ABSTRACT
<p><b>OBJECTIVE</b>To investigate the molecular epidemiological characteristics of norovirus in Guangzhou from 2009 to 2011.</p><p><b>METHODS</b>A total of 183 water samples, 1162 seafood samples and 1066 diarrhea stool specimens were collected from January 2010 to May 2011, June 2009 to June 2011 and July 2009 to December 2010 respectively in Guangzhou. Norovirus was detected by real time reverse transcript-PCR (qRT-PCR). The partial polymerase gene was amplified from norovirus positive samples, then sequenced and compared with the sequences of norovirus in GenBank. The phylogenetic tree was created.</p><p><b>RESULTS</b>The positive rate was 19.67% (36/183), 8.26% (96/1162) and 37.05% (395/1066) in water samples, seafood and diarrhea patients respectively. Noroviruses from positive samples could be divided into 10 representative strains, in which 7 representative strains of genotype of 208 samples was type G2-4. The sequences from water, seafood and stool specimens were highly homologous with the similarity of 94% - 100%.</p><p><b>CONCLUSION</b>In Guangzhou, the predominant Norovirus genotype was G2-4 and the positive rate of samples was high.</p>
Subject(s)
Humans , Base Sequence , Caliciviridae Infections , Epidemiology , Virology , China , Epidemiology , Diarrhea , Virology , Genotype , Molecular Epidemiology , Norovirus , Classification , Genetics , Phylogeny , RNA, Viral , Genetics , Seafood , Virology , Water MicrobiologyABSTRACT
To investigate the inhibitory effect of RNA interference (RNAi) on dengue virus I (DENV-1) replication. Small interfering RNA (siRNA) against the PreM gene of dengue virus was synthesized and transfected into C6/36 cells with liposome, which was then attacked by DENV-1 virus. The antiviral effect of siRNA was evaluated by cytopathic effect (CPE), the cell survival rate measured by MTT, and virus RNA quantified by real-time RT-PCR. The results showed that after 7 days post infection of dengue virus, the transfected C6/36 cells showed less CPE. The cell survival rate of the transfected C6/36 cells increased by 2.26 fold, and the amount of virus RNA in the transfected cells was reduced by about 97.54% as well. These findings indicated that the siRNA could effectively inhibit dengue virus RNA replication, and protect C6/36 cells from viral attack, indicating its potential role in prevention and treatment of dengue fever.