Larsen L E, Tjørnehøj K, Viuff B
Danish Veterinary Laboratory, DK-1790 Copenhagen V, Denmark.
J Clin Microbiol. 2000 Nov;38(11):4222-7. doi: 10.1128/JCM.38.11.4222-4227.2000.
The nucleotides coding for the extracellular part of the G glycoprotein and the full SH protein of bovine respiratory syncytial virus (BRSV) were sequenced from viruses isolated from numerous outbreaks of BRSV infection. The isolates included viruses isolated from the same herd (closed dairy farms and veal calf production units) in different years and from all confirmed outbreaks in Denmark within a short period. The results showed that identical viruses were isolated within a herd during outbreaks and that viruses from recurrent infections varied by up to 11% in sequence even in closed herds. It is possible that a quasispecies variant swarm of BRSV persisted in some of the calves in each herd and that a new and different highly fit virus type (master and consensus sequence) became dominant and spread from a single animal in connection with each new outbreak. Based on the high level of diversity, however, the most likely explanation was that BRSV was (re)introduced into the herd prior to each new outbreak. These findings are highly relevant for the understanding of the transmission patterns of BRSV among calves and human respiratory syncytial virus among humans.
对从多次牛呼吸道合胞病毒（BRSV）感染暴发中分离出的病毒，测定了编码G糖蛋白胞外部分的核苷酸以及BRSV全SH蛋白的核苷酸序列。这些分离株包括不同年份从同一牛群（封闭式奶牛场和犊牛生产单位）分离出的病毒，以及短期内丹麦境内所有确诊暴发中的病毒。结果显示，暴发期间在同一牛群中分离出了相同的病毒，而且即使在封闭式牛群中，反复感染的病毒在序列上也最多有11%的差异。有可能在每个牛群的一些犊牛中存在BRSV的准种变异群，并且一种新的、不同的高适应性病毒类型（主序列和共有序列）在每次新的暴发中从单头动物开始占主导并传播。然而，基于高度的多样性，最有可能的解释是在每次新的暴发之前BRSV被（重新）引入了牛群。这些发现对于理解BRSV在犊牛之间的传播模式以及人呼吸道合胞病毒在人类之间的传播模式具有高度相关性。
