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Thirty-three field isolates of avian infectious bronchitis virus (IBV) were recovered from commercial chicken flocks in Korea between 2003 and 2006 and were characterized phylogenetically by nucleotide sequence analysis of the IBV S1 gene hyper-variable region. Our phylogenetic analysis revealed that recent field isolates of IBV formed at least three distinct phylogenetic types, including K-I, K-II, and K-III. K-I type IBV consisted of indigenous, 13 IBV isolates which evolved from the Kr-EJ/95 strain and then separated into the lineages of type K-Ia and type K-Ib. K-II type IBV isolates (n = 19) were closely related to nephropathogenic IBV variants from China and Japan. The K-III type isolate (Kr/D064/05), first identified by this study, was closely related to enteric IBV variants from the Chinese strains that cause proventriculitis. Sequence comparisons showed amino acid differences of >27.5% between IBV types. The molecular epidemiologic characteristics of IBV field isolates are briefly discussed.  相似文献   

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Seventeen isolates of infectious bronchitis virus (IBV) were obtained from various prefectures of Japan during 2008–2019 and genetically analyzed. The IBV isolates were classified into six genetic groups, based on phylogenetic analysis of the S1 gene. The S1 genotypes were distinguishable by a newly developed restriction fragment length polymorphism (RFLP) method using three endonucleases, Hae II, Hpa I, and Fok I. Moreover, the isolates were classified into four genetic groups, based on phylogenetic analysis of the S2 gene. However, novel genetic groups based on a combination of S1 and S2 genotypes, which were undetected previously, were confirmed in this study, indicating that various recombinant IBV strains were prevalent in poultry in Japan.  相似文献   

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Yu L  Wang Z  Jiang Y  Low S  Kwang J 《Avian diseases》2001,45(1):201-209
In order to trace the origin and evolution of avian infectious bronchitis virus (IBV) isolates in China and Southeast Asia, genomic sequencing was used for molecular characterization of 24 IBV isolates and two reference strains in comparison with the published sequences. The 5' region of the S1 genes, containing hypervariable regions I and II, and 3' region of the nucleocapsid genes, containing cytotoxic T lymphocyte epitopes, were used to construct phylogenetic trees for analysis. The results showed that the 24 isolates could be divided into three distinct groups, that is, American, Asian, and European. Some isolates formed a distinct Asian phylogenetic group, suggesting that IBV has existed for some time in Asia. Our results also showed that in vivo recombination of IBV may have occurred at a rather high frequency, contributing to the diversity of these IBV isolates. Importantly, recombination events have probably occurred between vaccine strains and field strains in the natural condition.  相似文献   

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参考GenBank上的IBVS1基因序列,自行设计合成了一对跨幅约0.6kb的引物,RT-PCR对6株IBV分离株的S1基因进行扩增。序列分析显示,这些病毒从时间、空间和组织嗜性都没有明显的规律可循。2株从传染性腺胃炎病鸡中获得病毒(ZC4-3株和DB239-1株)属于既不同于国内其他分离毒株,又不同于国际参考毒株的独立一群。通过对IBV的分析,认为现流行的IBV已发生了很大的变异,分别利用嗜肾性、嗜呼吸道性和嗜腺胃性的毒株研制疫苗,对我国IBV的防疫十分重要。  相似文献   

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鸡传染性支气管炎病毒CQ/01/2004株的分离与鉴定   总被引:2,自引:0,他引:2  
2004年从重庆某肉用鸡场疑似鸡传染性支气管炎的病鸡中采集病料,按常规处理后接种9~10日龄鸡胚,通过鸡胚连续传代培养3代,并对该分离毒株的鸡胚致病性、血凝性和NDV的干扰特性进行检测.同时进行了动物回归试验。结果表明,该分离株具有IBV感染特征,可使鸡胚胚体出血、蜷缩、矮化;该分离毒株无直接血凝性,对NDV有明显的干扰作用;动物回归试验中有75%的感染鸡在10d内发病或死亡。剖检病死鸡可见肾苍白、肿胀,肾小管内充塞大量尿酸盐,支气管有出血点、有大量粘液。采用反转录.聚合酶链式反应(RT-PCR)技术对CQ/01/2004的纤突蛋白S1基因进行扩增、克隆和序列测定,结果表明该基因具有IBVSl基因的共有分子特征,将测序结果提交GenBank进行同源性检索,发现分离株CQ/01/2004和J株S1的同源性最高,核苷酸同源性为94%,氨基酸同源性为89.4%,与M41的核苷酸同源性为80.6%,氨基酸同源性为78.0%。试验结果表明,分离的病毒株CQ/01/2004为鸡传染性支气管炎病毒。  相似文献   

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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   

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Sixteen infectious bronchitis virus (IBV) isolates were recovered from broilers and layers from five geographic poultry regions in Colombia. The viruses were isolated from tracheas, lungs, and cecal tonsils of birds, previously vaccinated with the Massachusetts strain, that were showing respiratory signs. Further analysis of the IBV isolates was achieved by phylogenetic analysis comparing their deduced amino acid sequences in the hypervariable region 1 of the S1 gene with reference strains. Four unique genotype clusters containing isolates with indigenous genotypes were observed. One isolate was found to be the Connecticut genotype and three isolates were found to be the Massachusetts genotype.  相似文献   

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The aim of this study was to develop a standardized molecular assay that used limited resources and equipment for routine genotyping of isolates of the fish rhabdovirus, viral haemorrhagic septicaemia virus (VHSV). Computer generated restriction maps, based on 62 unique full-length (1524 nt) sequences of the VHSV glycoprotein (G) gene, were used to predict restriction fragment length polymorphism (RFLP) patterns that were subsequently grouped and compared with a phylogenetic analysis of the G-gene sequences of the same set of isolates. Digestion of PCR amplicons from the full-length G-gene by a set of three restriction enzymes was predicted to accurately enable the assignment of the VHSV isolates into the four major genotypes discovered to date. Further sub-typing of the isolates into the recently described sub-lineages of genotype I was possible by applying three additional enzymes. Experimental evaluation of the method consisted of three steps: (i) RT-PCR amplification of the G-gene of VHSV isolates using purified viral RNA as template, (ii) digestion of the PCR products with a panel of restriction endonucleases and (iii) interpretation of the resulting RFLP profiles. The RFLP analysis was shown to approximate the level of genetic discrimination obtained by other, more labour-intensive, molecular techniques such as the ribonuclease protection assay or sequence analysis. In addition, 37 previously uncharacterised isolates from diverse sources were assigned to specific genotypes. While the assay was able to distinguish between marine and continental isolates of VHSV, the differences did not correlate with the pathogenicity of the isolates.  相似文献   

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