Confirmation of the existence of two distinct genetic groups of infectious bursal disease virus in Australia
Confirmation of the existence of two distinct genetic groups of infectious bursal disease virus in Australia
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DOI：
10.1111/j.1751-0813.2002.tb11299.x
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发表时间：
2002-11-01
影响因子：
1.1
通讯作者：
Sapats, S
中科院分区：
文献类型：
--
作者：
Ignjatovic, J;Sapats, S
目的对澳大利亚主要商业场所流行的传染性法氏囊病病毒（infectious bursal disease viruses，IBDV）进行鉴定，并与国外毒株进行核酸序列比较。设计从澳大利亚新南威尔士州（New South Wales，NSW）、昆士兰州（Old）、维多利亚（维克）、Western（WA）和南澳（SA）。将囊组织匀浆，并使用检测IBDV毒株中抗原变异的四种单克隆抗体（Mab）检测IBDV抗原的存在。测定了IBDV VP 2基因内的高变区（HVR）的核苷酸序列，并将推导的氨基酸序列与3种疫苗株和6种先前表征的澳大利亚IBDV株进行了比较。推导的氨基酸序列与国外已发表的氨基酸序列进行了比较。结果在抽样的20个农场中，有14个农场的家禽中检测到IBDV。用4种单克隆抗体进行分型，结果表明，来自维克（6）和SA（10）的所有病毒均为抗原变异株，而来自NSW（29）、Old（4）和WA（5）的所有病毒均为经典样株。对来自检测到IBDV的14个农场的每个农场的一个样品进行核苷酸测序，证实了用Mab获得的结果。所有澳大利亚病毒的氨基酸序列与国外IBDV毒株的氨基酸序列不同。系统发育分析表明，澳大利亚IBDV病毒属于两个不同的遗传组。超强毒株属于第三遗传群，国外经典毒株和变异毒株属于第四遗传群。大多数为经典样毒株，与疫苗株002/73和V877在抗原性和遗传学上相似。这些经典菌株在三个州（NSW、Old和WA）的肉鸡中流行。第二组菌株是抗原变异体，仅在维克和SA两个州的肉鸡中发现。迄今为止，所有澳大利亚IBDV的特征在遗传上都是不同的，可以与所有其他海外毒株区分开来。这使得能够鉴定入侵澳大利亚家禽的任何外来毒株，无论是经典毒株、美国变异毒株还是vvIBDV毒株。
Objective To characterise infectious bursal disease viruses (IBDVs) prevalent at major commercial sites throughout Australia and to compare the nucleic acid sequences of local strains of IBDV with those of characterised overseas strains.Design Samples of bursae were collected from 20 broiler farms that belonged to different poultry companies in New South Wales (NSW), Queensland (Old), Victoria (Vic), Western (WA) and South Australia (SA).Method Bursae were collected from broilers between 24 and 35 days of age. Bursal tissue was homogenised and tested for the presence of IBDV antigen using four monoclonal antibodies (Mabs) which detect antigenic variation in IBDV strains. The nucleotide sequences of the hypervariable region (HVR) within the VP2 gene of IBDVs was determined and the deduced amino acid sequences compared with three vaccine strains and six previously characterised Australian IBDV strains. The deduced amino acid sequences were also compared with the published amino acid sequences of overseas strains. The phylogenetic relationships between Australian strains and overseas strains were then determined.Results IBDV was detected in birds from 14 out of 20 farms sampled. Typing with four Mabs showed that all viruses from Vic (6) and SA (10) were antigenic variants, whereas all viruses from NSW (29), Old (4) and WA (5) were classical-like strains. Nucleotide sequencing of one sample from each of the 14 farms on which IBDV was detected confirmed results obtained with Mabs. The amino acid sequences of all Australian viruses differed from the amino acid sequences of foreign IBDV strains. Phylogenetic analysis showed that Australian IBDV viruses belonged to two distinct genetic groups. Very virulent (vv) IBDV strains belonged to a third genetic group, and overseas classical and variant strains belonged to a fourth genetic group.Conclusions The results confirmed previous findings that there are two groups of IBDV strains circulating in commercial broilers in Australia. The majority are classical-like strains that are antigenically and genetically similar to vaccine strains 002/73 and V877. These classical strains were prevalent in broilers in three states, NSW, Old and WA. The second group of strains are antigenic variants that were only found in broilers in two states, Vic and SA. All Australian IBDVs characterised to date are genetically distinct and can be differentiated from all other overseas strains. This enables identification of incursion of any exotic strain into Australian poultry, be it classical, US variant or vvIBDV strains.