China ; Encephalitis Virus, Japanese ; genetics ; immunology ; isolation & purification ; Encephalitis, Japanese ; virology ; Humans ; Research ; trends

To explore the spatial distribution mechanism of Japanese encephalitis virus (JEV), PhyML v3.0 was used to build phylogenetic tree using JEV sequences in the dataset. PAUP v4.0 and Migrapyhla softz ware were then used to analyze the migration events. The results showed that a total of 95 migration events were observed during the dispersal of JEV throughout Asia. Further analysis revealed that Thailand, and several Chinese provinces (including Shandong, Shanghai, Sichuan and Yunnan), were the main migration sources of JEV. JEV spread from these migration sources as follows: from Thailand to Australia, Cambodia, Tibet and India; from Shanghai to eastern coastal Asian regions and Yunnan; from Shandong to Korea, Zhejiang, Hubei, Shanxi and Liaoning; from Sichuan mainly to inland regions of China, as well as Vietnam and Japan; and from Yunnan to Zhejiang. This study indicated that frequent migration events occurred during the dispersal of JEV in the Asia and Pacific regions, and that Thailand, Shandong, Shanghai, Sichuan and Yunnan were the sources of JEV dispersal.
Asia ; epidemiology ; China ; epidemiology ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; physiology ; Encephalitis, Japanese ; epidemiology ; transmission ; virology ; Phylogeny

OBJECTIVESequence and analysis the complete nucleotide of the Japanese encephalitis virus (JEV) newly strain SD08-10, isolated in 2008 in Shandong, China in order to understand the characterization of the virus.

METHODSOverlapping primers were designed according to the full-length genomes in GenBank. RT-PCR was used to amplify the fragments and the full-length genome was obtained by sequencing and splicing. Using the computer software to analysis the nucleic acid data, deduced amino acid sequence and phylogenetic tree, including Clustal X (1.8), DNASTAR, GENEDOC (3.2).

RESULTSThe result of sequence analysis shows that the genome of SD08-10 strain was 10 965 nucleotides long. An open reading frame from 96 to 10 392 including 10 296 nucleotides is capable of coding for a 3432 amino acid polyprotein. Compared with the live attenuated vaccine strain SA-14-14-2 in China, there was 1253 nucleotide difference and 82 amino acid divergence. Comparison of the complete genome sequences with 59 different JEV isolates showed a 0.7%-18.9% nucleotide sequence divergence among them, which resulted in 0.1%-5.2% amino acid sequence divergence. Phylogenetic analysis of full-length genome showed that the SD08-10 strain was belonging to genotype I.

CONCLUSIONAnalysis based on the complete genome sequences of different JEV isolates showed that the SD08-10 strain isolated in 2008 in Shandong was belonging to genotype I and close to SH17M-07 isolated in 2007 in China.

China ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Encephalitis, Japanese ; virology ; Genome, Viral ; Molecular Sequence Data ; Phylogeny

OBJECTIVETo investigate the molecular basis of pathogenicity of Japanese encephalitis virus (JEV) by sequencing of complete nucleotide sequence and analyze the characteristics of full-length genome of genotype I Japanese encephalitis virus strains (GZ56) which was isolated from the first cerebrospinal fluid (CSF) of Japanese encephalitis patients.

METHODSThe complete nucleotide sequence was obtained by RT-PCR and sequencing was performed directly. Bioinformatics was used to analyze the nucleic acid data, deduced amino acid sequence and phylogenetic trees.

RESULTSThe result of sequence analysis showed that the genome of GZ56 strains had 10 965 nucleotides, which coded for a 3432-amino acid polyprotein. Phyolngenetic analysis based on full-length genome showed that GZ56 strains and M-28 strains which were the first isolated from mosquitoes in Yunnan in 1977 were in the same evolutionary branch. GZ56 strains belongs to genotype I of Japanese encephalitis virus, the homology of genome ranged from 96.2% to 98.6% in nucleotide and from 98.2% to 99.7% in amino acid sequences respectively when compared with selected genotype I of JEV strains in GenBank. There were 11 amino acid divergences in E protein when compared with the JEV inactivated P3 strain but they are not the key virulence sites. However, there were 14 amino acid divergences in E protein when compared with the JEV live attenuated vaccine SA14-14-2 strain and 8 amino acid divergences were the key virulence sites.

CONCLUSIONThis study indicated that the full length of genome GZ56 strains had no ignificant change. It can be hypothesized from genomic level that the currently available JEV vaccines(inactivated and live attenuated) can protect against GZ56 strains infection, meanwhile, the JEV live attenuated vaccine (SA14-14-2) formulation conferred higher levels of protection.

Computational Biology ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Encephalitis, Japanese ; virology ; Enzyme-Linked Immunosorbent Assay ; Genome, Viral ; Genotype ; Japanese Encephalitis Vaccines ; immunology ; Phylogeny ; Sequence Analysis, DNA

OBJECTIVETo investigate the species and distribution of mosquitoes and mosquito-borne arboviruses in Yuncheng city of Shanxi province, China.

METHODSMosquito samples were collected in 19 collection sites from Linyi county and Yongji city in Yuncheng city, in August, 2012. After identification and classification, all the specimens were homogenized and centrifuged to acquire supernatant before being inoculated to both C6/36 and BHK21 cells for viral isolation. Positive isolates were identified with arbovirus species-specific primers under RT-PCR, for further sequencing and phylogenetic analysis.

RESULTSA total of 10 455 mosquitoes of 7 species in 4 genuese were collected. The predominant mosquito species in Linyi county was Culex pipens pallens (91.96%, 3 911/4 253), but the one in Yongji city was Culex tritaeniorhynchus (72.85%, 4 518/6 202). A total of 23 strains of viruses were isolated from the mosquito pools. 15 strains from Culex tritaeniorhynchus and Culex pipens pallens were identified as genotype I Japanese encephalitis virus (JEV). Four strains from Culex pipens pallens were identified as Culex flavivirus (CxFV). Three strains from Culex pipens pallens were identified as Culex pipiens pallens densovirus (CppDNV). One strain from Armigeres subalbatus and Aedes albopictus was identified as Getah virus (GETV).

CONCLUSIONFour kinds of arboviruses were isolated from the mosquito pools, including GETV and CxFV, which were isolated and documented in Shanxi province for the first time. In the city of Yuncheng, Culex tritaeniorhynchus had been the predominant species and major vector for transmitting JEV. Genotype I JEV remained the major JEV circulating in the local natural environment.

Animals ; Arboviruses ; genetics ; isolation & purification ; China ; Cities ; Culicidae ; virology ; Encephalitis Virus, Japanese ; genetics ; Phylogeny ; Species Specificity

OBJECTIVETo sequence and analyze the whole genome of Japanese encephalitis virus (JEV) strain named 47 which was isolated from patient's cerebrospinal fluid sample in Heilongjiang province in 1950.

METHODSRNA was extracted from the recovery strain 47 and amplified with self-designed JEV genome sequencing primers. The differentiation analysis for nucleotides and coding amino acids and phylogenetic analysis were performed by the software of DNAStar, Modeltest, and Phylip.

RESULTSThe whole genome of strain 47 has 10,977 nucleotides. An open reading frame from 95 to 10,391 including 10,296 nucleotides is capable of coding a 3432 amino acid polyprotein. The nucleotide difference between strain 47 and 5 vaccine strains is 2.4%-4.4%, the amino acid difference between strain 47 and 5 vaccine strains is 0.3%-1.1%. The best evolution model for the whole genome is GTR + I + G. Based on the phylogenetic analysis, strain 47 belongs to the genotype III JEV.

CONCLUSIONStrain 47 is highly conserved on whole genome nucleotide and amino acid sequence. And it is belongs to the genotype III JEV.

China ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Encephalitis, Japanese ; virology ; Genome, Viral ; Humans ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; RNA, Viral ; cerebrospinal fluid ; genetics ; isolation & purification

OBJECTIVEFor constructing the high-throughput platform of sequencing the JEV whole genome, the two systems of multiplex primers for genotype I and III should be designed and used for detected the whole genome of genotype I and III JEV in the research.

METHODSThe two systems of JEV genotype-specific primers was designed based on the reference sequence of all the available genotype I and III JEV genome sequence on GenBank, then, they were used to amply and sequence the 121 JEV strains isolated in China contains 63 GIII JEV and 58 GI JEV.

RESULTSThe self-designed genotype-specific primers for genotype I and genotype III JEV were 16 pairs and 17 pairs respectively, which were used for detecting the whole genome of 121 JEV. The average quality value for GI JEV is 40.037. The average quality value for GIII JEV is 40.857.

CONCLUSIONThe two systems of JEV genotype-specific primers could sequenced the genotype I and III JEV qualified and specific. It is the basis of the high throughput platform of sequencing the JEV whole genome.

China ; DNA Primers ; genetics ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Encephalitis, Japanese ; virology ; Genotype ; Humans ; Molecular Sequence Data ; Phylogeny ; Species Specificity

OBJECTIVETo sequence and analyze the whole genome of Japanese encephalitis virus (JEV) isolated from mosquitoes in Liaoning province in 2008.

METHODSUsing RT-PCR to amplify fragments with genome sequencing primer. The full-length genome was obtained by sequencing and splicing. The differentiation analysis for nucleotides, deduced amino acid sequence and phylogenetic tree was performed by the software of Clustal X (1.83), ATGC (V4), DNAStar, GENEDOC (3.2) and Mega (4.0).

RESULTSThe whole genome of strain LN0828 possesses 10 965 nucleotides. An open reading frame from 97 to 10 392 including 10 296 nucleotides is capable of coding for a 3432 amino acid polyprotein. Comparison of strain LN0828 genomic sequence with those of 32 JEV isolates in GenBank showed that nucleotide sequence divergence ranges from 1.6% to 16.4%, which resulted in amino acid sequence divergence from 0.3% to 5.1%. In comparison with live attenuated vaccine stain SA14-14-2 in open reading frame, strain LN0828 has a total of 1186 nucleotide substitutions, 86 amino acid divergences. Based on phylogenetic analysis, the strain LN0828 belongs to the genotype I JEV.

CONCLUSIONThe whole genome of strain LN0828 is close to those of isolates from Liaoning in 2002 and 2007, which were grouped into genotype I JEV.

China ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Encephalitis, Japanese ; virology ; Genome, Viral ; Humans ; Molecular Sequence Data ; Phylogeny ; Viral Proteins ; genetics

To conduct sequencing of full-length genomes of two Japanese encephalitis virus strains (JEV) newly isolated in 2009 in China and analyze the characteristics of complete nucleotide sequences. The complete genomic sequences were obtained by RT-PCR and sequencing directly. Bioinformatics was used to analyze the nucleic acid data, deduced amino acid sequence and phylogenetic trees. The result of sequence analysis showed that the genomes of YN0911 and YN0967 strains were both 10965nt in length, which coded 3432 amino acid polyprotein. The homology of genome ranged from 83.3% to 98.9% in nt and from 94.8% to 99.7% in aa, respectively, when compared with selected JEV strains in GenBank. There were 13 amino acid divergences which were not the key virulence sites in E protein when compared with vaccine strain SA14-14-2. There were 11nt deletions in the 3' UTR region. Phylogenetic analyses based on C/ PrM, E gene and full-length genome all showed that YN0911 and YN0967 strains belonged to genotype I. The result also showed that two new JEVs had close phylogenetic relationship with the strains from Viet Nam, Sichuan Province, Guizhou Province, Guangxi Province, China. This study indicated that JEV strains newly isolated in 2009 in China were the members of JEV genotype I. The key virulence sites in E protein did not change.
Amino Acid Sequence ; Base Sequence ; China ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Encephalitis, Japanese ; virology ; Genome, Viral ; genetics ; Humans ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA

The biological and genetic characteristics of a highly neurovirulent JE virus strain SA4 were studied. Mice were inoculated intracerebrally with strain SA4 and SA14, and observed for 14 days, respectively. On different days, mice brains were harvested for titrations of the virus content in the brains. Full-length genome of SA4 was sequenced and compared with SA14 as well as other JE virus strains in the world. The results indicated that the mice inoculated by SA4 induced sickness and death more rapidly (24 hours faster) than those induced by the SA14. The virus titers in the brains of mice infected with SA4 were 0.5-1.0 lg PFU/mL higher than that infected with SA14. The sequence comparison indicated that the nucleotide and amino acid homology between SA4 and the other 21 JE strains were 84.6%-99.0% and 95.2%-99.7% respectively. Comparison with strain SA14 revealed that there were 17 amino acid differences between the two strains, of which 5 were in the E protein region. The results demonstrate that strain SA4 is a highly neurovirulent strain. The substitutions of the 17 amino acids in the SA4 strain can be the molecular basis for the biological characteristics of high neurovirulence.
Animals ; Brain ; virology ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; pathogenicity ; Encephalitis, Japanese ; mortality ; virology ; Genotype ; Humans ; Mice ; Sequence Analysis ; Viral Envelope Proteins ; genetics ; Virulence