Jackwood Daral J, Sommer-Wagner Susan
Food Animal Health Research Program, The Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Avenue, Wooster, Ohio 44691, USA.
Virology. 2007 Sep 1;365(2):369-75. doi: 10.1016/j.virol.2007.03.046. Epub 2007 May 8.
Following the initial discovery of very virulent infectious bursal disease virus (vvIBDV) strains in Europe, these viruses spread to many parts of the world. In this study, we examined the phylogenetic relationship of never-before-published IBDV from 18 countries on four continents. All the samples were collected between 1997 and 2005 and were reported to be from broiler flocks experiencing higher than expected mortality which is often associated with acute very virulent infectious bursal disease. A total of 113 samples were imported into the U.S. and viral genetic material was used to determine the nucleotide sequence of the VP2 gene hypervariable region. Although all the samples were reported to be associated clinically with high mortality, genetic analysis suggests that some were not vvIBDV strains. Two viruses from South Africa were genetically similar to U.S. variant viruses. A majority (71/113) of the viruses examined had the amino acid Alanine at position 222 and sixty-seven of these suspect vvIBDV also had amino acids I242, I256, I294 and S299 which are highly conserved among vvIBDV strains. Phylogenetic analysis placed putative vvIBDV strains from many different countries and geographic regions in a single clade with some minor non-significant branching.
在欧洲首次发现超强毒传染性法氏囊病病毒（vvIBDV）毒株之后，这些病毒传播到了世界许多地区。在本研究中，我们检测了来自四大洲18个国家的此前从未发表过的传染性法氏囊病病毒（IBDV）的系统发育关系。所有样本均采集于1997年至2005年期间，据报告来自肉鸡群，这些鸡群经历了高于预期的死亡率，这通常与急性超强毒传染性法氏囊病有关。共有113个样本被引入美国，利用病毒遗传物质来确定VP2基因高变区的核苷酸序列。尽管所有样本在临床上均报告与高死亡率有关，但基因分析表明，其中一些并非vvIBDV毒株。来自南非的两种病毒在基因上与美国变异病毒相似。所检测的大多数病毒（71/113）在第222位氨基酸为丙氨酸，其中67种疑似vvIBDV在第242、256、294和299位氨基酸也具有在vvIBDV毒株中高度保守的氨基酸。系统发育分析将来自许多不同国家和地理区域的推定vvIBDV毒株置于一个单一分支中，有一些微小的、无显著意义的分支。
