Heterogeneity and genetic variations of serotypes O and Asia 1 foot-and-mouth disease viruses isolated in Vietnam.
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.
Le
Van Phan
VP
Foreign Animal Disease Division, National Veterinary Research and Quarantine Service, Anyang, Gyeonggi 430-757, Republic of Korea.
Nguyen
Tung
T
Park
Jong-Hyeon
JH
Kim
Su-Mi
SM
Ko
Young-Joon
YJ
Lee
Hyang-Sim
HS
Nguyen
Van Cam
VC
Mai
Thuy Duong
TD
Do
Thi Hoa
TH
Cho
In-Soo
IS
Lee
Kwang-Nyeong
KN
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics; D016000:Cluster Analysis; D004196:Disease Outbreaks / Q000662:veterinary*; D005536:Foot-and-Mouth Disease / Q000453:epidemiology / Q000821:virology*; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics*; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014744:Vietnam / Q000453:epidemiology
D036022:Capsid Proteins; D012367:RNA, Viral; C442501:VP1 protein, Foot-and-mouth disease virus