%（21/28）;成年母牛中泌乳期母牛、干奶期母牛IBRV抗体阳性率分别为81.46%（145/178）、95.04%（115/121）。阴性数共44 份,可疑数8 份,IBRV抗体平均阳性率为88.38%;结果表明,疫苗接种后,不同生产阶段牛群均可产生不错的抗体保护效果,为奶牛场防控IBR提供依据。     

牛传染性鼻气管炎疫苗研究进展

牛传染性鼻气管炎(IBR)是由牛传染性鼻气管炎病毒(IBRV)感染家养牛引起的一种热性接触性传染病。由于缺乏有效的治疗性药物,因此疫苗免疫仍然是防控该病的关键措施。针对该病常用的疫苗主要有灭活疫苗和活疫苗,而基因缺失活疫苗由于具有免疫标识,已成为新型疫苗研发的主流方向。一些发达国家已利用基因缺失标记疫苗,如IBRV gE缺失疫苗,进行免疫根除计划并净化了该病。然而,由于现存的疫苗仍存在免疫抑制与潜伏感染等问题,亟需研制更有效的标记疫苗。论文就牛传染性鼻气管炎病毒的病原学特征、免疫抑制及疫苗研发进展进行综述,以期为IBR有效疫苗的研发及其在防控上的应用提供参考。     

Nontransmission of bluetongue virus by embryos from bluetongue virus-infected sheep

Donor sheep were infected either by bites of bluetongue virus (BTV)-infected (serotype 11, "Texas Station strain") Culicoides variipennis or by inoculation with 100,000 median chicken embryo intravascular lethal doses of BTV (serotype 11) from a suspension made from infected C variipennis. Fourteen embryos from 4 BTV-infected ewes bred by rams not infected with BTV were transferred to 8 BTV-seronegative recipient ewes, and 35 embryos and 4 unfertilized eggs from 14 BTV-infected ewes bred by BTV-infected rams were transferred to 19 BTV-seronegative recipient ewes. Eleven pregnancies and 12 lambs resulted. None of the recipients or lambs seroconverted, and BTV was not isolated from the pregnant recipient ewes or their lambs at slaughter 30 days after parturition.     

牛传染性鼻气管炎病毒的分离鉴定与灭活疫苗免疫效果研究

由2例疑似牛传染性鼻气管炎（IBR）病例的荷斯坦奶牛分离到一株病毒,命名为IBRV—C1株。该病毒可被IBR标准阳性血清完全中和;接种MDBK细胞可出现IBR病毒典型细胞病变效应;选取IBR病毒gB蛋白基因序列设计引物进行PCR检测和基因测序,结果可扩增出特异性目的片段;动物回归试验显示,3头牛均可见体温升高、鼻流粘液、呼吸困难等典型的IBR临床症状。在此基础上制备了三批牛传染性鼻气管炎灭活疫苗,并进行了疫苗安全性和效力试验,结果表明三批疫苗对靶动物安全,免疫效果较好,免疫牛中和抗体效价几何平均值可达1：41以上,攻毒保护率达5／5。     

牛传染性鼻气管炎病毒致病机制研究进展

牛传染性鼻气管炎病毒(IBRV)主要引起牛的呼吸道、生殖道等炎症反应,也可以引起呼吸困难及流产。IBRV的致病机制尚不清楚,目前发现IBRV的非结构蛋白和结构糖蛋白与病毒毒力相关,不但影响病毒的复制及对宿主细胞的感染,同时也与病毒的免疫逃逸密切相关。除此之外,IBRV通过诱导宿主细胞凋亡造成持续性感染及激活炎症复合体诱导严重的炎症反应,造成宿主广泛病理反应的发生。因此,探索IBRV毒力蛋白结构功能、IBRV感染诱导的细胞凋亡及宿主炎性复合体激活的分子机制,将成为未来IBRV研究的热点。     

1株牛传染性鼻气管炎病毒的分离鉴定

在对进口种用奶牛隔离检疫期间,从1头IBRV中和抗体阳性奶牛中分离出1株病毒。该分离株表现类似于IBRV特征的细胞病变,细胞圆缩,聚集成葡萄串样群落,在单层细胞上形成空洞。用特异性抗IBRV阳性血清与其进行中和试验,发现IBRV标准阳性血清对分离株的中和抗体滴度为27,与IBRV标准株的中和抗体滴度相差不到1个滴度。用OIEV推荐的IBR特异性引物对分离病毒进行PCR扩增,获得与设计基因片段大小一致的特异性条带,表明分离到的病毒为IBRV。     

牛传染性鼻气管炎检测方法的研究进展

牛传染性鼻气管炎病毒(IBRV)是引起牛传染性鼻气管炎的病原。文中介绍了牛传染性鼻气管炎的各种检测方法的研究进展,包括病理组织学诊断、病毒的分离鉴定、免疫学检测和核酸分子检测,为牛传染性鼻气管炎的检测提供了有价值的参考。     

Comparison of persistence of seven bovine viruses on bovine embryos following in vitro exposure

The ability of seven cytopathic strains of bovine viruses to adhere to the zona pellucida of six-to-eight day-old bovine embryos were compared. Embryos were exposed to virus by placing them either in virus suspensions or by culturing them on infected bovine turbinate cultures for 18-24 h. After exposure to bovine virus diarrhea virus (BVDV), infectious bovine rhinotracheitis virus (IBV), bluetongue virus (BTV), pseudorabies virus (PRV), vesicular stomatitis virus (VSV), parainfluenza 3 virus (PI3), or bovine enterovirus virus (BEV), the embryos were tested for virus by culture in bovine turbinate cells and by morphological examination using electron microscopy (EM). A special technique to minimize loss of embryos processed for EM was developed. More embryos had viral particles on the surface of the zona pellucida after exposure to 18-24 hour infected cell cultures than did embryos exposed to viral culture suspensions. The most dramatic finding was that BTV adhered in large numbers to the surface of the zona pellucida of exposed embryos. IBRV, PRV, and VSV comprised an intermediate group, with virions occasionally detected on the surface of exposed embryos after 5 washes. Therefore, extensive washing is required. The PI3 and BEV were easily removed from embryo-exposed virus by washing. BVD was difficult to identify morphologically, making assessment by EM unreliable. There was no evidence that any one of the seven viruses penetrated the intact zona pellucida. Using a micromanipulator, 42 embryos were also directly inoculated through the zona pellucida with +/- 50 picoliters of virus inoculum or medium.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ornithodoros coriaceus (pajaroello tick) as a vector of bluetongue virus

Preliminary studies demonstrated that the argasid tick, Ornithodoros coriaceus Koch, could become infected with bluetongue virus (BTV). Ticks became infected after feeding through artificial membranes on BTV-infected suspensions of cell cultures, chicken embryos, and sheep blood. Ticks also became infected after natural feeding on viremic sheep (BTV serotype 17) and cattle (BTV serotype 11). Virus was recovered from the hemolymph and salivary glands of ticks which had ingested BTV either through an artificial membrane or by natural feeding on a host animal. Ticks infected with BTV serotype 13 were capable of transmitting the virus to a susceptible cow at 42 days after ingestion of virus-infected cultures, thus demonstrating the potential of the tick to serve as a biological vector of BTV.     

宁夏吴忠地区规模化奶牛场流产牛病原血清学调查

为了调查宁夏吴忠地区奶牛场因传染性因素造成流产的基本情况,应用酶联免疫吸附试验(ELISA)对可能造成感染流产的牛传染性鼻气管炎病毒、新孢子虫、牛病毒性腹泻病毒的抗体及布鲁菌的抗原进行了血清学检测。结果显示,牛传染性鼻气管炎病毒抗体阳性率为48.84%,新孢子虫抗体阳性率为30.23%,牛病毒性腹泻病毒抗体阳性率为19.77%,布鲁菌抗原阳性率为24.42%。牛场阳性率高达100%。根据统计显示,不同妊娠胎次的奶牛流产率差异显著(P0.05),其中第1胎流产率与其他胎次间差异极显著(P0.01)。不同妊娠时间的奶牛流产率差异不显著(P0.05)。调查表明,宁夏部分奶牛场存在不同程度的牛传染性鼻气管炎病毒、新孢子虫、牛病毒性腹泻病毒和布鲁菌感染。     

牛传染性鼻气管炎病毒攻毒方式的对比研究

本试验旨在建立牛传染性鼻气管炎病毒的攻毒模型,明确病毒在牛体内的分布及确定最佳攻毒方式,建立牛传染性鼻气管炎的发病标准,用来评价IBRV LNM弱毒疫苗的保护效力。试验共使用健康断乳牛9头,设鼻内喷雾组、滴鼻组和对照共3组,每组3头牛。将实验室分离保存的IBRV LN01/08强毒株采用鼻内喷雾和滴鼻两种方式接种试验组动物后,连续14 d,每日观察临床症状,监测体温及采集鼻拭子,对收集的试验数据进行对比分析。选取临床发病不同时期剖杀动物,采取主要脏器进行病毒分离。结果显示,所有动物攻毒后有不同程度的临床表现,以鼻内喷雾组临床表现最为严重,剖检可见肺部病变明显。病毒主要分布在呼吸道和眼结膜组织中。研究结果显示,采用IBRV自然感染方式攻击动物,喷雾方法攻毒临床效果明显强于滴鼻方式,保证了临床发病模型的建立,可以用来IBRV疫苗免疫效果评价,为研制IBR疫苗提供前提基础。     

Efficacy of viral components of a nonabortigenic combination vaccine for prevention of respiratory and reproductive system diseases in cattle

Efficacy and safety of components of an IM-administered vaccine for prevention of infectious bovine rhinotracheitis virus (IBRV), parainfluenza type-3 (PI-3) virus, bovine viral diarrhea virus (BVDV), and respiratory syncytial virus (RSV) infections and campylobacteriosis and leptospirosis were evaluated in cattle, including calves and pregnant cows. Challenge of immunity tests were conducted in calves for IBRV, PI-3 virus, or BVDV vaccinal components. All inoculated calves developed serum-neutralizing antibodies and had substantially greater protection (as measured by clinical rating systems) than did controls after challenge exposure to virulent strains of IBRV, PI-3 virus, BVDV, or RSV. In in utero tests, IBRV or bovine RSV vaccinal strains were inoculated into fetuses of pregnant cows. Histologic changes or abortions did not occur after fetal inoculation of the RSV vaccinal strain, and 10 of 14 fetuses responded serologically. Of 9 fetuses, one responded serologically to the IBRV vaccinal strain after in utero inoculation and was aborted 3 weeks later. In an immunologic interference test, 10 calves vaccinated with 2 doses of the multivalent vaccine, containing the 4 viral components and a Campylobacter-Leptospira bacterin, developed serum-neutralizing antibodies to IBRV, PI-3 virus, BVDV, and RSV without evidence of serologic interference. Under field conditions, 10,771 cattle, including 4,543 pregnant cows, were vaccinated. Vaccine-related abortions did not occur.     

牛传染性鼻气管炎诊断方法研究进展

牛传染性鼻气管炎(IBR)是由牛传染性鼻气管炎病毒(IBRV),即牛疱疹病毒1型(BoHV-1)所引起的以上呼吸道炎症为主的一种牛的急性、热性、接触性传染病,呈世界性流行。IBR的早期准确诊断,对该病的防控具有不可忽视的作用。目前,IBR的诊断方法主要包括病原学诊断和血清学诊断方法。病原学诊断具有特异和敏感及准确等特点,而血清学诊断具有敏感、快速、方便和价廉等特点。为了实施IBR的净化和根除计划,部分国家和地区已逐渐采用IBR基因缺失疫苗,配套使用鉴别诊断方法来鉴别IBR疫苗免疫和自然感染。论文就牛传染性鼻气管炎常用诊断方法的研究进展进行综述,以期为IBR的诊断和防控提供参考。     

Transmission of bovine virus diarrhoea virus (BVDV) by artificial insemination (AI) with semen from a persistently-infected bull

Twelve heifers that did not have antibodies to bovine virus diarrhoea virus (BVDV) were inseminated with semen from a bull that was persistently infected with the virus and contained 10(4.0)-10(6.5) TCID50 0.1 ml-1. All 12 became infected, as indicated by seroconversion within 2 weeks of insemination. Four control heifers were inseminated with virus-free semen. The virus was not transmitted to these animals in spite of close contact with the heifers inseminated with the infected semen. All the heifers became pregnant and gave birth to clinically normal calves at term. However, one calf was born persistently infected with BVDV. After the birth of this persistently-infected calf the control heifers and their calves seroconverted. The study demonstrates that BVDV may be transmitted in cattle by artificial insemination (AI). Therefore entry of persistently-infected animals into AI centres should be prevented.     

河南孟津地区6种引起奶牛流产病原的PCR检测及分析

为调查孟津地区引起奶牛流产的主要病原,本实验采集该地区8个规模化奶牛养殖场共52头新鲜流产胎牛,及其母体的血液、阴道分泌物和鼻腔分泌物。对所采集样本进行新孢子虫（N.caninum）、弓形虫(T.gondii)、胎儿三毛滴虫(T. foetus)、布氏杆菌(B.abortus)、牛传染性鼻气管炎病毒（IBRV）和牛病毒性腹泻病毒（BVDV）6种常见流产病原的PCR和RT-PCR检测。结果显示,被检样本总感染率为44.2%（23/52）,其中新孢子虫感染率最高,为32.7%（17/52）;IBRV次之,为13.5%（7/52）;胎儿三毛滴虫、布氏杆菌、弓形虫和BVDV感染率分别为1.9%、1.9%、1.9%和0。11.5%（6/52）的被检样本存在混合感染,其中以新孢子虫+IBRV混合感染为主（50%,3/6）。结合被检流产奶牛的临床特征及饲养管理等因素,推断新孢子虫是导致该地区奶牛流产的主要病原。     

Susceptibility of a fetal tongue cell line derived from bighorn sheep to five serotypes of bluetongue virus and its potential for the isolation of viruses

A cell line (BHFTE) was derived from a tongue explant of a bighorn sheep fetus (Ovis canadensis nelsoni). The cells have been maintained through 23 serial passages, and the modal number of chromosomes was calculated to be 55. Monolayer cultures were shown to be susceptible to various viruses, including bluetongue virus (BTV). Of 5 BTV serotypes (2, 10, 11, 13, and 17) tested, each produced a cytopathic effect (CPE) on initial passage at 33 C. A field isolate (serotype 10) of BTV from a black-tailed deer (Odocoileus hemionus columbianus) in its second passage in Vero-M cells also produced CPE when inoculated into BHFTE cells. Antigens of BTV were demonstrated by direct immunofluorescence in the cytoplasm of BHFTE cells inoculated with homogenates of chicken embryos injected with clinical specimens from a domestic sheep and an Arabian oryx (Oryx gazella leucoryx). A suspension of BTV-infected gnats (Culicoides spp.) produced CPE and BTV-specific fluorescence on the first passage in cells inoculated with a suspension of blood from sheep experimentally infected with BTV. Additionally, selected bovine viruses induced CPE in the cells. The cell line, which is free of mycoplasma and bovine viral diarrhea virus contamination, may be useful in diagnostic medicine and research involving the ruminant species.     

In vitro interferon production by bovine tissues: induction with infectious bovine rhinotracheitis virus.

The interferon-inducing ability of infectious bovine rhinotracheitis (IBR) virus was determined in tissue cultures of bovine origin inoculated with untreated and ultraviolet (UV) irradiated IBR viruses. Interferon was assayed by the plaque-reduction method in bovine fetal kidney (BFK) cell cultures, using vesicular stomatitis virus as challenge virus. Highest interferon concentrations were produced by cultures of bovine fetal (BF) spleen cells and aveolar macrophage cultures derived from adult cattle. Moderate interferon concentrations were produced by peripheral blood leukocyte (PBL) suspension cultures from adult cattle with serum-neutralizing antibodies against IBR virus. Cultures of PBL from 1 cow without detectable serum-neutralizing antibodies against IBR virus did not produce detectable interferon in response to IBR virus. Cultures of PBL from cattle with or without detectable serum-neutralizing antibodies against IBR virus produced interferon when stimulated with phytohemagglutinin (PHA). Low levles of viral inhibitors were detected infrequently in monolayer cultures of BFK and BF nasal mucosa inoculated with UV-irradiated IBR virus and in BF tracheal organ cultures inoculated with untreated IBR virus. Interferon was not detected in fluids collected from IBR virus-exposed monolayer cultures of primary and secondary BF lung, secondary BF tracheal mucosa, secondary BF liver, secondary BF adrenal, and PBL in the 4th and 7th passages. The antiviral inhibitors from BF spleen, bovine alveolar macrophage, and PBL cultures induced with IBR virus, as well as inhibitors from PBL cultures induced with PHA, had the usual properties of interferon.     

THE EFFECT OF NATURAL AND ARTIFICIAL BREEDING USING BULLS INFECTED WITH, OR SEMEN CONTAMINATED WITH, INFECTIOUS BOVINE RHINOTRACHEITIS VIRUS

Ten cows and heifers (Group B) were inoculated into the uterus at oestrus with semen followed by IBR virus for the first insemination and semen alone if a second insemination was necessary. All animals developed infectious pustular vulvo-vaginitis (IPV), and 2 cows conceived to the first and 2 to the second insemination (pregnancy rate of 40 percent requiring 4.5 services per conception). This group was compared with 10 control animals (Group A) which were treated similarly but received tissue culture fluid instead of virus at the first insemination. Group A had a pregnancy rate of 90 percent requiring 1.7 services per conception. Natural mating of 4 bulls with preputial infections due to infectious bovine rhinotracheitis (IBR) virus with 9 susceptible cows and heifers (group D), resulted in the production of lesions of IPV. The IPV infection did not affect their fertility (pregnancy rate of 89 percent requiring 1.4 services per conception) when it was compared to a similar group of females (group C) mated to the same bulls prior to infection with IBR virus (pregnancy rate of 100 percent requiring 1.2 services per conception). The 6 animals in Group B that were not pregnant and returned to oestrus 3 times were found on slaughter to have endometritis, salpingitis and vaginitis. A high incidence, 5 out of 18 (28 percent), of shortened oestrous cycles (less than 18 days) was a feature of the breeding pattern of this group. The undesirable consequences of distributing semen contaminated with IBR virus from artificial insemination centres are apparent.     

Effect of infectious bovine rhinotracheitis virus immunization on viral shedding in challenge-exposed calves treated with dexamethasone

Calves not vaccinated with infectious bovine rhinotracheitis virus (IBRV) became latently infected when challenge exposed and treated with dexamethasone (DM). Calves that shed IBRV after DM treatment were considered to be latently infected. Vaccination with a temperature-sensitive intranasal vaccine or with formalinized IBRV in Freund's complete adjuvant (IBRV-FCA) protected some, but not all, calves against latent infection--indicating a role for the immune response in preventing latent infection. That all latently infected calves were not detected after DM treatment was indicated by the fact that after a 2nd DM treatment of 3 calves treated 6 months previously and not found to shed virus, 1 of the calves was latently infected. Latently infected calves were inoculated with successive doses of IBRV-FCA and treated with DM. Nonvaccinated calves shed virus, whereas vaccinated calves similarly treated did not shed virus. Because both groups had a comparable cell-mediated immune response, as determined by blastogenic response to IBRV, but the vaccinated group had significantly higher virus-neutralizing antibody titers, a role for humoral antibody in preventing viral shedding was indicated.     

Insemination of Susceptible Heifers with Semen from a Non-Viraemic Bull with Persistent Bovine Virus Diarrhoea Virus Infection Localized in the Testes

Bulls shedding bovine viral diarrhoea virus (BVDV) in semen and simultaneously having a high concentration of circulating antibodies may cause reproductive problems and spread the viral infection within cattle populations. To investigate this in detail, three heifers were inseminated with BVDV‐infected semen from a non‐viraemic, seropositive Holstein–Friesian bull, named `Cumulus'. One control heifer was inseminated with semen from a healthy bull that was free of BVDV. All four heifers remained clinically healthy throughout the experiment. The conception succeeded in the control animal and in two of the three heifers inseminated with semen containing BVDV. The heifer with the failed conception was the only one that became systemically infected with BVDV. This animal was deemed non‐pregnant by ultrasonic examination on day 34 after insemination and showed no signs of subsequent oestrus during the entire experimental period. At slaughter, 42 days after insemination, there were no histopathological changes in the ovaries and virus was not detected in ovarian tissue. The fact that seronegative dams served with semen from persistently infected bulls have occasionally produced persistently infected calves together with the present findings and the fact that non‐viraemic, seropositive bulls can constantly shed BVDV, suggest that the use of semen from such bulls in BVDV‐free herds could have far‐reaching consequences, especially if it led to the birth of persistently infected (P1) calves.