Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, USA.
PLoS One. 2013 Aug 12;8(8):e68777. doi: 10.1371/journal.pone.0068777. eCollection 2013.
A cytopathic virus was isolated using Madin-Darby bovine kidney (MDBK) cells from lung tissue of alpaca that died of a severe respiratory infection. To identify the virus, the infected cell culture supernatant was enriched for virus particles and a generic, PCR-based method was used to amplify potential viral sequences. Genomic sequence data of the alpaca isolate was obtained and compared with sequences of known viruses. The new alpaca virus sequence was most similar to recently designated Enterovirus species F, previously bovine enterovirus (BEVs), viruses that are globally prevalent in cattle, although they appear not to cause significant disease. Because bovine enteroviruses have not been previously reported in U.S. alpaca, we suspect that this type of infection is fairly rare, and in this case appeared not to spread beyond the original outbreak. The capsid sequence of the detected virus had greatest homology to Enterovirus F type 1 (indicating that the virus should be considered a member of serotype 1), but the virus had greater homology in 2A protease sequence to type 3, suggesting that it may have been a recombinant. Identifying pathogens that infect a new host species for the first time can be challenging. As the disease in a new host species may be quite different from that in the original or natural host, the pathogen may not be suspected based on the clinical presentation, delaying diagnosis. Although this virus replicated in MDBK cells, existing standard culture and molecular methods could not identify it. In this case, a highly sensitive generic PCR-based pathogen-detection method was used to identify this pathogen.
使用来自死于严重呼吸道感染的羊驼肺组织的 Madin-Darby 牛肾 (MDBK) 细胞分离出一种致病变病毒。为了鉴定该病毒，用浓缩病毒颗粒的方法从感染细胞培养物上清液中提取病毒，并使用基于通用 PCR 的方法扩增潜在的病毒序列。获得了羊驼分离株的基因组序列数据，并与已知病毒序列进行了比较。该新的羊驼病毒序列与最近命名的肠道病毒属 F 型最相似，以前称为牛肠道病毒 (BEV)，该病毒在全球牛群中普遍存在，尽管它们似乎不会引起严重疾病。由于牛肠道病毒以前未在美国家养羊驼中报道过，我们怀疑这种类型的感染相当罕见，并且在这种情况下，感染似乎没有超出最初的爆发范围。检测到的病毒的衣壳序列与肠道病毒 F 型 1 具有最大同源性（表明该病毒应被视为血清型 1 的成员），但在 2A 蛋白酶序列中与 3 型的同源性更大，表明它可能是一种重组病毒。首次鉴定感染新宿主物种的病原体可能具有挑战性。由于新宿主物种中的疾病可能与原始或天然宿主中的疾病大不相同，因此可能不会根据临床表现怀疑病原体，从而导致诊断延误。尽管该病毒在 MDBK 细胞中复制，但现有的标准培养和分子方法无法鉴定它。在这种情况下，使用高度敏感的基于通用 PCR 的病原体检测方法来鉴定该病原体。
