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1.
鸡传染性支气管炎(IB)是由鸡传染性支气管炎病毒(IBV)引起的危害养鸡业的重要传染病之一,临床上可分为呼吸型、肾型、肠型、腺胃型和输卵管型.长期以来我国采用H120和H52疫苗预防该病,取得了一定成效.但近年来国内一些经过上述疫苗免疫的鸡群中出现了嗜肾型传染性支气管炎病毒的感染和流行,给养鸡业造成了巨大的经济损失.IBV基因组为单股正链RNA,长约27.6Kb,主要编码膜蛋白(M)、核衣壳蛋白(N)和纤突蛋白(S).其中M基因长约670bp,决定病毒的感染性,并与病毒的复制、抗感染、刺激白细胞产生干扰素以及基因组的变异等有关.  相似文献   

2.
鸡传染性支气管炎是由鸡传染性支气管炎病毒(Infectious bronchitis virus, IBV)感染引起的鸡的一种急性、高度接触性传染性病。IBV基因组非常容易发生突变和重组,给该病防控带来巨大困难,因此高效疫苗和有效药物的研发非常重要。反向遗传技术是研究RNA病毒的重要技术。通过反向遗传技术可以在DNA分子水平定向改造病毒序列,对病毒的基因功能、致病机制以及新型疫苗进行研究。论文对构建IBV操作系统的策略、利用反向遗传技术研究IBV基因结构和功能、研发新型疫苗以及开发病毒载体的最新进展进行综述,为IBV及其他冠状病毒相关研究提供参考。  相似文献   

3.
以两个人工合成引物进行聚合酶链(PCR)反应,成功地扩增了鸡传染性支气管炎病毒(IBV)核衣壳蛋白基因(N)。PCR 扩增的模板 DNA 分别为含有 IBV N 基因cDNA 的重组质粒和病毒基因组 RNA 反转录产物.PCR扩增产物的大小与预期的相同,同时核酸序列分析的结果也与已发表的序列一致.  相似文献   

4.
传染性支气管炎病毒(IBV)为冠状病毒科冠状病毒属成员,基因组为单股正链RNA,长27.6 kb,带有poly ( A)尾.病毒粒子基因组编码6种蛋白,其中位于病毒囊膜表面的纤突蛋白(spike protein , S )是病毒主要的免疫原蛋白基因,IBV纤突蛋白是由2~3个拷贝的S1, S2亚单位组成.由于IBV的特殊的转录合成机制使得S1基因易发生点突变、插入、缺失和基因重组,使得IBV极易产生变异株.S1蛋白具有许多重要的生物学功能,是IBV主要的免疫原蛋白,它能刺激机体产生中和及血凝抑制抗体.因此,根据不同地区的分离毒株S1基因的差异,来确定流行IBV的血清型,研究其分子生物学特性,深入分析IBV的变异原因,进一步揭示IBV分离株的变异机制,对从根本上控制IB,具有重要意义.  相似文献   

5.
鸡肾型传染性支气管炎是严重危害我国养鸡业的传染病之一,目前尚无特效疗法。除采用常规疫苗预防之外,临床上主要采用中药、西药或中西药结合治疗的方法,基因工程疫苗、活载体疫苗和核酸疫苗是近年来研究的热点。在对鸡传染性支气管炎病毒(IBV)研究方面除了对主要结构蛋白S、N和M蛋白进行深入研究外,对其他辅助蛋白也进行了研究和分析,并探讨了短的双链RNA(siRNA)对IBV增殖的干扰作用。另外,用中草药或中药复方制剂防治鸡肾型传染性支气管炎也越来越受到关注,并在预防和治疗此病的过程中发挥着越来越大的作用。  相似文献   

6.
本研究旨在克隆并表达鸡传染性支气管炎病毒(IBV)的核衣壳蛋白(N)。根据IBV ZZ2004株的N基因设计1对引物,提取IBV ZZ2004株的RNA,利用RT-PCR技术扩增大小约1.23 kb的片段,将其插入克隆载体pGEM-T构建pGEM-T-N。将pGEM-T-N用EcoRⅠ和XhoⅠ进行双酶切,将酶切后的N基因片段克隆到表达载体pGEX-6P-1,转入大肠杆菌BL21(DE3)菌中,经IPTG诱导表达,进行SDS-PAGE电泳,结果显示外源基因获得了表达且为可溶性蛋白;Western blotting检测结果显示N蛋白可与相应的IBV ZZ2004阳性血清发生特异性反应,结果表明N蛋白有一定的生物活性。本研究为IBV诊断试剂盒及新型IBV重组亚单位疫苗研制奠定基础。  相似文献   

7.
鸡传染性支气管炎病毒分子变异机制的研究   总被引:2,自引:2,他引:0  
鸡传染性支气管炎(IB)目前已成为养鸡业中危害最大的病毒性传染病之一。病毒基因组RNA的点突变、缺失、插入和不同毒株基因组间的同源重组所导致的病毒血清型、基因型和组织嗜性的改变是造成现用疫苗免疫失败的主要原因。病毒的变异已成为当前对IBV病原学及本病免疫防制研究中的热点,作者重点就IBV变异机制及其变异株的来源等方面作一综述。  相似文献   

8.
廖娟  王红宁  黄勇  周生  田浪 《中国家禽》2006,28(11):45-46
鸡传染性支气管炎(IB)是由鸡传染性支气管炎病毒(IBV)引起的鸡的一种急性、高度接触性传染病,是严重危害养禽业的重要传染病之一.IBV为冠状病毒科(Coronavirdae),冠状病毒属(Coronavirus)的代表成员,病毒粒子有囊膜和纤突,基因组为一条单股正链RNA,具有27kb,分为10个开放阅读框架(ORF);基因组主要编码3种结构蛋白:纤突(S)蛋白、膜(M)蛋白和核衣壳(N)蛋白,其中S蛋白由S1和S2两种糖蛋白组成,血凝抑制和大多数中和抗体由S1蛋白引起.  相似文献   

9.
近年鸡传染性支气管炎病毒流行状况   总被引:1,自引:1,他引:0  
1病原 鸡传染性支气管炎病毒(Infectious bronchitis virus,IBV)为冠状病毒科(Coronaviridae)冠状病毒属(Coronavirus)第三群成员,为单股正链、不分节段的RNA病毒,基因组长约2 716 kb.病毒主要有磷酸化的核衣壳蛋白(N)、糖基化的膜蛋白(M)、小膜糖蛋白(E)和纤突蛋白(S)4种结构蛋白组成.S蛋白转译后裂解成N端的S1和C端的S2,其中S1为重要的抗原蛋白,能诱导机体产生中和抗体,也是决定IBV血清型特异性的主要蛋白,由于高度易变,其点突变、插入、缺失或重组是新血清型、亚型或变异株产生的主要原因.  相似文献   

10.
核衣壳蛋白(N)是鸡传染性支气管炎病毒(IBV)的重要结构蛋白。根据GenBank报道的IBV的M41株的N基因序列设计一对引物,从提取的M41株的RNA中利用RT-PCR技术扩增获得了约1.23kb的片段,将该片段插入克隆载体pMD18-T,经测定核苷酸序列证实N基因扩增正确,表明已成功构建pMD18-T-N。再将pMD18-T-N用BamHⅠ和HindⅢ双酶切,将酶切后的N基因片段克隆到表达载体pET-32a,转化入大肠杆菌Rossetta中,用IPTG诱导,进行SDS-PAGE电泳,电泳结果显示外源基因获得了表达且为可溶性蛋白,Western-blotting检测表明N蛋白可与相应IBV病毒抗体发生特异性的反应,表明N蛋白有一定的生物活性,可为用于生产检测IB的诊断试剂和研制新型IB重组亚单位疫苗奠定基础。  相似文献   

11.
Avian metapneumovirus (aMPV), Newcastle disease virus (NDV), and infectious bronchitis virus (IBV) are important respiratory pathogens of chickens. To achieve early posthatch protection against all three diseases it would be helpful to deliver live aMPV, IBV, and NDV vaccines simultaneously at 1 day of age. However, previous work has indicated that the efficacy of aMPV vaccines may be affected when codelivered with IBV or NDV vaccines. The efficacy of an aMPV vaccine when codelivered to chickens in a trivalent combination with an NDV and an IBV vaccine was examined. The serological antibody response to the aMPV vaccine given with the IBV and NDV vaccine was significantly lower than when the aMPV vaccine was given alone. However, the aMPV vaccine did not affect the serological response to the IBV and NDV vaccines. Irrespective, the efficacy of the aMPV vaccine was not affected based on clinical signs postchallenge. This is the first report showing aMPV, IBV, and NDV vaccines can be codelivered without affecting the efficacy of the aMPV vaccine.  相似文献   

12.
Infectious bronchitis (IB) is an economically important viral disease with worldwide distribution. Every country with an intensive poultry industry has infectious bronchitis virus (IBV). The virus rapidly spreads from bird to bird through horizontal transmission by aerosol or ingestion. Sentinel bird studies were carried out in southern Ontario and IBV has been isolated from layer flocks. Genetic analysis of the S1 region of the strains showed that they were not vaccine related. The pathogenicity of selected Ontario variants of IBV isolates was studied and the subsequent work was to determine the degree of protection against field isolates provided by a commonly used vaccine MILDVAC-Ma5 in Ontario. The protection was evaluated by challenging immunized chickens with the respiratory (IBV-ON1) and nephropathogenic (IBV-ON4) viruses. The mean vaccine efficacy for IBV-ON1 was 66.7% indicating that a Massachusetts serotype vaccine would provide some protection against IBV field isolates.  相似文献   

13.
对鸡传染性支气管炎病毒(IBV)陕西分离株SX-H09株膜蛋白(M)基因进行克隆和序列分析.根据GenBank发表的IBV基因序列设计1对特异性引物,RT-PCR扩增IBV M基因片段,并进行克隆、序列测定和分析.结果表明,SX-H09株M基因全长为678 bp,编码225个氨基酸.同源性比较可知,SX-H09株M基因...  相似文献   

14.
为研究山东省鸡传染性支气管炎病毒(IBV)的遗传变异规律,本研究2006年~2010年从山东省发病的商品鸡中分离鉴定了17株IBV,并对其S1基因、N基因和M基因分别进行RT-PCR扩增、测序及遗传进化分析.序列分析结果表明:与疫苗株H120相比,17个分离株S1蛋白的变异程度较大,存在广泛的基因突变和氨基酸替代,多数病毒株还存在氨基酸的插入;N蛋白无碱基的缺失和插入,仅存在核苷酸的突变和氨基酸的替代;M蛋白除病毒株CK/CH/SD09/005插入3个碱基外,其它16个分离株仅存在少数的碱基突变和氨基酸替代.S1基因、N基因和M基因的系统进化分析结果表明多数分离株的3个基因在进化上相对平行,与国内分离株LX4同属一个进化分支,同源性较高;分离株SDYT0605的3个基因与疫苗株H120同源性较高,可能是免疫压力下变异的疫苗株;分离株SDTA06111、SDWF0608和CK/CH/SD09/005的S1基因、N基因和M基因分属于不同的进化分支,可能发生了基因重组.本研究结果显示基因突变、插入和不同基因之间的重组是免疫压力下IBV变异的主要方式.  相似文献   

15.
16.
Infectious bronchitis virus (IBV) poses a severe threat to the poultry industry and causes heavy economic losses worldwide. Vaccination is the most effective method of preventing infection and controlling the spread of IBV, but currently available inactivated and attenuated virus vaccines have some disadvantages. We developed a chimeric virus-like particle (VLP)-based candidate vaccine for IBV protection. The chimeric VLP was composed of matrix 1 protein from avian influenza H5N1 virus and a fusion protein neuraminidase (NA)/spike 1 (S1) that was generated by fusing IBV S1 protein to the cytoplasmic and transmembrane domains of NA protein of avian influenza H5N1 virus. The chimeric VLPs elicited significantly higher S1-specific antibody responses in intramuscularly immunized mice and chickens than inactivated IBV viruses. Furthermore, the chimeric VLPs induced significantly higher neutralization antibody levels than inactivated H120 virus in SPF chickens. Finally, the chimeric VLPs induced significantly higher IL-4 production in mice. These results demonstrate that chimeric VLPs have the potential for use in vaccines against IBV infection.  相似文献   

17.
The aim of this study was to quantify transmission of infectious bronchitis virus (IBV) H120 vaccine strain among broilers, and to assess whether birds that have been exposed to vaccine strain-shedding birds were protected against clinical signs after infection with a virulent strain of the same serotype. A transmission experiment and a replicate were carried out, each with six groups of commercial broilers. At day of hatch (n = 30) or at 15 days of age (n = 20), half of each group was inoculated with either IBV H120 vaccine (H120 group), virulent IBV M41 (M41 group), or were mock-infected, thereby contact-exposing the other half of each group. Nasal discharge was recorded, and antibody response and virus shedding were measured. To measure clinical protection, four weeks after inoculation all birds, in all groups, were challenged with IBV M41. The reproduction ratio (R; the average number of contact infections caused by one infectious bird) was determined to quantify virus transmission. All contact-exposed birds, except for one in an H120 group, became infected with either IBV H120 or IBV M41. Almost all birds contact-infected with IBV H120 or IBV M41 were subsequently protected against clinical signs after challenge with IBV M41. The lower limits of the 95% confidence interval (CI) of the R of IBV H120 vaccine, and of IBV M41, were significantly <1. For both IBV H120 and IBV M41, the 95% CI was [2.1-infinity] following inoculation at day of hatch and [1.8-infinity] after inoculation at 15 days of age. This finding demonstrates that IBV H120 vaccine is able to spread extensively among broilers. This implies that this vaccine strain might be able to become endemically present in the poultry population. It also implies that, even if not all birds received vaccine during spray application, due to the ability of the vaccine to spread in the flock, they will most likely be protected against clinical signs after a subsequent field virus infection.  相似文献   

18.
19.
Colibacillosis results from infection with avian pathogenic Escherichia coli bacteria. Healthy broilers are resistant to inhaled E. coli, but previous infection with vaccine or virulent strains of Infectious Bronchitis Virus (IBV) predisposes birds for severe colibacillosis. The aim of this study was to investigate how IBV affects the course of events upon infection with E. coli. Broilers were inoculated with IBV H120 vaccine virus or virulent M41 and challenged 5 days later with E. coli 506. A PBS and E. coli group without previous virus inoculation were included. Sections of trachea, lung and airsacs were stained for CD4, CD8, gammadelta-TCR, alphabeta1-TCR, and for macrophages (KUL-01) and both pathogens. Changes in the mucociliary barrier of trachea, lung and airsacs did not predispose for bacterial superinfection. The disease in the lungs of the E. coli group and both IBV/E. coli groups was similar. Lesions in the airsacs were more pronounced and of longer duration in the IBV/E. coli groups. The immunocytological changes differed substantially between the E. coli group and both IBV/E. coli groups. In trachea, lungs and airsacs the CD4+ and CD8+ populations were significantly larger than in the E. coli and PBS groups. In the lungs and the airsacs the macrophages were more numerous in the IBV/E. coli and the E. coli groups than in the PBS group. The presence of high numbers of T cells and macrophages in IBV infected birds most likely induced an altered immune response, which is responsible for the enhanced clinical signs of colibacillosis.  相似文献   

20.
本研究通过RT-PCR分别获得了4个国内IBV分离株的S1、M和N基因,并进行了克隆及测序。序列分析结果表明:HaN2-95株的S1、M和N基因核苷酸序列均与IBV H120疫苗株的同源性最高;尽管HaN1-95株的S1基因与IBV H52疫苗株的亲缘关系最近,但是该毒株的M基因和N基因却与IBV Gray株的同源性最高;GX1-98株的S1和M基因均与IBV H52疫苗株的亲缘关系最近,但其N基因却与IBV Gray株和Ark99株有高度的同源性;GX2-98株的S1基因却与IBV Holte株的亲缘关系最近。上述结果提示国内有些IBV分离株的出现可能与疫苗株的使用有关。  相似文献   

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