Isolation and identification of Japanese encephalitis virus in Liaoning Province / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To study arboviruses carried by mosquitoes in Liaoning Province in 2002.</p><p><b>METHODS</b>Totally 4927 mosquitoes were collected from Liaoning Province in July 2002. Virus strains were isolated by inoculating BHK-21, C6/36 and Vero cells. The newly isolated strains were identified by serological (ELISA and IFA) and molecular methods (Real-Time PCR and RT-PCR).</p><p><b>RESULTS</b>Two strains were isolated from mosquitoes causing cytopathogenic effect (CPE) on cells and were fatal to suckling mice. Serological tests showed that both were positive for the antibody to JEV. The PrM and E gene were cloned and sequenced. The phylogenetic analysis showed that the new isolates belonged to genotype I, JEV. Sequence analysis showed that the homology of nucleotide sequences and amino acid (AA) sequences between the two strains was 100%. Compared with the nucleotide sequences between the two strains and the standard JEV vaccine strain SA14-14-2, the difference was up to 4.11%, and the difference of AA was 0.6%.</p><p><b>CONCLUSION</b>Two strains of JEV were isolated and identified in Liaoning province, both belonged to genotype I JEV.</p>

Arbovirus survey in some regions in Heilongjiang province / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>Mosquitoes were collected in Heilongjiang province in 2002, four virus strains were isolated by inoculation of homogenates onto BHK cell lines. The viruses were identified. Multiple alignment and phylogenetic analysis were carried out by Clustal X (1.8) program.Amino acid (AA) analysis was carried out by GENEDOS (3.2).</p><p><b>RESULTS</b>Biological characters of four newly isolated strains were examined and it was found that all of them could produce cytopathogenic effect (CPE) in BHK cells, killing sucking mice. Serological tests showed that all of these stains reacted positively to JEV antibodies. PrM and E gene regions were amplified and sequenced. Phylogenic analysis showed that all the newly isolated JEV strains belong to genotype III. Using the vaccine strains (SA14-14-2) as control, analysis of the E gene of the new strains and two JEV strains (47, Ha-3) isolated previously from Heilongjiang province showed that these new strains' nucleotide sequence had a homology of up to 99.9% and the amino acid sequence homology up to 99.8%, respectively. Compared with the standard JE vaccine strain SA-14-14-2 and the four new strains, the nucleotide sequence homology was 97.3% and amino acid sequence homology was between 96.8% and 97.0%, respectively. Compared with vaccine strain, there were seven common variations in all the four newly isolated strains.</p><p><b>CONCLUSION</b>Four JE virus strains were isolated in Heilongjiang province. As compared to the vaccine strain, six variations were found in the newly isolated strains at the eight sites relevant to the virulence of the virus.</p>

Isolation and identification of arboviruses from mosquito pools in Yunnan Province / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To survey arboviruses in Yunnan province.</p><p><b>METHODS</b>Mosquitoes were collected from Yunnan Province in 2002 and 2004. Virus strains were isolated by the inoculation of homogenates of the mosquitoes onto BHK cell line. The isolated strains and their molecular biological characteristics were identified by real-time PCR, reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescent antibody technique.</p><p><b>RESULTS</b>Twelve strains of viruses producing CPE in BHK cells were isolated from 4810 mosquitoes. All the 12 isolates were identified to be Japanese encephalitis viruses. Genotype analysis showed the new virus (DL-0437 strain) belonged to genotype III.</p><p><b>CONCLUSION</b>Twelve strains of Japanese encephalitis viruses were isolated from mosquito pools collected in Yunnan. It was the first isolation of genotype III Japanese encephalitis viruses in Yunnan Province in recent years.</p>