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1.
Red blood cells (RBC) become sensitized following the elution of strain 575 Newcastle disease virus (NDV). The neuraminidase (NA) in the haemagglutinin (HA)-sialic acid configuration is inactive. The HA on sensitized RBC agglutinates normal RBC. The sialic acid on normal RBC initiated reactivation of the NA-a newly described function. Then normal-sensitized RBC agglomerates separated at 37 degrees C in the irreversible agglutination-separation (AS) reactions. With separation the AS products. HN spikes (150-200 kDa) and altered NDV, which contain fewer HN spikes than intact allantoic NDV, were removed from the sensitized RBC and the NDV membrane. Extraction of HN spikes from the membrane required more sialic acid than the removal of AS products from RBC. Thus 2 reactions were delineated for the orderly removal. Amounts of each released AS product suggest the source of the HN spikes. AS reactions and ether treatment of NDV increased the HA titres up to 19.2 fold. HA-sialic acid configurations were estimated by the amounts of normal RBC agglutinated by sensitized RBC and also by agglutination with fetuin. Elution of B1 vaccine, HN spikes from ether-treated NDV as well as AS products separated on sephadex resulted in incompletely sensitized RBC; fewer configurations were titrated with normal RBC; all failed to respond to anti-NA antibody. In contrast, sensitized RBC or suspensions of 575 NDV, but not the B1 vaccine strain, responded to both anti-NA and anti-HA antibody. Sensitization, slow elution, and responding to anti-NA antibody, which was accompanied by fluorescent foci on sensitized RBC, required intact NDV and the infrequent HA-sialic acid configuration. The NA was inactive for the HA-sialic acid configuration but cleaved fetuin, indicating substrate specificity. An inactive NA would allow time for fusion and NDV penetration rather than elution by an active NA early in NDV infection.  相似文献   

2.
新城疫病毒F48E9株病毒糖蛋白的功能分析   总被引:4,自引:1,他引:3  
对抗新城疫病毒(NDV)HN和F糖蛋白的单克隆抗体(McAb)的生物学活性,应用ELISA、HI、HLI、Westernblot等进行了分析,结果证明,NDVF48E9株HN蛋白除有HA和NA功能区外,还有一个促进(启动)融合的功能区。此外,还筛选到4株NDV强毒株特异性McAb,为NDV强弱毒株的鉴别打下了基础  相似文献   

3.
To analyze the contribution of neuraminidase (NA) toward protection against avian influenza virus (AIV) infection, three different recombinant Newcastle disease viruses (NDVs) expressing hemagglutinin (HA) or NA, or both, of highly pathogenic avian influenza virus (HPAIV) were generated. The lentogenic NDV Clone 30 was used as backbone for the insertion of HA of HPAIV strain A/chicken/Vietnam/P41/05 (H5N1) and NA of HPAIV strain A/duck/Vietnam/TG24-01/05 (H5N1). The HA was inserted between the genes encoding NDV phosphoprotein (P) and matrixprotein (M), and the NA was inserted between the fusion (F) and hemagglutinin-neuraminidase protein (HN) genes, resulting in NDVH5VmPMN1FHN. Two additional recombinants were constructed carrying the HA gene between the NDV P and M genes (NDVH5VmPM) or the NA between F and HN (NDVN1FHN). All recombinants replicated well and stably expressed the HA gene, the NA gene, or both. Chickens immunized with NDVH5VmPMN1FHN or NDVH5VmPM were protected against two different HPAIV H5N1 and also against HPAIV H5N2. In contrast, immunization of chickens with NDVN1FHN induced NDV- and AIV N1-specific antibodies but did not protect the animals against a lethal dose of HPAIV H5N1. Furthermore, expression of AIV N1, in addition to AIV H5 by NDV, did not increase protection against HPAIV H5N1.  相似文献   

4.
D J King 《Avian diseases》1991,35(3):505-514
Viruses conveyed in shipments of eggs, viral diagnostic reagents, or avian serum samples are a potential hazard for susceptible poultry. Different methods of treatment of those materials to eliminate the hazard of virulent and avirulent strains of Newcastle disease virus (NDV) or avian influenza virus (AIV) were evaluated. The NDV strains tested were more thermostable than the AIV strains. The results suggest that standard pasteurization methods would not reliably inactivate the concentrations of NDV used. beta-Propiolactone (BPL) (greater than or equal to 0.025%) inactivated NDV or AIV in allantoic fluid, but higher concentrations were needed to inactivate virus diluted in serum. Hemagglutination (HA) of NDV and AIV and hemolysis (HL) activity of NDV were reduced or eliminated by 0.4% BPL. Formalin (greater than or equal to 0.04%) inactivated either virus but adversely affected HA and HL activity. NDV or AIV was inactivated by binary ethylenimine (BEI) (0.01 M) with no adverse effect on HA or HL. Heat (56 C) or BEI (0.01 M) had no apparent effect on hemagglutination-inhibition (HI) titers of NDV and AIV antisera, the effect of formalin (0.1%) was variable, and BPL (greater than or equal to 0.25%) depressed the HI titers of both antisera. The optimum method should achieve virus inactivation without harming the treated material.  相似文献   

5.
The effects of viral vaccinations and immunization with sheep red blood cells (SRBC) on the humoral response of pullets were investigated. Pullets were vaccinated with Marek's disease virus, Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and infectious bursal disease virus at appropriate ages used in commercial practice. At seven weeks, the pullets were intramuscularly immunized with SRBC. NDV and IBV antibodies were detected by hemagglutination-inhibition tests. Hemagglutination (HA) titers were established against SRBC. IBV antibody titers were not affected by vaccination or by immunization with SRBC. NDV antibody titers were significantly increased by vaccination and by immunization with SRBC. The SRBC agglutinin response was also positively affected by vaccination. The HA titer increase consisted of a rise in 2-mercaptoethanol (2-ME)-sensitive antibodies and a fall in 2-ME-resistant antibodies.  相似文献   

6.
Vaccination of chickens with an oil-emulsion vaccine containing a recombinant baculovirus that expressed the hemagglutinin-neuraminidase (HN) of Newcastle disease virus (NDV)-induced hemagglutination-inhibition (HI) and virus-neutralizing antibodies against NDV. HI antibody titers obtained in response to vaccination with the live recombinant virus were higher than those obtained when the recombinant was inactivated with beta-propiolactone, and the titers were lower than those obtained in response to the same HN concentrations in live or beta-propiolactone-inactivated NDV strain B1. The serological response to the recombinant baculovirus was differentiated from the response to NDV by an enzyme-linked immunosorbent assay in which purified NDV nucleoprotein was used as antigen. Chickens vaccinated with the live recombinant or with inactivated NDV resisted an oculonasal challenge with the neurotropic velogenic Texas GB strain of NDV, which was lethal in unvaccinated controls. It was concluded that the HN protein of NDV expressed as a subunit by a recombinant baculovirus was protective against Newcastle disease.  相似文献   

7.
The potency of inactivated Newcastle disease virus (NDV) vaccines in the United States is currently determined using vaccination and challenge of experimental animals against a velogenic strain of NDV. Because velogenic strains of NDV are now classified as select agents in the United States, all vaccine potency testing must be performed in live animals under biosafety level 3 agriculture conditions. If the minimum amount of inactivated viral antigen required for clinical protection can be determined using other methods, vaccines meeting these criteria might be considered of adequate potency. The linearity of correlation between the hemagglutination (HA) assay measurement and the 50% embryo infectious dose titer ofNDV Hitchner B1 vaccine virus was determined. Correlation between hemagglutinin units (HAU) per vaccine dose, clinical protection, and antibody response was then determined using a vaccinate-and-challenge model similar to Chapter 9 of the U.S. code of federal regulations approved method for vaccine potency testing. The dose providing 50% protection of an in-house water-in-oil emulsion vaccine formulated with inactivated NDV B1 was determined to be between 400 and 600 HAU from two separate trials. A positive correlation (R2 = 0.97) was observed between antibody response and HAU per vaccine dose. Serum antibody responses from vaccinated birds indicate HA inhibition titers >2(5) log2 would provide 100% protection from morbidity and mortality and require a minimum protective dose of 1000 HAU per bird. These are the first studies to examine establishing both a minimum protective HAU content for inactivated ND vaccines and a minimum serologic response necessary to ensure potency.  相似文献   

8.
从广东省各地方分离10余株地方强毒株,对其中的五株地方强毒株进行了分离鉴定,将各毒株病肝研磨离心后取上清,绒毛尿囊腔接种9-11日龄的鸡胚,鸡胚接种后36-42h死亡,鸡胚全身出血,含病毒的尿囊液红血球凝集效价(HA)为1:9^9-1:2^15,并能被ND阳性血清特异性抑制,却不能被AIVH5亚型血清所抑制,用自己设计的特异性检测引物,对五个毒株进行了PCR鉴定,可扩增出特异性的目的条带,再结合临床症状和剖检病变,可初步判定为新城疫病毒,为以后进行广东省新城疫病毒分子流行病学研究打下了基础。  相似文献   

9.
参考国外发表的新城疫病毒 ( NDV)的 HN基因序列设计了 1对特异性引物 ,应用 RT-PCR对 NDV昌黎株 (野毒 )的 HN基因进行了扩增 ,扩增产物克隆后测序。扩增出的 HN基因核苷酸长度为 1 74 2 bp,编码 571个氨基酸 ,序列中有 6个糖基化位点 ,1 3个半胱氨酸残基 ,与国外发表的强毒株序列相符。核苷酸同源性在 88.5%~ 92 .9%,推导的氨基酸序列同源性在 90 .0 %~ 94 .2 %之间。  相似文献   

10.
60Coγ射线对不同状态不同体积的鸡新城疫病毒(NDV)、H9N2亚型禽流感(H9N2 AIV)和猪繁殖与呼吸综合征病毒(PRRSV)进行辐照,研究60Coγ射线对灭活疫苗中病毒的灭活效果。结果表明,6.0 kGy 60Coγ射线辐照对冷冻和液态下5000和10000 mL的NDV、H9N2亚型AIV和PRRSV均不能灭活,辐照后NDV和H9N2亚型AIV冷冻尿囊液的HA效价降低而液态尿囊液的HA效价升高;液态下,60Coγ射线能够灭活250 mL细胞培养液中的PRRSV,不能灭活250、5000和10000 mL尿囊液中的NDV和H9N2 AIV,250 mL与5000、10000 mL的NDV HA效价间差异显著(P<0.05)。60Coγ射线辐照对液态的PRRSV细胞培养液灭活效果良好,有望用于灭活苗的病毒灭活。  相似文献   

11.
从山东济南某非典型新城疫发病鸡群中分离到一株新城疫病毒株(ShD-5—06),研究其生物学特性表明,该病毒具有新城疫强毒株的一些特征。从该分离株扩增出其F和HN基因,并与标准株进行同源性比较,为探讨NDV是否发生变异提供理论依据。本试验通过RT—PCR法特异性地扩增出F和HN基因全基因序列,并对其与已经发表的序列进行核苷酸序列测定和分析。结果表明,ShD-5—06株的F和HN基因开放性阅读框架(ORF)为1662bp和1716bp,分别编码489个和571个氨基酸。与国外发表的部分新城疫病毒强毒株和弱毒株之间相应序列进行比较,F基因核苷酸序列的同源性在84.1%~88.7%之间,氨基酸同源性在88.1%~93.3%之间;HN基因核苷酸序列的同源性在82.19,5~87.4%之间,氨基酸同源性在88.6%~90.9%之间;F蛋白裂解位点区(112~117)氨基酸组成与强毒株一致,说明NDV山东分离株(ShD-5—06)为新城疫强毒株。  相似文献   

12.
With the advent of subunit vaccines for microbial diseases it is becoming increasingly important to be able to differentiate naturally infected animals from those vaccinated with the corresponding subunit vaccine. For avian viruses such as Newcastle disease virus (NDV), a whole virus-based ELISA cannot make such a differential diagnosis since in both cases the antisera would react with the whole virus. The nucleocapsid protein (NP) gene of the NDV Hitchner B1 strain was cloned, sequenced and expressed to develop a differential ELISA. The B1 NP had 95.7 and 96.1% amino acid identities with the NP of the d26 and Ulster 2C strains, respectively. The B1 NP expressed in a baculovirus expression vector (recNP) was the expected size and reacted with NDV-specific antibodies (Ab) in Western blots and by radioimmunoprecipitation. The ELISA using recNP-coated wells, tested on serum samples from flocks pretested with a commercial NDV kit gave results corresponding to those of the kit. Furthermore, use of both the renNP-based ELISA and a whole virus ELISA allowed the differentiation of birds vaccinated and a NDV haemagglutinin-neuraminidase (HN) expressing fowlpox virus from birds infected with NDV. This provides the basis for establishing an ELISA that discriminates between the antibody response to a recombinant fowlpox vaccine (expressing NDV HN protein) and that to live and inactivated NDV.  相似文献   

13.
采用RT-PCR技术对Ⅰ类新城疫病毒(NDV)09-014分离株完整的融合蛋白(F)基因和血凝素-神经氨酸酶(HN)基因进行了扩增和遗传进化分析。F基因的序列测定结果表明:该分离株F基因全长为1 792 bp,可编码553个氨基酸,裂解位点的氨基酸组成为112E-R-Q-E-R-L117,具有典型的新城疫弱毒株特征。同源性分析表明本分离株的F基因与Ⅰ类新城疫病毒代表毒株之间核苷酸的同源性为93%~95.2%,而与Ⅱ类新城疫病毒代表毒株的同源性较低,介于70.6%~72.4%。HN基因的序列测定结果表明:HN基因全长2 001 bp,可编码616个氨基酸,同源性分析表明本分离株的HN基因与Ⅰ类新城疫病毒代表毒株之间核苷酸的同源性在92.7%~94.7%之间,而与Ⅱ类新城疫病毒同源性较低,为70.7%~71.5%。根据完整的F基因和HN基因构建的遗传进化树均表明:本分离株在分类地位上属于Ⅰ类新城疫病毒基因3型,因此Ⅰ类新城疫病毒的F基因和HN基因具有相似的进化速率。  相似文献   

14.
The complete genome sequence of the Australian I-2 heat-tolerant Newcastle disease virus (NDV) vaccine (master seed stocks) was determined and compared to the sequence of the parent virus from which it had been derived after exposure of the parent stock at 56 degrees C for 30 min. Nucleotide changes were observed at a number of positions with synonymous mutations being greater than those observed for non-synonymous mutations. Sequence data for the HN gene of a parental culture of V4 and two heat-tolerant variants of V4 were obtained. These were compared with the data for the I-2 viruses and with published sequences for parental V4 and for a number of ND vaccine strains. Sequence analyses did not reveal the ARG(303) deletion in the HN protein, previously claimed to be responsible for the thermostable phenotype. No consistent changes were detected that would indicate involvement of the HN protein in heat resistance. The majority of alterations were observed in the L protein of the virus and it is proposed that these alterations were responsible for the heat-tolerant phenotype of the I-2 NDV vaccine.  相似文献   

15.
A Newcastle disease virus (NDV) isolate designated IBS002 was isolated from a commercial broiler farm in Malaysia. The virus was characterised as a virulent strain based on the multiple basic amino acid motif of the fusion (F) cleavage site 112RRRKGF117 and length of the C-terminus extension of the hemagglutinin-neuraminidase (HN) gene. Furthermore, IBS002 was classified as a velogenic NDV with mean death time (MDT) of 51.2 h and intracerebral pathogenicity index (ICPI) of 1.76. A genetic distance analysis based on the full-length F and HN genes showed that both velogenic viruses used in this study, genotype VII NDV isolate IBS002 and genotype VIII NDV isolate AF2240-I, had high genetic variations with genotype II LaSota vaccine. In this study, the protection efficacy of the recombinant genotype VII NDV inactivated vaccine was also evaluated when added to an existing commercial vaccination program against challenge with velogenic NDV IBS002 and NDV AF2240-I in commercial broilers. The results indicated that both LaSota and recombinant genotype VII vaccines offered full protection against challenge with AF2240-I. However, the LaSota vaccine only conferred partial protection against IBS002. In addition, significantly reduced viral shedding was observed in the recombinant genotype VII-vaccinated chickens compared to LaSota-vaccinated chickens.  相似文献   

16.
从山东潍坊某非典型新城疫发病鸡群中分离到一株新城疫病毒(暂命名:ShD-5-04),其生物学特性表明该病毒具有新城疫强毒株的一些特征。通过RT-PCR特异性地扩增出F和HN基因序列,并对其进行核苷酸序列测定和分析,结果表明ShD-5-04株的F和HN基因开放性阅读框架(ORF)为1662bp和1716bp,分别编码489个和571个氨基酸,与国外发表的部分新城疫病毒强毒株和弱毒株之间相应序列进行比较,F基因核苷酸序列的同源性在84.1%~88.7%之间,氨基酸同源性在88.1%~93.3%之间;HN基因核苷酸序列的同源性在82.1%~87.4%之间,氨基酸同源性在88.6%~90.9%之间;F蛋白裂解位点区(112-117)氨基酸组成与强毒株一致,说明NDV山东分离株(ShD-5-04)为新城疫强毒株。  相似文献   

17.
新城疫病毒HN蛋白单克隆抗体的制备   总被引:2,自引:1,他引:1  
为制备新城疫病毒HN蛋白的单克隆抗体,本研究采用新城疫病毒CK/AH/100/2010作为免疫原,免疫6~8周龄BALB/c小鼠,3次免疫后取脾细胞与SP2/0融合,用血凝抑制(HI)方法检测筛选,具有HI活性的单抗有6株:PX1-PX6。6株单抗与AIV、EDS等其它具有血凝活性的病毒的交叉血凝抑制试验结果表明,6株单抗具有良好的特异性。间接免疫荧光试验结果表明,PX1、PX3可与新城疫病毒CK/GD/263/2010 HN抗原发生特异性反应,而其它单抗不反应。  相似文献   

18.
本研究旨在从分子水平上掌握中国新城疫病毒的变异情况和新城疫的流行规律,对2008-2009年从中国部分省市养殖场分离的9株新城疫病毒毒株,采用RT-PCR方法扩增其F和HN基因,经克隆和测序,对所得序列进行同源性和遗传进化分析。结果显示,9株分离株有8株为基因Ⅶ型,1株为基因Ⅱ型,F基因开放性阅读框架(ORF)为1662 bp,强毒株同La Sota的核苷酸同源性为83.5%~84.2%。HN基因开放性阅读框架(ORF)为1716或1734 bp,强毒株在538位缺失1个糖基化位点。结果表明,近年流行的ND疫情主要是由基因Ⅶ型NDV引起,F和HN基因的变异可能与频繁的疫苗免疫选择压力有关。  相似文献   

19.
10株新城疫病毒广西分离株HN蛋白基因的克隆与序列分析   总被引:4,自引:2,他引:4  
根据基因库(GenBank)新城疫病毒(NDV)的HN基因序列设计了2对特异性引物,应用RT-PCR技术对广西在2000~2003年暴发新城疫的鸡群中分离的10株NDV毒株的HN基因进行了扩增,扩增产物克隆并测序,拼接出10个NDV广西分离株的HN基因全序列,其序列全长均为1 713 bp,编码571个氨基酸,均有13个半胱氨酸残基。其中GX8/03有6个糖基化位点,而GX2/00、GX6/02、GX7/02和GX5/00有5个糖基化位点,GX1/00、GX3/00、GX4/00和GX9/03有4个糖基化位点。除GX5/00和GX10/03分离株外,其他8个NDV分离株在HN基因抗原位点Ⅰ发生变异,即347位由谷氨酸(E)被甘氨酸(G)替代,GX8/03分离株在HN基因抗原位点Ⅱ的495位由赖氨酸(K)替代谷氨酸(E)。与11株已发表的NDV HN基因全序列相比较,其核苷酸同源性在79.6%~97.9%之间,推导的氨基酸同源性在87.2%~98.1%之间。  相似文献   

20.
为确定西藏新城疫病毒(Newcastle disease virus,NDV)分离株HN基因结构特征及其与已知毒株的遗传相关性,本试验应用RT-PCR技术对西藏NDV分离株HN基因进行扩增,然后克隆至pMD18-T载体测序,并与国内外代表性毒株和当前疫苗株进行比对及系统发育分析。结果表明,NDV分离株HN基因片段长度为1734 bp, 编码577个氨基酸;推导的氨基酸序列均有5个糖基化位点, XZ10和XZ17有12个半胱氨酸残基,XZ20只有11个半胱氨酸残基。NDV西藏分离株HN基因与国内代表性毒株核苷酸同源性在81.1%~93.0%之间,氨基酸同源性在81.1%~93.6%之间;与疫苗株核苷酸同源性在87.8%~98.7%之间,氨基酸同源性在88.0%~98.9%之间。系统进化分析结果表明,NDV西藏分离株HN基因均属于Ⅱ型。  相似文献   

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