东北地区新城疫流行株的分子生物学特性调查

从东北地区发生新城疫(ND)的病鸡、病鸽和产蛋下降鸡分离到19株NDV，对其融合蛋白(F)基因532bp或280bp片段进行了克隆、测序(在GenBank中的登录号为AY208680～AY208698)，并对各株的F基因序列进行了比较。结果，各毒株之间的核苷酸同源性为83．1％～100％，氨基酸同源性为85．5％～100％；系统发育进化树分析表明，其中2株与疫苗株V4同属基因Ⅰ型，为弱毒株；其余17株为强毒株，其中2株为基因Ⅵ型，其余为基因Ⅶ型。表明东北地区目前由3种基因型的NDV毒株(Ⅰ型、Ⅵ型、Ⅶ型)所引发，并以基因Ⅶ型为主。另外，对其中的代表毒株APMV1／chiclierl／China／JL-11／02进行了免疫学试验，结果显示，LaSota疫苗的免疫保护效果不理想，可能是LaSota疫苗免疫鸡群发生ND的主要原因。     

免疫鸡群非典型新城疫流行特点及防治

鸡新城疫（NewcastleDisease,ND）一直是危害养鸡业的重要疫病之一。自发现本病以来,各国都采取了多种方法通过不同途径加以控制,如疫苗株的研制、免疫程序的完善等。但到目前为止,除少数发达国家可以基本控制本病的发生外,世界多数地区仍无法解决这一问题。尤其是目前免疫鸡群发生的非典型新城疫,临床上缺乏典型的症状和病理变化,很难诊断和及时控制,并且如果有霉形体、大肠杆菌病或其它病毒性疾病伴发感染时,死亡数量明显增多,危害极大[1-3]。去年,我市郊县一些鸡场有不同程度的ND暴发,给鸡场造成较大的损失。因此,控制免…     

新城疫近期流行特点及防治

<正>近一段时间,新城疫一反常态,在养殖集中的小区呈流行趋势,给养殖户带来的经济损失较大,现将其流行特点及防治措施总结如下:供一线兽医和广大养殖户参考。     

近期鸡新城疫的流行特点及其防制

鸡新城疫是严重危害养禽业的疾病，笔者就近期鸡新城疫的流行特点及其综合防制进行综述。     

免疫鸡群感染新城疫的流行特点及防治

免疫鸡群感染新城疫的流行特点及防治赵玉儒（山西省晋中地区畜牧中心０３０６００）史金柱（山西省昔阳县兽医院）在迅速发展的养鸡事业中，鸡新城疫病仍是危害较大的重要传染病。我区该病主要在免疫鸡群中发生和流行。发病后的鸡群临床症状不明显、病理变化不典型，这就...     

鸡新城疫的流行特点和有效控制办法

目前,鸡新城疫仍然是养鸡生产的大敌。特别是在农村肉仔鸡养殖户中,由于防疫观念差,不按有效的免疫程序进行免疫,使新城疫在鸡群中时有发生,给养鸡生产造成严重的经济损失。为此,在生产中应充分认识鸡新城疫的流行特点,以便采取更有效的控制方法,避免不应有的经济损失。     

黑龙江省禽肉厂新城疫流行情况调查

通过对黑龙江省7个禽肉厂养禽场的饲养情况，疲劳免疫、消毒隔离措施及疫情发生情况进行调查，统计各禽肉厂新城疫疫情的流行情况，并对出口的18批次90栋舍540只宰前肉用禽类进行新城疫（NDV）血清血凝抑制抗体检测和病毒分离鉴定。共从12批次25栋舍87只肉用禽中分离出新城疫病毒，并对其中69株新城疫病毒进行毒力鉴定。均为中等以下毒力，来分离出强毒株。     

新城疫的流行特点与防控措施

文章在调查无规定疫病区、活禽交易市场新城疫流行病学的基础上,对新城疫在我国的流行特点、分子流行病学以及不同动物中的流行情况进行了总结,通过探讨我国新城疫防疫中的薄弱环节,提出相应的对策.     

我国家禽新城疫流行现状

1鸡新城疫仍然是最重要的直接危害 虽然我国各地所有鸡群对鸡新城疫采取了强化的免疫预防措施,包括多次使用弱毒疫苗和灭活油乳苗,但鸡新城疫仍然在各地不同程度的流行.可以这样说,几乎很难说有哪一个鸡群真正消灭了鸡新城疫病毒(NDV)强毒感染.然而,在不同类型的鸡群,NDV强毒感染发生和流行的特点各不相同.     

鸡新城疫的流行特点

新城疫是由副粘病毒科副粘病毒亚科腮腺炎病毒属的禽副粘病毒Ⅰ型引起的高度接触性禽类烈性传染病,是危害养禽业的主要传染病：之一,近些年来,随着疫苗的普遍使用,在临床上典型新城疫已很难见到,但非典型新城疫及其混合感染却逐渐增多。     

1株鸭源Ⅰ类新城疫病毒分离株F和HN基因的分子特性分析

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。     

我国家禽新城疫病毒流行基因型分析

新城疫病毒(NDV)为RNA病毒,突变频率高,已进化出21种基因型.NDV强毒株引起的新城疫(ND)对我国养禽业造成巨大威胁.疫苗株与流行株基因型的不匹配导致疫苗效果不佳,影响了ND的防控.NDV可感染多种家禽,在不同宿主中流行的NDV基因型不同.目前,缺乏对我国家禽中NDV流行基因型的系统分析,影响了针对不同家禽ND...     

Characterization of pigeon-origin Newcastle disease virus isolated in China

Fourteen pigeon-origin Newcastle disease virus (NDV) isolates were obtained from sick pigeons in China between 1996 and 2005. The mean death time (MDT) of embryonated eggs and the intracerebral pathogenicity indices (ICPI) were tested to determine the virulence of the field isolates. The result indicated that most isolates were proved to be mesogenic (MDT 60-90 hr and ICPI > 1.2). The main function regions of F protein gene of the isolates were amplified and sequenced for phylogenetic and residue substitutive analysis. The fusion protein cleavage site sequences of most isolates had multiple basic amino acids R/KRQKRF at positions 112-116 and a phenyl alanine at position 117, characteristic of velogenic isolates. In the phylogenetic tree, the majority of the isolates were clustered into a single genetic lineage, termed genotype VIb, and were typical pigeon paramyxovirus type 1, whereas a small number of recent isolates (three strains) were grouped into genotype VIId, a predominant genotype responsible for most Newcastle disease outbreaks in chickens and geese since the end of last century. One isolate, PK9901, was proved to be a lentogenic strain, of genotype II NDV, to which the vaccine strain La Sota belongs.     

Molecular characterization of a recent Newcastle disease virus outbreak in Jordan

Newcastle disease (ND) is a highly contagious viral disease and is a continuous threat to the poultry industry worldwide. In the early months of 2011, several devastating ND outbreaks occurred in Jordan affecting broilers, layers and breeders. The fusion gene of the isolated Newcastle disease virus (NDV) was partially amplified by RT-PCR, then directly sequenced. The NDV isolates were found to have the motif(112)RRQKRF(117). This motif and a mean death time (MDT) of 46h are indicative of the velogenic nature of these NDV isolates. Phylogenetic analysis showed that the new NDV strain belongs to the lineage 5d (Aldous et al., 2003) and is closely related to the Chinese strain SG/Liaoning/2009. NDV outbreaks in 2010 and 2011 have been noted in neighboring countries. Based on the high nucleotide similarity between our isolated NDV isolates and the Chinese NDV strain, the origin of these recent NDV isolates might be from China.     

Molecular characterization and phylogenetic analysis of new Newcastle disease virus isolates from the mainland of China

Seventy-nine velogenic Newcastle disease virus (NDV) isolates were obtained from infected chicken flocks during the outbreaks of Newcastle disease (ND) in various regions of the mainland of China in 2006. The F gene fragment (535 bp, from nt 47 to 581 of the F gene) which codes the main functional region of the F protein was obtained by RT-PCR and sequenced. All sequences obtained in this study have been submitted to GenBank. All the isolates have the motif ¹¹²R-R-Q/R-K/R-R-F¹¹⁷ at the cleavage site of the fusion protein, which is typical of velogenic NDV isolates. For genotyping, a phylogenetic tree based on nucleotides 47–435 of the F gene was constructed, and the 79 isolates could be divided into two genotypes, namely VIId and III. Most of the isolates proved to be of genotype VIId; only two isolates were of genotype III. Genotype VIId NDV has been the predominant pathogen responsible for most Newcastle disease outbreaks in China. The proportion of isolates of genotype VIId NDV shows an increasing trend, according to studies on the molecular epidemiology of NDV in China from 2002 to 2006.     

Molecular characterization and phylogenetic analysis of new Newcastle disease virus isolates from the mainland of China

Seventy-nine velogenic Newcastle disease virus (NDV) isolates were obtained from infected chicken flocks during the outbreaks of Newcastle disease (ND) in various regions of the mainland of China in 2006. The F gene fragment (535 bp, from nt 47 to 581 of the F gene) which codes the main functional region of the F protein was obtained by RT-PCR and sequenced. All sequences obtained in this study have been submitted to GenBank. All the isolates have the motif ¹¹²R-R-Q/R-K/R-R-F¹¹⁷ at the cleavage site of the fusion protein, which is typical of velogenic NDV isolates. For genotyping, a phylogenetic tree based on nucleotides 47–435 of the F gene was constructed, and the 79 isolates could be divided into two genotypes, namely VIId and III. Most of the isolates proved to be of genotype VIId; only two isolates were of genotype III. Genotype VIId NDV has been the predominant pathogen responsible for most Newcastle disease outbreaks in China. The proportion of isolates of genotype VIId NDV shows an increasing trend, according to studies on the molecular epidemiology of NDV in China from 2002 to 2006.