Foreign Animal Disease Division, National Veterinary Research and Quarantine Service, Anyang, Gyeonggi 430-757, Republic of Korea.
Vet Microbiol. 2010 Oct 26;145(3-4):220-9. doi: 10.1016/j.vetmic.2010.04.005. Epub 2010 Apr 18.
Six field foot-and-mouth disease viruses (FMDVs), including four serotype O and two serotype Asia 1 strains, were collected from endemic outbreaks in 2005, 2006, and 2007 from four different provinces in Vietnam. The viruses were isolated and genetically characterized for their complete genomic sequences. The genetic analysis based on the complete genomic coding sequences revealed that the four serotype O FMDVs were related to each other, sharing 95.2% nucleotide (nt) identity and 97.5-97.6% amino acid (aa) identity. Genetic analysis and a phylogenetic tree, based on the VP1 gene of FMDV, showed that the four present Vietnamese serotype O strains have a high level of identity with other serotype O representatives of the Mya-98 lineage of the Southeast Asian (SEA) topotype. The four viruses were all clustered into the Mya-98 lineage of the SEA topotype, sharing 92.3-95.6% nt and 93.4-96.7% aa identity. This finding of the Mya-98 lineage was different from previous reports that the Vietnamese serotype O strains belonged to the Cam-94 lineage of the SEA topotype and two other topotypes, Middle East-South Asia (ME-SA) and Cathay. For the two serotype Asia 1 FMDVs, the genetic analysis based on the complete genomic coding sequences as well as on the VP1 gene revealed that they belonged to two genogroups, IV and V. Of note, the As1/VN/QT03/2007 strain of genogroup V, isolated in 2007, was very closely related to the pandemic Asia 1 strain which caused FMD outbreaks in China (Asia1/WHN/CHA/06, FJ906802) and Mongolia (Asia1/MOG/05, EF614458) in 2005, sharing 99.0-99.3% nt and 99.5-100% aa identity. In contrast, the second strain As1/VN/LC04/2005 of genogroup IV, isolated in 2005, was closely related to all referenced Vietnamese serotype Asia 1 strains found in the GenBank databases, sharing 86.4-100% nt and 90.9-100% aa identity with each. This study is the first description of the full-length genomic sequence of Vietnamese FMDV serotypes O and Asia 1 and may provide the evidence of the concurrent circulation of different serotypes and subtypes of FMDV in recent years in Vietnam.
从 2005 年、2006 年和 2007 年越南四个不同省份的地方流行爆发中，收集了六种口蹄疫病毒（FMDV），包括四种血清型 O 和两种血清型亚洲 1 株。对这些病毒进行了分离和遗传特征分析，以获得其完整基因组序列。基于完整基因组编码序列的遗传分析表明，四种血清型 O FMDV 彼此相关，核苷酸（nt）同一性为 95.2%，氨基酸（aa）同一性为 97.5-97.6%。基于 FMDV 的 VP1 基因的遗传分析和系统发育树表明，这四种目前越南血清型 O 株与东南亚（SEA）拓扑结构的 Mya-98 谱系的其他血清型 O 代表具有高度的同一性。四种病毒均聚类到 Mya-98 谱系的 SEA 拓扑结构中，核苷酸（nt）同一性为 92.3-95.6%，氨基酸（aa）同一性为 93.4-96.7%。这一发现在以前的报告中有所不同，以前的报告表明，越南血清型 O 株属于东南亚（SEA）拓扑结构的 Cam-94 谱系和另外两个拓扑结构，中东-南亚（ME-SA）和中国（Cathay）。对于两种血清型亚洲 1 FMDV，基于完整基因组编码序列以及 VP1 基因的遗传分析表明，它们属于两个基因群，IV 和 V。值得注意的是，2007 年分离的 V 群的 As1/VN/QT03/2007 株与引起中国（亚洲 1/WHN/CHA/06，FJ906802）和蒙古（亚洲 1/MOG/05，EF614458）口蹄疫爆发的大流行亚洲 1 株非常密切相关，核苷酸（nt）同一性为 99.0-99.3%，氨基酸（aa）同一性为 99.5-100%。相比之下，2005 年分离的 IV 群的第二株 As1/VN/LC04/2005 与在 GenBank 数据库中发现的所有参考的越南血清型亚洲 1 株密切相关，核苷酸（nt）同一性为 86.4-100%，氨基酸（aa）同一性为 90.9-100%。本研究首次描述了越南口蹄疫病毒血清型 O 和亚洲 1 的全长基因组序列，可能为近年来越南不同血清型和亚型口蹄疫病毒的同时流行提供了证据。
